Linking changes in species-trait relationships and ecosystem function using a network analysis of traits

Area of Science:

• Ecology
• Environmental Science
• Network Analysis

Background:

• Linking ecological community composition shifts to ecosystem functions is a significant challenge.
• Understanding how species traits influence ecosystem processes is crucial for environmental management.

Purpose of the Study:

• To develop and test a novel method, Network Analysis of Traits (NAT), for assessing changes in community structure and function.
• To investigate the impact of nitrogen addition on species-trait network structure and functional diversity in an intertidal sandflat ecosystem.

Main Methods:

• Developed the Network Analysis of Traits (NAT) to analyze community network structure based on species traits and composition.
• Applied NAT to a 113-species intertidal sandflat community subjected to experimental nitrogen addition (0, 150, and 600 g N/m²).
• Mechanistically linked changes in community composition and function to trait-space network patterns.

Main Results:

• Under medium nitrogen (150 g N/m²), functional diversity remained consistent.
• High nitrogen addition (600 g N/m²) significantly altered the species-trait network structure.
• The high nitrogen treatment led to the merging of functional clusters, indicating a loss of functional trait diversity.

Conclusions:

• Network Analysis of Traits (NAT) effectively links community composition and function to network patterns.
• Experimental nitrogen addition can disrupt ecological networks and reduce functional diversity, particularly at higher concentrations.
• The study highlights the sensitivity of intertidal ecosystems to nutrient enrichment and its consequences for ecosystem function.