Data from: Fractal triads efficiently sample ecological diversity and processes across spatial scales

The relative influence of ecological assembly processes, such as
environmental filtering, competition, and dispersal, vary across spatial
scales. Changes in phylogenetic and taxonomic diversity across
environments provide insight into these processes, however, it is
challenging to assess the effect of spatial scale on these metrics. Here,
we outline a nested sampling design that fractally spaces sampling
locations to concentrate statistical power across spatial scales in a
study area. We test this design in northeast Utah, at a study site with
distinct vegetation types (including sagebrush steppe and mixed conifer
forest), that vary across environmental gradients. We demonstrate the
power of this design to detect changes in community phylogenetic diversity
across environmental gradients and assess the spatial scale at which the
sampling design captures the most variation in empirical data. We find
clear evidence of broad-scale changes in multiple features of phylogenetic
and taxonomic diversity across aspect. At finer scales, we find additional
variation in phylodiversity, highlighting the power of our fractal
sampling design to efficiently detect patterns across multiple spatial
scales. Thus, our fractal sampling design and analysis effectively
identify important environmental gradients and spatial scales that drive
community phylogenetic structure. We discuss the insights this gives us
into the ecological assembly processes that differentiate plant
communities found in northeast Utah.