RT Journal Article T1 New ecological change indicators using breakpoints in vegetation trends applied to a dryland pastoral catchment in the Moroccan high atlas A1 Vermeer, Angelique A1 Foerster, Saskia A1 Mayor, Ángeles G. AB This study aims to improve ecological change quantification from remote sensing-based methods by incorporating the sign of breakpoints in vegetation productivity trends and proposing a new breakpoint typology. The typology distinguishes between positive and negative breakpoints reflecting either an improvement or deterioration in ecosystem functioning. Using 35 years of Landsat NDVI data, the analysis focused on a dryland pastoral catchment in Morocco's High Atlas, including the most severe drought during this period. The frequency of negative breakpoints increased with aridity, especially in areas of scant vegetation, while positive breakpoints were more evenly distributed throughout the catchment. Regions with smaller NDVI changes over time exhibited a higher number of breakpoints with a similar share of positive and negative, compared to areas with stronger greening or browning. During the drought, positive breakpoints (positive reversals) were most common, followed by negative breakpoints (interrupted decreases). Areas with positive reversals experienced fewer total breakpoints over the study period and had a greater share of positive breakpoints than areas with interrupted decreases. The contrasting vegetation responses to drought may have reflected the interaction between grazing pressure and aridity, with positive drought responses aligning with herd collapses and higher aridity limiting recovery despite reduced grazing. These findings highlight the importance of analysing the balance of positive and negative breakpoints alongside their total count for understanding ecological change. The study also revealed significant ecosystem resilience to severe drought across much of the catchment, but underscored the potential risk of crossing resilience thresholds as aridity intensifies. PB Elsevier SN 2665-9727 YR 2025 FD 2025-03-28 LK https://hdl.handle.net/20.500.14352/123261 UL https://hdl.handle.net/20.500.14352/123261 LA eng NO Vermeer, A., Foerster, S., & Mayor, Á.G. (2025). New ecological change indicators using breakpoints in vegetation trends applied to a dryland pastoral catchment in the Moroccan high atlas. Environmental and Sustainability Indicators, 26, 100672. https://doi.org/10.1016/j.indic.2025.100672 NO We are deeply grateful for the collaboration of the NGO PermaAtlas (https://perma-atlas.com/) and the Anguelz Youth Association for Sustainability in this research. We received seed funding from Future Food Utrecht (Utrecht University) and Grant PID2023-148484OB-I00 funded by MICIU/AEI/10.13039/501100011033/FEDER, EU. NO Utrecht University (Future Food Utrecht) NO Ministerio de Ciencia, Innovación y Universidades (España) NO Agencia Estatal de Investigación (España) NO Unión Europea DS Docta Complutense RD 28 dic 2025