Crown morphometry for Quercus crassifolia Humb. & Bonpl. and Quercus rugosa Née in Hidalgo, Mexico

Quercus crassifolia y Quercus rugosa son especies de importancia ecológica y económica por su distribución geográfica, intervalo altitudinal, abundancia en regiones montañosas y plasticidad. Sin embargo, la gestión y aprovechamiento forestal han sido incompatibles con las necesidades ecológicas de cada especie de Quercus, en parte por la falta de herramientas silvícolas cuantitativas. Por tal motivo, se plantearon los objetivos de i) determinar los índices morfométricos (IM) y su correlación con el diámetro normal (dn), altura total (At), diámetro de copa (dc) y altura de fuste limpio (Afl); y ii) ajustar con Modelos de Efectos Mixtos (MEM), las características de la copa de Quercus crassifolia y Quercus rugosa en función del dn, con la inclusión de la covariable altitud. Con información dasométrica de 128 sitios de muestreo distribuidos en 32 conglomerados en bosques de clima templado del estado de Hidalgo, se calcularon y correlacionaron ocho IM mediante el coeficiente de Pearson. Además, se ajustaron con MEM los modelos de Schumacher, Alométrico y Lineal para estimar el dc, área de proyección de copa (Apc) y proporción de la copa en porcentaje (pc%), respectivamente. Para Quercus crassifolia, por cada metro que crece el radio de copa se tiene un incremento de 8,8 cm en dn, mientras que en Quercus rugosa el aumento es de 9,8 cm. El índice de esbeltez promedio es de 0,53 y 0,51, respectivamente. La correlación de Pearson entre variables dasométricas e IM con la forma de copa fue de -0,61 y para la altura total, Apc, dc y pc% con el dn resulto >0,64, ambos para las dos especies. Los MEM fueron estadísticamente robustos y sin violaciones de los supuestos de regresión. La información silvícola generada puede ser referencia para planear las actividades de gestión y monitoreo en los rodales Quercus crassifolia y Quercus rugosa.Quercus crassifolia and Quercus rugosa are species of ecological and economic importance due to their geographical distribution, altitudinal range, abundance in mountainous regions, and plasticity. However, forest management and exploitation have proven incompatible with the ecological needs of each Quercus species, partly due to the lack of quantitative silvicultural tools. For this reason, the following objectives were established i) to determine the morphometric indices (MI) and their correlation with the normal diameter (dn), total height (At), crown diameter (dc) and clean stem height (Afl); and ii) to adjust with Mixed Effects Models (MEM), the characteristics of the Quercus crassifolia and Quercus rugosa crown as a function of dn, with the inclusion of the altitude covariate. With dasometric information from 128 sampling sites distributed in 32 clusters in temperate climate forests of the state of Hidalgo, eight MI were calculated and correlated using the Pearson coefficient. In addition, the Schumacher, Allometric and Linear models were adjusted with MEM to estimate the dc, crown projection area (Apc), and crown proportion in percentage (pc%), respectively. For Quercus crassifolia, for every meter that the crown radius grows there is an increase of 8.8 cm in dn, while in Quercus rugosa the increase is 9.8 cm. The average slenderness index is 0.53 and 0.51, respectively. The Pearson correlation between dasometric variables and MI with the cup shape was -0.61 and for the total height, Apc, dc and pc% with the dn it was >0.64, both for the two species. The MEMs were statistically robust and without violations of the regression assumptions. The silvicultural information generated can be a reference to plan management and monitoring activities in the Quercus crassifolia and Quercus rugosa stands

Conceptual proposal of the landscape as an environmental indicator for the spatial and temporal study of the territory

Objective: To propose the landscape as an environmental indicator that describes, analyzes and spatially and temporarily evaluates a territory, through changes in natural, social, economic and cultural components. Approach: Different methodological concepts of the landscape and environmental indicator were reviewed, as well as their characteristics to describe and evaluate the environment. Results: It was found that the landscape is a comprehensive analysis method for the study of the environment, by selecting the parameters that describe and represent each landscape, through shape, size, colors, textures, shadows, patterns, situations, associated features and structures arranged under a spatial and temporal order, which when perceived by man, present a certain form of organization or disorganization in the environment. Implications: The environmental indicator allows analyzing and evaluating changes in space and time, with updated qualitative and quantitative research, these changes play an important role in building the perception of environmental problems through the landscape. Conclusions: The landscape is an integral component that describes the biotic and abiotic elements that make up a space. While, as an environmental indicator, it analyzes and evaluates the change in the composition and configuration of the environment spatially and temporally.Objective: To propose the landscape as an environmental indicator that spatially and temporally, describes, analyzes, and evaluates territory, by changing some natural, social, economic, and cultural components. Approach: Different methodological concepts of the landscape and environmental indicators were reviewed, as well as their characteristics to describe and evaluate the environment. Results: It was found that the landscape is a comprehensive analysis method for the study of the environment, by selecting the parameters that describe and represent each landscape, through shapes, size, colors, textures, shadows, patterns, situations, associated features, and structures arranged under a spatial and temporal order which, when perceived by humans, present a given form of organization or disorganization in the environment. Implications: The environmental indicator allows to analyze and evaluate the changes in space and time, with updated qualitative and quantitative research. These changes play an important role in building the perception of environmental problems through the landscape. Conclusion: Landscape is an integral component that describes the biotic and abiotic elements of a given space. While, as an environmental indicator, it analyzes and evaluates changes in the composition and configuration of the environment, both spatially and temporally