The Aranjuez Experimental Station: Lessons from two decades of dryland ecology research

Abstract

Drylands cover a large fraction of the terrestrial surface and are highly vulnerable to climate change; yet, long-term experimental platforms devoted to their study remain scarce. This case study synthesizes nearly two decades of research conducted at the Aranjuez Experimental Station (AES), a semiarid gypsum steppe in central Spain that has supported multiple observational studies, manipulative experiments and long-term monitoring aimed at understanding how plants, soils and biocrusts interact to regulate dryland structure and functioning and how organisms modulate ecosystem responses to climate change. Research at the AES has shown that plant–plant interactions vary with microclimate, ontogeny, water availability and herbivory; that biocrusts are key regulators of nitrogen, phosphorus and carbon cycling, soil respiration, infiltration and soil water dynamics; and that lichen-dominated biocrusts are highly sensitive to warming. At the same time, a long-term climate change experiment conducted at the AES has revealed that well-developed biocrusts can buffer warming effects on nutrient pools, greenhouse gas fluxes and soil moisture. The results obtained from the AES illustrate the value of long-term, integrative field research for understanding dryland resilience and vulnerability and highlight the key role of biocrusts as modulators of ecosystem responses to climate change.