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Background: The inclusion of information on the phenology of any given species can significantly improve the resulting of potential distribution models. Scientific literature does not provide up-to-date information on the abiotic and biotic factors that determine the distribution of Croton guatemalensis , a species native to communities in south Mexico. For the first time, the potential distribution of C. guatemalensis was determined using a model which includes reproductive biology data. Questions: Which bioclimatic and climatic variables most contribute to the distribution of C. guatemalensis ? Does reproductive biology data contribute significantly to the prediction of the species distribution? Studied species/Mathematical model: Croton guatemalensis / Maximum Entropy Modeling Study area and dates: Chiapas, Mexico, January - December 2020. Methods: The MaxEnt 4.4.4 algorithm was used, incorporating 16 variables, including bioclimatic, climatic and elevation. In addition, a habitat suitability layer was built. Results: The model presented a precision of AUC = 0.964 ± 0.004. Eight variables contributed to explain 86.5 % of the potential distribution of the species. According to their contribution to the model, the most important were the seasonality of precipitation, habitat suitability, elevation and April solar radiation. The species was found in the physiographic regions Central America South Mountain Range Subprovince, Central Depression of Chiapas Discontinuity, and Altos de Chiapas Subprovince. Conclusions: The inclusion reproductive biology data of C. guatemalensis contributed to improve the model. This information allows the development of more effective management and conservation plans by identifying the precise regions in which the species is found.

The order Odonata has been regularly used as an indicator of the ecosystem's condition. The objective of this review was to analyze the importance of Odonata for environmental assessments (assessment types, statistical approach, life stages, and sampling method, or particular metric), summarizing the current state, the trends, and identifying related research issues in the Neotropical region. Therefore, we selected 62 articles from 2007 to 2018 based on published research to monitor Odonata assessments in the Neotropical region. We compiled a database and ran statistical analyses for the observed frequencies. We found that ecosystem health was the most frequent assessment type and quality the most used objective. In the case of statistical tests and metrics, multivariate analyses and species richness were most used in these papers. However, because there is a great diversity of habitats in this region, there is no unique monitoring protocol to assess the quality of ecosystem health and it is needed to create a proposal for a standard evaluation protocol. Consequently, guidelines for monitoring are presented, and we suggest three stages to establish a specific protocol for each site, which records the set of species most sensitive to the exchange rate evaluated, as well as the use of rarefaction methods, the index of diversity based on the area under the curve, and multivariate analysis, among other recommendations.

Human activities have impacted many different habitat types on Earth, and there is a requirement for tools with which to accurately assess the level of damage incurred by ecosystems. For environmental analyses and monitoring, rapid stream assessment techniques emphasize geomorphological characteristics, biological potential, and habitat integrity characteristics. Using the principles and concepts of aquatic biology and ecology, we determined whether the visual-based habitat evaluation score is related to Odonata species diversity at different taxonomic levels. We hypothesized that habitat assessment is correlated positively with the local diversity of one Odonata taxonomic group. We found that the abundance, species richness, and diversity of Argia, one of the most locally diverse genera in southeastern Mexico, are positively correlated with habitat integrity scores. High richness (of up to eight species per site) corresponds to high integrity scores. Simultaneously, habitat integrity scores increase 23.51 times when Argia diversity (surface area) increases. We discuss the possible advantages of using a diverse Odonata clade (Argia) as a surrogate for local habitat assessments. Long-term biomonitoring programs could be applied using this novel approach in this specific Neotropical area. This study is framed within the focus of biodiversity and ecosystem functioning (BEF), however, it must be tested with other indices and a reliable and consistent relationship must be verified between diverse clades and environmental assessment scores.

Croton guatemalensis is a threatened and multipurpose species in communities of southeastern Mexico and Central America. For the first time, its reproductive phenology and its relationship with environmental variables present in four different natural protected areas of the Zoque Tropical Forest Biological Corridor was determined. Throughout a year the flowering and fructification of the species was monitored, the local environmental variables were recorded and fruits and seeds were collected to determine, under a random design, the germination of the seeds and the growth of seedlings in the laboratory and in nursery respectively. In all cases, flowering was presented from July to April, while fructification occurred from March to September, coinciding with the months where the rains diminish considerably. In terms of seed germination, it presented a statistically significant difference between seeds from the four protected areas. The most contrasting results were presented between La Pera and Area Villa de Allende (98% ± 3.84% and 6% ± 3.84% respectively). According to the generalized linear model, soil porosity was the only variable that influenced the germination of the species (the higher the porosity, the higher the percentage of final germination, t = 2.237, P = 0.0503). Because this is the first study on the ecophysiology of C. guatemalensis in southern Mexico, the importance of it becomes relevant when providing fundamental reproductive information for the generation of strategies for conservation, restoration and forest management of the species.

Introduction: Understanding how species respond to climate change is critical for implementing conservation strategies. Objective: We explain through potential distributions and changes in altitudinal variation, the possible impacts of climate change in an endangered micro-endemic rodent of Mexico with narrow altitudinal range, Heteromys nelsoni and a rodent with a wide distributional and altitudinal range, Heteromys goldmani. Methods: We obtained historical and current records of both Heteromys species. Potential distribution models were generated using Maxent, including altitudes for each species and bioclimatic layers. We determined the Extent of Occurrence and Area of Occupancy for H. nelsoni according to the criteria of the IUCN in order to generate information about its risk status. Results: The altitude is not a variable that determines a shift in the distribution caused by climate change. In contrast, the temperature and precipitation are important for the potential distribution of both Heteromys species. The future changes in climatic conditions could reduce the area of suitable habitat for both species. Conclusions: The distribution surface is not greater than 33.44 km2 for H. nelsoni. Therefore, is urgent to re-evaluate their conservation status by the IUCN, mainly in its B criterion, and to take specific actions for their conservation. We suggest the creation of a terrestrial protected area. RESUMEN Introducción: El entendimiento de cómo las especies responden al cambio climático es crítico para la implementación de estrategias de conservación. Objetivo: Explicar a través de distribuciones potenciales y cambios en la variación altitudinal, los posibles impactos del cambio climático en un roedor micro endémico de México, en peligro de extinción y con un rango altitudinal estrecho, Heteromys nelsoni y un roedor con una amplia distribución y rango altitudinal, Heteromys goldmani. Metodología: Obtuvimos registros históricos y actuales de ambas especies. Los modelos de distribución potencial se generaron utilizando Maxent, incluyendo altitudes y capas bioclimáticas. Determinamos la extensión de su presencia y el área de ocupación para H. nelsoni según los criterios de la IUCN, para generar información sobre su estado de riesgo. Resultados: La altitud no es una variable que determina un cambio en la distribución causada por el cambio climático. En contraste, la temperatura y precipitación son importantes para la distribución potencial de ambas especies de Heteromys. Los análisis sugieren que los cambios futuros en las condiciones climáticas podrían reducir el área de hábitat adecuado para ambas especies. Conclusión: La superficie de distribución de H. nelsoni no es mayor a 33.44 km2. Es urgente reevaluar su estado de conservación de la UICN, principalmente en su criterio B y tomar medidas específicas para su conservación. Sugerimos la creación de un área terrestre protegida.

Es de gran importancia conocer y evaluar las enfermedades zoonóticas emergentes que existen en el sureste de México, ya que representan una amenaza significativa para la salud pública. Los cambios antropogénicos, por ejemplo, la deforestación, el establecimiento de monocultivos, el aumento de la urbanización y la densidad poblacional humana son responsables de la mayoría de las enfermedades infecciosas emergentes zoonóticas. Pronósticos de eventos emergentes indican que en los países con ambientes tropicales (como México) existe una mayor diversidad de zoonosis transmitidas por animales silvestres, por lo que debemos contener y dar rápida respuesta ante posibles brotes de dengue hemorrágico y otras fiebres hemorrágicas virales (FHV). Es importante contar con datos actualizados de las posibles áreas de distribución y ecosistemas de las especies de mamíferos (en particular roedores y murciélagos) que potencialmente pueden ser reservorios o vectores de varias de las FHV, crear modelos con información base para contener brotes de FHV, así como determinar los cambios en los ambientes y la distribución de especies afectadas por actividades humanas.

epus flavigularis Wagner 1844 (Liebre de Tehuantepec), es una especie endemica del sur de Oaxaca, Mexico. Actualmente considerada como la liebre en mayor peligro de extincion en todo el mundo. En Santa Maria del Mar, en Oaxaca, la liebre habita en pastizales abiertos, compartiendo su habitat con el ganado domestico (Bos taurus); nuestra hipotesis es que L. flavigularis prefiere establecer sus sitios de alimentacion y de descanso en potreros donde el ganado esta presente. Se registro el numero de liebres radio-marcadas y sin marcar que establecieron sus sitios de alimentacion y de descanso en potreros con presencia y ausencia de ganado bovino y se llevo a cabo un analisis composicional de la preferencia de habitat. L. flavigularis prefiere establecer sus sitios de alimentacion (ʎ = 0.8010, P = 0.0020) y sitios de descanso (ʎ = 0,6605, P = 0,016) en potreros con presencia de ganado. La seleccion de estos sitios se puede atribuir al hecho de que la presencia de ganado puede funcionar como un sistema de alarma contra posibles depredadores, mientras que el pastoreo del ganado podria en si promover especies palatables de Poaceae que forman parte de la dieta local de este leporido. Esta informacion es clave para la creacion de planes de manejo para ambas especies y su ecosistema. Se requiere un estudio a largo plazo para determinar la viabilidad de la cohabitacion de la liebre y el ganado. Proponemos que un programa de rotacion de ganado eficiente podria contribuir a la conservacion de esta poblacion de liebres

El manejo actual de los centros ecoturisticos se basa en el conocimiento intrinseco de los espacios naturales y de los recursos culturales y economicos de las comunidades locales donde se encuentran No obstante, el conocimiento y uso de indicadores que permitan el diagnostico y evaluacion de la sostenibilidad aun estan limitados. Se hace una revision sobre el uso de indicadores turisticos de sostenibilidad en Mexico y se analizan los vacios de informacion, ademas de examinar algunas implicaciones para el ecoturismo. Se propone que la construccion de un sistema de indicadores con generalidades y especificidades promoveria el manejo mas sostenible del turismo y podria representar un medio de dialogo entre los actores involucrados

Antecedentes y Objetivos: Croton guatemalensis es una especie nativa que tiene diversos usos locales y juega un papel importante en la medicina tradicional de los habitantes de las comunidades campesinas de la Selva Zoque, Chiapas, México. Actualmente, la especie se encuentra protegida por la NOM-059-SEMARNAT-2010 bajo “Protección Especial”. El presente trabajo tuvo como objetivos evaluar la morfometría, viabilidad, sanidad y germinación de semillas recolectadas en poblaciones silvestres de cuatro Áreas Naturales Protegidas de la Selva Zoque, Chiapas, así como generar información básica que permita desarrollar en un futuro programas o proyectos locales de conservación, restauración y manejo forestal de la especie, para así contribuir a disminuir el impacto sobre las poblaciones silvestres.Métodos: De noviembre 2016 a octubre 2017 se recolectó material vegetal para corroborar la identificación taxonómica de Croton guatemalensis, y frutos y semillas para determinar, bajo un diseño al azar, el tamaño (longitud × grosor), peso, porcentaje de viabilidad, sanidad y germinación de las semillas. Debido a la anormalidad de los datos resultantes, la comparación y determinación de las diferencias estadísticas entre zonas se realizó mediante los análisis de Kruskal-Wallis y Mann-Whitney, por el software R 3.24.Resultados clave: Los resultados indican que existen diferencias estadísticamente significativas entre las cuatro zonas de recolecta. Los resultados más contrastantes se presentaron en la Zona Sujeta a Conservación Ecológica La Pera y Zona Protectora Forestal Vedada Villa de Allende. En la primera, las semillas presentaron mayor tamaño (5.13±0.06 × 3.26±0.06 mm), alto porcentaje de sanidad, viabilidad y germinación final (98±2.16, 98±2.30, 98±3.84%, respectivamente), mientras que en la segunda, las semillas fueron más pequeñas (4.63±0.09 × 2.69±0.08 mm), obtuvieron 68±6.65% de sanidad, 19±5.03% de viabilidad y 6±3.84% de germinación final.Conclusión: El presente estudio aporta información reproductiva fundamental para la generación de estrategias de conservación, restauración y manejo forestal de Croton guatemalensis.

ResumenSe recolectaron 512 adultos del orden Odonata, que corresponden a 41 especies. Estas se agrupan en 24 géneros que pertenecen a las familias Calopterygidae, Coenagrionidae y Libellulidae. El porcentaje de individuos recolectados fue del 58.54% para el suborden Zygoptera y 41.46% para el suborden Anisoptera. La representatividad del muestreo de las especies esperadas a lo largo de todo el estudio varió de 75.6% para septiembre hasta 95.2% para enero. Se registra por primera vez a la especie Brachymesia herbida para Chiapas. La especie dominante fue Argia pulla, la cual se recolectó en todos los sitios. Mediante el índice de similitud de Morisita-Horn, se agruparon las especies y se relacionaron con las características del ambiente en las subregiones: alta, media y baja.AbstractFive hundred and twelve adults of the Odonata order, which correspond to 41 species were collected. These are grouped in 24 genera belonging to the families Calopterygidae, Coenagrionidae and Libellulidae. The percentage of individuals collected was 58.54% for the suborder Zygoptera and 41.46% for the suborder Anisoptera. Expected species accumulation curves ranged from 75.6% in September to 95.2% in January. Brachymesia herbida constitutes the first record for Chiapas. The dominant species was Argia pulla, which was collected at all sites. Using the Morisita-Horn similarity index, species were grouped and related to the characteristics of the environment in the subregions: high, medium and low.

Introduction: Lagomorphs (rabbits, hares, and pikas) are widely distributed in every continent of the world, except Antarctica. They include 91 species: 31 rabbits of the genera Brachylagus , Bunolagus , Caprolagus , Nesolagus , Pentalagus , Poelagus , Prolagus , Pronolagus , Romerolagus, and Sylvilagus ; 32 hares of the genus Lepus and 28 pikas of the genus Ochotona . According to the International Union for Conservation of Nature (IUCN 2014), the list of threatened species of lagomorphs includes one extinct, three critically endangered, ten endangered, five near threatened, five vulnerable, 61 of least concern, and six with deficient data. Although a rich diversity of lagomorphs and endemic species exists, some of the wild populations have been declining at an accelerated rate, product of human activities and climate change. In order to evaluate specific conservation actions for species at risk in the near future, the aim of this study is to determine the state of knowledge of endangered and critically endangered species and conservation proposals based on recent studies. This work should serve as a starting point for proposing management and habitat conservation plans for these species and filling the information gaps to address them as soon as possible. Methods: We performed an analysis of the recent trends in the state of knowledge of worldwide endangered and critically endangered lagomorphs, based on the compilation of the recent bibliographic citations in the IUCN list of endangered species (2014), the Lagomorphs Specialist Group of the IUCN web page, and on published studies focusing on these species. Each study was divided into various topics to know those that need to be addressed. We show detailed information for species that are at risk of extinction in the near future (critically endangered and endangered categories), describing the threats to their populations and existing conservation proposals. Results: A total of 13 endangered and critically endangered species of lagomorphs have been the subject of study with a total of 78 contributions, of which the most frequently represented (25) refer to phylogeny, systematics, taxonomy, and evolution, followed by conservation (18), and ecology (14); the least represented are studies of reproduction and morphology with only one each. The critically endangered and endangered species have restricted distributions and in general, their threat factors are introduction of exotic species; habitat loss due to development of human settlements and productive activities; induced fires for the growth of new grass shoots for livestock; poaching; and the presence of predators and feral dogs. Discussion and Conclusions: Worldwide human activities have affected the survival of species of lagomorphs, especially those with restricted distributions. Less than 55 % (7 species) of the total number of species of endangered and critically endangered lagomorphs has been subject of specific study in recent works (2011 to date); moreover, in some cases only one publication was found. Although recent efforts have generated knowledge about the state of conservation and threat factors of some species of endemic lagomorphs, more detailed and long-term studies are needed to propose management and conservation of their habitats in collaboration with society and different academic and institutional sectors. Key words: Conservation, endemism, hares, lagomorphs, pikas, rabbits, risk category.

Se determinó la composición anual y estacional de la diversidad de anfibios y reptiles de Montecillo Santa Cruz, municipio de San Francisco del Mar, Oaxaca, en el Istmo de Tehuantepec. Entre noviembre de 2010 y noviembre de 2011, a lo largo de 48 días de muestreo (24 en la temporada seca y 24 durante la temporada húmeda), se establecieron transectos diurnos y nocturnos de 500 metros de longitud y ancho aproximado de 10 metros en pastizal abierto, nanchal, selva baja caducifolia y vegetación riparia. En un área de 20 km2 se registró un total de 49 especies (10 especies de anfibios y 39 especies de reptiles), lo que representa el 11.52% de la herpetofauna total para Oaxaca. De éstas, 46 especies se registraron en la temporada húmeda (10 anfibios y 36 reptiles) y 37 en la temporada seca (4 anfibios y 33 reptiles). El 30.61% del total se encuentra en alguna categoría de riesgo en la NOM-059-SEMARNAT-2010, una especie está catalogada como críticamente en peligro (Ctenosaura oaxacana) en la lista roja de la UICN, y cuatro más están en el apéndice II de la CITES. A lo largo del estudio, la selva baja caducifolia fue la asociación vegetal que presentó la mayor diversidad alfa (H´ = 3.2900, 1/D = 20.6), mientras que el pastizal presentó la menor diversidad (H´ = 3.1664, 1/D = 17.14). Para las dos temporadas monitoreadas, la selva baja caducifolia presentó la mayor diversidad (H´ = 3.2900, 1/D = 20.6; H´ = 3.0850, 1/D = 17.71, respectivamente), mientras que la menor diversidad se presentó en la vegetación riparia durante la temporada húmeda (H´ = 3.1009, 1/D = 16.61), y en el pastizal (H´ = 2.7095, 1/D = 11.40) durante la temporada seca. A lo largo de todo el estudio, las asociaciones vegetales que compartieron mayor número de especies fueron la selva baja caducifolia y la vegetación riparia (J = 0.7045 y S = 0.5613), coincidiendo con los resultados estacionales (J = 0.6500 y S = 0.4921 temporada húmeda; J = 0.6333 y S = 0.4489 temporada seca). Se registró una alta diversidad en un área relativamente pequeña, por lo que puede considerarse a la zona como de importancia para la distribución de anfibios y reptiles, de ahí que sea indispensable el establecimiento de medidas de manejo y conservación para estas especies y sus hábitats.

Resumen The biological knowledge, current distribution and conservation status of the species of jackrabbits (Lepus) in risk category distributed in islands of Baja California Sur, Mexico is very useful to take specific actions for its management and conservation. The objective of this work was to spread recent results on the actual state that keep the populations from two species of Lepus with presence in the Islands Margarita and Magdalena (L. californicus magdalenae), Carmen (L. c. sheldoni), and Espiritu Santo (L. insularis). We analyzed their distribution, density, habitat, associate fauna, and human impact in their populations. Additionally, we proposed new risk categories for the species and subspecies of jackrabbits following the criteria of the method of evaluation of extinction risk for the wild species in Mexico (MER), and were included data on their behavior, food habits and signs of reproductive activity.

It has been recognized the need for studies to determine the long-term viability of populations of endangered species, such as the Tehuantepec jackrabbit ( Lepus flavigularis ) populations. Currently the total population is estimated at less than 1000 individuals. We developed a viable population analysis to determine the extinction risk of the Tehuantepec jackrabbit population of Santa Maria del Mar, Oaxaca. A total of 31 scenarios were modeled in order to test independent and combined effect of flooding, predation by domestic dogs and poaching; also we tested the effect of inbreeding depression and a hypothetical reintroduction program. The results show that the Tehuantepec jackrabbit population is at high risk of extinction. The population survived over the 500 years of simulation only in the model which involved the hunt, besides the base model. The effects of the three catastrophic scenarios in combination, as well as the inbreeding, increased the risk of extinction up to 100% and an average of 41.60 ± 25.88 years. Based on our results, we propose that conservation and management strategies should include the elimination of threats that affect the Tehuantepec jackrabbit, as well as improvement of habitat quality. Also, assess the relevance of a translocation program with individuals from other populations.

We evaluated breeding season and breeding behavior of two populations (Los Angeles and La Perforadora) of the Mexican prairie dog (Cynomys mexicanus) in northeastern Mexico during January–June 2002 and 2003. We observed 18 coteries in each colony. The breeding season began at the end of January and extended into late April for both colonies. Males were sexually active January–March, and females were in estrus in early March. However, 7 and 10 mature females in La Perforadora and Los Angeles, respectively, underwent estrus in mid-February. Gestation lasted from early March to early April, parturition occurred in early April, and weaning occurred in late April. Infanticide was not observed. Mature females and dominant males of each coterie cut fresh vegetation, possibly for construction of the nest inside the burrow. A series of sexual-mounting exercises occurred outside burrows between young of the same coterie. We describe fights that occurred frequently between adults after the young emerged fro...

Oaxaca hosts one of the greatest biodiversity in México, occupying first place in avian diversity compared to other regions of the country. However, the area is undergoing serious problems such as high deforestation rates, soil erosion and over exploitation and extinction of species. These factors have all contributed to the current loss of biodiversity. Also, biological inventories are still incomplete. One of the least explored sites is the semiarid zone of Tehuantepec isthmus, around the locality of Santa Maria del Mar, Oaxaca, México. The area includes floodable grasslands, mangrove areas and dry forest, providing a range of potential habitats for different species. Our objective was to evaluate the effect of temporal lakes on spatial and temporal composition of the avifauna in Santa Maria del Mar, in order to generate information regarding this group within the region and the state, and to understand the importance of flood areas for resident and transitory birds. We conducted 12 avifauna surveys between July 2006 and June 2008, and established two transects of 2km length in each of four habitat types (beach, grassland, dry forest, and mangrove). We found a total of 75 species, corresponding to 16 orders and 30 families. Within an area of 26km2, we significantly found 10.1% of the total number of bird species recorded for the entire state, and 6.6% of the total reported in Mexico. The families most represented were: Ardeidae, Laridae and Scolopacidae. Over the entire study period, dry forest was the most diverse habitat; followed by mangrove, grassland and the beach. Of all the species recorded, 38.6% were found at the edge or in the temporal lakes. We found a significant difference in species composition between seasons in the grassland, but no difference in the other habitats. Our results showed a significant effect of temporary lakes on avian diversity during the wet season; it also demonstrated the importance of grassland conservation given its relevance for presence of waterbirds. We suggested a continued and more intense monitoring; and proposed the designation of the area as an Important Conservation Bird Area (AICA). Tamara Rioja-Paradela1,2, Arturo Carrillo-Reyes1,2 & Eduardo Espinoza-Medinilla1 1Sustentabilidad y Ecología Aplicada, Universidad de Ciencias y Artes de Chiapas. Libramiento Nte. Pte. 1150, Col. Lajas Maciel, Tuxtla Gutiérrez, Chiapas, México; tamararioja@gmail.com, arturocarrilloreyes@gmail.com, eduardo.espinoza@unicach.mx2Oikos: Conservación y Desarrollo Sustentable, A.C., Bugambilias 5, Col. Bismark, San Cristóbal de las Casas, Chiapas, México

The persistence of reptile populations in a specific location is influenced by individuals' capacity to regulate their body temperatures, among other factors. Anthropogenic climate change may pose a risk to the survival of ectothermic animals due to their dependence on external heat sources to thermoregulate. In this study, we calculated indices of thermal habitat quality, thermoregulatory precision, and thermoregulatory effectiveness for the endemic spiny-tailed iguana Ctenosaura oaxacana. We evaluated these indices and the thermoregulatory behavior of the iguanas in the four types of vegetation that provide the most favorable conditions for thermoregulation. We also performed our experiments during both the wet and dry seasons to capture the full range of thermal conditions available to C. oaxacana over the course of a year. Finally, we evaluated the potential niche for the iguana in the years 2020, 2050, and 2080. Thermoregulation depends on both seasonal and environmental factors in this species. We found that thermoregulation effectiveness in both wet and dry seasons depends not only on the thermal conditions of the immediate environment, but also on the cover vegetation and habitat structure available across the range of habitats the species uses. Thus, heterogeneous habitats with dispersed vegetation may be most suitable for this species' thermoregulatory strategy. Likewise, niche modeling results suggested that suitable habitat for our study species may continue to be available for the next few decades, despite global warming tendencies, as long as cover vegetation remains unaltered. Our results suggest that thermoregulation is a complex process that cannot be generalized for all ectothermic species inhabiting a given region. We also found that temperature changes are not the only factor one must consider when estimating the risk of species loss. To understand the necessary thermal conditions and extinction risk for any ectothermic species, it is necessary to focus studies on the species' general ecology.

Southern Mexico is well known for its high biodiversity (CONABIO, 2008). This biodiversity is a result of several factors like its geographic position, geographic diversity, and physiographic richness (Ferrusquilla-Villafranca, 1998). In particular, Chiapas, Mexico's southernmost state holds seven physiographic zones, including valleys, mountain chains, plateaus, and coastal plains (Mullerried, 1957). Most of this biological richness is to be found in the eastern moist forest, northern mountains, central plateau, and Sierra Madre (Breedlove, 1981). The Sierra Madre mountain chain harbors some of the very last patches of Cloud Forest, which is one of the most endangered ecosystems both in Mexico and at a global scale (Challenger, 1998; Toledo-Aceves et al., 2010). Fortunately, three existing biosphere reserves namely El Triunfo, La Sepultura and Volcan Tacana, aim to protect and maintain this highly threatened ecosystem. As elsewhere, natural areas compete for land with human activities such as agriculture and cattle ranching, recently, climate change has added up to the list of threats. Only at El Triunfo reserve between 1983 and 1993 were lost 8,946 ha, including 5,084 ha of Cloud Forest (March & Flamenco, 1996). As a region, the Sierra Madre de Chiapas, was between 1998 and 2005, the region that suffered the greatest impact related to climate change in the form of massive landslides. For example, more than 15,000 ha of Cloud Forest were affected in Chiapas by Hurricane Isis (Richter, 2000), while this phenomenon has also occurred in other parts of the Americas (Restrepo & Alvarez, 2006). The loss of forest cover in the upper parts of the mountain chain generates a reduction of water retention and filtering capability which results in soil loss and consequently in river sedimentation. This also has occasioned an increment of water flow volume which augments flood risk. One way to help to reduce flood risk is through the ecological restoration of forest systems in the upper basin, and subsequent recovery of the ecological services associated to forest. Hence, information on the structure of natural plant communities, including structure and floristic composition, is central to establish sound ecological restoration strategies and policies. Our research objective, was thus, to evaluate and analyze the natural successional process in a cloud forest along a successional gradient