SlideShare une entreprise Scribd logo
1  sur  17
Télécharger pour lire hors ligne
Feddes Repertorium 115 (2004) 3 – 4 , 248 – 264     DOI: 10.1002/fedr.200311041       Weinheim, August 2004

Martin-Luther-University Halle-Wittenberg, Institute of Geobotany and Botanical Garden, Halle (Saale)
University of Hawai’i Manoa, Institute of Botany, Honolulu


C. OHL & R. BUSSMANN

Recolonisation of natural landslides in tropical mountain forests
of Southern Ecuador
With 2 Map; 4 Figures and 2 Tables




Summary                                                    Zusammenfassung
The regeneration of the vegetation of natural land-        Rekolonisation auf natürlichen Hangrutschun-
slides was studied at Estación Científica San Fran-        gen in tropischen Bergwäldern Südecuadors
cisco (ECSF) in a tropical mountain forest area of
Southern Ecuador, north of Podocarpus National Park.       Im tropischen Bergwald Südecuadors (nördlich des
The study focused on the process of regeneration on        Podocarpus Nationalparks im Gebiet der Estación
natural landslides and the vegetation change along an      Científica San Francisco, ECSF) wurden Artenzu-
altitudinal gradient using space-for-time substitution.    sammensetzung und Rekolonisationsprozesse früher
The most important plant families present on the           Sukzessionsstadien entlang eines Höhengradienten
landslides during the first stages of succession are       auf natürlichen Hangrutschungen untersucht.
Gleicheniaceae (Pteridophyta), Melastomataceae, Eri-            Besonders Gleicheniaceae, Melastomataceae, Eri-
caceae and Orchidaceae. Species of the genus Stiche-       caceae und Orchidaceae sind von Bedeutung. Arten
rus (Gleicheniaceae) are dominant, and species com-        der Gattung Sticherus (Gleicheniaceae) sind sehr
position varies with altitude and soil conditions.         zahlreich vertreten. Die Artenzusammensetzung wech-
Colonisation of landslides is not homogeneous. Zones       selt entlang des Höhengradienten und in Abhängigkeit
with bare ground, sparsely vegetated patches and           von den Bodenbedingungen. Die mosaikartige Vertei-
densely covered areas may be present within the same       lung der Vegetation auf den Rutschungen (gänzlich
slide. This small scale spatial heterogeneity is often     unbedeckte bis stark überwucherte Zonen) ist auf
created by local ongoing sliding processes and differ-     häufige lokale Nachrutschungen sowie auf unter-
ent distances towards undisturbed areas. Therefore,        schiedliche Geschwindigkeiten der Wiederbesiedlung
the duration of the successional process is highly         entsprechend der Distanz zu ungestörter Vegetation
variable. The initial stage of the succession is a com-    zurückzuführen. Die Dauer der Sukzession ist daher
munity of non vascular plants interspersed with scat-      sehr variabel. Das Initialstadium wird von Moosen
tered individuals of vascular plants. By means of          und Flechten gebildet. Im weiteren Verlauf führt die
runner-shoots they form vegetation patches which           überwiegend vegetative Ausbreitung einzelner Gefäß-
start growing into each other. The second stage is         pflanzen zum zweiten Sukzessionsstadium. Dieses ist
dominated by Gleicheniaceae (species composition           durch die Dominanz von Gleicheniaceae gekenn-
varying in altitude and soil chemistry). In the third      zeichnet, während im dritten Stadium im Schutze der
stage, bushes and trees colonise, sheltered by the         Farne erste Büsche und Bäume heranwachsen und den
ferns, and a secondary forest develops with pioneer        Pionierwald bilden. Da diese Arten nicht im Primär-
species that are not found in the primary forest vegeta-   wald vertreten sind, kommt es regional zu einer be-
tion. The common phenomenon of the natural land-           trächtlichen Erhöhung der Artenzahl und der struktu-
slides leads to an increase in structural and species      rellen Diversität.
diversity on a regional scale.

Introduction                                               of roads and catastrophic events burying houses
                                                           or even villages are common. Such slides,
Landslides are extremely frequent in the tropi-            however, are usually initiated by human im-
cal mountain regions of Ecuador. Destruction               pact; most often by construction projects weak-


© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 0014-8962/04/3-408-0248




2041275 Feddes Repertorium 3-4/2004 FED0681u.doc                      WinXP: Patrick Ahlemann/Pfü. /Sch.
Beitrag: 5                          Diskettenartikel
C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests               249




Fig. 1
View of the research area. Note the high number of natural landslides


ening the underground and by deforestation                  In the present study natural slides in Ecua-
accelerating erosion. At some distance from             dor were analysed for vegetation characteristics
roadsides and settlements, dense forests still          during regeneration, species composition at
exist. Even in these untouched areas, landslides        different altitudes, succession and the role of
are a very common phenomenon (Fig. 1). Such             landslides for the biodiversity at the landscape
natural slides are usually of smaller size than         level.
the anthropogenic slides.
    Little vegetation research has been done on
landslides. Research on the regeneration of the         Study area
plant cover of a single landslide in Northern
Ecuador was carried out by STERN (1995).                The research was done in the easternmost
KESSLER (1999) studied succession on land-              mountain chain (Cordillera de Consuelo) in the
slides in Bolivia, and ERICKSON et al. (1989) in        Southern Ecuadorian Andes (Cordillera de
the central and southern Andes. In other tropi-         Numbala). The study area is part of the biologi-
cal mountain areas species colonisation on              cal reserve “Estación Científica San Fran-
landslides was analysed by GARWOOD (1981 in             cisco”. It is situated in the province Zamorra-
Panama) and GUARIGUATA (1990 in Puerto                  Chinchipe (03°59′S, 79°04′W). Altitude ranges
Rico) and geomorphological processes by                 from 1800 m up to 3150 m. The well-known
BATARYA & VALDIYA (1989 in the Lesser                   Podocarpus National Park borders the south of
Himalaya in India). KEEFER (1984) studied               the site (Map 1).
earthquake triggered landslides all over the                The southern part of the Ecuadorian Andes
world.                                                  is the lowest part of the Andes near the equator.


                                                         © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
250                                                            Feddes Repert., Weinheim 115 (2004) 3 – 4




Map 1
The study site is located in southern Ecuador at the northern fringes of Podocarpus National Park between
peak 3100 and ECSF (Estación Científica San Francisco)


The substrate is built of pre-Creataceous to          landslides in the research area are predomi-
Tertiary material (HALL 1977; CLAPPERTON              nantly caused by steep relief, long and heavy
1986). The geology of the study area varies.          rainfalls, occasional earthquakes and a sub-
Strongly weathered clay to sand stones are            strate consisting mainly of highly weathered
common while phyllitic slates are abundant in         clay-stone; ideal conditions for the heavy wa-
the lowest areas (ZECH & WILCKE 1999, own             ter-logged organic layer to slip down. Roots
obs.). The soils are mainly Aquic and Oxaquic         rarely penetrate down to the mineral soil, and
Dystropepts (SCHRUMPF et al. 2001).                   subsequently do not prevent the upper layers
    The precipitation regime is bimodal as in         from sliding.
the larger part of the Ecuadorian Andes. One              The flora of Ecuador consists of approxi-
peak of high rainfall occurs from February to         mately 16000– 20000 species of vascular plants
May and the other from October to December            (GENTRY 1977; JØRGENSEN & ULLOA ULLOA
(HOFSTEDE et al. 1998; BENDIX & LAUER                 1994; JØRGENSEN & LEON-YANEZ 1999).
1992). The climate at 1950 m a.s.l. is semi-          Given that Ecuador covers a relatively small
humid with 10 humid months, has a mean tem-           area, it is one of the most species-rich floras of
perature of 15.5 °C and an annual precipitation       the world. This richness is not equally distrib-
of 2031 mm. Above 2200 m a.s.l. the climate is        uted over the country. Only 10% of the coun-
per-humid (EMCK, pers. comm.). The natural            try’s surface falls into the altitudinal range of


© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests                   251

900 to 3000 m a.s.l but it is at this altitude          4 m2, as suggested by species area-curve analyses.
where about 50% of the species and 39% of               Each plot was photographed.
the endemics are found (MADSEN & ØLLGAARD                    The cover of the floristic releves was estimated
1994). KESSLER (2002) counted 1138 endemic              using the Londo scale (LONDO 1976). The vegetation
                                                        table was sorted by hand and with the help of
species in Ecuador at altitudes between 2500            TWINSPAN (HILL 1979) according to floristic
and 3000 m.                                             similarity (Table 1).
    The altitudinal zonation of the vegetation in            The plots were sampled only once during the
the study area is as follows:                           period between September and December 1999. The
    < 2100 m: Montane Broad-leaved Forest               identification of plants was based on literature, and
    2100–2700 m: Upper Montane forest or                later compared to specimens in the “Herbario de la
    Ceja Andina                                         Estacion Cientifica San Francisco”, the “Herbario de
    (2500–3100 m: Subalpine Elfin Forest or             la Universidad Nacional de Loja” (Loja) and in the
    Yalca)                                              “Herbario de la Pontifica Universidad Catolica”
                                                        (QCA) in Quito. Angiosperm identification followed
    > 2700 m: Grass-Páramo, in wind-protected           HUTCHINSON (1967), HARLING & SPARRE (1973–
    areas Shrub-Páramo.                                 2000), KELLER (1996), BRAKO & ZARUCHI (1993),
    The Montane Broad-leaved Forest is cha-             MADSEN & ØLLGAARD (1993), ULLOA ULLOA &
racterised by trees up to 30 m high, not exceed-        JØRGENSEN (1993) and GENTRY (1996). Ferns have
ing this height at exposed sites. Epiphytes,            been identified according to the publications of
especially ferns, Bromeliads and Orchids are            TRYON & STOLZE (1989–1993), MACBRIDE (1930–
highly abundant. Important taxa are Lauraceae           1970), ØSTERGAARD (1995) and ØLLGAARD (1979).
(Ocotea, Nectandra, Persea), Melastomataceae            Non vascular plants were not identified. Nomencla-
                                                        ture of higher plants follows JØRGENSEN & LEON-
(Miconia) and Rubiaceae (Psychotria, Pali-              YANEZ (1999). Taxa missing in this work are named
courea) (BUSSMANN 2001). The canopy is very             according to the QCA specimens.
dense and therefore herbal plants near the                   The collection of environmental data included
ground are less common than at higher alti-             soil texture of the upper mineral layer, and the soil
tudes. Philodendron (Araceae) and Cyat-                 pH. The depth of the humus layer was measured as
heaceae dominate the shrub layer.                       an important indicator of successional age and ongo-
    The vegetation composition of the Upper             ing erosion. The inclination and position on the slide
Montane Forest and the transition towards the           was recorded as well as the altitude above sea level,
Yalca vegetation was studied in 1999 and 2000           the direction aspect and the geographical position of
                                                        the landslide.
by HOMANN. The zone up to about 2400 m is                    Space-for-time substitution (PICKETT 1989) was
dominated by Purdiaea nutans (Cyrillaceae), a           employed to describe successional processes of
stunted growing tree, and Guzmannia vanvolx-            initial stages. Knowledge about the history of the
emii (a terrestrial Bromeliaceae) building a            slides can be gained by studying the aerial pictures
dense ground-covering layer. Occasionally the           of the region from 1962, 1976, 1989 (Instituto
latter is replaced by Neurolepis elata (Poaceae).       Geographico Militar, Quito) and 1998. However, the
Other important taxa include Clusiaceae, Me-            time since the last major sliding event for the plots
lastomataceae and the genus Schefflera (Ara-            could not be assessed accurately because most of the
liaceae). Above 2400 m Purdiaea nutans                  landslide material is not displaced by one big event
                                                        but by several consecutive slides. This type of land-
becomes less important while species of Melas-          slide has been called “ongoing slide” by STOYAN
tomataceae become more abundant. Trees are              (2000). Further on, many of the slides were invisible
between 5 and 10 meters high. In wind-exposed           at the aerial pictures due to their small size and the
positions paramos occur as low down as                  steep relief. Therefore, the vegetation table was
2700 m a.s.l.                                           organised according to their number of strata, in-
                                                        creasing vegetation cover and height (Table 2). In
                                                        this way the successional sequence can be inferred
Methods                                                 but not their duration. Patterns of succession in the
                                                        early to intermediate stages were investigated in this
23 landslides were selected between 2000 m and          study; however there are no samples in the late
2700 m a.s.l. Selection criteria were: accessibility,   successional stage. This is due to the logistical prob-
aspect and altitude. On each selected slide between 2   lem of finding well-grown slides, as they are invisi-
and 5 plots in homogenous zones were chosen for         ble in aerial pictures and hard to find by walking
the vegetation survey. The plot size was generally      through the steep and dissected terrain.


                                                         © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
252                                                                Feddes Repert., Weinheim 115 (2004) 3 – 4

Table 1
Vegetation types of landslides – frequency table, reduced to common and diagnostic species
                                      Sticherus rubiginosus-   Sticherus revolutus types
                                      type
                                                               variant with           variant with Sticherus
                                                               Sticherus bifidus      melanoblastus
number of plots                       13                        31                    32
Average altitude in m a.s.l.          2030                      2290                  2480
Sticherus rubiginosus                 V                        I                      I
Elleanthus aurantiacus                IV                       I                      II
Diplopterygium bancroftii             III                                             I
Sticherus arachnoideus                II
Isachne cf rigens                     II
Andropogon bicornis                   II
Ageratina dendroides                  II
Munnozia senecionidis                 II                                              I
Sticherus bifidus                     I                        IV
Purdiaea nutans                                                II                     I
Graffenrieda harlingii                                         II                     I
Sticherus melanoblastus                                                               IV
Viola stipularis                                                                      III
Rhynchospora cf macrochaeta                                                           II
Sticherus revolutus                   I                        V                      V
Bejaria aestuans                      I                        V                      III
Blechnum sp.                          I                        III                    V
Brachyotum campanulare                                         II                     II
Disterigma acuminatum                                          II                     II
Baccharis genistelloides              IV                       V                      V
Lycopodiella glaucescens              III                      V                      V
Tibouchina lepidota                   III                      III                    III
Pitcairnea trianae                    II                       III                    IV
Lophosoria quadripinnata              II                       IV                     III
Rhynchospora cf vulcani               II                       III                    III
Cortaderia bifida                     I                        II                     II



Results                                                Gleicheniaceae, of which nine species of Glei-
                                                       cheniaceae were found. The genus Sticherus is
Floristic Composition                                  the most important with seven species.
146 species of more than 40 families grew on
                                                       Vegetation: altitudinal
the studied sites. 22 species belong to the Pteri-     and edaphic differentiation
dophyta. Families with ten or more representa-
tives in the data set are the Melastomataceae,         Two major groups are recognisable in the vege-
Orchidaceae, Ericaceae, Asteraceae and Glei-           tation table classified according to floristic
cheniaceae (Pteridophyta). Poaceae, Bromeli-           similarity (Table 1). One is dominated by
aceae and Rubiaceae are frequently found, too.         Sticherus rubiginosus (Gleicheniaceae) while
56 species were recorded only once. 75% of             Sticherus revolutus (Gleicheniaceae) is com-
the total cover of vascular plants is composed         mon in the other. The second group is clearly
of different species of Pteridophyta especially        divided into two sub-clusters. The first is char-


© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests              253

acterised by Sticherus bifidus (Gleicheniaceae),       already on first stage sites points to an ad-
the second by Sticherus melanoblastus (Glei-           vanced age of at least 5 to 10 years (for exam-
cheniaceae).                                           ple Tibouchina lepidota, Vismia tomentosa or
    Other species are frequently occurring all         Bejaria aestuans in plot 5, 12, 15, and 16). The
over the studied plots. These include Baccharis        second stage (Fig. 4) develops with the exten-
genistelloides (Asteraceae) and Lycopodiella           sion of the scattered plant individuals and
glaucescens (Lycopodiaceae).                           ramets that established in the first stage of
    Altitude is a major factor influencing the         succession using vegetative propagation, espe-
species composition of the landslides. Fig. 2          cially Gleicheniaceae (see upper left corner of
demonstrates the change of dominance of spe-           Fig. 3) and Lycopodiaceae. Lycopodiella
cies of Gleicheniaceae at different altitudes. At      glaucescens and Lycopodium clavatum spread
low altitudes Sticherus rubiginosus dominates.         more quickly than the Gleicheniaceae with long
At higher slides it is replaced by Sticherus           looping runner-shoots but build stands of less
revolutus accompanied by Sticherus bifidus or          density (8, 10, 17, 19, or 27). Locally Viola
Sticherus melanoblastus. The latter species            stipularis spreads successfully using runner
were never recorded both at the same slide. The        shoots (plots 4, 20 and 21). The species compo-
landslides colonised by Sticherus bifidus (slide       sition seems to be random up to the point when
3, 4, 5, 6, 7, 8, 9, 10 and 22) and Sticherus          the patches meet and competitive effects occur.
melanoblastus (slide 19, 20, 21 and 23) are                The month of October 1999 was a period of
located on different mountain ridges (Map 2).          extremely dry weather conditions. Locally,
This shows that another environmental factor           entire populations of Lycopodiella or Sticherus
overlapping with the change in altitude is re-         vanished suddenly (leaving patches of dead
sponsible for this vegetation change. Slightly         above ground plant material) probably as a
different pH-values and a different percentage         result of competition for water between the
of exchangeable Ca2+ (VALLADAREZ, pers.                individuals, ramets and species. The second
comm.; ZECH et al. 2000) are characteristic for        stage vegetation is made up by dense covers of
the different ridges.                                  Sticherus and Lycopodiaceae. Sticherus rubigi-
                                                       nosus does not seem to have serious opponents
                                                       at slides 1, 2, 11 and 12. Sticherus bifidus and
Vegetation: time factor
                                                       Lycopodiella tend to take over the dominant
Table 2 shows a chronosequence of three suc-           role at slides 3 – 10. Sticherus revolutus pre-
cessional stages. The first stage (Fig. 3) is ra-      vails at slide 22 and Sticherus melanoblastus
ther similar at all altitudes with mosses and          and Sticherus revolutus at slides 19– 21, 23
lichens covering the ground. The percentage            and 13 – 18. The dominant role of Lycopo-
cover of the layer of lichens and mosses is            diella glaucescens vanishes usually with in-
highly dependent on the soil and water condi-          creasing total vegetation coverage (plots 59, 70,
tions at a very small spatial scale and therefore      or 75).
not useful as an indicator for succession. A few           Some species are equally present in early
scattered vascular plants establish themselves.        and later stages but never become dominant.
The duration of this stage is highly variable          Rhynchospora cf. vulcanii for example builds
depending on the erosion of the site. The areas        tufts and resists against the dominant species in
in the first stage of succession on the slides are     low numbers from the first stage to the end of
freshly slipped parts, rocky parts, ever-eroding       the second (plots 3, 11, 27, 38, or 70). Baccha-
slopes or ever-accumulating zones with little          ris genistelloides does not build dense colonies,
inclination. Only some robust and runner-shoot         and due to its straight and narrow growth form,
building species can cope with strong erosion.         percentage cover is usually very low but there
In particular Baccharis genistelloides (As-            are some plots where it is of greater importance
teraceae) and Lycopodaceae are found.                  (plots 31, 43, 45, or 67). Seedlings of bushes
    The duration of the first or early second          like Tibouchina lepidota, Graffenrieda harlin-
stage is quite impossible to estimated, as ongo-       gii (both Melastomataceae) or Bejaria aestuans
ing erosion disturbs the successional sequence.        (Ericaceae) are frequently found under dense
The occasional presence of lignified plants            layers of Sticherus in the first herbal layer.


                                                        © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
254                                                                             Feddes Repert., Weinheim 115 (2004) 3 – 4

                     100
                                            Sticherus rubiginosus
   dominance in %




                      80
                      60
                      40
                      20
                       0


                     100                     Sticherus revolutus
   dominance in %




                      80
                      60
                      40
                      20
                       0

                     100
                                              Sticherus bifidus
    dominance in %




                      80
                      60
                      40
                      20
                       0

                     100
                                        Sticherus melanoblastus
    dominance in %




                      80
                      60
                      40
                      20
                       0
                       1900   2000   2100   2200   2300   2400    2500   2600   2700   2800   2900
                                               altitude in m a.s.l.

Fig. 2
Altitudinal preference of some common Gleicheniaceae species on revegetating landslide plots

Usually, these species are not found in primary                       undecomposed organic matter are very thick
forest but form the pioneer forests. Seedlings of                     (plots 49, 50, and 51). The shady edges of the
Purdiaea nutans (Cyrillaceae), the dominant                           slides are dominated by either Sticherus arach-
species in the upper primary forest, may be                           noideus, or St. tomentosus. The woody plants
found but apparently never mature to shrubs or                        Ageratina dendroides (Asteraceae), Munnozia
trees in any of the early successional stages                         senecionidis (Asteraceae) and Liabum kingii
(plots 17 or 29).                                                     (Asteraceae) are present.
    The third stage: Vegetation development at                            At the Sticherus melanoblastus or St. bifi-
the Sticherus rubiginosus-dominated sites does                        dus dominated sites Cortaderia bifida (Poa-
not show great variability. High stands of St.                        ceae) climbs with long, looping runner-shoots
rubiginosus are covered with climbing Diplop-                         through the dense layer, hardly ever touching
terygium bancroftii (plots 48, 49, or 50) which                       the ground (59, 64, 65, or 71). In the upper
may locally dominate (plot 51); the mats of                           strata Tibouchina lepidota (Melastomataceae)


© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests                  255




Map 2
Position of the investigated landslides in the area. The landslides are aligned along three different mountain
ridges


and other species build bushes or small trees.          like, varying between about 30° and 80°. This
The fern Lophosoria quadripinnata (Lopho-               leads to different erosive forces at different
soriaceae) grows up to 2 meters in height (plot         parts of the slide. Nevertheless, a direct correla-
59).                                                    tion between vegetation cover and inclination
                                                        or erosive energy would only partly account for
                                                        the distribution of the vegetation. The study of
Discussion                                              soil cores of the slides under more, and less,
                                                        dense vegetation did not produce results with
The first remarkable thing we noted when we             significant differences in regard to soil texture,
were climbing around the landslides, was the            structure, colour and pH. This excludes the
‘patchy’ distribution of vegetation. What is the        edaphic conditions as principal responsible
reason for this? The slides are very similar in         factors.
shape, being long and narrow, although they                 Landslide areas are colonised quickly either
vary in size. The surface is smooth and very            at the borders of the slide or around islands that
few rocks are present. Inclination changes step-        slipped down without being overturned due to


                                                         © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
256                                                 Feddes Repert., Weinheim 115 (2004) 3 – 4




© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests              257




                                                        © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
258                                                 Feddes Repert., Weinheim 115 (2004) 3 – 4




© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests              259




                                                        © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
260                                                                 Feddes Repert., Weinheim 115 (2004) 3 – 4




Fig. 3
Aspect of a plot in late first stage. Sticherus bifidus is spreading in the upper left corner (scale on the right
= 2 m)


vegetative propagation from the undisturbed               established themselves after a few months. In
neighbouring areas and possibly due to a fa-              contrast, a landslide exposed to wind and direct
vourable microclimate. Other patches of high              sunlight was bare of any vegetation about eight
vegetation cover are created by the clonal,               months after the slide event.
looping runner-shoot building growth of most                  Differences in vegetation along the altitudi-
of the individual pioneers that managed to                nal gradient have been found. The main flo-
establish seedlings first (Gleicheniaceae, Lyco-          ristic change occurs at an elevation of about
podiaceae and Ericaceae).                                 2100 m. This altitude corresponds to the chan-
    The majority of the abundant species are              ge in the vegetation zonation in the surrounding
wind-dispersed and produce many seeds. The                forests: from the Montane Broad-leaved Forest
only frequent Angiosperm is Baccharis genis-              to the Upper Montane Forest (BUSSMANN
telloides (Asteraceae) which flowers all year             2001). On the landslides at higher altitudes
round, so fruits are permanently available.               some species typical for paramo vegetation are
    Under certain conditions freshly slipped              found (Paepalanthus meridensis – Eriocaula-
slides do not last very long in the first stage and       ceae or Xyris subulata – Xyridaceae). Other
lichens and mosses do not develop well as the             distribution patterns do not correspond to vege-
colonisation by higher plants starts already in           tation changes along the altitudinal gradient but
the first year of succession. In addition to the          show similar patterns to differences in soil
23 landslides studied in detail some sites of             chemistry. An explanation of the allopatric
very recent origin were examined. On land-                distribution of Sticherus bifidus and St. mela-
slides well protected against wind and direct             noblastus by the altitudinal gradient alone is
sunlight, seedlings of the surrounding flora              not possible, while the difference in altitude is


© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests               261




Fig. 4
Early stage 2, dominant species are Sticherus bifidus and Lycopodiella glaucescens


too small and no transition zone with the pre-          compares the effect of landslides to the mean-
sence of both species was found. Contrarily, as         dering rivers of the lowland ecosystems. They
described in the results, the influence of differ-      create secondary forests dominated by colonis-
ent soil chemistry combined with the influence          ing species which are not able to survive in
of changing altitude would offer an explana-            mature stands.
tion. Slightly different pH-values and a differ-            In this work species richness during the first
ent percentage of exchangeable Ca2+ (ZECH et al.        two stages of regeneration is low due to the
2000) are characteristic for the different ridges.      dominance of a few species of ferns. However,
The amount of Ca2+ correlates negatively with           during the third stage of succession, species
the abundance of Al3+-ions which are toxic to           composition still differs somewhat completely
plants and could therefore be responsible for           to the surrounding forest, but diversity is high.
the differences in floristic composition (LAN-              The second stage with a dense cover of
DON 1991; ZECH & WILCKE 1999; WILCKE,                   Gleicheniaceae has not been described from
pers. comm.). Correlations to other factors             northern Ecuador (STERN 1995) but it was
which could be responsible for the vegetation           found on landslides in Bolivia (KESSLER 1999).
change such as aspect were not found.                   There, the role of Gleicheniaceae seems simi-
    Landslides are a common phenomenon in               lar. Diplopterygium bancroftii and species of
most tropical mountain systems. STERN (1995)            Sticherus dominate. In contrast, STERN (1995)
and KESSLER (1999) hypothesised that landsli-           found a dominant species of Chusquea, 3 ½
des maintain species diversity. STERN (1995)            years after the slide event at the lower zone of a


                                                         © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
262                                                           Feddes Repert., Weinheim 115 (2004) 3 – 4

landslide. She adds that the presence of the         gered slides along the roads? Studies on the
bamboo is especially noteworthy because under        regeneration of the latter type of slides close to
certain environmental conditions it can grow         the research area have been carried out by
quickly and aggressively. Further on, she desc-      HARTIG (2000). These slides are usually very
ribes the great density of the bamboo, thereby       extensive. The surface is not smooth but often
having a profoundly limiting effect on the es-       rocky. Natural slides are mainly created by a
tablishment of other plant species. The bamboo       heavy organic layer slipping over the mineral
occurred at sites with a reasonable upper layer      soil. If thick mats of organic material become
of organic debris. Other interesting differences     water-logged due to long-lasting heavy rains,
in her work are that species of the genus Equi-      the weight of the material reaches a critical
setum are important in the early stage and           point when the adhesive strength gives in to
Blechnum dominates locally. No species of            gravity and a slide-event is initiated. The thres-
Gleicheniaceae were found. Reasons for those         hold in this area is very low as the adhesive
variations might be found in the obvious differ-     strength is low due to the slippery mineral soil
ences in geological substrate (of quaternary         and the lack of a well developed root-system in
volcanic origin) and the lower humidity and          the B-horizon which could help to fix the upper
altitude of the site (1440 m). Gleicheniaceae do     layers (own obs.; STERN 1995). The human
not hinder the establishment of bushes, though       triggered slides are usually initiated due to the
the time period from when seedlings of bushes        weakened geological underground and have
appear to when they manage to break through          more in common with rock-falls. Succession
the fern layer, varies. Different types of succes-   differs between the two types of slides. Grasses
sional models seem to correspond to the rege-        largely replace the Gleicheniaceae and build a
neration processes at the slides studies by          very dense layer often limiting the establish-
STERN on one hand and on the other hand the          ment of bush species. Succession seems to
slides observed by KESSLER and the work on           follow the inhibition model (CONNELL & SLA-
hand. Following the division of successional         TYER 1977; PICKETT et al. 1987). Especially the
models according to CONNELL & SLATYER                number of orchids is tremendous which leads
(1977) and PICKETT et al. (1987) the model of        to a very high diversity on man-made slides
inhibition will have to be used to describe the      (GROSS 1998). In contrast, there are not many
situation in northern Ecuador as observed by         species of orchids found at the natural slides
STERN (1995). In contrast, the tolerance model       but in the few areas with rocky relief they be-
combined with the facilitation model could be        come more abundant (see plot 21 or 48).
used to describe the situation in Bolivia (KESS-         The aerial pictures of the region show a
LER) and southern Ecuador. Little change in          very unequal distribution of the natural slides.
species composition but mainly a change in           One possible explanation for the clustered
vegetation density or -height was observed due       occurrence of the slides might be reached by
to local erosive energy, time elapsed since the      studying the direction of the geological struc-
last destruction, depth of the organic layer or      tures. If the layers are aligned parallel to the
the distance towards densely covered sites.          slope, the risk of a slide-event arises. Consider-
Mosses and lichens are not only abundant dur-        ing that on most of the slides the soil is not
ing the first stage but also during the second       dragged down to the C-horizon, this explana-
and third stage (though we do not know if the        tion is probably not of great significance, but
species are similar) and Gleicheniaceae are          locally this certainly encourages or deters a
present in the second and third stage though         sliding process. Probably, the heavy organic
they loose importance as they are overgrown by       soil layer is responsible for the majority of
the bushes and trees of the pioneer forests. Up      sliding processes. Under mature forest organic
to this point, the model of tolerance seems to fit   layers build up, but due to evaporation and
while the missing of species of the primary          transpiration they will not get heavily water-
forests during the third stage follows the facili-   logged. In contrast, comparable amounts of
tation model.                                        water do not transpire from senescent forest. A
    What is the main difference between the          mosaic-like forest structure with younger and
studied natural landslides and the human trig-       older forest stages is described in KESSLER


© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests               263

(1999) from the montane forest in the Bolivian         BENDIX, J. & LAUER, W. 1992: Die Niederschlags-
Andes. He observed irregularly formed and                 jahreszeiten in Ecuador und ihre klimadyna-
spaced patches of senescent forest with single            mische Interpretation. – Erdkunde 46: 118 – 134.
trees having already collapsed. This could             BRAKO, L. & ZARUCHI, J. L. 1993: Catalogue of the
                                                          flowering plants and Gymnosperms of Peru. –
explain the clustered occurrence of landslides            Monographs in Systematic Botany 45.
as the risk of slipping in zones of senescent          BUSSMANN, R. 2001: The montane forests of
forest is higher than in zones of mature forest.          Reserva Biológica San Francisco. – Die Erde
In this case the effect of landslides in the eco-         132: 9 – 25.
system would be very important for the natural         CLAPPERTON, C. M. 1986: Glacial Geomorphology,
regeneration of the system. At altitudes above            Quaternary glacial sequence and palaeoclimatic
2100 m, especially under senescent forest, very           inferences in the Ecuadorian Andes: 843 – 870. –
dense layers of terrestrial Bromeliads are                In: V. GARDINER (ed.), Proceed. Intern. Conf.
found. Germination of other species is very               Geomorphology II. – Cluchester.
                                                       CONNELL, J. H. & SLATYER, R. O. 1977: Mechanisms
difficult under these circumstances. In contrast,         of succession in natural communities and their
a landslide provides light and a high availabil-          role in community stability and organization. –
ity of minerals for successful plant growth.              Am. Nat. 111: 1119 – 1144.
    There are still plenty of open questions           DE NONI, G.; VIENNOT, M. & TRIJILLO, G. 1989–
concerning the governing factors and the pro-             1990: Mesures de l‘erosion dans les Andes de
cesses going on at landslides in the research             l‘Equateur. – Cahier ORSTOM, Serie Pedologie
area. Further research will have to deal in parti-        25(1–2): 183 – 196.
cular with the influence of the soil chemistry on      ERICKSON, G. E.; RAMIREZ, C. F.; CONCHA, J. F.;
                                                          TISNADO, M. G. & URQUIDI, B. F. 1989: Land-
species composition and succession and the                slide hazards in the central and southern Andes:
development of the pioneer forests towards the            111 – 117. – In: E. E. BRABB & B. L. HARROLD
climax stage.                                             (eds.), Landslides: extend and economic signi-
                                                          ficance. – Rotterdam.
Acknowledgements                                       GARWOOD, N. C. 1981: Earthquake-caused land-
                                                          slides in Panama: recovery of the vegetation. –
We would like to express our cordial thanks to            Res. Rep. Natl. Geogr. Soc. 21: 181 – 184.
Prof. Dr. Ankea Sieg l and Prof. Dr. Ulrich            GENTRY, A. H. 1977: Endangered plant species and
Deil for helpful discussions and revisions                habitats of Ecuador and Amazonian Peru: 136 –
concerning this work and our Ecuadorian coun-             149. – In: G. T. PRANCE & T. S. ELIAS (eds.),
terparts of the Universidad Nacionál Loja                 Extinction is forever. – The New York Botanical
                                                          Garden, New York.
(Ing. N. Mald o nad o , Ing. W. Ap lo , Dr. L.         GENTRY, A. H. 1996: A field guide to the families
L o ján), Herbario Reinaldo Espinosa Loja                 and genera of woody plants of north-west South
(Ing. Z. Agu ir r e, Ego. B. Mer in o , Dra. B.           America (Colombia, Ecuador, Peru) with supple-
K l i t g a a r d ), the herbaria QCA y QCNE in           mentary notes on herbaceous taxa. – Chicago,
Quito, and ECSF, for all their collegial help at          London.
all times throughout the study. We thank INE-          GROSS, A. 1998: Terrestrische Orchideen einer
FAN for the research permit (now Ministerio               Hangrutschung im Bergwald Süd-Ecuadors: Ver-
de Medio Ambiente de Ecuador; no. 16-IC                   teilung, Phytomasse, Phänologie und Blüten-
                                                          merkmale. – Univ. Ulm, Diploma Thesis,
INEFAN DNAN VS/VS). We would also like
                                                          unpubl.
to thank the Deutsche Forschungsgemeinschaft           GUARIGUATA, M. R. 1990: Landslide disturbance and
for financing the project (DFG, Be 473/28-1,              forest regeneration in the upper Luquillo
Bu 886/1-1/2).                                            Mountains of Puerto Rico. – J. Ecol. 78: 814 –
                                                          832.
                                                       HALL, M. 1977: El volcanismo en el Ecuador. –
                                                          Biblioteca Ecuador. – Quito.
References                                             HARLING, G. & SPARRE, B. 1973 – 2000: Flora of
                                                          Ecuador. – Bot. Mus., Copenhagen.
BATARYA, S. K. & VALDIYA, K. S. 1989: Landslides       HARTIG, K. 2000: Pflanzensoziologische Untersu-
  and erosion in the catchment of the Gaula River,        chungen von anthropogen gestörten Flächen im
  Kumaun Lesser Himalaya, India. – Mountain               tropischen Bergwald Südecuadors. – Univ.
  Research and Development 9(4): 405 – 419.               Bayreuth, Diploma Thesis, unpubl.


                                                        © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
264                                                              Feddes Repert., Weinheim 115 (2004) 3 – 4

HILL, M. O. 1979: TWINSPAN – a FORTRAN                  PICKETT, S. T. A. 1989: Space-for-time substitution
   program for arranging multivariate data in an           as an alternative to long-term studies: 110 – 135.
   ordered two-way table by classification of the          – In: G. E. LIKENS (ed.), Long-term studies in
   individuals and attributes. – New York.                 ecology. – New York.
HOFSTEDE, R.; LIPS, J.; JONGSMA, W. & SEVINK, Y.        PICKETT, S. T. A.; COLLINS, S. L. & ARMESTO, J. J.
   1998: Geografia, ecologia y forestacion de la           1987: Models, mechanisms and pathways of
   sierra alta del Ecuador. Revision de literatura. –      succession. – Bot. Rev. 53: 335 – 371.
   ABYA-YALA, Quito.                                    SCHRUMPF, M.; GUGGENBERGER, G.; VALAREZO, C.
HUTCHINSON, J. 1967: Key to the families of                & ZECH, W. 2001: Tropical montane rain forest
   flowering plants of the world. – Oxford.                soils: development and nutrient status along an
JØRGENSEN, P. M. & LEON-YANEZ, S. (eds.) 1999:             altitudinal gradient in the south Ecuadorian
   Catalogue of the vascular plants of Ecuador. –          Andes. – Die Erde 132: 43 – 59.
   Monographs in Systematic Botany from the             STERN, M. J. 1995: Vegetation recovery on earth-
   Missouri Botanical Garden 75. – St Louis.               quake-triggered landslide sites in the Ecuadorian
JØRGENSEN, P. M. & ULLOA ULLOA, C. 1994: Seed              Andes: 207 – 220. – In: S. P. CHURCHILL; H.
   plants of the high Andes of Ecuador – a check-          BALSLEV; E. FORERO & J. L. LUTEYN (eds.),
   list. – Aarhus University (AAU) Reports 34.             Biodiversity and conservation of neotropical
KEEFER, D. K. 1984: Landslides caused by earth-            montane forests. – New York.
   quakes. – Geol. Soc. Amer., Bull. 95: 406 – 421.     STOYAN, R. 2000: Aktivität, Ursachen und Klassifi-
KELLER, R. 1996: Identification of tropical woody          kation der Rutschungen in San Francisco/Süd-
   plants in the absence of flowers and fruits. –          ecuador. – Univ. Erlangen, Diploma Thesis, un-
   Basel.                                                  publ..
KESSLER, M. 1999: Plant species richness and            TRYON, R. M. & STOLZE, R. G. 1989 – 1993: Pterido-
   endemism during natural landslide succession in         phyta of Peru I–V. – Fieldiana (Botany). N.S. –
   a perhumid montane forest in the Bolivian               Chicago.
   Andes. – Ecotropica 5: 123 – 136.                    ULLOA ULLOA, C. & JØRGENSEN, P. M. 1993: Arbo-
KESSLER, M. 2002: The elevational gradient of              les y arbustos de los Andes del Ecuador. –
   Andean plant endemism: varying influences of            Aarhus University (AAU) Reports 30.
   taxon-specific traits and topography at different    ZECH, W. & WILCKE, W. 1999: Einfluß der Land-
   taxonomic levels. – J. Biogeogr. 29: 1159 – 1165.       nutzung auf Bodeneigenschaften sowie auf die
LANDON, J. R. (ed.) 1991: Booker tropical soil manu-       Wasser- und Elementflüsse in Bergwäldern Süd-
   al. – Essex, New York.                                  ecuadors. – Bericht zum bodenkundlichen Teil-
LONDO, G. 1976: The decimal scale for releves of           projekt des Projektverbunds „Ökosystemare
   permanent quadrats. – Vegetatio 33(1): 61 – 64.         Kenngrössen gestörter und ungestörter tropischer
MACBRIDE, J. F. (ed.) 1930 – 1970: Flora of Peru. –        Bergwälder“. Zwischenbericht. – Univ. Bay-
   Chicago.                                                reuth, unpubl.
MADSEN, J. E. & ØLLGAARD, B. 1993: Inventario           ZECH W.; WILCKE, W. & VALAREZO, C. 2000: In-
   preliminar de las especies vegetales en el Parque       fluencia del uso de la tierra en los propiedades
   Nacional Podocarpus. – Ciencias agricolas de            del suelo y en los flujos de aqua y de elementos
   la Universidad Nacional de Loja 22–23(1 – 2):           en los bosques montanosos del Ecuador del sur.
   66 – 87.                                                Zwischenbericht. – Univ. Bayreuth, unpubl.
MADSEN, J. E. & ØLLGAARD, B. 1994: Floristic com-
   position, structure, and dynamics of an upper
   montane rain forest in Southern Ecuador. – Nord.     Addresses of the authors:
   J. Bot. 14: 403 – 423.                               Dr. Constanze O h l (corresp. author), Martin-Luther-
ØLLGAARD, B. 1979: Lycopodium in Ecuador – ha-          Universität Halle-Wittenberg, Institut für Geobotanik
   bits and habitats: 381 – 395. – In: K. LARSEN &      und Botanischer Garten, Am Kirchtor 1, D-06108
   L. B. HOLM-NIELSEN (eds.), Tropical botany. –        Halle, Deutschland
   Proceed. sympos. Univ. Aarhus on 10–12 August        e-mail: ohl@botanik.uni-halle.de
   1978, organized on the occasion of the 50th          Dr. R. B u s s m a n n , University of Hawai’i Manoa,
   anniversary of this university. – London.            3860 Manoa Road, Honolulu, Hawai’i,
ØSTERGAARD, E. 1995: Gleicheniaceae – en gruppe         bussmann@hawaii.edu, USA.
   pioner plantenblandt tropiske bregner. Afdeling
   for Systematik Botanik. Specialerapport marts
   1995. – Biologisk Institut Aarhus Universitet,       Manuscript received: September 29th, 2003/revised
   Aarhus.                                              version: December 15th, 2003.




© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Contenu connexe

Tendances

Franklin_Canyon_Santa_Monica_Mountains
Franklin_Canyon_Santa_Monica_MountainsFranklin_Canyon_Santa_Monica_Mountains
Franklin_Canyon_Santa_Monica_Mountainsluciaiman
 
SOILS OF ARGENTINA_pazos moscatelli_sn_bibliografia
SOILS OF ARGENTINA_pazos moscatelli_sn_bibliografiaSOILS OF ARGENTINA_pazos moscatelli_sn_bibliografia
SOILS OF ARGENTINA_pazos moscatelli_sn_bibliografiaUCA-agrarias_ 2do._I.P.A
 
Climatic variability and spatial distribution of herbaceous fodders in the Su...
Climatic variability and spatial distribution of herbaceous fodders in the Su...Climatic variability and spatial distribution of herbaceous fodders in the Su...
Climatic variability and spatial distribution of herbaceous fodders in the Su...IJERA Editor
 
SPATIOTEMPORAL VARIABILITY IN TREE GROWTH IN THE CENTRAL PYRENEES: CLIMATIC ...
SPATIOTEMPORAL VARIABILITY IN TREE GROWTH IN THE CENTRAL  PYRENEES: CLIMATIC ...SPATIOTEMPORAL VARIABILITY IN TREE GROWTH IN THE CENTRAL  PYRENEES: CLIMATIC ...
SPATIOTEMPORAL VARIABILITY IN TREE GROWTH IN THE CENTRAL PYRENEES: CLIMATIC ...Hibrids
 
Longleaf Pine Final Paper
Longleaf Pine Final PaperLongleaf Pine Final Paper
Longleaf Pine Final PaperKevin Willson
 
Report of guanica and yunque
Report of guanica and yunqueReport of guanica and yunque
Report of guanica and yunqueGustavo Perez
 
An investigation of the vegetation dynamics on Aride
An investigation of the vegetation dynamics on ArideAn investigation of the vegetation dynamics on Aride
An investigation of the vegetation dynamics on ArideRobert Gavan
 
Capstone Project pgs 1-7
Capstone Project pgs 1-7Capstone Project pgs 1-7
Capstone Project pgs 1-7Steven Kelley
 
Report of guanica and yunque (1)
Report of guanica and yunque (1)Report of guanica and yunque (1)
Report of guanica and yunque (1)angelicagonzalez10
 
Effects of a severe drought on Quercus ilex radial growth and xylem anatomy
Effects of a severe drought on Quercus ilex radial growth  and xylem anatomyEffects of a severe drought on Quercus ilex radial growth  and xylem anatomy
Effects of a severe drought on Quercus ilex radial growth and xylem anatomyHibrids
 
Alien grasses in_brazilian_savannas
Alien grasses in_brazilian_savannasAlien grasses in_brazilian_savannas
Alien grasses in_brazilian_savannasFilipe de Oliveira
 
patterns and determinants of floristic variation across lowland forests of bo...
patterns and determinants of floristic variation across lowland forests of bo...patterns and determinants of floristic variation across lowland forests of bo...
patterns and determinants of floristic variation across lowland forests of bo...Valderes Sarnaglia
 
A High Grassland Bee Community in Southern Brazil: Survey and Annotated Check...
A High Grassland Bee Community in Southern Brazil: Survey and Annotated Check...A High Grassland Bee Community in Southern Brazil: Survey and Annotated Check...
A High Grassland Bee Community in Southern Brazil: Survey and Annotated Check...Label-ha
 
JesseMiller_MalcolmNichols_FireAndLULCResearchPaper.docx
JesseMiller_MalcolmNichols_FireAndLULCResearchPaper.docxJesseMiller_MalcolmNichols_FireAndLULCResearchPaper.docx
JesseMiller_MalcolmNichols_FireAndLULCResearchPaper.docxMalcolm Nichols
 

Tendances (18)

Franklin_Canyon_Santa_Monica_Mountains
Franklin_Canyon_Santa_Monica_MountainsFranklin_Canyon_Santa_Monica_Mountains
Franklin_Canyon_Santa_Monica_Mountains
 
SOILS OF ARGENTINA_pazos moscatelli_sn_bibliografia
SOILS OF ARGENTINA_pazos moscatelli_sn_bibliografiaSOILS OF ARGENTINA_pazos moscatelli_sn_bibliografia
SOILS OF ARGENTINA_pazos moscatelli_sn_bibliografia
 
Climatic variability and spatial distribution of herbaceous fodders in the Su...
Climatic variability and spatial distribution of herbaceous fodders in the Su...Climatic variability and spatial distribution of herbaceous fodders in the Su...
Climatic variability and spatial distribution of herbaceous fodders in the Su...
 
SPATIOTEMPORAL VARIABILITY IN TREE GROWTH IN THE CENTRAL PYRENEES: CLIMATIC ...
SPATIOTEMPORAL VARIABILITY IN TREE GROWTH IN THE CENTRAL  PYRENEES: CLIMATIC ...SPATIOTEMPORAL VARIABILITY IN TREE GROWTH IN THE CENTRAL  PYRENEES: CLIMATIC ...
SPATIOTEMPORAL VARIABILITY IN TREE GROWTH IN THE CENTRAL PYRENEES: CLIMATIC ...
 
Longleaf Pine Final Paper
Longleaf Pine Final PaperLongleaf Pine Final Paper
Longleaf Pine Final Paper
 
Valgma landscape
Valgma landscapeValgma landscape
Valgma landscape
 
Report of guanica and yunque
Report of guanica and yunqueReport of guanica and yunque
Report of guanica and yunque
 
An investigation of the vegetation dynamics on Aride
An investigation of the vegetation dynamics on ArideAn investigation of the vegetation dynamics on Aride
An investigation of the vegetation dynamics on Aride
 
Final Paper
Final PaperFinal Paper
Final Paper
 
Capstone Project pgs 1-7
Capstone Project pgs 1-7Capstone Project pgs 1-7
Capstone Project pgs 1-7
 
Report of guanica and yunque (1)
Report of guanica and yunque (1)Report of guanica and yunque (1)
Report of guanica and yunque (1)
 
Effects of a severe drought on Quercus ilex radial growth and xylem anatomy
Effects of a severe drought on Quercus ilex radial growth  and xylem anatomyEffects of a severe drought on Quercus ilex radial growth  and xylem anatomy
Effects of a severe drought on Quercus ilex radial growth and xylem anatomy
 
Gjesm150171451593800
Gjesm150171451593800Gjesm150171451593800
Gjesm150171451593800
 
Alien grasses in_brazilian_savannas
Alien grasses in_brazilian_savannasAlien grasses in_brazilian_savannas
Alien grasses in_brazilian_savannas
 
Advanced ecology notes 2020,
Advanced ecology notes 2020, Advanced ecology notes 2020,
Advanced ecology notes 2020,
 
patterns and determinants of floristic variation across lowland forests of bo...
patterns and determinants of floristic variation across lowland forests of bo...patterns and determinants of floristic variation across lowland forests of bo...
patterns and determinants of floristic variation across lowland forests of bo...
 
A High Grassland Bee Community in Southern Brazil: Survey and Annotated Check...
A High Grassland Bee Community in Southern Brazil: Survey and Annotated Check...A High Grassland Bee Community in Southern Brazil: Survey and Annotated Check...
A High Grassland Bee Community in Southern Brazil: Survey and Annotated Check...
 
JesseMiller_MalcolmNichols_FireAndLULCResearchPaper.docx
JesseMiller_MalcolmNichols_FireAndLULCResearchPaper.docxJesseMiller_MalcolmNichols_FireAndLULCResearchPaper.docx
JesseMiller_MalcolmNichols_FireAndLULCResearchPaper.docx
 

Similaire à Ecuador Regeneration Of Natural Landslides (Ohl Y Bussman Citado)

Reforestation in the Cerro Candelaria Reserve
Reforestation in the Cerro Candelaria ReserveReforestation in the Cerro Candelaria Reserve
Reforestation in the Cerro Candelaria ReserveChristopher Chang
 
Journal of medicinal plants research vol
Journal of medicinal plants research volJournal of medicinal plants research vol
Journal of medicinal plants research volRahmat Alam
 
Vegetation dynamics in the western himalayas, diversity indices and climate c...
Vegetation dynamics in the western himalayas, diversity indices and climate c...Vegetation dynamics in the western himalayas, diversity indices and climate c...
Vegetation dynamics in the western himalayas, diversity indices and climate c...Shujaul Mulk Khan
 
L03 Ecosystems Biomes
L03 Ecosystems BiomesL03 Ecosystems Biomes
L03 Ecosystems BiomesFatimah Yusof
 
analisis_vegetation-analisis_vegetation.pdf
analisis_vegetation-analisis_vegetation.pdfanalisis_vegetation-analisis_vegetation.pdf
analisis_vegetation-analisis_vegetation.pdfAgathaHaselvin
 
El yunque presentation pdf
El yunque presentation pdfEl yunque presentation pdf
El yunque presentation pdfjmz7
 
The North America and Eurasia Arctic transects:
The North America and Eurasia Arctic transects: The North America and Eurasia Arctic transects:
The North America and Eurasia Arctic transects: Edie Barbour
 
Evs2011 talk two_transects20110404(3)
Evs2011 talk two_transects20110404(3)Evs2011 talk two_transects20110404(3)
Evs2011 talk two_transects20110404(3)Edie Barbour
 
Salient features of grassland, forest and desert ecosystem
Salient features of grassland, forest and desert ecosystemSalient features of grassland, forest and desert ecosystem
Salient features of grassland, forest and desert ecosystemsuru_yadav
 
myers_et_al_2012_palaeoclimate_of_the_late_jurassic_of_portugal_comparison_wi...
myers_et_al_2012_palaeoclimate_of_the_late_jurassic_of_portugal_comparison_wi...myers_et_al_2012_palaeoclimate_of_the_late_jurassic_of_portugal_comparison_wi...
myers_et_al_2012_palaeoclimate_of_the_late_jurassic_of_portugal_comparison_wi...NowelNjamnsi1
 
Soil Degradation By Different Land Use Impacts In Tropical Rainforests
Soil Degradation By Different Land Use Impacts In Tropical RainforestsSoil Degradation By Different Land Use Impacts In Tropical Rainforests
Soil Degradation By Different Land Use Impacts In Tropical RainforestsChristina Parmionova
 
INCREASING ARIDITY IS ENHANCING SILVER FIR (ABIES ALBA MILL.) WATER STRESS I...
INCREASING ARIDITY IS ENHANCING SILVER FIR  (ABIES ALBA MILL.) WATER STRESS I...INCREASING ARIDITY IS ENHANCING SILVER FIR  (ABIES ALBA MILL.) WATER STRESS I...
INCREASING ARIDITY IS ENHANCING SILVER FIR (ABIES ALBA MILL.) WATER STRESS I...Hibrids
 
Dust career impacts on Pinus halepensis growth
Dust career impacts on Pinus halepensis growthDust career impacts on Pinus halepensis growth
Dust career impacts on Pinus halepensis growthAgriculture Journal IJOEAR
 
Aquatic environment: concept, meaning and its division
Aquatic environment: concept, meaning and its divisionAquatic environment: concept, meaning and its division
Aquatic environment: concept, meaning and its divisionDr. Neelesh Kumar
 
Landscape ecology (2013bpln010)
Landscape ecology (2013bpln010)Landscape ecology (2013bpln010)
Landscape ecology (2013bpln010)Bhupendra Singh
 
The amphibian’s fauna of a West African forest relict near a hydroelectric Da...
The amphibian’s fauna of a West African forest relict near a hydroelectric Da...The amphibian’s fauna of a West African forest relict near a hydroelectric Da...
The amphibian’s fauna of a West African forest relict near a hydroelectric Da...Innspub Net
 

Similaire à Ecuador Regeneration Of Natural Landslides (Ohl Y Bussman Citado) (20)

Reforestation in the Cerro Candelaria Reserve
Reforestation in the Cerro Candelaria ReserveReforestation in the Cerro Candelaria Reserve
Reforestation in the Cerro Candelaria Reserve
 
Journal of medicinal plants research vol
Journal of medicinal plants research volJournal of medicinal plants research vol
Journal of medicinal plants research vol
 
Vegetation dynamics in the western himalayas, diversity indices and climate c...
Vegetation dynamics in the western himalayas, diversity indices and climate c...Vegetation dynamics in the western himalayas, diversity indices and climate c...
Vegetation dynamics in the western himalayas, diversity indices and climate c...
 
L03 Ecosystems Biomes
L03 Ecosystems BiomesL03 Ecosystems Biomes
L03 Ecosystems Biomes
 
analisis_vegetation-analisis_vegetation.pdf
analisis_vegetation-analisis_vegetation.pdfanalisis_vegetation-analisis_vegetation.pdf
analisis_vegetation-analisis_vegetation.pdf
 
El yunque presentation pdf
El yunque presentation pdfEl yunque presentation pdf
El yunque presentation pdf
 
The North America and Eurasia Arctic transects:
The North America and Eurasia Arctic transects: The North America and Eurasia Arctic transects:
The North America and Eurasia Arctic transects:
 
Evs2011 talk two_transects20110404(3)
Evs2011 talk two_transects20110404(3)Evs2011 talk two_transects20110404(3)
Evs2011 talk two_transects20110404(3)
 
Salient features of grassland, forest and desert ecosystem
Salient features of grassland, forest and desert ecosystemSalient features of grassland, forest and desert ecosystem
Salient features of grassland, forest and desert ecosystem
 
myers_et_al_2012_palaeoclimate_of_the_late_jurassic_of_portugal_comparison_wi...
myers_et_al_2012_palaeoclimate_of_the_late_jurassic_of_portugal_comparison_wi...myers_et_al_2012_palaeoclimate_of_the_late_jurassic_of_portugal_comparison_wi...
myers_et_al_2012_palaeoclimate_of_the_late_jurassic_of_portugal_comparison_wi...
 
Soil Degradation By Different Land Use Impacts In Tropical Rainforests
Soil Degradation By Different Land Use Impacts In Tropical RainforestsSoil Degradation By Different Land Use Impacts In Tropical Rainforests
Soil Degradation By Different Land Use Impacts In Tropical Rainforests
 
INCREASING ARIDITY IS ENHANCING SILVER FIR (ABIES ALBA MILL.) WATER STRESS I...
INCREASING ARIDITY IS ENHANCING SILVER FIR  (ABIES ALBA MILL.) WATER STRESS I...INCREASING ARIDITY IS ENHANCING SILVER FIR  (ABIES ALBA MILL.) WATER STRESS I...
INCREASING ARIDITY IS ENHANCING SILVER FIR (ABIES ALBA MILL.) WATER STRESS I...
 
Dust career impacts on Pinus halepensis growth
Dust career impacts on Pinus halepensis growthDust career impacts on Pinus halepensis growth
Dust career impacts on Pinus halepensis growth
 
Aquatic environment: concept, meaning and its division
Aquatic environment: concept, meaning and its divisionAquatic environment: concept, meaning and its division
Aquatic environment: concept, meaning and its division
 
Ecology ecological succession
Ecology  ecological successionEcology  ecological succession
Ecology ecological succession
 
Landscape ecology (2013bpln010)
Landscape ecology (2013bpln010)Landscape ecology (2013bpln010)
Landscape ecology (2013bpln010)
 
Making Forest Landscape Restoration a force of change
Making Forest Landscape Restoration a force of changeMaking Forest Landscape Restoration a force of change
Making Forest Landscape Restoration a force of change
 
The amphibian’s fauna of a West African forest relict near a hydroelectric Da...
The amphibian’s fauna of a West African forest relict near a hydroelectric Da...The amphibian’s fauna of a West African forest relict near a hydroelectric Da...
The amphibian’s fauna of a West African forest relict near a hydroelectric Da...
 
Lecture5
Lecture5Lecture5
Lecture5
 
Bird_International_Conservation
Bird_International_ConservationBird_International_Conservation
Bird_International_Conservation
 

Ecuador Regeneration Of Natural Landslides (Ohl Y Bussman Citado)

  • 1. Feddes Repertorium 115 (2004) 3 – 4 , 248 – 264 DOI: 10.1002/fedr.200311041 Weinheim, August 2004 Martin-Luther-University Halle-Wittenberg, Institute of Geobotany and Botanical Garden, Halle (Saale) University of Hawai’i Manoa, Institute of Botany, Honolulu C. OHL & R. BUSSMANN Recolonisation of natural landslides in tropical mountain forests of Southern Ecuador With 2 Map; 4 Figures and 2 Tables Summary Zusammenfassung The regeneration of the vegetation of natural land- Rekolonisation auf natürlichen Hangrutschun- slides was studied at Estación Científica San Fran- gen in tropischen Bergwäldern Südecuadors cisco (ECSF) in a tropical mountain forest area of Southern Ecuador, north of Podocarpus National Park. Im tropischen Bergwald Südecuadors (nördlich des The study focused on the process of regeneration on Podocarpus Nationalparks im Gebiet der Estación natural landslides and the vegetation change along an Científica San Francisco, ECSF) wurden Artenzu- altitudinal gradient using space-for-time substitution. sammensetzung und Rekolonisationsprozesse früher The most important plant families present on the Sukzessionsstadien entlang eines Höhengradienten landslides during the first stages of succession are auf natürlichen Hangrutschungen untersucht. Gleicheniaceae (Pteridophyta), Melastomataceae, Eri- Besonders Gleicheniaceae, Melastomataceae, Eri- caceae and Orchidaceae. Species of the genus Stiche- caceae und Orchidaceae sind von Bedeutung. Arten rus (Gleicheniaceae) are dominant, and species com- der Gattung Sticherus (Gleicheniaceae) sind sehr position varies with altitude and soil conditions. zahlreich vertreten. Die Artenzusammensetzung wech- Colonisation of landslides is not homogeneous. Zones selt entlang des Höhengradienten und in Abhängigkeit with bare ground, sparsely vegetated patches and von den Bodenbedingungen. Die mosaikartige Vertei- densely covered areas may be present within the same lung der Vegetation auf den Rutschungen (gänzlich slide. This small scale spatial heterogeneity is often unbedeckte bis stark überwucherte Zonen) ist auf created by local ongoing sliding processes and differ- häufige lokale Nachrutschungen sowie auf unter- ent distances towards undisturbed areas. Therefore, schiedliche Geschwindigkeiten der Wiederbesiedlung the duration of the successional process is highly entsprechend der Distanz zu ungestörter Vegetation variable. The initial stage of the succession is a com- zurückzuführen. Die Dauer der Sukzession ist daher munity of non vascular plants interspersed with scat- sehr variabel. Das Initialstadium wird von Moosen tered individuals of vascular plants. By means of und Flechten gebildet. Im weiteren Verlauf führt die runner-shoots they form vegetation patches which überwiegend vegetative Ausbreitung einzelner Gefäß- start growing into each other. The second stage is pflanzen zum zweiten Sukzessionsstadium. Dieses ist dominated by Gleicheniaceae (species composition durch die Dominanz von Gleicheniaceae gekenn- varying in altitude and soil chemistry). In the third zeichnet, während im dritten Stadium im Schutze der stage, bushes and trees colonise, sheltered by the Farne erste Büsche und Bäume heranwachsen und den ferns, and a secondary forest develops with pioneer Pionierwald bilden. Da diese Arten nicht im Primär- species that are not found in the primary forest vegeta- wald vertreten sind, kommt es regional zu einer be- tion. The common phenomenon of the natural land- trächtlichen Erhöhung der Artenzahl und der struktu- slides leads to an increase in structural and species rellen Diversität. diversity on a regional scale. Introduction of roads and catastrophic events burying houses or even villages are common. Such slides, Landslides are extremely frequent in the tropi- however, are usually initiated by human im- cal mountain regions of Ecuador. Destruction pact; most often by construction projects weak- © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 0014-8962/04/3-408-0248 2041275 Feddes Repertorium 3-4/2004 FED0681u.doc WinXP: Patrick Ahlemann/Pfü. /Sch. Beitrag: 5 Diskettenartikel
  • 2. C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests 249 Fig. 1 View of the research area. Note the high number of natural landslides ening the underground and by deforestation In the present study natural slides in Ecua- accelerating erosion. At some distance from dor were analysed for vegetation characteristics roadsides and settlements, dense forests still during regeneration, species composition at exist. Even in these untouched areas, landslides different altitudes, succession and the role of are a very common phenomenon (Fig. 1). Such landslides for the biodiversity at the landscape natural slides are usually of smaller size than level. the anthropogenic slides. Little vegetation research has been done on landslides. Research on the regeneration of the Study area plant cover of a single landslide in Northern Ecuador was carried out by STERN (1995). The research was done in the easternmost KESSLER (1999) studied succession on land- mountain chain (Cordillera de Consuelo) in the slides in Bolivia, and ERICKSON et al. (1989) in Southern Ecuadorian Andes (Cordillera de the central and southern Andes. In other tropi- Numbala). The study area is part of the biologi- cal mountain areas species colonisation on cal reserve “Estación Científica San Fran- landslides was analysed by GARWOOD (1981 in cisco”. It is situated in the province Zamorra- Panama) and GUARIGUATA (1990 in Puerto Chinchipe (03°59′S, 79°04′W). Altitude ranges Rico) and geomorphological processes by from 1800 m up to 3150 m. The well-known BATARYA & VALDIYA (1989 in the Lesser Podocarpus National Park borders the south of Himalaya in India). KEEFER (1984) studied the site (Map 1). earthquake triggered landslides all over the The southern part of the Ecuadorian Andes world. is the lowest part of the Andes near the equator. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 3. 250 Feddes Repert., Weinheim 115 (2004) 3 – 4 Map 1 The study site is located in southern Ecuador at the northern fringes of Podocarpus National Park between peak 3100 and ECSF (Estación Científica San Francisco) The substrate is built of pre-Creataceous to landslides in the research area are predomi- Tertiary material (HALL 1977; CLAPPERTON nantly caused by steep relief, long and heavy 1986). The geology of the study area varies. rainfalls, occasional earthquakes and a sub- Strongly weathered clay to sand stones are strate consisting mainly of highly weathered common while phyllitic slates are abundant in clay-stone; ideal conditions for the heavy wa- the lowest areas (ZECH & WILCKE 1999, own ter-logged organic layer to slip down. Roots obs.). The soils are mainly Aquic and Oxaquic rarely penetrate down to the mineral soil, and Dystropepts (SCHRUMPF et al. 2001). subsequently do not prevent the upper layers The precipitation regime is bimodal as in from sliding. the larger part of the Ecuadorian Andes. One The flora of Ecuador consists of approxi- peak of high rainfall occurs from February to mately 16000– 20000 species of vascular plants May and the other from October to December (GENTRY 1977; JØRGENSEN & ULLOA ULLOA (HOFSTEDE et al. 1998; BENDIX & LAUER 1994; JØRGENSEN & LEON-YANEZ 1999). 1992). The climate at 1950 m a.s.l. is semi- Given that Ecuador covers a relatively small humid with 10 humid months, has a mean tem- area, it is one of the most species-rich floras of perature of 15.5 °C and an annual precipitation the world. This richness is not equally distrib- of 2031 mm. Above 2200 m a.s.l. the climate is uted over the country. Only 10% of the coun- per-humid (EMCK, pers. comm.). The natural try’s surface falls into the altitudinal range of © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 4. C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests 251 900 to 3000 m a.s.l but it is at this altitude 4 m2, as suggested by species area-curve analyses. where about 50% of the species and 39% of Each plot was photographed. the endemics are found (MADSEN & ØLLGAARD The cover of the floristic releves was estimated 1994). KESSLER (2002) counted 1138 endemic using the Londo scale (LONDO 1976). The vegetation table was sorted by hand and with the help of species in Ecuador at altitudes between 2500 TWINSPAN (HILL 1979) according to floristic and 3000 m. similarity (Table 1). The altitudinal zonation of the vegetation in The plots were sampled only once during the the study area is as follows: period between September and December 1999. The < 2100 m: Montane Broad-leaved Forest identification of plants was based on literature, and 2100–2700 m: Upper Montane forest or later compared to specimens in the “Herbario de la Ceja Andina Estacion Cientifica San Francisco”, the “Herbario de (2500–3100 m: Subalpine Elfin Forest or la Universidad Nacional de Loja” (Loja) and in the Yalca) “Herbario de la Pontifica Universidad Catolica” (QCA) in Quito. Angiosperm identification followed > 2700 m: Grass-Páramo, in wind-protected HUTCHINSON (1967), HARLING & SPARRE (1973– areas Shrub-Páramo. 2000), KELLER (1996), BRAKO & ZARUCHI (1993), The Montane Broad-leaved Forest is cha- MADSEN & ØLLGAARD (1993), ULLOA ULLOA & racterised by trees up to 30 m high, not exceed- JØRGENSEN (1993) and GENTRY (1996). Ferns have ing this height at exposed sites. Epiphytes, been identified according to the publications of especially ferns, Bromeliads and Orchids are TRYON & STOLZE (1989–1993), MACBRIDE (1930– highly abundant. Important taxa are Lauraceae 1970), ØSTERGAARD (1995) and ØLLGAARD (1979). (Ocotea, Nectandra, Persea), Melastomataceae Non vascular plants were not identified. Nomencla- ture of higher plants follows JØRGENSEN & LEON- (Miconia) and Rubiaceae (Psychotria, Pali- YANEZ (1999). Taxa missing in this work are named courea) (BUSSMANN 2001). The canopy is very according to the QCA specimens. dense and therefore herbal plants near the The collection of environmental data included ground are less common than at higher alti- soil texture of the upper mineral layer, and the soil tudes. Philodendron (Araceae) and Cyat- pH. The depth of the humus layer was measured as heaceae dominate the shrub layer. an important indicator of successional age and ongo- The vegetation composition of the Upper ing erosion. The inclination and position on the slide Montane Forest and the transition towards the was recorded as well as the altitude above sea level, Yalca vegetation was studied in 1999 and 2000 the direction aspect and the geographical position of the landslide. by HOMANN. The zone up to about 2400 m is Space-for-time substitution (PICKETT 1989) was dominated by Purdiaea nutans (Cyrillaceae), a employed to describe successional processes of stunted growing tree, and Guzmannia vanvolx- initial stages. Knowledge about the history of the emii (a terrestrial Bromeliaceae) building a slides can be gained by studying the aerial pictures dense ground-covering layer. Occasionally the of the region from 1962, 1976, 1989 (Instituto latter is replaced by Neurolepis elata (Poaceae). Geographico Militar, Quito) and 1998. However, the Other important taxa include Clusiaceae, Me- time since the last major sliding event for the plots lastomataceae and the genus Schefflera (Ara- could not be assessed accurately because most of the liaceae). Above 2400 m Purdiaea nutans landslide material is not displaced by one big event but by several consecutive slides. This type of land- becomes less important while species of Melas- slide has been called “ongoing slide” by STOYAN tomataceae become more abundant. Trees are (2000). Further on, many of the slides were invisible between 5 and 10 meters high. In wind-exposed at the aerial pictures due to their small size and the positions paramos occur as low down as steep relief. Therefore, the vegetation table was 2700 m a.s.l. organised according to their number of strata, in- creasing vegetation cover and height (Table 2). In this way the successional sequence can be inferred Methods but not their duration. Patterns of succession in the early to intermediate stages were investigated in this 23 landslides were selected between 2000 m and study; however there are no samples in the late 2700 m a.s.l. Selection criteria were: accessibility, successional stage. This is due to the logistical prob- aspect and altitude. On each selected slide between 2 lem of finding well-grown slides, as they are invisi- and 5 plots in homogenous zones were chosen for ble in aerial pictures and hard to find by walking the vegetation survey. The plot size was generally through the steep and dissected terrain. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 5. 252 Feddes Repert., Weinheim 115 (2004) 3 – 4 Table 1 Vegetation types of landslides – frequency table, reduced to common and diagnostic species Sticherus rubiginosus- Sticherus revolutus types type variant with variant with Sticherus Sticherus bifidus melanoblastus number of plots 13 31 32 Average altitude in m a.s.l. 2030 2290 2480 Sticherus rubiginosus V I I Elleanthus aurantiacus IV I II Diplopterygium bancroftii III I Sticherus arachnoideus II Isachne cf rigens II Andropogon bicornis II Ageratina dendroides II Munnozia senecionidis II I Sticherus bifidus I IV Purdiaea nutans II I Graffenrieda harlingii II I Sticherus melanoblastus IV Viola stipularis III Rhynchospora cf macrochaeta II Sticherus revolutus I V V Bejaria aestuans I V III Blechnum sp. I III V Brachyotum campanulare II II Disterigma acuminatum II II Baccharis genistelloides IV V V Lycopodiella glaucescens III V V Tibouchina lepidota III III III Pitcairnea trianae II III IV Lophosoria quadripinnata II IV III Rhynchospora cf vulcani II III III Cortaderia bifida I II II Results Gleicheniaceae, of which nine species of Glei- cheniaceae were found. The genus Sticherus is Floristic Composition the most important with seven species. 146 species of more than 40 families grew on Vegetation: altitudinal the studied sites. 22 species belong to the Pteri- and edaphic differentiation dophyta. Families with ten or more representa- tives in the data set are the Melastomataceae, Two major groups are recognisable in the vege- Orchidaceae, Ericaceae, Asteraceae and Glei- tation table classified according to floristic cheniaceae (Pteridophyta). Poaceae, Bromeli- similarity (Table 1). One is dominated by aceae and Rubiaceae are frequently found, too. Sticherus rubiginosus (Gleicheniaceae) while 56 species were recorded only once. 75% of Sticherus revolutus (Gleicheniaceae) is com- the total cover of vascular plants is composed mon in the other. The second group is clearly of different species of Pteridophyta especially divided into two sub-clusters. The first is char- © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 6. C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests 253 acterised by Sticherus bifidus (Gleicheniaceae), already on first stage sites points to an ad- the second by Sticherus melanoblastus (Glei- vanced age of at least 5 to 10 years (for exam- cheniaceae). ple Tibouchina lepidota, Vismia tomentosa or Other species are frequently occurring all Bejaria aestuans in plot 5, 12, 15, and 16). The over the studied plots. These include Baccharis second stage (Fig. 4) develops with the exten- genistelloides (Asteraceae) and Lycopodiella sion of the scattered plant individuals and glaucescens (Lycopodiaceae). ramets that established in the first stage of Altitude is a major factor influencing the succession using vegetative propagation, espe- species composition of the landslides. Fig. 2 cially Gleicheniaceae (see upper left corner of demonstrates the change of dominance of spe- Fig. 3) and Lycopodiaceae. Lycopodiella cies of Gleicheniaceae at different altitudes. At glaucescens and Lycopodium clavatum spread low altitudes Sticherus rubiginosus dominates. more quickly than the Gleicheniaceae with long At higher slides it is replaced by Sticherus looping runner-shoots but build stands of less revolutus accompanied by Sticherus bifidus or density (8, 10, 17, 19, or 27). Locally Viola Sticherus melanoblastus. The latter species stipularis spreads successfully using runner were never recorded both at the same slide. The shoots (plots 4, 20 and 21). The species compo- landslides colonised by Sticherus bifidus (slide sition seems to be random up to the point when 3, 4, 5, 6, 7, 8, 9, 10 and 22) and Sticherus the patches meet and competitive effects occur. melanoblastus (slide 19, 20, 21 and 23) are The month of October 1999 was a period of located on different mountain ridges (Map 2). extremely dry weather conditions. Locally, This shows that another environmental factor entire populations of Lycopodiella or Sticherus overlapping with the change in altitude is re- vanished suddenly (leaving patches of dead sponsible for this vegetation change. Slightly above ground plant material) probably as a different pH-values and a different percentage result of competition for water between the of exchangeable Ca2+ (VALLADAREZ, pers. individuals, ramets and species. The second comm.; ZECH et al. 2000) are characteristic for stage vegetation is made up by dense covers of the different ridges. Sticherus and Lycopodiaceae. Sticherus rubigi- nosus does not seem to have serious opponents at slides 1, 2, 11 and 12. Sticherus bifidus and Vegetation: time factor Lycopodiella tend to take over the dominant Table 2 shows a chronosequence of three suc- role at slides 3 – 10. Sticherus revolutus pre- cessional stages. The first stage (Fig. 3) is ra- vails at slide 22 and Sticherus melanoblastus ther similar at all altitudes with mosses and and Sticherus revolutus at slides 19– 21, 23 lichens covering the ground. The percentage and 13 – 18. The dominant role of Lycopo- cover of the layer of lichens and mosses is diella glaucescens vanishes usually with in- highly dependent on the soil and water condi- creasing total vegetation coverage (plots 59, 70, tions at a very small spatial scale and therefore or 75). not useful as an indicator for succession. A few Some species are equally present in early scattered vascular plants establish themselves. and later stages but never become dominant. The duration of this stage is highly variable Rhynchospora cf. vulcanii for example builds depending on the erosion of the site. The areas tufts and resists against the dominant species in in the first stage of succession on the slides are low numbers from the first stage to the end of freshly slipped parts, rocky parts, ever-eroding the second (plots 3, 11, 27, 38, or 70). Baccha- slopes or ever-accumulating zones with little ris genistelloides does not build dense colonies, inclination. Only some robust and runner-shoot and due to its straight and narrow growth form, building species can cope with strong erosion. percentage cover is usually very low but there In particular Baccharis genistelloides (As- are some plots where it is of greater importance teraceae) and Lycopodaceae are found. (plots 31, 43, 45, or 67). Seedlings of bushes The duration of the first or early second like Tibouchina lepidota, Graffenrieda harlin- stage is quite impossible to estimated, as ongo- gii (both Melastomataceae) or Bejaria aestuans ing erosion disturbs the successional sequence. (Ericaceae) are frequently found under dense The occasional presence of lignified plants layers of Sticherus in the first herbal layer. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 7. 254 Feddes Repert., Weinheim 115 (2004) 3 – 4 100 Sticherus rubiginosus dominance in % 80 60 40 20 0 100 Sticherus revolutus dominance in % 80 60 40 20 0 100 Sticherus bifidus dominance in % 80 60 40 20 0 100 Sticherus melanoblastus dominance in % 80 60 40 20 0 1900 2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 altitude in m a.s.l. Fig. 2 Altitudinal preference of some common Gleicheniaceae species on revegetating landslide plots Usually, these species are not found in primary undecomposed organic matter are very thick forest but form the pioneer forests. Seedlings of (plots 49, 50, and 51). The shady edges of the Purdiaea nutans (Cyrillaceae), the dominant slides are dominated by either Sticherus arach- species in the upper primary forest, may be noideus, or St. tomentosus. The woody plants found but apparently never mature to shrubs or Ageratina dendroides (Asteraceae), Munnozia trees in any of the early successional stages senecionidis (Asteraceae) and Liabum kingii (plots 17 or 29). (Asteraceae) are present. The third stage: Vegetation development at At the Sticherus melanoblastus or St. bifi- the Sticherus rubiginosus-dominated sites does dus dominated sites Cortaderia bifida (Poa- not show great variability. High stands of St. ceae) climbs with long, looping runner-shoots rubiginosus are covered with climbing Diplop- through the dense layer, hardly ever touching terygium bancroftii (plots 48, 49, or 50) which the ground (59, 64, 65, or 71). In the upper may locally dominate (plot 51); the mats of strata Tibouchina lepidota (Melastomataceae) © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 8. C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests 255 Map 2 Position of the investigated landslides in the area. The landslides are aligned along three different mountain ridges and other species build bushes or small trees. like, varying between about 30° and 80°. This The fern Lophosoria quadripinnata (Lopho- leads to different erosive forces at different soriaceae) grows up to 2 meters in height (plot parts of the slide. Nevertheless, a direct correla- 59). tion between vegetation cover and inclination or erosive energy would only partly account for the distribution of the vegetation. The study of Discussion soil cores of the slides under more, and less, dense vegetation did not produce results with The first remarkable thing we noted when we significant differences in regard to soil texture, were climbing around the landslides, was the structure, colour and pH. This excludes the ‘patchy’ distribution of vegetation. What is the edaphic conditions as principal responsible reason for this? The slides are very similar in factors. shape, being long and narrow, although they Landslide areas are colonised quickly either vary in size. The surface is smooth and very at the borders of the slide or around islands that few rocks are present. Inclination changes step- slipped down without being overturned due to © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 9. 256 Feddes Repert., Weinheim 115 (2004) 3 – 4 © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 10. C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests 257 © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 11. 258 Feddes Repert., Weinheim 115 (2004) 3 – 4 © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 12. C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests 259 © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 13. 260 Feddes Repert., Weinheim 115 (2004) 3 – 4 Fig. 3 Aspect of a plot in late first stage. Sticherus bifidus is spreading in the upper left corner (scale on the right = 2 m) vegetative propagation from the undisturbed established themselves after a few months. In neighbouring areas and possibly due to a fa- contrast, a landslide exposed to wind and direct vourable microclimate. Other patches of high sunlight was bare of any vegetation about eight vegetation cover are created by the clonal, months after the slide event. looping runner-shoot building growth of most Differences in vegetation along the altitudi- of the individual pioneers that managed to nal gradient have been found. The main flo- establish seedlings first (Gleicheniaceae, Lyco- ristic change occurs at an elevation of about podiaceae and Ericaceae). 2100 m. This altitude corresponds to the chan- The majority of the abundant species are ge in the vegetation zonation in the surrounding wind-dispersed and produce many seeds. The forests: from the Montane Broad-leaved Forest only frequent Angiosperm is Baccharis genis- to the Upper Montane Forest (BUSSMANN telloides (Asteraceae) which flowers all year 2001). On the landslides at higher altitudes round, so fruits are permanently available. some species typical for paramo vegetation are Under certain conditions freshly slipped found (Paepalanthus meridensis – Eriocaula- slides do not last very long in the first stage and ceae or Xyris subulata – Xyridaceae). Other lichens and mosses do not develop well as the distribution patterns do not correspond to vege- colonisation by higher plants starts already in tation changes along the altitudinal gradient but the first year of succession. In addition to the show similar patterns to differences in soil 23 landslides studied in detail some sites of chemistry. An explanation of the allopatric very recent origin were examined. On land- distribution of Sticherus bifidus and St. mela- slides well protected against wind and direct noblastus by the altitudinal gradient alone is sunlight, seedlings of the surrounding flora not possible, while the difference in altitude is © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 14. C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests 261 Fig. 4 Early stage 2, dominant species are Sticherus bifidus and Lycopodiella glaucescens too small and no transition zone with the pre- compares the effect of landslides to the mean- sence of both species was found. Contrarily, as dering rivers of the lowland ecosystems. They described in the results, the influence of differ- create secondary forests dominated by colonis- ent soil chemistry combined with the influence ing species which are not able to survive in of changing altitude would offer an explana- mature stands. tion. Slightly different pH-values and a differ- In this work species richness during the first ent percentage of exchangeable Ca2+ (ZECH et al. two stages of regeneration is low due to the 2000) are characteristic for the different ridges. dominance of a few species of ferns. However, The amount of Ca2+ correlates negatively with during the third stage of succession, species the abundance of Al3+-ions which are toxic to composition still differs somewhat completely plants and could therefore be responsible for to the surrounding forest, but diversity is high. the differences in floristic composition (LAN- The second stage with a dense cover of DON 1991; ZECH & WILCKE 1999; WILCKE, Gleicheniaceae has not been described from pers. comm.). Correlations to other factors northern Ecuador (STERN 1995) but it was which could be responsible for the vegetation found on landslides in Bolivia (KESSLER 1999). change such as aspect were not found. There, the role of Gleicheniaceae seems simi- Landslides are a common phenomenon in lar. Diplopterygium bancroftii and species of most tropical mountain systems. STERN (1995) Sticherus dominate. In contrast, STERN (1995) and KESSLER (1999) hypothesised that landsli- found a dominant species of Chusquea, 3 ½ des maintain species diversity. STERN (1995) years after the slide event at the lower zone of a © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 15. 262 Feddes Repert., Weinheim 115 (2004) 3 – 4 landslide. She adds that the presence of the gered slides along the roads? Studies on the bamboo is especially noteworthy because under regeneration of the latter type of slides close to certain environmental conditions it can grow the research area have been carried out by quickly and aggressively. Further on, she desc- HARTIG (2000). These slides are usually very ribes the great density of the bamboo, thereby extensive. The surface is not smooth but often having a profoundly limiting effect on the es- rocky. Natural slides are mainly created by a tablishment of other plant species. The bamboo heavy organic layer slipping over the mineral occurred at sites with a reasonable upper layer soil. If thick mats of organic material become of organic debris. Other interesting differences water-logged due to long-lasting heavy rains, in her work are that species of the genus Equi- the weight of the material reaches a critical setum are important in the early stage and point when the adhesive strength gives in to Blechnum dominates locally. No species of gravity and a slide-event is initiated. The thres- Gleicheniaceae were found. Reasons for those hold in this area is very low as the adhesive variations might be found in the obvious differ- strength is low due to the slippery mineral soil ences in geological substrate (of quaternary and the lack of a well developed root-system in volcanic origin) and the lower humidity and the B-horizon which could help to fix the upper altitude of the site (1440 m). Gleicheniaceae do layers (own obs.; STERN 1995). The human not hinder the establishment of bushes, though triggered slides are usually initiated due to the the time period from when seedlings of bushes weakened geological underground and have appear to when they manage to break through more in common with rock-falls. Succession the fern layer, varies. Different types of succes- differs between the two types of slides. Grasses sional models seem to correspond to the rege- largely replace the Gleicheniaceae and build a neration processes at the slides studies by very dense layer often limiting the establish- STERN on one hand and on the other hand the ment of bush species. Succession seems to slides observed by KESSLER and the work on follow the inhibition model (CONNELL & SLA- hand. Following the division of successional TYER 1977; PICKETT et al. 1987). Especially the models according to CONNELL & SLATYER number of orchids is tremendous which leads (1977) and PICKETT et al. (1987) the model of to a very high diversity on man-made slides inhibition will have to be used to describe the (GROSS 1998). In contrast, there are not many situation in northern Ecuador as observed by species of orchids found at the natural slides STERN (1995). In contrast, the tolerance model but in the few areas with rocky relief they be- combined with the facilitation model could be come more abundant (see plot 21 or 48). used to describe the situation in Bolivia (KESS- The aerial pictures of the region show a LER) and southern Ecuador. Little change in very unequal distribution of the natural slides. species composition but mainly a change in One possible explanation for the clustered vegetation density or -height was observed due occurrence of the slides might be reached by to local erosive energy, time elapsed since the studying the direction of the geological struc- last destruction, depth of the organic layer or tures. If the layers are aligned parallel to the the distance towards densely covered sites. slope, the risk of a slide-event arises. Consider- Mosses and lichens are not only abundant dur- ing that on most of the slides the soil is not ing the first stage but also during the second dragged down to the C-horizon, this explana- and third stage (though we do not know if the tion is probably not of great significance, but species are similar) and Gleicheniaceae are locally this certainly encourages or deters a present in the second and third stage though sliding process. Probably, the heavy organic they loose importance as they are overgrown by soil layer is responsible for the majority of the bushes and trees of the pioneer forests. Up sliding processes. Under mature forest organic to this point, the model of tolerance seems to fit layers build up, but due to evaporation and while the missing of species of the primary transpiration they will not get heavily water- forests during the third stage follows the facili- logged. In contrast, comparable amounts of tation model. water do not transpire from senescent forest. A What is the main difference between the mosaic-like forest structure with younger and studied natural landslides and the human trig- older forest stages is described in KESSLER © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 16. C. OHL & R. BUSSMANN: Recolonisation of natural landslides in tropical mountain forests 263 (1999) from the montane forest in the Bolivian BENDIX, J. & LAUER, W. 1992: Die Niederschlags- Andes. He observed irregularly formed and jahreszeiten in Ecuador und ihre klimadyna- spaced patches of senescent forest with single mische Interpretation. – Erdkunde 46: 118 – 134. trees having already collapsed. This could BRAKO, L. & ZARUCHI, J. L. 1993: Catalogue of the flowering plants and Gymnosperms of Peru. – explain the clustered occurrence of landslides Monographs in Systematic Botany 45. as the risk of slipping in zones of senescent BUSSMANN, R. 2001: The montane forests of forest is higher than in zones of mature forest. Reserva Biológica San Francisco. – Die Erde In this case the effect of landslides in the eco- 132: 9 – 25. system would be very important for the natural CLAPPERTON, C. M. 1986: Glacial Geomorphology, regeneration of the system. At altitudes above Quaternary glacial sequence and palaeoclimatic 2100 m, especially under senescent forest, very inferences in the Ecuadorian Andes: 843 – 870. – dense layers of terrestrial Bromeliads are In: V. GARDINER (ed.), Proceed. Intern. Conf. found. Germination of other species is very Geomorphology II. – Cluchester. CONNELL, J. H. & SLATYER, R. O. 1977: Mechanisms difficult under these circumstances. In contrast, of succession in natural communities and their a landslide provides light and a high availabil- role in community stability and organization. – ity of minerals for successful plant growth. Am. Nat. 111: 1119 – 1144. There are still plenty of open questions DE NONI, G.; VIENNOT, M. & TRIJILLO, G. 1989– concerning the governing factors and the pro- 1990: Mesures de l‘erosion dans les Andes de cesses going on at landslides in the research l‘Equateur. – Cahier ORSTOM, Serie Pedologie area. Further research will have to deal in parti- 25(1–2): 183 – 196. cular with the influence of the soil chemistry on ERICKSON, G. E.; RAMIREZ, C. F.; CONCHA, J. F.; TISNADO, M. G. & URQUIDI, B. F. 1989: Land- species composition and succession and the slide hazards in the central and southern Andes: development of the pioneer forests towards the 111 – 117. – In: E. E. BRABB & B. L. HARROLD climax stage. (eds.), Landslides: extend and economic signi- ficance. – Rotterdam. Acknowledgements GARWOOD, N. C. 1981: Earthquake-caused land- slides in Panama: recovery of the vegetation. – We would like to express our cordial thanks to Res. Rep. Natl. Geogr. Soc. 21: 181 – 184. Prof. Dr. Ankea Sieg l and Prof. Dr. Ulrich GENTRY, A. H. 1977: Endangered plant species and Deil for helpful discussions and revisions habitats of Ecuador and Amazonian Peru: 136 – concerning this work and our Ecuadorian coun- 149. – In: G. T. PRANCE & T. S. ELIAS (eds.), terparts of the Universidad Nacionál Loja Extinction is forever. – The New York Botanical Garden, New York. (Ing. N. Mald o nad o , Ing. W. Ap lo , Dr. L. GENTRY, A. H. 1996: A field guide to the families L o ján), Herbario Reinaldo Espinosa Loja and genera of woody plants of north-west South (Ing. Z. Agu ir r e, Ego. B. Mer in o , Dra. B. America (Colombia, Ecuador, Peru) with supple- K l i t g a a r d ), the herbaria QCA y QCNE in mentary notes on herbaceous taxa. – Chicago, Quito, and ECSF, for all their collegial help at London. all times throughout the study. We thank INE- GROSS, A. 1998: Terrestrische Orchideen einer FAN for the research permit (now Ministerio Hangrutschung im Bergwald Süd-Ecuadors: Ver- de Medio Ambiente de Ecuador; no. 16-IC teilung, Phytomasse, Phänologie und Blüten- merkmale. – Univ. Ulm, Diploma Thesis, INEFAN DNAN VS/VS). We would also like unpubl. to thank the Deutsche Forschungsgemeinschaft GUARIGUATA, M. R. 1990: Landslide disturbance and for financing the project (DFG, Be 473/28-1, forest regeneration in the upper Luquillo Bu 886/1-1/2). Mountains of Puerto Rico. – J. Ecol. 78: 814 – 832. HALL, M. 1977: El volcanismo en el Ecuador. – Biblioteca Ecuador. – Quito. References HARLING, G. & SPARRE, B. 1973 – 2000: Flora of Ecuador. – Bot. Mus., Copenhagen. BATARYA, S. K. & VALDIYA, K. S. 1989: Landslides HARTIG, K. 2000: Pflanzensoziologische Untersu- and erosion in the catchment of the Gaula River, chungen von anthropogen gestörten Flächen im Kumaun Lesser Himalaya, India. – Mountain tropischen Bergwald Südecuadors. – Univ. Research and Development 9(4): 405 – 419. Bayreuth, Diploma Thesis, unpubl. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
  • 17. 264 Feddes Repert., Weinheim 115 (2004) 3 – 4 HILL, M. O. 1979: TWINSPAN – a FORTRAN PICKETT, S. T. A. 1989: Space-for-time substitution program for arranging multivariate data in an as an alternative to long-term studies: 110 – 135. ordered two-way table by classification of the – In: G. E. LIKENS (ed.), Long-term studies in individuals and attributes. – New York. ecology. – New York. HOFSTEDE, R.; LIPS, J.; JONGSMA, W. & SEVINK, Y. PICKETT, S. T. A.; COLLINS, S. L. & ARMESTO, J. J. 1998: Geografia, ecologia y forestacion de la 1987: Models, mechanisms and pathways of sierra alta del Ecuador. Revision de literatura. – succession. – Bot. Rev. 53: 335 – 371. ABYA-YALA, Quito. SCHRUMPF, M.; GUGGENBERGER, G.; VALAREZO, C. HUTCHINSON, J. 1967: Key to the families of & ZECH, W. 2001: Tropical montane rain forest flowering plants of the world. – Oxford. soils: development and nutrient status along an JØRGENSEN, P. M. & LEON-YANEZ, S. (eds.) 1999: altitudinal gradient in the south Ecuadorian Catalogue of the vascular plants of Ecuador. – Andes. – Die Erde 132: 43 – 59. Monographs in Systematic Botany from the STERN, M. J. 1995: Vegetation recovery on earth- Missouri Botanical Garden 75. – St Louis. quake-triggered landslide sites in the Ecuadorian JØRGENSEN, P. M. & ULLOA ULLOA, C. 1994: Seed Andes: 207 – 220. – In: S. P. CHURCHILL; H. plants of the high Andes of Ecuador – a check- BALSLEV; E. FORERO & J. L. LUTEYN (eds.), list. – Aarhus University (AAU) Reports 34. Biodiversity and conservation of neotropical KEEFER, D. K. 1984: Landslides caused by earth- montane forests. – New York. quakes. – Geol. Soc. Amer., Bull. 95: 406 – 421. STOYAN, R. 2000: Aktivität, Ursachen und Klassifi- KELLER, R. 1996: Identification of tropical woody kation der Rutschungen in San Francisco/Süd- plants in the absence of flowers and fruits. – ecuador. – Univ. Erlangen, Diploma Thesis, un- Basel. publ.. KESSLER, M. 1999: Plant species richness and TRYON, R. M. & STOLZE, R. G. 1989 – 1993: Pterido- endemism during natural landslide succession in phyta of Peru I–V. – Fieldiana (Botany). N.S. – a perhumid montane forest in the Bolivian Chicago. Andes. – Ecotropica 5: 123 – 136. ULLOA ULLOA, C. & JØRGENSEN, P. M. 1993: Arbo- KESSLER, M. 2002: The elevational gradient of les y arbustos de los Andes del Ecuador. – Andean plant endemism: varying influences of Aarhus University (AAU) Reports 30. taxon-specific traits and topography at different ZECH, W. & WILCKE, W. 1999: Einfluß der Land- taxonomic levels. – J. Biogeogr. 29: 1159 – 1165. nutzung auf Bodeneigenschaften sowie auf die LANDON, J. R. (ed.) 1991: Booker tropical soil manu- Wasser- und Elementflüsse in Bergwäldern Süd- al. – Essex, New York. ecuadors. – Bericht zum bodenkundlichen Teil- LONDO, G. 1976: The decimal scale for releves of projekt des Projektverbunds „Ökosystemare permanent quadrats. – Vegetatio 33(1): 61 – 64. Kenngrössen gestörter und ungestörter tropischer MACBRIDE, J. F. (ed.) 1930 – 1970: Flora of Peru. – Bergwälder“. Zwischenbericht. – Univ. Bay- Chicago. reuth, unpubl. MADSEN, J. E. & ØLLGAARD, B. 1993: Inventario ZECH W.; WILCKE, W. & VALAREZO, C. 2000: In- preliminar de las especies vegetales en el Parque fluencia del uso de la tierra en los propiedades Nacional Podocarpus. – Ciencias agricolas de del suelo y en los flujos de aqua y de elementos la Universidad Nacional de Loja 22–23(1 – 2): en los bosques montanosos del Ecuador del sur. 66 – 87. Zwischenbericht. – Univ. Bayreuth, unpubl. MADSEN, J. E. & ØLLGAARD, B. 1994: Floristic com- position, structure, and dynamics of an upper montane rain forest in Southern Ecuador. – Nord. Addresses of the authors: J. Bot. 14: 403 – 423. Dr. Constanze O h l (corresp. author), Martin-Luther- ØLLGAARD, B. 1979: Lycopodium in Ecuador – ha- Universität Halle-Wittenberg, Institut für Geobotanik bits and habitats: 381 – 395. – In: K. LARSEN & und Botanischer Garten, Am Kirchtor 1, D-06108 L. B. HOLM-NIELSEN (eds.), Tropical botany. – Halle, Deutschland Proceed. sympos. Univ. Aarhus on 10–12 August e-mail: ohl@botanik.uni-halle.de 1978, organized on the occasion of the 50th Dr. R. B u s s m a n n , University of Hawai’i Manoa, anniversary of this university. – London. 3860 Manoa Road, Honolulu, Hawai’i, ØSTERGAARD, E. 1995: Gleicheniaceae – en gruppe bussmann@hawaii.edu, USA. pioner plantenblandt tropiske bregner. Afdeling for Systematik Botanik. Specialerapport marts 1995. – Biologisk Institut Aarhus Universitet, Manuscript received: September 29th, 2003/revised Aarhus. version: December 15th, 2003. © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim