Biological Survey of a Cloud Forest in Southwestern Mexico: Plants, Amphibians, Reptiles, Birds, and Mammals
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Biota Neotropica 18(2): e20170444, 2018 www.scielo.br/bn ISSN 1676-0611 (online edition) Inventory Biological survey of a cloud forest in southwestern Mexico: plants, amphibians, reptiles, birds, and mammals R. Carlos Almazán-Núñez1* , Edson A. Alvarez-Alvarez2, Fernando Ruiz-Gutiérrez1, Ángel Almazán-Juárez3, Pablo Sierra-Morales2 & Sarahi Toribio-Jiménez1 1Universidad Autónoma de Guerrero, Facultad de Ciencias Químico Biológicas, Laboratorio Integral de Fauna Silvestre, Av. Lázaro Cárdenas, 39090, Ciudad Universitaria, Chilpancingo, Guerrero, Mexico 2Universidad Autónoma de Guerrero, Facultad de Ecología Marina, Maestría en Recursos Naturales y Ecología, 39390, Acapulco, Guerrero, Mexico 3Universidad Autónoma de Guerrero, Instituto de Investigación Científica Área Ciencias Naturales, 39000, Chilpancingo, Guerrero, Mexico *Corresponding author: R. Carlos Almazán-Núñez, e-mail: [email protected] ALMAZÁN-NÚÑEZ, R. C., ALVAREZ-ALVAREZ, E. A., RUIZ-GUTIÉRREZ, F., ALMAZÁN-JUÁREZ, A., SIERRA-MORALES, P., TORIBIO-JIMÉNEZ, S. Biological survey of a cloud forest in southwestern Mexico: plants, amphibians, reptiles, birds, and mammals. Biota Neotropica. 18(2): e20170444. http://dx.doi.org/10.1590/1676-0611-BN-2017-0444 Abstract: Cloud forest ecosystems contain unique flora and fauna characterized by high levels of richness and endemism. However, this ecosystem is one of the most threatened because of land-use changes stemming from anthropogenic activities. Therefore, biological inventories are necessary to adequately assess the effects of land-use changes on species now and in the future. In this study, we conducted an inventory of plants and terrestrial vertebrates (amphibians, reptiles, birds, and mammals) in three fragments of cloud forest in southwestern Mexico. Field work was carried out for 15 days per biological group during distinct time periods (2005-2008). Conventional methods of species capture and observation were employed to record species. Recorded species were then categorized based on their endemism and risk category. A total of 67 species of plants, 17 species of amphibians, 25 species of reptiles, 93 species of birds, and 46 species of mammals were recorded. The species accumulation curves for most taxa, except for birds and mammals, showed an asymptotic trend. A total of 56 species endemic to Mexico and four quasi-endemic species were recorded. Plants, amphibians, and reptiles presented the greatest number of species exclusive to Mexico (13 species). Six species of herpetofauna endemic to Guerrero were recorded. According to Mexican laws, 24 of the encountered species are under special protection, while 16 are categorized as threatened and seven as endangered. Reptiles and birds presented the greatest number of at-risk species (14 species). Bird and mammal richness in this study is high in comparison to that recorded in the cloud forests of the entire Mexican state of Guerrero (157 and 75 species, respectively). This data highlights the importance of cloud forests in the study area for local and regional biodiversity. Effective conservation strategies should be prioritized in cloud forests, as this ecosystem is poorly represented in natural protected areas. Keywords: cloud forest, conservation, diversity, terrestrial vertebrates, flora, species richness. Estudio biológico del bosque mesófilo de montaña en el suroeste de México: plantas, anfibios, reptiles, aves y mamíferos Resumen: Los bosques mesófilos de montaña son ecosistemas que contienen flora y fauna única, y son caracterizados por sus altos niveles de riqueza y endemismo. Este ecosistema es uno de los más amenazados debido a los cambios en el uso del suelo por actividades antropogénicas. Por tanto, los inventarios bióticos en este ecosistema son necesarios para evaluar adecuadamente los cambios en el uso del suelo sobre las especies en la actualidad y en el futuro. En este estudio se desarrollaron inventarios de plantas y vertebrados terrestres (anfibios, reptiles, aves y mamíferos) en tres fragmentos de bosque mesófilo de montaña en el suroeste de México. El trabajo de campo se realizó durante 15 días por cada grupo biológico durante distintos períodos de tiempo (2005 al 2008). Los registros de las especies se obtuvieron mediante métodos convencionales de captura y observación. Se categorizaron a las especies por su endemismo y categoría de riesgo. Se registró un total de 67 especies de plantas, 17 especies de anfibios, 25 especies de reptiles, 93 especies de aves y 46 especies de mamíferos. Las curvas de acumulación http://dx.doi.org/10.1590/1676-0611-BN-2017-0444 http://www.scielo.br/bn 2 Biota Neotrop., 18(2): e20170444, 2018 Almazán-Núñez, R.C. et al. mostraron un comportamiento asintótico para la mayoría de los taxa, excepto aves y mamíferos. Se obtuvo un total de 56 especies endémicas a México y cuatro cuasiendémicas. Los grupos de plantas, anfibios y reptiles presentaron el mayor número de especies exclusivas al país (13 especies), y se obtuvo un total de seis especies de herpetofauna endémicas a Guerrero. De acuerdo con las leyes mexicanas, se registró un total 24 especies en protección especial, 16 amenazadas y siete en peligro de extinción, de los cuales los grupos de los reptiles y aves presentaron el mayor número de especies en categoría de riesgo (14 especies). La riqueza de especies de aves y mamíferos en este estudio representa un número importante comparado con el total de especies registradas en los bosques mesófilos del estado de Guerrero (157 y 75 especies, respectivamente). Estos datos resaltan la importancia de los bosques mesófilos de montaña del área de estudio para la biodiversidad local y regional, por lo que deben priorizarse estrategias de conservación efectivas para este ecosistema poco representado en áreas naturales protegidas. Palabras clave: bosque mesófilo, conservación, diversidad, vertebrados terrestres, flora, riqueza de especies. Introduction Also, our study represents an important contribution to the national biotic inventory and serves as a baseline of biodiversity with which Mexico is a country that contains a large portion of the world’s future scenarios and studies can be compared. Ultimately, this inventory biodiversity and is well represented in worldwide diversity lists, serves as a tool for conservation efforts in the study region, especially usually occupying one of the first places. Overall, Mexico contains considering that CF are highly threatened by human activities. approximately 10% of global biological richness (Mittermeier & Goettsch de Mittermeier 1992, Rammamorthy et al. 1998, Martínez- Material and Methods Meyer et al. 2014). Among higher organisms, Mexico occupies fourth place in plant richness (Villaseñor 2016), fifth in amphibian richness 1. Study area (Parra-Olea et al. 2014), second in reptile richness (Flores-Villela & García-Vázquez 2014), eleventh in bird richness (Navarro-Sigüenza et The study area is located to the west of the biotic province of SMS al. 2014), and third in mammal richness (Ramírez-Pulido et al. 2014). in the state of Guerrero in southwestern Mexico between 101°6’30.84” These high levels of biodiversity are partly due to the convergence of to 100°57’57.86” W and 17°46’16.87” to 17°43’24.45” N (Figure 1). the Nearctic and Neotropical biogeographical regions within Mexico’s The studied CF fragments comprise a total area of 11 km2 and present an territory, giving rise to species with both temperate and tropical affinities altitude between 1700 and 2200 masl (Figure 1). The climate is humid (Plascencia et al. 2011). Despite the vast biological resources of Mexico, and sub-humid temperate, with a mean annual temperature between 16 the flora and fauna of this country have not been fully documented and 20 °C and a mean annual precipitation between 1200 and 2000 mm (Martínez-Meyer et al. 2014), and several regions with potentially (García 2004). The study area is characterized by rugged orography with high levels of diversity and endemism remain relatively unexplored. slopes of 4° to 60°. Several types of land management are practiced in The Sierra Madre del Sur (SMS) in western Mexico is an important the CF of the study area, including agriculture (e.g., mainly corn, bean, region from a biological perspective. This region is characterized and squash crops) and forestry, wherein species of economic importance by a complex orography and geological history that has promoted (e.g., Quercus glaucoides and Q. candicans) are harvested. the development of a wide range of environments and ecosystems (Ferrusquía 1998, Luna-Vega et al. 2016), including cloud forests (CF). In the SMS, CF covers approximately 1,765 km2 and corresponds to 20% of the territory (INEGI 2010). As previously mentioned, this ecosystem is highly diverse and contains many exclusive flora and fauna species (Challenger 1998, Gual-Díaz & Rendón-Correa 2014). Notably, various fragments of this ecosystem are distributed in the form of an archipelago across the mountainous environments of the SMS, and each fragment has a particular biotic composition (Gual-Díaz & Rendón-Correa 2014). However, limited biological information is available on the CF of this region. The lack of biological studies on the CF of western Mexico is related to the physical inaccessibility of some sites (e.g., because of difficult terrain or lack of roads) and social problems. As few biotic inventories have been conducted in this region to date, our study serves as an initial approximation for increasing knowledge on the biological diversity