Advancing terrestrial biodiversity monitoring with satellite remote sensing in the context of the Kunming-Montreal global biodiversity framework

Abstract

Satellite remote sensing (SRS) provides huge potential for tracking progress towards achieving global conservation targets and goals. To make a transformative impact, SRS workflows should be tailored towards the requirements of ecological users and policymakers. Here, we assess requirements from the post-2020 global biodiversity framework of the Convention of Biological Diversity (CBD) by ranking the use of SRS products in biodiversity indicator workflows. Fifty unique indicators were identified for tracking the state of terrestrial biodiversity, spanning two goals and six targets across seventeen target components. Twentynine indicators shared enough information to analyse workflows and to classify underlying (spatial information) products into the Essential Biodiversity Variable (EBV) framework. We further quantified the policy relevance of EBVs by counting EBV usage across the CBD goals and targets. Combined with scores on the technical feasibility, accuracy, and immaturity of SRS products, we then identified which EBVs offer promising opportunities for workflow development from SRS. Top priority SRS products included the fraction of vegetation cover, plant area index profile, above-ground biomass, foliar N/P/K content, land cover (vegetation type), leaf area index, carbon cycle (above-ground biomass), chlorophyll content & flux, ecosystem fragmentation, ecosystem structural variance, and gross primary productivity. Our results showed that spatial information products related to ecosystem distribution, live cover fraction and species distribution EBVs are currently most widely used in the CBD context, while primary production and physiology EBVs remain under-used. To advance the monitoring of ecosystem distributions, harmonized and high resolution SRS products with higher thematic detail on specific ecosystems and habitat types are needed. Likewise, live cover fraction EBVs (e.g. fraction of vegetation cover and plant area index profile) would require developing and harmonizing ecosystem taxonomies and relating the fraction of vegetation (functional) types to a desired ecosystem reference state. Finally, to enable the monitoring of plant species phenology, stoichiometry and alien invasive species (impact), novel workflows need to combine very high resolution and multi-spectral satellite observations for mapping and monitoring the physiological traits of plant species (e.g. leaf area index, chlorophyll content & flux, and foliar N/P/K content). Capitalizing on these opportunities for SRS-enabled EBVs could improve the tracking of CBD goals and targets, e.g. in the context of ecosystem restoration, productivity and sustainability of agricultural and forested ecosystems, effective management of protected areas, reduction of species extinction rates, or a better management of the impact of alien invasive species.