Kelp forests versus urchin barrens: a comparison of ecosystem functions and services provided by two alternative stable marine habitats.

Kelp forests and urchin barrens are two stable states in rocky reef ecosystems, each providing unique ecosystem functions like habitat for marine species and primary production. While studies frequently show that kelp forests support higher levels of some ecosystem functions than urchin barren habitats, no research has yet compared average differences. To address this gap, we first conducted a meta-analysis of studies that directly compared the ecosystem functions, services and general attributes provided by each habitat.

The development of terrestrial ecosystems emerging after glacier retreat.

The global retreat of glaciers is dramatically altering mountain and high-latitude landscapes, with new ecosystems developing from apparently barren substrates. The study of these emerging ecosystems is critical to understanding how climate change interacts with microhabitat and biotic communities and determines the future of ice-free terrains. Here, using a comprehensive characterization of ecosystems (soil properties, microclimate, productivity and biodiversity by environmental DNA metabarcoding) across 46 proglacial landscapes worldwide, we found that all the environmental properties change with time since glaciers retreated, and that temperature modulates the accumulation of soil nutrients.

Dynamics and drivers of mycorrhizal fungi after glacier retreat.

The development of terrestrial ecosystems depends greatly on plant mutualists such as mycorrhizal fungi. The global retreat of glaciers exposes nutrient-poor substrates in extreme environments and provides a unique opportunity to study early successions of mycorrhizal fungi by assessing their dynamics and drivers. We combined environmental DNA metabarcoding and measurements of local conditions to assess the succession of mycorrhizal communities during soil development in 46 glacier forelands around the globe, testing whether dynamics and drivers differ between mycorrhizal types.