Abundance-Occupancy Relationships are Informed by Species Temporal Occupancy

Area of Science:

• Macroecology
• Community Ecology
• Population Ecology

Background:

• A central goal in macroecology is understanding species occupancy and abundance relationships.
• The positive link between spatial occupancy and mean local abundance is considered a 'macroecological law'.
• Temporal occupancy, reflecting species persistence, has not been clearly linked to local abundance.

Purpose of the Study:

• To explore the relationship between spatial and temporal occupancy.
• To investigate how spatial and temporal occupancy relate to mean local abundance.
• To determine if temporal occupancy can explain abundance patterns, especially for range-restricted species.

Main Methods:

• Utilized standardized small mammal community sampling data from the National Ecological Observatory Network (NEON).
• Data spanned across the United States from 2014 to 2019.
• Analyzed relationships between spatial occupancy (fraction of sites occupied), temporal occupancy (site occupancy frequency), and mean local abundance.

Main Results:

• Species occupying a greater fraction of sites also tended to occupy individual sites more frequently (positive spatial-temporal occupancy relationship).
• Species with high spatial occupancy and/or high temporal occupancy generally exhibited greater local abundance.
• The highest local abundance was observed in geographically restricted but temporally persistent species.

Conclusions:

• Spatial occupancy alone may underestimate the abundance of range-restricted species.
• Temporal occupancy is crucial for understanding abundance patterns, particularly for species with limited geographic ranges.
• Considering both spatial and temporal occupancy provides a more comprehensive understanding of species abundance dynamics.