Revegetation of retired croplands in Kern County, CA: Observations from satellite and airborne remote sensing, 1982-Present

Keywords: Landsat; Sentinel-2; Drought; Spatiotemporal; Agroecology
Session Type: Virtual Paper Abstract
Day: Friday
Session Start / End Time: 2/25/2022 11:20 AM (Eastern Time (US & Canada)) - 2/25/2022 12:40 PM (Eastern Time (US & Canada))
Room: Virtual 38

Abstract

The cessation of agricultural production ("land retirement") has risks and opportunities for rural livelihoods, ecological communities, and ecosystem services worldwide. Here, we focus on land retirement in California’s Kern County, the most valuable crop producing county in the US, associated with the severe 2011-2017 drought. Using Landsat and Sentinel-2 multispectral satellite remote sensing, we quantify trends and annual phenology of green and nonphotosynthetic vegetation in retired fields using spectral and temporal mixture analysis and compare to wildlife refuges and other protected areas. We additionally compare to evapotranspiration estimated from NASA’s ECOSTRESS mission and spectral diversity and plant trait metrics estimated from multi-year AVIRIS airborne imaging spectroscopy. We find diverse vegetation trajectories and conditions on retired lands with a broad diversity of similarity/dissimilarity to protected areas. We also find evidence of adjacency effects on cropland immediately abutting retired fields. Post-retirement vegetation is found to be strongly dependent on both pre-retirement crop type and spatial context. Ongoing work is underway to link these results to additional agroecological (pesticide use, connectivity, species suitability) and social (farmer interview) variables, setting the stage for a holistic understanding of human-environment interactions across a rapidly changing multi-billion dollar agricultural landscape.