Lab postdoc Pierre and students Ivanna and Courtenay have just published a study on trait-based community assembly in Functional Ecology. Pierre wrote a blog post for the journal which I copy below.

Are ecological communities saturated with species? This question is linked to whether ecosystems can reach equilibrium, and whether introduced species are likely to invade ecosystems. The concept of ecological niche can be described as a multidimensional space where dimensions are environmental conditions and resources that define the requirements of an individual or a species. If ecological communities are not saturated with species, we can expect to find vacant niches by detecting empty volumes in the multidimensional niche space of communities. We here investigated the existence of vacant niches by searching for empty volumes in the ecological niche space of forest plant communities. We simulated forest dynamics under different processes known to shape ecological communities. We then computed the niche space of forest communities after 2000 years of simulated growth, and detected potential empty volumes. We showed that vacant niches could emerge from both environmental filtering and competition between plants. We further created virtual species able to invade these vacant niches, and showed that almost all vacant niches detected were invasible. Our study supports the view that communities are not saturated with species, and that invasible vacant niches can arise from the interplay between environment filtering and species interactions in plant communities.

You can read the paper at the journal here.