Multitrophic diversity effects of network degradation.

Area of Science:

• Ecology
• Biodiversity research
• Ecosystem function

Background:

• Predicting the functional consequences of biodiversity loss in complex, multitrophic communities is challenging.
• Existing studies often lack integrated analysis of species traits, network topology, and extinction across trophic levels.
• These factors are independently recognized as critical drivers of post-extinction ecosystem structure and function.

Purpose of the Study:

• To compare the functional consequences of simulated species loss within (monotrophic) and across (bitrophic) trophic levels.
• To investigate the impact of species traits, network structure, and extinction patterns on ecosystem function.
• To assess the importance of realistic functional metrics in evaluating biodiversity loss impacts.

Main Methods:

• Developed an ecological interaction network from field data of tropical mammals and dung beetles.
• Simulated trait-ordered extinction of mammals and dung beetles (monotrophic extinction).
• Simulated coextinction of dung beetles following mammal loss (bitrophic extinction) based on network structure.
• Compared diversity effects using standard monotrophic and novel bitrophic functional metrics.

Main Results:

• Monotrophic and bitrophic diversity effects were similar regardless of the species traits driving extinctions.
• Divergent predictions of ecosystem function arose when different functional metrics were applied.
• Network structure information had minimal impact on the qualitative relationship between diversity and function.

Conclusions:

• Species traits and realistic functional metrics are crucial for assessing ecosystem impacts of biodiversity loss.
• The choice of functional metric significantly influences predictions of ecosystem function following species loss.
• Understanding multitrophic interactions is essential for accurate biodiversity-ecosystem function assessments.