Mediterranean forests are characterized by high complexity and biological richness at all levels. Genetic diversity of Mediterranean forest species has been found to be higher than the one of central and northern Europe. It is important for the maintenance of forest cover and the adaptation of forests under adverse conditions towards environmental change. Genetic diversity in the Mediterranean forests has been shaped by the climatic and the geographical history of the region. However, the most important factor influencing diversity is the presence of human in the region. The impact of forest management techniques and other human activities on genetic diversity is analyzed. Sustainable forest management in the Mediterranean should take this information in account and include measures for the maintenance of genetic diversity of forest species. This will then secure the long-term character of forestry in the region and the production of goods and services for the society.

1. Genetic Implications of
Forest Management
in the Mediterranean
Aristotelis C. Papageorgiou
Department of Forestry, Environment and Natural Resources,
Democritus University of Thrace, Greece
Solsona 2004

2. Presentation plan
• Genetic diversity in Mediterranean forests
• Factors influencing genetic diversity
• Impact of forest management
• SFM and genetic diversity
• Research and policy priorities
April 4, 2004 MEDFOREX meeting 2

3. What is so special about the Med?
• Biological, cultural, social, historical diversity
• Biological diversity:
– rich mosaic of changing ecosystems and land use
patterns (from alpine to tropical)
– Large amount of species (especially plants) – high
endemism
– Populations of species with a broader distribution
are the most variable in terms of genetic diversity
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4. Genetic diversity
• Differentiation among individuals and groups
of individuals (populations) exists.
• Differentiation at the gene level can be
inherited = genetic variation
• Key for adaptation in changing
environments over space and time
• Connection between generations
• Is usually measured in traits that are not
important for forestry (e.g. DNA markers)
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5. Genetic system of a forest population
Hattemer & Gillet 2000
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6. Generations of forest trees
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7. Genetics of Mediterranean forests
• Disjunct distribution of populations and species –
high differentiation
• Usually high genetic variation within populations –
comparison with N/C Europe
• Many small populations
• Large distributions of species over different
environments (e.g. Pinus species)
• Unique alleles and races
• Paradox of variation in several cases
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8. Genetic diversity of forest species
Petit et al. 2003
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9. Reasons for high diversity
• The relief of the Mediterranean basin
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10. Reasons for high diversity
• The Mediterranean
climate
• The existence of
tectonic microplates
and their move
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11. Reasons of high diversity
• The glaciations era – refugia
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12. Human and forests
• Most ancient
human cultures
• Centre of the
“known world”
• Organized trade
and land use
• First “globalized”
economies
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13. Direct use of plant species
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14. Direct use of plant species
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15. Human shaping nature
Agriculture, grazing,
fuelwood collection, etc.
shape the landscape…
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16. “Mosaic” - forest landscape
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17. Mediterranean forests
• Forest includes terrestrial ecosystems in a broad sense
• Natural forest ecosystems – mixed forests – complex age
structures – connection between generations
• Mainly small scale activities – high land use diversity –
fragmentation – mixed with other activities
• Degradation – desertification – loss of ecosystem
productivity – land abandonment
• High protective role against erosion, drought – social
importance for rural development
• Recreation – quality of life – Non Wood Goods
• Culture – spirituality
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18. Human impact on gene diversity
• Far-reaching / global
– Emission of air pollutants
– Greenhouse gases
– Policy processes
• Local
– Forest destruction (land conversion)
– Forest fragmentation
– Forest management
• Introduction of new species & populations
• Silvicultural activities
• Other forms on management (e.g. grazing)
April 4, 2004 MEDFOREX meeting 18

19. Destruction and fragmentation
• Forest destruction (deforestation)
– Loss of species with small scale (e.g. Abies
nebrodensis, Quercus euboica, Cedrus brevifolia)
– Loss of populations (differentiated – adapted)
• Forest fragmentation
– Reduction of effective population size – drift
effects – genetic bottlenecks
– Increase vulnerability of populations
– Caused by development, agriculture, grazing
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20. Genetic bottleneck
1400
1200
1000
RECOVERY
800
N
600
400 CRASH
200
0 Bottleneck
TIME
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21. Example: Pinus leucodermis in Italy
• Only a few small
populations
remaining –
fragmented – no
connection possible
• Low genetic variation
– large differentiation
among populations
Morgante & Vendramin 1991
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22. Artificial regeneration
• Adaptation on the final site in question
– Different adaptations at the original site
– Adaptation in nurseries
• Genetic variation (evolutionary adaptability) reduced
due to drift effects
– Harvest from small number of plants (founder)
– Unknown material – provenance ignored
• Possible impact on surrounding forests due to gene
flow
• However: development of new land races (e.g.
Quercus rubra in France)
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23. Example: Cupressus sempervirens
• Low genetic variation
of planted stands
• Canker attack in
planted stands
• Gene flow from
planted stands in
natural populations
Papageorgiou et al. 1994
April 4, 2004 MEDFOREX meeting 23

24. Natural regeneration
• Connection between generations - maintenance of
dynamics of genetic structures in life cycle of forest
trees – evolution goes on
• How many individuals participate in the next
generation? Where?
– Natural processes (very improbable in the Med)
– Non-forestry activities (e.g. grazing)
– Forestry operations (e.g. light felling)
• Limited potential for changes of genetic structures
– No safeguard against unintentional & random changes of
genetic structures, losses of genetic variation
April 4, 2004 MEDFOREX meeting 24

25. Silvicultural treatments
• Low population densities
• Reduced gene flow
– Possible founder effects (a few seeder trees)
– Increased inbreeding – low germinability
– Inbreeding depression
• Threshold values for
– Population sizes
– Population densities
• Problem for scattered species
– Particularly in species-rich mixed forests
– Species with “peculiar” mating system (Taxus baccata)
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26. Example: Abies cephalonica
• Higher values of inbreeding levels in uneven
aged forests with lower population densities
Fady & Conkle 1993
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27. Selective cutting
• Selection against superior phenotypes
– Selective logging with short cutting cycles
– Exclusion of superior phenotypes from
reproduction
• Reduction of mating trees
– effective population size
– Inbreeding
• Coppice forests
– Clear cuts with a few remaining trees
April 4, 2004 MEDFOREX meeting 27

28. Is genetic diversity at stake?
• Disturbance of human – nature balance
• The dynamic systems are broken (genetic, ecological,
nutrients, water, energy, etc.)
• Ecosystem are not able to provide goods and services in the
long term – desertification.
• Main problems occur mainly from factors outside SFM
• The maintenance / restoration of the ability of
Mediterranean ecosystems to continue their
dynamic function should become the target of
any conservation effort in the region
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29. Forest management
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30. Forest management in the Med
• Management strategies & techniques imported from
the central and northern counties of Europe -
production of timber is priority in most cases
• Apply on the more temperate forests of the
Mediterranean region - ignore the non-productive
terrestrial ecosystems (e.g. maquis)
• Fail to capture the complexity of Mediterranean
forests & land use systems
• The spatial reference of SFM is the stand and not
the broader landscape - more appropriate for the
description of the human - nature dynamics
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31. Protection of forest biodiversity
SFM as a tool to achieve biodiversity conservation
Protects BD elements, including genes & provenances
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32. Forest protection in the Med
• Protection concepts and strategies imported from
northern counties with empty spaces and productive
forests - human influence on BD is ignored
• Based mainly on the “set – aside” principle
• Focus on absolute protection or special
management of specific biological entities (e.g.
genes) or spatial units – miss the broader picture
• Restricted to reserves and networks
• Selection of protected items – majority remains
unprotected
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33. Forest conservation genetics
• Forest genetic resources
– Included in broader BD policies & plans
– Most under-represented part of BD
– Based in “genetic inventories” (assessments)
• In situ
– Actions of strict protection of rare or endangered entities
– Gene reserves (special management allowed)
– Conservation in managed ecosystems (Namkoong).
• Ex situ
– Protection of endangered or rare tree species
– Storage of “useful” genes (gene banks)
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34. An important gap
• “Other wooded land” – not protected, not managed
• The classical protection / SFM approach
– has a spatial gap of about 50%
– cannot cope with the dynamic nature of Mediterranean
forests
• Conservation of forest genetic diversity cannot be
seen separately from the general use and
management of forest resources
• Inventories possible in a few cases only (no time, no
money for “total inventories”)
April 4, 2004 MEDFOREX meeting 34

35. Linking SFM and BD
• Environmental agencies consider BD as a priority in
all management activities
• Forestry parties see the economic aspect of forestry
as a priority.
• BD conservation and SFM can be linked:
– Complexity of both concepts
– Long term character
• “Ecosystem approach” & “close to nature” forestry
• Tools, such as SFM certification, “criteria &
indicators”, Special Management plans, NFP
April 4, 2004 MEDFOREX meeting 35

36. The challenge
• Maintaining adequate levels of genetic diversity of
tree (& other) species is crucial for adaptation and
adaptability processes
• Dynamic processes must maintain their role for the
maintenance of productivity of goods and services
• Genetic diversity is not just another goal of SFM,
but the means to achieve it
• We need: Management techniques that will
prevent disturbances in critical ecological and
genetic processes
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37. The challenge
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38. Future research priorities
• Develop inventory systems for genetic diversity
status of terrestrial ecosystems (stand types)
– Use results of existing genetic research projects
– Plan future genetic research
– Use models to simulate evolution under forest
management scenarios
– Connect gene diversity with stand & age structure,
density, mating system, etc.
• Develop criteria & indicators for genetic diversity
– adjust existing efforts to the Mediterranean
– introduce genetic criteria into existing SFM C&Is
(certification standards, MCPFE criteria, etc.)
April 4, 2004 MEDFOREX meeting 38

39. Future research priorities
• Connect specific management techniques of
Mediterranean forests with the previous steps
– Give a “genetic grade” for each technique
– Evaluate human impact on genetic diversity
• Set priorities for SFM considering genetic diversity
• Extrapolate of appropriate strategies for most taxa
from the results of studies of a few model cases
• Identify genetic aspects that may become limiting
for certain types of species and ecosystems
• Monitoring and evaluation
April 4, 2004 MEDFOREX meeting 39

40. SFM for the Med
• Develop management plans for the
Mediterranean beyond the classical forestry
approach, including broader ecosystems and
activities, based on the maintenance of
genetic diversity
• Protecting biodiversity through management
and planning, following rules that need minor
assessments
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41. Thank you for your attention
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