Tropical Land-Use Change Disrupts Zeta-Diversity Across Taxa

Area of Science:

• Ecology and Conservation Biology
• Biodiversity Research
• Landscape Ecology

Background:

• Land-use change drives species turnover, influencing biotic homogenization/heterogenization.
• Current diversity metrics overlook the role of widespread species in these changes.
• Zeta-diversity offers a framework to analyze community turnover across space, considering both rare and widespread species.

Purpose of the Study:

• To investigate the impact of land-use change on zeta-diversity in the Colombian Andes.
• To understand how land-use conversion affects rare and widespread species across different taxa (birds, dung beetles, orchids).
• To identify drivers of biodiversity pattern changes in natural versus transformed habitats.

Main Methods:

• Community sampling of birds, dung beetles, and orchids across 341 plots.
• Comparison of natural (forest, paramo) and transformed (pasture) habitats.
• Analysis of zeta-diversity patterns along an elevational gradient and across land uses.

Main Results:

• Land-use conversion led to significant species richness loss and disrupted zeta-diversity.
• Bird and dung beetle communities became structured by dispersal ability, overriding natural drivers.
• Biotic homogenization observed in birds; subtractive heterogenization in dung beetles; high turnover in orchids.

Conclusions:

• Deforestation simplifies communities and reduces widespread species populations.
• Habitat transformation increases extinction risk for both rare and widespread species.
• Orchids are particularly sensitive to land-use change, highlighting conservation concerns.