Monitoring Vegetation Structure, Function and Composition with Remote Sensing

Biodiversity monitoring is important to support decision-making for managing landscapes sustainably and supporting national and international policy targets for nature conservation and restoration, including the Global Biodiversity Framework. While assessing the status, change and drivers of biodiversity remains challenging, we have new opportunities to support biodiversity monitoring from space with a growing suite of Earth observation satellites. Remote sensing is especially well suited to monitor ecosystems in terms of their vegetation structure and forest structural diversity with lidar and radar, as well as vegetation functions, foliar functional diversity and community composition with imaging spectroscopy and multispectral imaging. In this talk, we will provide examples for monitoring forest structural diversity using the spaceborne lidar GEDI. We evaluated and compared structural diversity across contrasting biomes in the Western US and Central Africa, and we found that general biogeographic patterns of higher horizontal structural diversity in areas with higher disturbance, higher topographic variation and lower aridity hold across continents and scales. For monitoring ecosystem functions, we will provide examples for monitoring plant traits and functional diversity using imaging spectroscopy along elevation gradients in California. We will provide insights into the role of trait-trait relationships and trait selection for mapping trait diversity patterns at the landscape scale. We found that diversity patterns vary by the type and number of functional traits included in the analyses, and that the interpretation is context dependent. And for monitoring composition, we will provide examples indicating how well we can distinguish different vegetation types, communities and species with spectroscopy, and how well we predict animal composition and niche space using a remote sensing-based biodiversity data cube, BioCube. With these examples, we will demonstrate new capabilities and avenues for monitoring different aspects of biodiversity change using remote sensing at the landscape scale, and we will provide important context for the interpretation of these results. Remote sensing can provide information about biological communities and habitats, ecosystems and biomes at different spatial scales and time steps that should be integrated with other biodiversity data, models and decision support tools to fully leverage its potential for biodiversity monitoring.