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Tree structure and diversity in human-impacted littoral forests, madagascar
J Carter Ingram1, Robert J Whittaker, Terence P Dawson
1Biodiversity Research Group, School of Geography and the Environment, University of Oxford, Oxford, England. jci2102@columbia.edu
Environmental Management
|June 25, 2005
Summary
Human impact on Madagascar
Area of Science:
- Ecology
- Conservation Biology
- Forestry
Background:
- Human activities significantly impact forest ecosystems globally.
- Littoral forests in southeastern Madagascar face considerable human pressure.
- Understanding these impacts is crucial for effective conservation and sustainable resource management.
Purpose of the Study:
- To investigate the relationship between forest structural features and tree diversity (total, utilitarian, endemic) in human-impacted littoral forests.
- To analyze the distribution, abundance, and demographics of different tree species groups.
- To assess the basal area available for human use and its implications for sustainable management.
Main Methods:
- Conducted surveys across 22 transects (400 m2 each) in southeastern Madagascar.
- Recorded tree species, individuals, and structural features indicative of human impact.
- Calculated basal area and analyzed correlations with diversity indices (Shannon Weiner, Simpson's).
Main Results:
- Recorded 135 tree species and 2155 individuals, with 84% being utilitarian species.
- Found significant correlations between basal area and diversity indices for total, utilitarian, and endemic trees.
- Endemic tree species showed a strong correlation (r = 0.85) between basal area and diversity, suggesting high sensitivity to structural changes.
Conclusions:
- Despite perceived degradation, southeastern Madagascar's littoral forests retain significant value for conservation and livelihoods.
- Utilitarian species, particularly firewood, dominate the basal area, highlighting resource use patterns.
- Conservation incentives can be developed by integrating global conservation needs with local livelihood requirements.
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