Short- and long-term temporal changes in the assemblage structure of Amazonian dung beetles

Area of Science:

• Ecology
• Biodiversity research
• Tropical ecology

Background:

• Species diversity and community dynamics fluctuate across temporal and spatial scales.
• Understanding these temporal changes is crucial for effective conservation and ecosystem management.

Purpose of the Study:

• Investigate temporal shifts in Amazonian dung beetle assemblages across seasons, years, and forest successional stages.
• Determine if assemblage structure varies across different temporal scales.
• Assess the impact of these changes on the functional structure of dung beetle communities.

Main Methods:

• Dung beetles were sampled using linear transects of baited pitfall traps in two Amazonian reserves.
• Sampling occurred across dry and rainy seasons, spanning multiple years and successional stages (1, 5, 10, 20, 30, and 80 years post-logging).
• Statistical analyses included Generalized Linear Models for diversity changes and Non-metric Multidimensional Scaling (NMDS) for assemblage structure, with beta diversity partitioned into nestedness and turnover.

Main Results:

• Dung beetle abundance and richness declined from the rainy to the dry season and with earlier successional stages, but showed no significant interannual variation.
• Assemblage diversity exhibited distinct patterns at interannual and successional scales.
• Forest succession led to drastic changes in dung beetle assemblages, characterized by a nested structure reflecting species and functional group additions in later stages.

Conclusions:

• Dung beetle assemblage structure changes significantly with forest succession, indicating a non-deterministic process.
• Functional group composition displayed turnover between years, suggesting less predictable dynamics compared to successional changes.
• The findings highlight the importance of considering multiple temporal scales when assessing biodiversity dynamics in tropical ecosystems.