Quantifying landscape-level land-use intensity patterns through radar-based remote sensing

• Published in: Journal of Applied Ecology
• Main Authors: Howison, Ruth A., Piersma, Theunis, Kentie, Rosemarie, Hooijmeijer, Jos C.E.W., Olff, Han
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2018
• Subjects: Black-tailed godwit; Change detection; Habitat preference; Land-use intensity; MODIS EVI; Mowing frequency; Radar; Remote sensing; Sentinel C-SAR; Temporal stability; black-tailed godwit; Limosa limosa
• Online Access: https://hdl.handle.net/11370/1e0fb66f-b598-4a3c-bbea-2fb2efbbafc2; https://research.rug.nl/en/publications/1e0fb66f-b598-4a3c-bbea-2fb2efbbafc2; https://doi.org/10.1111/1365-2664.13077; https://pure.rug.nl/ws/files/61202696/Howison_et_al_2018_Journal_of_Applied_Ecology.pdf; http://www.scopus.com/inward/record.url?scp=85040742347&partnerID=8YFLogxK

The increasing availability of high resolution and high frequency, radar-based remote sensing data (i.e. observations on land surface characteristics, insensitive to cloud interference), makes it possible to track land-use intensity more precisely at the whole landscape scale. Here, we develop a new radar-based remote sensing technique for large-scale quantification of agricultural land-use intensity across human-dominated landscapes. We compare the respective abilities of Sentinel-1 C-band radar (C-SAR, C-band synthetic aperture radar) remote sensing data with the more traditional optical data, as MODIS enhanced vegetation indices (MODIS EVI), in capturing seasonality and the magnitude of land-use intensity (quantity and frequency of biomass removal). Linking our novel radar-based change detection algorithm to agricultural management activities on the ground, we quantify a whole landscape according to timing of mowing, a key grassland disturbance, thus capturing the dynamics of mowing regimes in grasslands. We found that the radar-based proxy provides a rapid and reliable measure of land-use intensity, reliably predicting plant community composition at the landscape scale. We tested this methodology using data on black-tailed godwits (Limosa limosa limosa), a specialist breeder of lowland meadows which, over the last 50 years, has shown dramatic declines. During territory establishment, black-tailed godwits preferentially used fields corresponding to intermediate radar-sensed land-use intensities. However, the present-day timing of mowing in these habitats was such that most godwit broods were less likely to be successful than broods in grasslands used at a lower intensity. Synthesis and applications. The newly developed radar-based land-use intensity quantification is a powerful tool that makes it possible for ecologists and land managers to include agricultural land-use intensity measurements in population studies of the plants, insects, birds and mammals using these landscapes, at the spatial scale of entire ...