Functional diversity governs ecosystem response to nutrient enrichment

Area of Science:

• Ecology
• Ecosystem Dynamics
• Environmental Science

Background:

• The relationship between species diversity and ecosystem functioning is a key ecological question.
• Traditional studies often use simplified linear food chains, overlooking complex species interactions.
• Predicting ecosystem responses to nutrient enrichment requires understanding how ecosystem structure influences these dynamics.

Purpose of the Study:

• To investigate the impact of ecosystem structure, specifically functional diversity, on ecosystem responses to nutrient enrichment.
• To compare the predictive power of complex ecosystem models versus linear food-chain models.
• To understand the mechanisms driving ecosystem changes under nutrient enrichment.

Main Methods:

• A mesocosm experiment was conducted in a lake ecosystem to simulate nutrient enrichment.
• An intermediate-complexity model was developed, categorizing trophic levels into functional groups based on size and diet.
• The model's predictions were compared against experimental results and predictions from linear food-chain models.

Main Results:

• The developed model, incorporating functional diversity and indirect interactions, successfully predicted experimental outcomes.
• Linear food-chain models failed to accurately predict the observed ecosystem responses.
• Functional diversity and indirect interactions were identified as critical factors in ecosystem responses to perturbations.

Conclusions:

• Ecosystem structure, particularly functional diversity, plays a vital role in mediating responses to nutrient enrichment.
• Complex models are essential for accurately predicting ecosystem behavior under environmental change.
• New management strategies are needed for freshwater ecosystems facing eutrophication, considering ecosystem complexity.