Protected areas are of paramount relevance to conserving wildlife and ecosystem contributions to people. Yet, their conservation success is increasingly threatened by human activities including habitat loss, climate change, pollution, and species overexploitation. Thus, understanding the underlying and proximate drivers of anthropogenic threats is urgently needed to improve protected areas’ effectiveness, especially in the biodiversity-rich tropics. We addressed this issue by analyzing expert-provided data on long-term biodiversity change (last three decades) over 14 biosphere reserves from the Mesoamerican Biodiversity Hotspot. Using multivariate analyses and structural equation modeling, we tested the influence of major socioeconomic drivers (demographic, economic, and political factors), spatial indicators of human activities (agriculture expansion and road extension), and forest landscape modifications (forest loss and isolation) as drivers of biodiversity change. We uncovered a significant proliferation of disturbance-tolerant guilds and the loss or decline of disturbance-sensitive guilds within reserves causing a “winner and loser” species replacement over time. Guild change was directly related to forest spatial changes promoted by the expansion of agriculture and roads within reserves. High human population density and low nonfarming occupation were identified as the main underlying drivers of biodiversity change. Our findings suggest that to mitigate anthropogenic threats to biodiversity within biosphere reserves, fostering human population well-being via sustainable, nonfarming livelihood opportunities around reserves is imperative.

Climatic variations influence the adaptive capacity of trees within tropical montane cloud forests species. Phenology studies have dominated current studies on tree species. Leaf vein morphology has been related to specific climatic oscillations and varies within species along altitudinal gradients. We tested that certain Neotropical broad leaf Magnolia species might be more vulnerable to leaf vein adaptation to moisture than others, as they would be more resilient to the hydric deficit. We assessed that leaf vein trait variations (vein density, primary vein size, vein length, and leaf base angle) among four Magnolia species (Magnolia nuevoleonensis, M. alejandrae, M. rzedowskiana, and Magnolia vovidesii) through the Mexican Tropical montane cloud forest with different elevation gradient and specific climatic factors. The temperature, precipitation, and potential evaporation differed significantly among Magnolia species. We detected that M. rzedowskiana and M. vovidesii with longer leaves at higher altitude sites are adapted to higher humidity conditions, and that M. nuevoleonensis and M. alejandrae inhabiting lower altitude sites are better adjusted to the hydric deficit. Our results advance efforts to identify the Magnolia species most vulnerable to climate change effects, which must focus priorities for conservation of this ecosystem, particularly in the Mexican tropical montane cloud forests.

In this study, we document the distribution, current knowledge, and conservation of twenty-six tree species of gymnosperms (four species) and angiosperms (twenty-two species) characteristic of the Mexican cloud forests and most endemic to Mexico. Many species are threatened and included in international and national Red Data List, such as the IUCN, and the Mexican Official Norm (NOM-059-SEMARNAT-2010). Distribution maps of these 26 species were generated based on information from herbarium specimens, specialized literature, web databases, and our own field surveys. All records were displayed on a map of the Mexican territory divided into grid cells of 15 × 20 min of latitude/longitude (a spatial resolution of approximately 27.75 km × 36.75 km) to obtain the richness patterns. Additionally, these records were displayed on the map of the current Mexican System of Natural Protected Areas (NPAs) to evaluate their representativeness in these areas of in situ conservation. We also include information on populations and the habitat status of these tree species in some Mexican locations. Most species studied here require particular policies for their conservation due to the problems affecting their natural populations and habitat. Our results indicate that three species are not represented in the Mexican System of NPAs and that some are underrepresented.

Geographical distribution, diversity, endemism, and conservation of Cactaceae in the Mexican state of Tamaulipas were analyzed based on distributional data obtained from specialized literature, fieldwork, and herbarium specimens. Tamaulipas territory was divided into grid-cells of 10 × 10 minutes latitude/longitude and was used as units of analysis. Cactaceae comprises 174 taxa and 33 genera in Tamaulipas, representing a high proportion of the Mexican cacti with 65% at the generic level and 23% at the specific level. The richest genera are Opuntia (40), Mammillaria (35), Echinocereus (16), and Turbinicarpus (14). Thirty one Cactaceae taxa are new records for the state. The highest diversity of species occurs in the southwestern region associated with the Sierra Madre Oriental slopes and the Jaumave Valley. Cacti are well represented in the state Natural Protected Areas of Tamaulipas compared to the federal conservation areas. We conclude that Tamaulipas constitutes a nodal area because it is located at the boundaries among four different biogeographic regions representing zones of biotic overlap promoted by historical and ecological changes allowing the mixture of different biotic elements and in situ speciation. For this, it is considered one of the richest Mexican states in terms of Cactaceae diversity.

Antecedentes y Objetivos: Cochemiea es un género que actualmente comprende cinco especies que se encuentran en México, y se caracteriza morfológicamente por sus tallos decumbentes cilíndricos o postrados y por su largo perianto zigomorfo rojo escarlata presumiblemente especializado para la polinización por colibríes. Como parte de los estudios taxonómicos en curso sobre la flora del norte de México proponemos como nueva especie una población descubierta por Thomas Linzen en 2012 en el centro de Sinaloa (México), previamente identificada como Mammillaria sp., se trata de una especie de Cochemiea que no concuerda con ninguna especie conocida del género, la cual proponemos como nueva especie para la ciencia. Métodos: Este trabajo se basa en estudios de campo (otoño 2018 y primavera 2019) en el centro de Sinaloa, la revisión de ejemplares de herbario y de literatura relevante. Se evaluó su estatus de conservación siguiendo los lineamientos propuestos por la IUCN; AOO y EOO fueron calculados usando el programa GeoCAT. Resultados clave: Cochemiea thomasii es descrita e ilustrada de Sinaloa. Esta nueva especie es morfológicamente similar a C. halei, de la cual difiere por sus tallos colgantes, los tubérculos cónicos más grandes, las espinas radiales menos numerosas y más cortas, y los frutos ovoides. Se incluye una clave diagnóstica de las especies conocidas de Cochemiea. Conclusiones: Cochemiea thomasii es endémica del estado de Sinaloa donde vive en un área reducida. Con base en los criterios B2a (distribución geográfica) y C (población pequeña) de la IUCN, esta especie se evalúa como En Peligro Crítico (CR) o Vulnerable (VU). Adoptando el principio de precaución, Cochemiea thomasii es considerada en Peligro Crítico (CR).

Echinoagave nievesiorum (Agavaceae, Asparagales), a new species endemic to the Sierra Wixárika (Huichola), part of the Sierra Madre Occidental, Jalisco, Mexico, is described. This species shares morphological characteristics with Echinoagave rzedowskiana but it differs from the latter by having narrower and striate leaves; leaf sheaths shorter, triangular and wider at the base; narrower ovary width; shorter tube length; tepal lobes at anthesis converging and tightening the filaments; larger filament length to flower length ratio; fruiting spikes thicker and denser with the peduncle covered by the capsules and the bracts usually deciduous; capsules broadly ellipsoid with dorsally blackish valves. A distribution map with biogeographic provinces is provided to place the species in an ecological and evolutionary context.