Hurricane impact on Thalassia testudinum (Hydrocharitaceae) beds in the Mexican Caribbean.Hurricanes have increased in strength and frequency as a result of global climate change. This research was conducted to study the spatio-temporal distribution and changes of Thalassia testudinum, the dominant species in Bahia de la Ascension (Quintana Roo, Mexico), when affected by heavy weather conditions. To complete this objective, a 2001 Landsat ETM+ image and the information from 525 sampling stations on morpho-functional and coverage of T. testudinum were used, and the seeds generated for the classification of eight benthic habitats. To quantify the changes caused by two hurricanes, we used two images, one of 1988 (Gilberto) and another of 1995 (Roxanne); other three data sets (2003, 2005 and 2007) were also used to describe the study area without major weather effects. Six categorial maps were obtained and subjected to analysis by 8 Landscape Ecology indexes, that describe the spatial characteristics, structure, function, change of the elements (matrix-patch-corridor), effects on ecosystems, connectivity, edges, shape and patch habitat fragmentation. Models indicate that T. testudinum may be classified as a continuum (matrix), since the fragments were not observed intermittently, but as a progression from minimum to maximum areas in reference to their coverage (ecological corridors). The fragments do not have a regular shape, indicating that the impacts are recent and may be due to direct effects (high-intensity hurricanes) or indirect (sediment). Fragments of type "bare soils" have a discontinuous distribution, and are considered to be the sites that have remained stable over a long timescale. While more dense coverage areas ("beds", "medium prairie" and "prairie") have low fragmentation and high connection of fragments. Features have an irregular perimeter and radial growth of formal; suggesting that the impact of meteors has no effect on the resilience of T. testudinum in this ecosystem, indicating good environmental quality to grow in this bay. Rev. Biol. Trop. 59 (1): 385-401. Epub 2011 March 01.

ABSTRACT. Conspicuous sedimentary deposits forming well-structured and prominent submarine dunes are found on the coast of Yucatan (Mexico), close to the ports of Dzilam de Bravo, San Felipe, and El Cuyo. The objective of this study was to evaluate the morphological and sedimentological features of these submarine dunes. Sub-bottom seismologic profiles were obtained and standardized sedimentological analyses were performed on sediment samples collected at the three study sites. Both the height and wavelength of dunes were different between the three sites, mean heights ranging from 0.84 to 2.28 m and mean wavelengths from 98 to 330 m. Most of the dunes showed a wellmarked asymmetry, which is related to the direction of their movements. Their granulometric composition was dominated by medium, moderately well-sorted sand. This study provides bases for future systematic monitoring of these peculiar ecosystems, including information to be considered for the evaluation of their ecological role in the marine system.Key words: dune field, dune morphology, sub-bottom profiles, sedimentology. RESUMEN.En la costa del estado de Yucatán existen áreas con campos conspicuos de depósitos sedimentarios que forman dunas submarinas bien estructuradas y sobresalientes, aledaños a los puertos de Dzilam de Bravo, San Felipe y El Cuyo. El objetivo de este trabajo fue evaluar la morfología y las características sedimentológicas de estas dunas sumergidas. Para esto, se obtuvieron perfiles sismológicos del subfondo y se realizaron análisis sedimentológicos estandarizados de muestras recolectadas en los tres sitios de estudio. Tanto la altura de las dunas como su longitud de onda fueron diferentes entre los tres sitios, donde se registraron dunas de entre 0.84 y 2.28 m de altura y con longitudes de onda promedio entre 98 y 330 m. La mayoría de las dunas mostró una asimetría bien marcada, que está relacionada con el sentido en que se mueven. En su composición granulométrica dominó el sedimento superficial del tipo arena media moderadamente bien clasificada. Este trabajo sienta bases para el monitoreo sistemático de estos ecosistemas peculiares, incluyendo información para considerarse en la evaluación del papel ecológico que desempeñan en el sistema.Palabras clave: campos de dunas, morfología de dunas, perfiles del subfondo, sedimentología.

We assessed the diversity, vertical distribution, and the effect of structural and geographical factors on the diversity of vascular epiphyte assemblages (VEAs) in two forest types in the “El Cielo” Biosphere Reserve. We found 2839 epiphyte individuals from 15 species on 240 host trees (27 species) in the semideciduous forest and 5085 individuals from 8 species on 215 host trees (12 species) in the pine–oak forest. Epiphytes showed a preference for the middle zone of the host trees. The diversity of VEAs was uneven in both forest types, although the VEA in the semideciduous forest was the most diverse. VEAs across forests were slightly similar in their composition (30% mean overlap), but very different in their structure (i.e., they did not share very abundant species). The variation in species richness among VEAs was influenced by forest structure, independently of forest type. Compositional differences of VEAs among forest types were explained by geographic distance and host-tree identity (31% and 28% variation explained, respectively). By characterizing the diversity of VEAs we provide a basic understanding of the factors influencing epiphyte diversity in these understudied ecosystems.

REVIEW 1 research, Trends on mexican ethnozoological vertebrates case: a systematic review ABSTRACT Systematic reviews and meta-analytical approach are a tool used in different social and biological disciplines, but its application in evaluating ethnobiological information is scarce. Thus, through this analytical approach, we seek to answer if there are any patterns in the mexican ethnozoological scientific production. We searched for studies published between 2005 and 2015 in catalogues, repositories and databases. For evaluating significative differences among seven variable datasets, we first used non parametric Kruskal-Wallis tests and then Tukey multiple comparison tests. We also determined the link between researchers and institutions with a multidimensional non-metric scaling analysis. We found 295 published studies, book chapters were the most representative (27%), diffusion articles (20%), impact factor articles (15%) and indexed articles (14%). There are significant differences in the number of publications among the evaluated years, among thematic areas, study focus (qualitative/quantitative), ethnographic and biological methods. Regarding academic linking, we identified 94 author adscription institutions, however, no research networks were identified. Our results suggest that the amount, diffusion and reach of mexican ethnozoological production show a tendency to non-periodic publishing, predilection for qualitative approach, a low use of statistical and ethnobiological analysis, as well as an inadequate selection of biological methods. We suggest this data analysis approach will allow a better standardization for information taking and processing, aiding the discipline in its growth and consolidation.

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Vascular epiphytes contribute significantly to tropical diversity. Research on the factors that determine vascular epiphytic diversity and composition in tropical areas is flourishing. However, these factors are entirely unknown in tropical-temperate transition zones, which represent the distribution limit of several epiphytic species. We assessed the degree to which climatic and structural variables determine the diversity of vascular epiphytic assemblages (VEAs) in a transition zone in Mexico: the El Cielo Biosphere Reserve. We found 12,103 epiphytic individuals belonging to 30 species and 15 genera along a climatic gradient from 300 to 2,000 m a.s.l. Bromeliaceae and Orchidaceae were the most species-rich families. Forests along the windward slope of the Sierra Madre Oriental (semideciduous forest and tropical montane cloud forest) had higher species richness than forests along the leeward slope (pine-oak forest and submontane scrub). Species richness was largely determined by seasonality and, to a lesser degree, by forest structure, whereas abundance was mainly determined by host tree size. Variation in VEAs composition was largely explained by climatic variables, whereas forest structure was not as important. VEAs differed among forest types and slopes in terms of taxonomic and functional composition. For example, certain bromeliad indicator species reflected differences between slopes. Although within-tree epiphytic species richness (alpha diversity) was low in this transition zone relative to other habitats, species turnover among forest types (beta diversity) was high. These findings suggest that each forest type makes a unique and important contribution to epiphytic diversity in this transition zone.

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