Resilience and Threshold-like Behavior of Moroccan Tetraclinis articulata (Vahl) Mast. Ecosystems Under Four Decades of Climate Warming

Climate warming and land degradation are reshaping Mediterranean and semi-arid ecosystems, yet their combined effects remain poorly quantified in North Africa. Using four Landsat reference epochs spanning 1984–2024, and four spectral/thermal indices (NDVI, EVI, NDMI, LST), we assessed vegetation dynamics and eco-climatic resilience of Tetraclinis articulata ecosystems in Morocco. Four study sites (Stehat, Merchouch, Tamanar, and Amskroud) distributed along a latitudinal gradient from the northern to southern limits of the species’ Moroccan range were chosen and analyzed. Results reveal a generalized decline in vegetation cover, strongly coupled with increasing land surface temperatures, with threshold-like patterns emerging above 74–75 °C that lead to a rapid reduction in NDVI. The northern site (Stehat) exhibited partial recovery, likely supported by local schist aquifers, whereas the arid southern sites (Tamanar and Amskroud) experienced near-total biomass loss and reduced climate buffering. Moisture indices limited hydrological mediation and suggest that shallow soil water availability constrains T. articulata functioning, amplifying vulnerability under recurrent warming. These findings demonstrate how local edaphic and hydrological conditions modulate the impacts of global change and provide early warning indicators of heightened vulnerability and potential threshold-like behavior in drylands. The study emphasizes the urgent need for targeted management strategies to sustain ecosystem resilience under accelerating climate stress.