Efecto del manejo forestal en la herpetofauna de un bosque templado del occidente de Oaxaca, México / Effect of forest management on the herpetofauna of a temperate forest of western Oaxaca, Mexico

ResumenEl desarrollo de técnicas y tratamientos silvícolas tiene como objetivo principal el aumento de la productividad forestal, al mismo tiempo que minimiza el impacto sobre la diversidad. A pesar de ello, estas actividades modifican la estructura de la vegetación, así como el clima local, alterando la composición de las comunidades. El efecto de estos cambios puede ser mayor en aquellos grupos taxonómicos con alta sensibilidad a las alteraciones del hábitat, como es el caso de los anfibios y reptiles, que al ser los únicos vertebrados terrestres ectotermos, pueden verse seriamente afectados por las variaciones de clima local. El presente trabajo tiene como objetivo conocer las diferencias en diversidad de anfibios y reptiles en un bosque templado bajo dos tratamientos silvícolas (uno intensivo y otro de baja intensidad) y con diferentes tiempos de regeneración (uno, cinco y diez años) en la Sierra Sur del estado de Oaxaca, México. Se obtuvieron registros de 21 especies de herpetofauna (seis anfibios y 15 reptiles). La riqueza total de especies fue similar en ambos tratamientos; sin embargo, la composición varió entre sitios con diferentes tiempos de recuperación. La mayor abundancia de anfibios se presentó en los sitios con el tratamiento de baja intensidad, mientras que los reptiles fueron más abundantes en los sitios con el tratamiento intensivo. Se observó un mayor número de especies raras en los sitios intervenidos con el tratamiento intensivo, aunque los valores de diversidad verdadera de anfibios fueron similares entre tratamientos con intensidades diferentes, mientras que en los reptiles se observó una diversidad 33 % menor en los sitios bajo el tratamiento intensivo y un 28 % en los sitios con baja intensidad respecto al sitio control. Un Análisis de Complementariedad mostró una diferencia de hasta 86 % de disimilitud entre la composición de especies en sitios con el tratamiento intensivo. La intensidad del tratamiento estuvo asociada con un aumento en el número de especies, sin embargo la manera en que responden ante las modificaciones de hábitat depende en gran medida de las características poblacionales de cada especie, así como su habilidad de adaptación a las nuevas condiciones del hábitat.

Abstract:The development of silvicultural techniques has as main objective to maximize the production of timber, whereas at the same time minimize the impact generated during and after forest intervention in the local diversity. However, these activities change local climate, and this, in turn, alter the composition of natural communities. The effect of these changes may be greater in those taxonomic groups with high sensitivity to habitat disturbance, such as amphibians and reptiles, which are the unique terrestrial ectothermic vertebrates. The present study aims to know the differences in diversity of amphibians and reptiles in a temperate forest under two silvicultural treatments, one of low and the other of high intensity, as well as from one, five and ten years of regeneration since the last logging event, Sierra Sur of Oaxaca, Mexico. Records of 21 species of herpetofauna (six amphibians and 15 reptiles) were obtained. The total species richness was similar in both treatments; however, the composition varied between sites with different recovery times. Higher abundance of amphibian was presented on sites with the low-intensity treatment, while reptiles were more abundant at sites with intensive treatment. Compared to a mature forest without management, sites with intensive treatment have more rare species, although the values of true diversity of amphibians were similar between treatments with different intensities, while for reptiles sites under treatment showed less diversity that unmanaged site: 33 % for intensive treatment and 28 % at sites with low intensity with respect to one control site. Complementary Analysis showed a difference of 86 % between the compositions of species in sites with intensive treatment. The treatment intensity was associated with an increase in the number of species, but the way they respond to changes in habitat depends largely on the population characteristics of each species and its ability to adapt to new conditions. Rev. Biol. Trop. 64 (3): 931-943. Epub 2016 September 01.

[Effect of forest management on the herpetofauna of a temperate forest of western Oaxaca, Mexico]. / Efecto del manejo forestal en la herpetofauna de un bosque templado del occidente de Oaxaca, México.

The development of silvicultural techniques has as main objective to maximize the production of timber, whereas at the same time minimize the impact generated during and after forest intervention in the local diversity. However, these activities change local climate, and this, in turn, alter the composition of natural communities. The effect of these changes may be greater in those taxonomic groups with high sensitivity to habitat disturbance, such as amphibians and reptiles, which are the unique terrestrial ectothermic vertebrates. The present study aims to know the differences in diversity of amphibians and reptiles in a temperate forest under two silvicultural treatments, one of low and the other of high intensity, as well as from one, five and ten years of regeneration since the last logging event, Sierra Sur of Oaxaca, Mexico. Records of 21 species of herpetofauna (six amphibians and 15 reptiles) were obtained. The total species richness was similar in both treatments; however, the composition varied between sites with different recovery times. Higher abundance of amphibian was presented on sites with the low-intensity treatment, while reptiles were more abundant at sites with intensive treatment. Compared to a mature forest without management, sites with intensive treatment have more rare species, although the values of true diversity of amphibians were similar between treatments with different intensities, while for reptiles sites under treatment showed less diversity that unmanaged site: 33 % for intensive treatment and 28 % at sites with low intensity with respect to one control site. Complementary Analysis showed a difference of 86 % between the compositions of species in sites with intensive treatment. The treatment intensity was associated with an increase in the number of species, but the way they respond to changes in habitat depends largely on the population characteristics of each species and its ability to adapt to new conditions.