Functional connectivity varies across scales in a fragmented landscape

Area of Science:

• Ecology
• Landscape Ecology
• Conservation Biology

Background:

• Ecological processes and species' habitat needs vary significantly with spatial scale.
• Landscape connectivity, crucial for species persistence, is scale-dependent.
• Previous connectivity studies often use arbitrary scales, failing to capture ecologically relevant thresholds.

Purpose of the Study:

• To objectively identify ecologically relevant scales for landscape connectivity analysis using a body mass discontinuity approach.
• To evaluate the connectivity of wetland habitats (wet meadow, emergent marsh) in the Central Platte River Valley (CPRV) across multiple scales.
• To determine if a connectivity threshold exists and its implications for species conservation.

Main Methods:

• Utilized a mammalian body mass discontinuity analysis to define scale-dependent species groupings.
• Applied graph-theoretic network analysis to assess landscape connectivity for two wetland types in the CPRV.
• Examined connectivity at scales defined by species' body mass-related dispersal capabilities.

Main Results:

• Landscape connectivity was found to be high at larger scales and low at smaller scales.
• A significant connectivity threshold was identified within dispersal distances of 500 m to 6,500 m.
• Species with dispersal distances near this threshold are potentially most vulnerable to habitat changes.

Conclusions:

• Landscape connectivity is scale-dependent and influenced by species' traits, particularly body mass and dispersal ability.
• A multiscale management approach is essential for maintaining connectivity for diverse species.
• Conservation strategies must consider identified connectivity thresholds to mitigate risks for vulnerable species.