Spatial analysis of Ecosystem Services at the periphery of Mexico City: Conservation implications: A case study of the Bosque de Agua

Protected Natural Areas have traditionally been employed to preserve natural ecosystems, although in recent decades, Payment for Ecosystem Services schemes has been added to complement these initiatives. However, the endemic Temperate Forests are exposed to strong pressures due to anthropic activities such as urban growth and high water demand to supply one of the largest cities in central Mexico. Evidence from Mexico shows that PES programs have had a limited impact on conservation, as in their early years, payments were allocated in areas with low risk of environmental degradation, mainly within the Protected Natural Areas. This association has sparked debates about their effectiveness in conservation and the provision of ecosystem services. The spatial effectiveness of Protected Natural Areas and the Payment for Ecosystem Services (PES) system in conserving Ecosystem Services was quantified in the central zone of Mexico, specifically in the area known as the 'Water Forest' (Bosque de Agua). The services of water provision and climate regulation were modeled using the InVEST software, while services related to agricultural food provision and timber were estimated based on the biomass stock coverage developed by the program for reducing emissions from deforestation and forest degradation. Utilizing these estimations at the finest analytical unit (1 ha), hotspot models were generated for each Ecosystem Service. Subsequently, areas with high values of these services ('hotspots') were overlaid with Protected Natural Areas and zones under Payment for Ecosystem Services. The results highlight that the Water Forest is not only a water provider but also hosts other significant services that require more effective protection. 62% of the total area of the Bosque de Agua (160,356 ha.) presents hotspots for at least one of the four measured services. However, 19% (28,864 ha.) of the service hotspots are not protected by any conservation instrument. This underscores the importance of reviewing and adjusting existing conservation approaches to ensure the sustainability of these valuable services provided by nature.