Field and analytical aspects in the mang-gurm
habitat in Abu Dhabi
AbdulSattar Salih Al-Mashhadani,
PRFD, Abu Dhabi Municipality, UAE
a.mashhadani@adm.abuhabi.ae
Abstract
The Avicennia marina Fork Vierk in its pure Mang-grum stands takes an
environmental importance in Abu Dhabi Emirate. The lonely woody species
represented its unique ecosystem besides of its biotic and important role in
maintaining the coastal zones of the Emirate and protecting the sea creatures.
The field observations revealed that the safety, life and stabilization of the Mang-
grum habitats depend on the percentage success of natural regeneration, which is
under the impacts of many factors. The main factors are the coast shape, stands
age, humanitarian activities and biotic attraction, moreover the range and
direction of the seed distribution after their ripening. We observed that high
density of new seedlings is concentrated in shallow floodplain that have
moderate littoral current and protected from the stream. It has been found that the
quantity of total soluble salts in the surface horizon of stand soil is less than
deeper horizons. The salt ions in the root zone are comparatively lesser due to
the absorption by the roots and annual leaching by tide process. In Mang-grum
stands, it has been clearly seen that the absorption of sodium salts is higher than
calcium salts, while this relation is converse in the bare land. It has been found
that there is an increase in sulfur percentage and gradual change in the color of
the soil to dark grays with the depth. From the analysis of plant samples , it has
been observed that many common diseases have affected them. To conclude, our
study has proved that Mang-grum stands can be the habitat of the vast expanse of
the UAE coastal regions.
Keywords: Coastal zone, Gurum, Habitat, Mang-grum, Natural regeneration

1 Introduction
The Gurum (Avicennia marina Fork Vierk), as recognized locally, is one of
Mangrove plants exceeding 80 species globally. They are covering
approximately 16530 Kilo-hectare distributed throughout the continents (FAO
1981; Saenger et al.1983; Wacharakitti 1983; FAO 1986).It is related to
Verbenaceae family. Its local name may have derived from the Malian word
Manggi-manggi. This named on the type of mangrove trees of the Avicennia
genus, which called in Arabic Gurum (Mang-gurm). This term could refer to the
specific species or plants or forest or its biotic community as a whole.
They are evergreen trees with heights rise up to 9 m and the rarest; it could reach
more than 20 m with 80 cm diameter (in the virgin Maldives islands). This
indicator varies according to the environmental suitability. In the open stands of
UAE, it ranged 2-4 m. This species considered as the most prevalent species in
the eastern half of the planet and it has the dominance within the mangrove
forests. In adapting on the early site settlement, it is better than any other species
because of its wide tolerance range against the conditions in the muddy soils. It
plays an important role in stabilizing of the large rivers and seashores. In
addition to its different advantages that mentioned in many references. It used as
the source of raw materials; fuel wood, fodder (particularly for goats, camels-the
protein in the dry material exceeds 11%), tanning materials and many others. It is
a biotic pioneer in maintaining a reserve of water and fishery wealth. This role
could strengthen by applying the protective measures against any negative
pressure that may be exposed those stands by man.
The Gurum covers vast areas along the shores of the Arabian Gulf and the Red
Sea, where spreading together with the species Rizophora mucronata in the
southern part of the Saudi Arabian coast.
In United Arab Emirates, it covers around 2900 hectare and has absolutely
dominance in all the stands scattered along the coast overlooking the Arabian
Gulf. The most famous among them are the oldest that located at Khor Kalba in
Sharjah Emirate.There are approximately 40 km (2500 hectare) of Mangrove
forests in Abu Dhabi Emirate ( concentrated on the Islands of Abu Dhabi , Al-
Sahdiat , Abu Al-Abiad and Al-Rwais coast) . Three quarters are open stands
density (subject of our study),a quarter- high density(Varopeif et al 1986; Al-
Hadrami et al 2000; Al-Mashhadani 2002 ). The features of Gurum Leaves,
flowers and fruits are well-known . The plant from the lower surface of the leaf
secretes salt. The root system is extensive and has many pneumatophores, which
are covered with much grey to white lenticels. This species has high
environmental importance in the Arab Gulf region. It grows in one of the most
drought habitats in the world, where it represents as only wood species
component of its distinct environmental systems. In the UAE, the habitat of
Mangrum stands is one of the most important natural features that get a high
attention by government. It is one of the basic elements of natural resources,

which are enriching the biodiversity with higher value environmentally, morally,
and economically. Because of its high tolerance, this species has proved a high
success in the settlement of the marine environment of the United Arab Emirates
as well as being the most salts tolerant species compared with other Mangrove
species.
Al Qurum ( Mangrove ) Timberlands are distributed in the UAE, as shown in
the table below:
Table 1: Al Qurum Timberlands area in UAE
Location Area ( ha ) Note
Khor Kalbaa 051 -
Al Ramass 01 -
Rass Al Khayma 01 -
Khor Un Al Queen 011 -
AD Emirate
(AlSahdyat Island)
0111
(0511)
30 Km2
(25 Km2
)
Total area 0101-0001
40 Km2*
(RS estimation)
*Mangrove Timberlands of which 30 km2
are open stands and 10 km2
close
stands
 The highest trees reached heights to 8.3 m
 Biomass of short plants above ground 14 to 65 tons / ha
 Biomass of long plants above ground from 78 to 110 tons / ha
 Falling residues of short plants were amounted between 5.1 to 6.9 t / ha
/ year
 Falling residues of long plants were amounted between 7.4 to 8.5 t / ha /
year
An average of 7 tons / ha / year
 Contribution to the addition of organic matter reached 21000 tones to
the UAE and a share of 17,500 tons of Abu Dhabi Emirate
 Plant density in Closed or dense excess of 40%.
 Plant densities in Open or not dense are ranging from 10 to 40% (on
average 25% )
Despite the general similarities of the Mangrum environmental requirements
along the coast regions of the State. However, many of the stands have their site
privacy specified by exchangeable influence of many environmental factors. It is
therefore necessary to apply well survey for all the sites before taking any
decision for planting to ensure the survive and sustainability of the stands
(Shabbir and Faisal 2000).
Overall, we can say that it is difficult to describe the habitat of Mangrum stands
accurately as being linked to the monitoring and follow-up of the direct and
indirect effects of a complex web of climatic, biological and edaphically factors.
As well as the impact of various humanitarian activities, which require research
projects aimed at undoing many of their symbols.

Our preliminary study was done by using simple available possibilities. It comes
to highlight, explain some of analytical and field indicators in this Mangrum
stands habitat and to put some recommendations about this specific environment.
2 METHODOLOGY
The study was based on the field reconnaissance for two consecutive years in
order to collect sufficient information about the site features of three Mangrove
stands; Two of them on West region;Close Al-Sameyria Island, Al-Marfa coast
(near Al Marfa hotel), and the third on Abu Dhabi Island . All of them related to
open-density type.
Al-Sameyria Island (Google image)
Al-Marfa coast (Google image)
AD Western Mangrove (Google image)

And on the standard chemical analysis of soil and water samples from Abu
Dhabi stands; thirty six soil samples were taken from four profiles in different
depth levels (0- 5 cm ,10-25 cm , 30-50 cm)from four places: Three of them
from the stand and one sample from outside the stand (for comparison-as
control), which is located along the same front. Each depth was replicated for
three times. Fifteen water samples were taken from five points. Two of them
from the water that covers Gurum stand area and two samples from the sea water
next to the stand; their distance was two metrs from the edge of the beach. Other
was from another location that parallel to them and from the site next to bare
area (outside the stand). Each sample was replicated three times. All the rates of
the indicators for chemical analyses of samples were calculated.
The study aimed to access some analyses of plant samples from Gurum stands to
identify their conditions and summarizes some symptoms and causes to which
they are exposed. These could be adopted as the course of first warning about the
necessity of their maintenance and study in detail by certain specialists in the
close future.All analyses were conducted at the laboratory of agricultural
research / Department of Agriculture / Abu Dhabi Municipality.
3 RESULTS AND DISCUSSION
3.1 ON THE FIELD
Generally, it is well known that the geological and environmental factors,
particularly the continuous coast exposure to the sea currents and waves, could
work towards the reformation of sandy coasts. In addition, it helps to support the
possibility of stabilizing the marine sediments on the protected beaches in
addition to their positive impact in warming the marine currents...and many other
appropriate conditions. Gradually, all of them have created a suitable
environment for the growth of Mangrove stands in this region.
It is clear that the existence and environmental balance of the Mangrove stands
(EEB) are mainly associated with seed germination and survival percentage of
the growths of natural regeneration. Actually, the Growth of young seedlings to
adult size occurs rarely and probably depends on the availability of light and
nutrients on certain site.
Our continued field observations on the growth status and natural regeneration of
Mangrove stands showed that their EEB could limit directly and indirectly by
many factors.
3.1.1 MAIN FACTORS
a) The form of the coast: It represented in different crooked forms,
especially the Crescent patterns which bordering the angles and the
fronts of exposure to different velocities of water and wind

currents.These factors affect on the amounts of sediments
accumulations and water depth along and within the stands, as well as
the level success of natural regeneration in the stand.
b) The age of stand: The positive Bio-physic-chemical influence of the
Mangrove stands on the coast soil increases with age. Due to this
influence, there was a variation in the environmental privacy of every
stand according to the age classes of its trees.Despite the impact of
water currents in removal of most of the involved and fallen materials
on the stand ground ,this could be relating to the difference between the
accumulated quantities of silt and organic materials on the stand
land.Therefore,the Gurum habitat considered as one of the sensitive
environments and easy intrusion by any external influences, especially
humanity. It is influencing by what water currents bring it of foodstuffs,
in addition to the impact of the volume of biodiversity in supporting its
productivity.
c) Irrational Humanitarian activities: There are many irrational
activities because of the absence of some rules, regulations and land use
standards according to land productivity in certain areas. Such as
indiscriminate fishing, construction and earth excavation operations...As
well as the effects of waste disposal and water pollution... and many
others .All those are contributing in clouding the virginity of Mangrove
stands.
d) The bio-attractions of the stands: Various organisms, from the least to
the climax level, could effect by this factor. Such as crustaceans,
molluscs, marine turtles, fish, different types of marine animals, and
various types of birds.Their numbers or intensity linked with the degree
of the impact of the foregoing factors. The stands attraction will
increase with their improvement and vice versa.
3.1.2 SECONDARY FACTORS (THE SPECIFICITY OF STAND)
a) The extent of seed distribution: The spreads’ distance of the mature
seeds from the mother trees could affected on their germination and
survival percentages. This happens because of the variations in the
protection and moisture levels that are available for the seeds in
stabilized positions.
b) The direction of the seed spread:the extent of seed distribution toward
the water could limit by the specificity of the site in terms of the depth
and protection.This indicator increases where there is lack of depth and
mild water currents and vice versa.

3.1.3 OTHER COMPLEMENTARY FACTORS
While the extent of seed distribution towards the land could determine by the
following factors:
a) Stand density and all the growths adjacent to water.
b) Site moisture (affected by shallow submerged area and that located
within the tide extent).
c) The impact of the sediments volume along the coastal strip.
d) The effect of the dominant winds during the maturation of seeds and
their exchangeable relationship with exposure side and the effect of the
coast form.
Under the influence of these circumstances, the extent will increase with their
improvement and vice versa.
The field observations indicate that the highest density of the growths of natural
regeneration located at the shallow submerged sites adjacent to water paths of
moderate movement (where there is good discharge and protection by the natural
constraints :silt accumulations, where the absence of water sweeping currents
that affect the success of the natural regeneration. In addition, they indicate that
the growth of survived seedlings to adult size occurs rarely and probably
depends on the availability of light and nutrients after their settlement.
The sandy soil of the barren area next to Mangrove stands is poor organic
material. On this area, it was Observed that the water movement and drainage by
the impact of tide is more freedom than stand area. This is a matter of course
because the water has not time to stagnate and smoothly withdraw from the site.
The situation is opposite in Mangrove stand as an ordinary impact of the stand
density which contributes as a barrier slowing the water movement during tide.
In addition to the affect of the relative difference in the organic matter that makes
most of its area in submerged status and poorly ventilated with sulfide smell.
This phenomenon is due to a lack of oxygen providing by the impact
submergence and the activity of anaerobic bacteria.
3.2 ANALYTICAL RESULTS
From the analysis of water and soil samples on table -2, we found the following
results: The soil of the stand and barren area are salty because the Electrical
Conductivity (EC) of their saturated extracts is over 2000 microSiemens per
centimeter (µS/cm) = an old unit ; micromhos per centimeter (µmhos/cm).

The total dissolved solid concentration (TDS) in high salinity seawater samples
that collected from the front along Gurum stand and reported in units of parts per
million is relatively more than from the same front adjacent to bare area. The
reason is likely to the influence of plant density that obstruct the rapid rise and
withdrawal of water from the territory of the stand during the tide movements.
This process allowing more time for washing the salts from the soil surface layer
compared with the barren area. This was confirmed by the analysis of water
samples collected from the stand ground during the tide. From the results of the
stand soil samples analysis that taken from different levels of profiles, It was
found that the proportion of TDS in the surface level of the stand area (0-5 cm) is
less than other levels (10-25 cm), (30-50 cm) about 32%. 34% respectively.
Table 2: Water and Soil Chemical Analysis in/out Mang-grum Stands
Indicators
Mangrove Stand Bared Area (Control)
Water Soil layers(cm) Sea
Water
Soil layers(cm)
Sea Stand 0-5 10-25 30-50 0-5 10-25 30-50
pH 7.9 7.9 7.2 7.0 6.9 8 7.3 7.1 7.2
EC 78617 82900 69200 100650 100200 78200 71700 69000 54800
TDS
(PPM)
48656 50041 43962 64261 66322 49666 45909 44094 36527
CO3
--
(PPM)
19 13 - - - 24 - - -
HCO3
-
(PPM)
76 122 103 91 81 67 71 68 73
Cl-
(PPM)
25391 26074 22225 33425 32225 25249 24449 23249 19499
SO4
--
(PPM)
3972 4304 4070 5302 5374 3915 4286 3970 3336
Ca++
(PPM)
534 497 872 972 782 569 872 882 841
Mg++
(PPM)
1722 1884 1569 2213 2347 1698 1569 1568 1240
Na+
(PPM)
16417 16594 14502 21459 24806 17604 14503 13754 10925
K+
(PPM)
521 547 581 768 671 533 626 547 508
NO3
-
(PPM)
6.9 7.5 43 32 33 7 73 55 105
SP% - - 37 36 30.7 - 39.5 36.5 37
SSP% 79.3 78 76.5 78.5 81 80 76 76 75
Na/Ca - - 16.6 22.1 31.7 - 16.6 15.6 13
This declination can be attributed to the high absorbing proportion of salt ions
:NO3¯, Ca++,K+,Mg++,SO4¯ ¯,Na+,Cl¯ especially the macro elements of plant

nutrition, Within this horizon as a result of the spread intensity of the root
systems compared with other horizons. In addition to the impact of periodical
washing (daily, seasonal) of the tide that influenced within the upper soil horizon
effectively.
It observes, from the results of analysis, that the Gurum trees absorb a large
proportion of sodium salts compared with calcium salts. This may related to their
needs to support the ability of absorbing the salty water with nutrients via
increasing the osmotic pressure of plant sap. This case was confirmed by some
references about the possibility of this species to expel the salts (around 95%)
from the absorbed water (Mark Curran and et al. 2004).
The comparison of the above results with the same soil levels samples, taken
from the comparative site (control), indicates that the previous relationship varies
than the recent one. Where the proportion of the salts in the surface (0-5cm) was
higher by about 4%, 20% compared with the levels (10-25cm), (30-50cm),
respectively.
It is confirmed to us that the sulfur proportion in Gurum soil increases with depth
increase. Where the soil changes its color to dark gray with increasing of a strong
and distinctive smell refers to the release of hydrogen sulfide gas due to the
activity of Anaerobic Sulfur-reducing bacteria (Peter 1999).
In addition, it was cleared that the saturation percentage sp % (representative
indicator of the clay by Salt) decreases with depth increase. This case could
relate to the biotic influence of the Gurum trees within the layer between the
levels of 25 cm depth up to surface. This happened through the additions of
organic biodegradable quantities, resulting from the trees fallout of vegetative
residues, as well as the various organisms that attracted by the stand. In addition,
other high and microorganisms, which affect the soil texture especially within
this layer.
The variation in salts concentration between the soil layers could affect their
exchangeable aquatic relations. This is because any salt increase will reduce the
osmotic pressure of the soil solution.With its continued reduction, the difference
with water potential in the root of trees will decreasing, this reduces the value of
the driving force of water absorbing. In general, as confirmed by Flowers 1985,
the plants vary on using the kind of ion and the compounds in osmotic
neutralism. This is could achieve through their absorption of inorganic ions such
as: sodium and potassium (preferable by the salty plants), which is increasingly
concentrated in the plant cells while increased on the external environment.
3.3 SYMPTOMS AND INJURIES
The Agricultural Research Laboratory of the Abu Dhabi Municipality has done
appreciable different analysis of samples taken from Gurum stands in Abu
Dhabi.
We follow-up and studied these available analysis in order to highlight the health
status of the stands.

We found some symptoms and injuries that any of them needs to conduct a
detailed study by related specialists. We enlisted them on the table-3 for the
purpose of information.
Table 3: Some of the symptoms and causes in Mangrove Stands
Symptoms Causes
leaves spots and scratches appearing on
the branches of the Crown
Alternaria sp.
Leaves and apexes wilting. Bottlenecks in
the stems. Blackish and rust-rooted
Fusarium sp.
Leaves Mosaic Aspergellus sp.
Scratching on seedlings roots Sick nematodes
(Scratching Nematode)
product of white blocks spread on the
surface of leaves
Crustily insects
Buds forms from shells accumulations. Marine invertebrates
4 CONCLUSIONS
From the obtained field observations and the interpretation of the analyses and
results, we can establish the following conclusions:
a) There are many factors that limited the balance of Gurum habitat, such
as coast pattern (form), stand age, humanitarian activities and the level
of biodiversity in addition to the impact of the local environmental
factors, that could combined with them interchangeably, on the success
of the annual natural regeneration.
b) Washing salt,due to tide movement impact, from the soil surface layer
of Gurum stand is higher than from the barren sites.
c) Gurum trees absorbing more sodium salts than calcium salts.
d) In the soil of Gurum stands, the sulfur percentage (SSP %) increases
with depth.
e) In the Gurum stand, the saturation percentage (SP %) decreases with
depth.
5 RECOMMENDATIONS
According to the bio-physiochemical impact of the Gurum, we considered the
necessity to adopt the following recommendations: -
a) Work towards the establishment of a public Gurum Directorate for
tending their stands on all the state coasts. The assigned authority could
take them under its control to carry out studies, researches and different
activities (some of them included on the following recommendations).

b) Establish specialized model Gurum nurseries on the coast of the state.
These could use as research units for carrying trails and experiments to
reach the best economic and feasible propagation methods, based on the
approved experiences of scientific researches.
c) Encourage to establish new stands compliance with the controls of
selecting their specialized sites. They have to ensure the provision of
most environmental requirements, which discussed in this study.
d) it is a vital important to rehabilitate the elder and stressed exist Gurum
stands because of their impact in improving the environmental
conditions.
e) Encourage the cultivation of most successful plant species of high salt
tolerance (forage, medical ...), within Gurum stands or in adjacent areas
to them, depending on their environmental specialty. Those species are
identified well by many relevant sides like the Ministry of Water and
environment, the International Centre of Saline Agriculture ... and many
others in UAE.
f) Relayed on the Guide of all the states experiences, international
organizations, the World Bank project for Mangrove and available and
used techniques, which published and distributed in many studies,
researches and international conferences ( particular, which held in
UAE).
g) Compliance with the controls of land use and not detriment the page-
wide of land in coastal strip, especially the locations along Gurum
stands. These including: moving away from the random dirt works,
which would discredit the ground, throwing the waste and polluting the
water… and many other practices that would prejudice the balance of
their environment.
h) Periodic alert for the recipients of public and private sectors, various
educational centers to contribute in the campaigns of Gurum cultivation
and raise awareness of the importance of such habitats.
Finally, the introduction of the above recommendations with the adoption of
principles and measures sound management and development Gurum stands,
mainly to reduce the negative impact of human activities, or isolate them
especially the degraded ones from any competitive human pressure. These
measures would enrich the biodiversity of such environment because of
encouraging their settlement by many different organisms that could find their
requirement in its water and terrestrial systems.

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