Remote sensing for a holistic and multi-scale grassland biodiversity monitoring system

Grasslands cover nearly 25% of Earth’s land surface, yet they remain among the most threatened ecosystems despite their ecological, economic, and cultural importance. The transformation of grasslands into other land-cover types and their widespread degradation have resulted in significant biodiversity loss and the erosion of ecosystem functions that underpin human well-being. Grasslands are also unique among the world’s biomes in that their structure, productivity, and biodiversity are maintained not by the absence of disturbance but by the recurrent action of disturbances such as prescribed fire and grazing. Although numerous studies have examined grassland biodiversity, most focus narrowly on a single dimension, such as plant taxonomic diversity, and are often limited to theoretical or small-scale experimental designs. Consequently, these studies frequently fall short of addressing critical knowledge gaps emerging at larger spatio-temporal scales. There is a need for a holistic approach to monitoring grassland biodiversity across scales while considering the role of real-world disturbances. To address these limitations, remote sensing technology has emerged as a viable option for developing a global biodiversity monitoring system. However, we argue that the full potential of remote sensing, particularly for monitoring biodiversity in grassy biomes, remains only partially realized.

We address this gap by leveraging spaceborne imaging spectroscopy (or hyperspectral imaging), which measures reflected light from the Earth's surface in many narrow, contiguous spectral bands, to investigate novel and important topics in grassland ecology. Specifically, we discuss two primary research advances in this talk: (1) using spaceborne imaging spectroscopy to capture both aboveground and belowground biodiversity and (2) integrating spaceborne imaging spectroscopy data with animal movement data to reveal the underlying drivers of grazer resource selection in grassy biomes. These advances are important for enhancing our understanding of grassland biodiversity across trophic levels, spatial scales, and time, including the mechanisms driving its change. Ultimately, our work informs the capability of current and next-generation spaceborne hyperspectral missions, including those from commercial platforms, to meet the requirements of a holistic and operational biodiversity monitoring system for grasslands and similar short-stature environments globally.