Estructura, composición y diversidad de la selva baja caducifolia del Cerro Verde, Nizanda (Oaxaca), México

Boletín de la Sociedad Botánica de México (Impact Factor: 0.8). 01/2005; 76.
Source: DOAJ


En este estudio se describe la estructura, la composición florística y los patrones de diversidad de la selva baja caducifolia del Cerro Verde, localizado en Nizanda (Istmo de Tehuantepec, Oaxaca, México). En 30 parcelas de 100 m2 se censaron las plantas leñosas con DAP ≥ 1 cm (estrato alto), y en cinco subcuadros de 4 m2 dentro de cada una se censaron las plantas con DAP < 1 cm, pero con altura > 30 cm (estrato bajo). Se encontraron 194 especies distribuidas en 52 familias. La riqueza de especies fue idéntica en ambos estratos (145 especies), y cada uno aportó de manera exclusiva ca. 25% de la riqueza total registrada. Leguminosae fue la familia más rica en especies (27), seguida por Asteraceae (20) y Euphorbiaceae (18). Las especies más frecuentes fueron Bursera simaruba + B. aff. cinerea (no distinguidas en el campo), Euphorbia schlechtendalii, Pilosocereus collinsii y Capparis verrucosa. La riqueza específica promedio por cuadro fue de 30 especies. Los índices basados en la riqueza y la abundancia de las especies (Berger-Parker = 0.20; Simpson = 0.09; α de Fisher = 9.47; Shannon = 2.78; equitatividad = 0.82) indican una alta diversidad y una consecuente baja dominancia en esta selva. Los valores extrapolados mostraron una densidad total (estratos alto + bajo) de 23,950 ind. ha-1 (830 ind. ha-1 con DAP ≥ 10 cm), una cobertura de 446.7%, y un área basal de 53 m2 ha-1. La altura promedio del 10% de los árboles más altos fue 9.1 m. La estructura de la selva baja del Cerro Verde es semejante a la de otras comunidades vegetales del trópico seco de México y denota un buen estado de conservación. Este hecho, aunado a su particular composición florística, enfatiza la pertinencia de su conservación formal.


Available from: Jorge A. Meave, Aug 01, 2014
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    • "Location of the study site in Oaxaca state, southern Mexico to the preparation of the regional floristic inventory, vegetation was sampled in 188 100-m 2 plots surveyed in different vegetation types; although minor sampling variants existed among them (Lebrija-Trejos 2001; Pérez-García and Meave 2004; Gallardo-Cruz et al. 2005; Sierra-Huelsz 2005), presence-absence data are comparable. For comparative purposes, we constructed a single database for all species recorded in the sampling. "
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    ABSTRACT: We updated the floristic checklist of the Nizanda region, Isthmus of Tehuantepec (southern Mexico), characterized the occurring plant communities based on dominant species, and described the region’s flora according to life form, growth form, growth type, and growth habit spectra. Ten years of botanical exploration, along with surveys in 188 100-m2 samples from different vegetation types, provided the baseline floristic information. Ordination and classification analyses were performed to examine the degree of differentiation between communities. Geographical ranges of all species were used to assess biogeographical relationships of this flora. The inventory includes 920 species (553 genera, 124 families). More than one-third of the families were represented by a single species, whereas the 10 richest families had 43% of the species richness. Dendrograms showing plot classification at three taxonomic levels (species, genus and family) revealed savannah as the most strongly differentiated community amid seven vegetation types. Regarding growth forms, forbs and trees prevailed. Phanerophytes were the most common life form category, whereas herbs and woody plants were the dominant growth types. The largest richness for all taxonomic levels was recorded in the tropical dry forest. The expanded floristic knowledge gained for the Nizanda region provided better criteria to revise the classification scheme of its vegetation. Our preliminary biogeographical analysis illustrates the role of the Isthmus of Tehuantepec as a corridor for thermophilous floras between two oceanic watersheds, and as a natural distributional limit for several Mesoamerican plant species. KeywordsIsthmus of Tehuantepec-Life-form spectrum-Phytogeography-Plant communities-Savannah-Seasonally dry tropical forest-Thermophilous flora
    Folia Geobotanica 06/2010; 45(2):143-161. DOI:10.1007/s12224-010-9064-7 · 1.78 Impact Factor
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    • "At the highest zones of Mt. Cerro Verde slopes are steep and soils very shallow, all of which considerably limits plant growth (Gallardo-Cruz et al. 2005). Moreover, wind turbulence typical of the upper reaches of the mountains (Huggett 1995; Beniston 2000), which on this mountain is particularly strong due to the high speed of the Trade Winds in this region (Romero-Centeno et al. 2003), may cause significant reductions in plant cover due to the shear force of the wind (Grace 1981). "
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    ABSTRACT: Topography strongly affects the distribution of insolation in the terrain. Patterns of incoming solar radiation affect energy and water balances within a landscape, resulting in changes in vegetation attributes. Unlike other regions, in seasonally dry tropical forest areas the potential contribution of topography-related environmental heterogeneity to β-diversity is unclear. In Mt. Cerro Verde (Oaxaca), S. Mexico, we: (1) modelled potential energy income for N- and S-facing slopes based on a digital elevation model, (2) examined the response of vegetation structure to slope aspect and altitude and (3) related variations in plant diversity to topography-related heterogeneity. Vegetation survey and modelling of potential energy income (SOLEI-32 model) were based on 30 plots equally distributed among three altitudinal belts defined for each slope of the mountain; combining the three altitudinal belts and the two slopes produced six environmental groups, represented by five vegetation plots each. Potential energy income was about 20% larger on the S than on the N slope (9,735 versus 8,138MJ/m2), but it did not vary with altitude. In addition, the temporal behaviour of potential energy income throughout the year differed greatly between slopes. Vegetation structure did not show significant changes linked to the environmental gradients analysed, but altitude and aspect did affect β-diversity. We argue that the classic model of slope aspect effect on vegetation needs reconsideration for tropical landscapes.
    Landscape Ecology 04/2009; 24(4):473-482. DOI:10.1007/s10980-009-9332-1 · 3.50 Impact Factor
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    ABSTRACT: We analyzed successional patterns in a very dry tropical deciduous forest by using 15 plots differing in age after abandonment and contrasted them to secondary successions elsewhere in the tropics. We used multivariate ordination and nonlinear models to examine changes in composition and structure and to estimate forest recovery rates and resilience. A shrub phase characterized early succession (0¿3 yr); afterwards, the tree Mimosa acantholoba became dominant. Below its canopy, sprouts and seed-regenerated individuals of mature forest species slowly accumulated. Canopy height, plant density, and crown cover stabilized in less than 15 yr, whereas species richness, diversity, and basal area continued to increase. The pioneer species group has very low diversity and the long-lived pioneer phase typical of humid forests is absent; species composition may therefore recover soon as suggested by convergence toward mature forest species composition. The time trend of plant density also differed from humid forests for it lacked its characteristic density decline, presumably because of differences in regeneration mechanisms between very dry and other less water-stressed forest types. As opposed to the prevailing hypothesis, resilience was not higher than in moister forests, and thus factors other than structure relative simplicity must be accounted for when assessing resilience
    Biotropica 07/2008; 40(4):422-431. DOI:10.1111/j.1744-7429.2008.00398.x · 2.08 Impact Factor
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