Convergence in floodplain pond communities indicates different pathways to community assembly

Area of Science:

• Ecology
• Environmental Science
• Freshwater Biology

Background:

• Disturbance significantly impacts ecosystems, but the roles of selection, drift, and dispersal in ecological community recovery remain unclear.
• Understanding these processes is crucial for predicting ecosystem resilience and managing aquatic habitats after disturbances like floods.

Purpose of the Study:

• To investigate the mechanisms governing the recovery of aquatic macroinvertebrate communities in an alluvial floodplain following flood disturbance.
• To determine the relative importance of selection, dispersal, and drift in structuring these communities during recovery.

Main Methods:

• Field surveys of natural floodplain habitats and a field experiment using newly created ponds were conducted.
• Macroinvertebrate communities were monitored post-flood and post-pond creation.
• Null models, Mantel tests, and joint species distribution models were employed to analyze community assembly and environmental variation.

Main Results:

• Beta diversity unexpectedly decreased over time in both natural and experimental habitats, contrary to expectations of increasing diversity.
• Environmental selection emerged as the dominant structuring process, with biotic interactions also playing a significant role.
• Flood heterogeneity and spatial scale differences influenced the balance of deterministic and stochastic processes.

Conclusions:

• Ecological community recovery is primarily shaped by environmental selection and biotic interactions, with dispersal and drift playing lesser roles.
• Disturbance characteristics and spatial scale are critical factors influencing metacommunity structuring in riverine landscapes.
• Findings offer insights into the complex dynamics of community assembly in response to environmental disturbances.