Seagrass macrofaunal abundance shows both multifractality and scale-invariant patchiness

Area of Science:

• Marine ecology
• Benthic ecology
• Seagrass ecosystem dynamics

Background:

• Understanding spatial patterns of species abundance is crucial for marine ecology.
• Seagrass meadows are vital habitats supporting diverse macrobenthic communities.
• Previous studies often assume scale-dependent processes in ecological patterning.

Purpose of the Study:

• To investigate the spatial distribution of macrobenthic assemblages and dominant species in an intertidal seagrass habitat.
• To determine if ecological patterns exhibit multifractality and scale-invariance.
• To assess the relationship between spatial patterning and species interaction levels.

Main Methods:

• Examined macrobenthic abundance across hierarchically nested spatial scales (33 to 2115 m²).
• Applied multifractal analysis to characterize spatial patterns of the entire assemblage and 10 dominant species.
• Analyzed abundance peaks and variance distribution across sampling stations.

Main Results:

• Multifractality characterized both the whole macrobenthic assemblage and its dominant species across scales.
• Patchiness in abundance exhibited scale-invariance for the assemblage and some dominant species.
• A small percentage of stations (12%) accounted for a large proportion of total variance (88%), indicating 'hot-spots'.

Conclusions:

• Ecological patterning in this seagrass system displays multifractality and scale-invariance, even with low species interactions.
• Critical self-organization is unlikely to be the sole driver of observed spatial patterns.
• Taylor's power-law coefficient (β) is not a reliable index of aggregation but indicates changes in dispersion patterns.