A systematic exploration of biodiversity-ecosystem function relationship using remote sensing and eddy covariance networks

Biodiversity positively affects vegetation productivity and the ability of ecosystems to withstand disturbance events and invasions of alien species (ecosystem stability). However, the relationship between biodiversity and ecosystem functioning remains understudied at the landscape or whole ecosystem scales.

In particular, biodiversity can not be easily monitored at large spatial scales or frequent intervals. Therefore, confronting measurements of biodiversity and ecosystem functioning at the same spatial and temporal scales remains challenging. In this work, we present new methods to systematically bridge these scale gaps. We focus on collecting ecosystem data and developing metrics able to decypher the effect of plant biodiversity on ecosystem functioning. Based on eddy covariance fluxes from 78 NEON and ICOS sites, we compute key ecosystem functional properties related to ecosystem productivity and stability. Moreover, we calculate biodiversity indices from field surveys of species abundances, functional traits, and structural properties at these sites. Finally, we compute remote sensing metrics of biodiversity based on Sentinel 2 measurements. These metrics exploit the fine scale multispectral information from different and complementary perspectives, and are adapted to match the footprint of typical eddy covariance sites.

We investigate the relationship between ground- and satellite-based biodiversity metrics to understand the capability of remote sensing to contribute to biodiveristy-ecosystem function analyses that may one day be scaled globally. Despite dominant environmental and climatic constraints, we hypothesize that ecosystem functional properties covary with biodiversity metrics. To elucidate this point, we analyze the multivariate relationship between the different biodiversity estimates, ecosystem functional properties related to water, carbon, and energy fluxes, structural variables of the vegetation, and climate.

Assessing whether biodiversity effects apply to the functioning and stability of ecosystems is pivotal to understanding ecosystem processes and developing appropriate forecast models and climate change mitigation strategies.