Framework for community functioning: synthesis of stress gradient and resource partitioning concepts

Area of Science:

• Ecology
• Community Ecology
• Aquatic Ecology

Background:

• Community abundance is shaped by environmental and spatial factors.
• Interactions between species guilds (competition or facilitation) can modify fundamental niches.
• Understanding these drivers is crucial for biodiversity and ecosystem functioning.

Purpose of the Study:

• Develop a framework integrating stress gradient and resource partitioning concepts.
• Test environmental and spatial mechanisms driving guild abundance across different interaction modes.
• Assess the roles of environment, space, and inter-guild richness on diatom guild density.

Main Methods:

• Developed a novel framework integrating stress gradient and resource partitioning concepts.
• Utilized continental-scale data on stream diatoms and physico-chemistry.
• Employed variance partitioning to assess influences of environment, space, and inter-guild richness.

Main Results:

• Environmental factors were the strongest constraints on dominant, acidophilous, and recipient guilds.
• Spatial effects (latitude, longitude) were significant only for the low-profile guild.
• Competitor richness generally decreased guild density, except for recipient density increasing with donor richness in nitrogen-poor environments.

Conclusions:

• Diatom guild abundance is primarily determined by biotic and environmental impacts.
• Spatial effects have limited influence on diatom guild abundance, with few exceptions.
• The developed framework provides insights into variability in diatom guild abundance and its implications for biodiversity-ecosystem functioning.