Regeneration patterns in relation to canopy species composition and site variables in mixed oak forests in the Sierra de Manantlán Biosphere Reserve, Mexico

Abstract

Regeneration patterns in relation to canopy species composition and site variables were analyzed in mixed oak forests of the Sierra de Manantlán in western Mexico with the aim of establishing an ecological basis for the design of management alternatives. Using ordination (canonical correspondence analysis) and classification (two‐way indicator species analysis) methods, five different canopy types and three different seedling associations were revealed according to species composition, all of them dominated by one or more oak species. Red–far red ratio, slope, altitude, topography, canopy type and grazing intensity were the main variables that explained differences in species composition among the seedling associations. Oak seedlings were relatively scarce in the sampling plots, with the lowest frequency values of all species recorded except for those of Quercus crassipes Humb. & Bonpl., and also the lowest density values. The presence of a particular oak seedling species was strongly associated with a particular percentage of canopy openness; Quercus candicans Née, Quercus laurina Humb. & Bonpl. and Quercus rugosa Née were present in the plots with the least‐open canopy (6.4%, 2.9 and 6.2%, respectively), while Quercus castanea Née and Quercus crassipes Humb. & Bonpl. were present in the plots with the most‐open canopy (13 and 8.1%, respectively). Every oak seedling species was more frequent, although not dependent, on the canopy type where the same oak species dominated. Because of the great heterogeneity in species composition and the physiographical factors of mixed oak forests in the Sierra de Manantlán, we concluded that management alternatives must be prescribed for each ecological situation where the different oak species are growing.

Modeling the Effect of Climate Change on the Distribution of Oak and Pine Species of Mexico

“…The only available studies are those related to seedling development under disturbed versus undisturbed forest conditions. Reportedly Q. laurina and Q. rugosa seedlings need a closed canopy to grow in upland forests of Jalisco, whereas Q. castanea can be found in plots with open canopies (Figueroa‐Rangel & Olvera‐Vargas 2000). Adaptation to disturbed environmental conditions has also been documented for Q. crispipilis (Quintana‐Ascencio et al 1992).…”

The combined role of topography and overstorey tree composition in promoting edaphic and floristic variation in a Mediterranean forest

“…In addition, the physical and chemical properties of the leaves determine the quality and quantity of organic debris and litter accumulation. This in turn affects the input of mineral nutrients into the forest floor (e.g., Ross et al 1986;Figueroa-Rangel and Olvera-Vargas 2000;Gallardo 2003). Therefore, we hypothesise that, besides the direct influence of the topography over species composition and abundance, overstorey species and community structure also influence environmental factors, and through the environmental factors, overstorey species and community structure may also play a role in determining floristic-environmental variation.…”

Una población relicta de Acer saccharum subsp. skutchii (Aceroideae) en el estado de Guerrero, México

“…se midieron los diámetros a la altura de 1.3 m (dap) de las plantas leñosas ≥1 cm (dap). También se registraron las alturas de plántulas (individuos ≤130 cm de altura) e individuos juveniles (<1 cm dap y ≥130 cm de altura) de arce azucarero en un círculo interior de 5.64 m de radio, concéntrico con el principal de 10 m. El criterio utilizado para el registro de alturas siguió a Olvera-Vargas et al (1996) y Figueroa-Rangel y Olvera-Vargas (2000. Se calculó el porcentaje de individuos ≥1 cm por categoría diamétrica y el porcentaje de individuos de plántulas e individuos juveniles por categoría de alturas.…”