Do Current Protected Areas Preserve Soil Health and Ecosystem Resilience? Contributions of Nematodes as Bioindicators in the Souss Massa National Park

Soil health underpins terrestrial ecosystems, agriculture, and global food security, yet its role as a biodiversity hotspot and carbon is often overlooked in policymaking. Alarmingly, 70% of global soil biodiversity hotspots remain outside protected areas. Soil health is shaped by biological, chemical, and physical properties that sustain life above and below ground. Among biological indicators, nematodes are highly valuable due to their functional diversity and sensitivity to environmental changes. They contribute to soil quality by mineralising nutrients and enhancing plant availability. In this review chapter, we studied the extent to which protected areas safeguard soil health and ecosystem resilience based on our published works and bibliography. Overall, results demonstrated that protected areas effectively preserve soil health and functioning. Nature conservation enhances nematode biodiversity and soil food webs complexity, with taxa characteristic of undisturbed soils serving as indicators of disturbance. Moreover, Meloidogyne spp., a phytoparasitic nematode of major economic importance, was absent in protected areas, suggesting improved regulation of soil organisms and stronger ecosystem resilience. On the other hand, predator and bacterivore nematodes supported soil carbon storage by transforming organic matter into biomass, highlighting their role in carbon cycling under conservation measures. As a conclusion, soil biodiversity protection requires strict preservation of sensitive ecosystems and delving into agroecological cropping that mimic natural undisturbed systems. No nature-based solution can succeed without explicitly considering soil biodiversity, which is central to climate change mitigation, sustainable development, and restoration of degraded ecosystems.