Unlocking Tropical Forest Complexity: How Tree Assemblages in Secondary Forests Boost Biodiversity Conservation

Area of Science:

• Ecology
• Forest Science
• Conservation Biology

Background:

• Secondary forests are vital for tropical biodiversity and conservation goals (COP15).
• Identifying and characterizing these forest ecosystems is essential for effective management.
• Dominant tree species are proposed as reliable indicators for delineating forest ecosystems.

Purpose of the Study:

• To develop a replicable national approach for identifying and characterizing forest ecosystems, emphasizing secondary forests.
• To test the hypothesis that dominant tree species indicate forest ecosystem types and biodiversity.
• To assess the distribution and role of secondary forests within identified ecosystems.

Main Methods:

• Hierarchical clustering of national forest inventory data based on dominant species abundance (Importance Variable Index).
• Object-oriented Random Forest modeling using NDVI, Sentinel-2 spectral data, and environmental variables.
• Characterization of identified clusters using species assemblages, interactions, and ecological factors.

Main Results:

• Successfully modeled 7 main forest ecosystem clusters in Costa Rica from 10 identified in situ clusters.
• The model achieved an F1-score of 0.73 and macro F1-score of 0.58.
• Ecosystems were characterized by distinct dominant species, topography, climate, and vegetation dynamics, aligning with local classifications.

Conclusions:

• Dominant tree species effectively delineate forest ecosystems and biodiversity complexity.
• The approach provides insights into secondary forest distribution and ecosystem vulnerability.
• In situ data acquisition remains a significant challenge for national-scale forest ecosystem assessments.