Scale-dependence of ecological assembly rules: insights from empirical datasets and joint species distribution modelling

• Main Authors: Mod, Heidi, Chevalier, Mathieu, Luoto, Miska, Guisan, Antoine
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2020
• Subjects: biotic interaction; local plant community; Multiple spatial scales; Spatial resolution; local and landscape spatial scales; Occurrence data; open habitat; tundra; Tundra
• Online Access: https://doi.org/10.5061/dryad.1c59zw3sf

1. A comprehensive understanding of the scale-dependency of environmental filtering and biotic interactions influencing the local assembly of species is paramount to derive realistic forecasts of the future of biodiversity and efficiently manage ecological communities. A classical assumption is that environmental filters are more prevalent at larger scales with diminishing effects towards the finest scales where biotic interactions become more decisive. Recently, a refinement was proposed stipulating that the scale-dependency of biotic interactions should relate to the type of interaction. Specifically, the effect of negative interactions (e.g. competition) should diminish with coarsening scale, whereas positive interactions (i.e. facilitation) should be detected irrespective of the scale. 2. We use multiple vascular plant species datasets sampled at nested spatial scales (plot size varying from 0.04 to 64 m2) and recently developed joint species distribution models (JSDM) to test the hypotheses. 3. Our analyses indicate slightly stronger environmental filtering with increasing plot size. While the overall strength of biotic interactions did not vary consistently across scales, we found a tendency for negative interactions to fade away with increasing plot size slightly more than positive interactions. Synthesis: We provide partial, but not unambiguous, evidence of the scale-dependency of ecological assembly rules. However, our correlative methodology only allows us to interpret the findings as indication of environmental filtering and biotic interactions. These datasets (partly or completely) have been used in many other publications from the groups ECOSPAT (University of Lausanne; led by Prof. Antoine Guisan) and BioGeoClimate Modelling Lab (University of Helsinki; led by Prof. Miska Luoto). Thus, subsets of sites and species of these datasets can already be found in DryAd. Sites can be connected based on siteID and species by their names (or abbreviations). Funding provided by: Schweizerischer Nationalfonds ...