The diversity of life has plummeted over the past 30 years in more than a dozen tropical forest reserves in Mexico, a new study shows. Even these highly protected areas are seeing the array of plant and animal life follow a now global trend in which a few groups thrive and proliferate in human-altered landscapes where most groups decline. …The 14 studied reserves, which are part of a biodiversity hotspot that spans across Mesoamerica, have each been designated under a UNESCO program aimed at establishing a scientific basis for improving human livelihoods and safeguarding ecosystems. In and around many of the protected areas, the authors found that new roads continued to go up and trees came down between 1990 and 2020 as people cleared forest for timber or cattle grazing. The abundance of long-lived, shade-tolerant tree species declined on average across all reserves by more than 25%.