Environmental filtering determines metacommunity structure in wetland microcrustaceans.

Area of Science:

• Ecology
• Biodiversity research
• Spatial ecology

Background:

• Metacommunity approaches are increasingly used to understand regional species distributions.
• Variation partitioning techniques are crucial for distinguishing spatial from environmental drivers.
• Previous methods struggled to link specific metacommunity structures to underlying ecological filters.

Purpose of the Study:

• To propose a novel framework connecting metacommunity structures (nested, Gleasonian, Clementsian) to spatial and environmental filters.
• To analyze how spatial and environmental drivers can lead to similar metacommunity structures.
• To test this framework using microcrustacean assemblages along a salinity gradient.

Main Methods:

• Identification of the best-fitting metacommunity structure for microcrustacean assemblages.
• Application of hierarchical variation partitioning to quantify environmental and spatial influences.
• Analysis of 110 wetland sites exhibiting a strong environmental gradient.

Main Results:

• Metacommunity structures were non-random under strong environmental filtering.
• Passive dispersers exhibited spatial signals even at large geographical scales.
• Inferring fine-scale biotic interactions from spatial signals presented challenges.

Conclusions:

• Elements of metacommunity structure combined with variation partitioning can detect environmental drivers and broad-scale patterns.
• The study highlights the interplay between environmental filtering and spatial processes in structuring communities.
• Caution is advised when interpreting fine-scale spatial signals, particularly regarding biotic interactions.