Current status of the remaining Mexican cloud forests: landscape findings and conservation initiatives.

Abstract

Tropical montane cloud forests are known for their unique biodiversity and their critical role in sustaining ecosystem services; however, approximately 50% of their original cover in Mexico was estimated to have been lost by 1998. The Mexican ecoregion that supports these ecosystems experienced one of the highest rates of deforestation between 2001 and 2021. Thus, a more recent evaluation of Mexico's cloud forests is required. There is limited data on the landscape structure of cloud forests in Mexico, despite the possible application of landscape factors in conservation planning. Here, we estimated the average total area, number of patches, effective mesh size, total edge, and the shape of mixed forests that was present in 2020 within polygons of cloud forests defined in 1999 by Mexico's National Commission for the Use and Knowledge of Biodiversity (CONABIO for its acronym in Spanish). We estimated land cover using data from the North American Land Change Monitoring System, which classifies cloud forests as mixed forests. We found that eight out of the 109 polygons have no mixed forests and that an average of 49% of the 1,768,914 ha of cloud forests polygons are now covered by mixed forests distributed across 13 states. Additionally, within the remaining 101 polygons that do contain this type of vegetation, mixed forest is distributed on average across 140 patches (range = 1-1,473); 80% of these forests have very low effective mesh size values; 90% of them have low total edge values (<2,000 km); and their shapes tend to be uniformly distributed. Furthermore, most of cloud forest polygons are located outside of federal protected areas. Overall, our results suggest that the remaining Mexican cloud forests are extremely vulnerable and fragmented and that their extent has steadily declined since 1999. To ensure the survival of Mexican cloud forests, it will be crucial to prioritize high-diversity areas, strengthen protection in critical zones, establish ecological corridors, encourage sustainable practices, and actively engage local communities. This study highlights the complex issues and inherent heterogeneity that characterize cloud forest ecosystems in Mexico and provides crucial insights for conservation.