Land use in Mexico has dramatically changed in recent decades since deforested lands have been repurposed for agriculture. We evaluated the amphibian taxonomic and functional diversity of a heterogeneous landscape with ten land cover/use types in west-central Mexico. Taxonomic diversity was evaluated with q-order indices, and functional diversity was calculated with three multivariate functional diversity indices by land cover/use. The relationship between amphibian diversity, habitat structure, and environmental variables was analyzed using multidimensional distance-based analyses. Our results showed that most native land cover types exhibited a similar species richness (low values) among the studied crops, except for the riparian habitat surrounded by tropical dry forest (high richness) and secondary vegetation (intermediate richness). Regarding functional diversity, the riparian habitat surrounded by tropical dry forest, sugar cane field, and secondary vegetation had the highest values. The secondary vegetation had more functional groups than other land cover/use types. Despite the lack of a clear spatial pattern of amphibian taxonomic and functional diversity, we determined that attributes such as herbaceous cover and water availability are essential to maintain both facets with high amphibian diversity in the land cover/use types (e.g., secondary vegetation and sugar cane).

The Mexican Republic ranks fifth in the world in terms of amphibian diversity, and within Mexico, the state of Oaxaca has the greatest amphibian richness and endemism. Unfortunately, various factors, such as land use change and global warming, have caused a global crisis that threatens the conservation of this class. In the face of these threats, an analysis of beta diversity provides information that can be applied to conservation strategies, since its study reveals the spatial scaling of diversity loss and clarifies the mechanisms of regional diversity maintenance. In this work, we analyzed the beta diversity at the species and higher taxa level (order, family, subfamily, genus and species) for the amphibians of Oaxaca and their replacement components and the differences in richness for anurans and caudates separately between physiographic subprovinces. Very high beta diversity was recorded, with higher diversity occurring among caudates (0.92) than among anurans (0.84). Species replacement was the component that most contributed to this result, and the subprovinces with substantial environmental differences had the most dissimilar amphibian communities. The results of this study show the need to implement conservation strategies in subprovinces with high amphibian richness and endemism levels, following the example of Sierra Madre de Oaxaca (SMO), where local communities have developed conservation actions in most of the territory.

Reptiles are threatened by anthropogenic landscape transformation, largely due to agriculture. However, ecosystems nowadays constitute a matrix of fragmented landscapes. We analyzed a heterogeneous landscape’s reptile taxonomic and functional diversity patterns across ten land cover/use types in Jalisco state, in west-central Mexico. At the alpha diversity level, we assessed the taxonomic diversity using q-order indices, and functional diversity with multidimensional indices (FRic, FDiv, and FEve) by land cover/use. We evaluated the differences in species composition among land cover/use types (beta diversity). We utilized multidimensional distance-based analyses (dbRDA) to evaluate the association between reptile diversity, habitat structure, and environmental variables. Species richness did not correlate with functional richness across land cover types overall, except for riparian habitat surrounded by crops (RH-C), which exhibited higher species richness and functional diversity. Secondary vegetation surrounded by temperate forest (SV-TF), riparian habitat surrounded by tropical dry forest (RH-TDF), and RH-C were the land cover/use types with the most functional groups. Herbaceous cover is crucial for preserving both reptile diversity facets in this landscape. These findings suggest that the availability of resources (e.g., riparian habitat and herbaceous cover) regardless of perturbation level could be more relevant for reptile diversity than the condition (tropical vs. temperate) due to the high plasticity and adaptation of the group. It is essential to recognize the ecological value of these habitats by adopting a holistic approach that values the intrinsic and ecological importance of reptile diversity.

La composición y diversidad de las lagartijas son influenciadas por el tipo de vegetación, debido a que éste determina la estructura física y ambiental de sus hábitats. El objetivo de este estudio fue determinar y analizar la diversidad taxonómica de las lagartijas del área prioritaria de conservación Sierra El Cuale, Jalisco, México, asociada a cuatro tipos de vegetación: bosque tropical subcaducifolio (BT), bosque de encino (BE), bosque de pino-encino (BPE) y bosque de pino (BP). Se realizaron muestreos mensuales entre julio de 2015 y junio de 2016. Se registró una riqueza total de 12 especies en el área de estudio: ocho en BT, nueve en BE, seis en BPE y seis en BP. Las curvas de acumulación de especies mostraron que se requiere más esfuerzo de muestreo para caracterizar en su totalidad a la comunidad de lagartijas. Anolis nebulosus, Sceloporus melanorhinus y S. utiformis se observaron en los cuatro tipos de vegetación, pero Basiliscus vittatus, Gerrhonotus liocephalus y Scincella assatus solo en uno. Un análisis de escalamiento multidimensional no métrico (NMDS) identificó dos grupos según la presencia de especies de lagartijas y estaciones del año (lluvias y seca): BPE-BP y BT-BE. La distintividad taxonómica promedio (Δ+) y la riqueza de especies fueron altas en la estación lluviosa. Los resultados de este estudio muestran que la riqueza de especies de lagartijas en la Sierra El Cuale está vinculada a la variedad de tipos vegetación. Por otro lado, el análisis comparativo de la Δ+ entre la Sierra El Cuale y las Reservas de la Biosfera de Chamela-Cuixmala y Manantlán, mostró que la Sierra El Cuale tiene un papel importante en la contribución regional de la diversidad de lagartijas.

In Mexico, land use changes have significantly impacted the diversity of amphibians and reptiles in a negative way. In light of this, we evaluate the alpha and beta components of the taxonomic diversity of amphibians and reptiles in a heterogeneous landscape in west-central Mexico. Additionally, we provide a checklist of amphibian and reptile species recorded over nine years of observations within the studied landscape and surrounding areas. The land cover/use types with the highest species richness and alpha taxonomic diversity differed between amphibians and reptiles. Overall beta taxonomic diversity was high for both groups, but slightly higher in reptiles. This taxonomic differentiation mainly corresponded to a difference in the turnover component and was greater in pristine habitats compared to disturbed ones. The checklist records 20 species of amphibians (ten of which are endemic) and 48 of reptiles (30 endemics). Additionally, the study expands the known geographical distribution range of one species of frog and three species of snakes. Our findings suggest that heterogeneous landscapes with diverse land cover/use types can provide essential habitats for the conservation of amphibian and reptile species.