Land-use changes in the Chignahuapan-Zacatlán region of the state of Puebla, Mexico, and in each of the two aforementioned counties, were determined using Landsat imagery and a bitemporal analysis of the period 1986-2011. The predominant land uses at the regional level are the agricultural (49.7 %) and forest (46.1) groupings. In the case of Chignahuapan county, agricultural use is the main activity with 58.9 % of the territory, while in Zacatlán county the predominant activity is forest use with 57.3 % of the land base. At the regional level and for Zacatlán county, the probabilistic model of forest land-use change was significantly correlated (P ≤ 0.05) with 21 independent variables; however, for Chignahuapan, the model only considered 16 variables. At the regional level, the probability of forest land changing to other uses ranged from 5-90 % and at the county level from 7-99.8 %. Finally, the projection for the year 2030 estimates that the deforestation risk at the regional level and in Chignahuapan and Zacatlán counties is 13,063.8, 10,966.6 and 4,405.5 ha, respectively.

     This study was conducted in a burned Pinus-Quercus forest in Chipinque Ecological Park (NE Mexico), where several restoration measures were implemented after a wildfire. The main objectives of the study were to evaluate the establishment of planted Pinus pseudostrobus (Lindl.) seedlings, and analyze the effect of contour-felled logs on soil retention, ten years after treatment implementation. A 35 % plantation survival rate, which is considered unacceptable, was recorded. Contour-felled logs significantly improved soil retention, increasing soil depth by 25%. We conclude that post-fire restoration measures were successful and their use in the rehabilitation of burned Pinus-Quercus forests in Sierra Madre Oriental is recommended as they contribute to the establishment of a key species and reduce soil loss.

   Morphometric variation and leaf symmetry was characterized in a population of Platanus mexicana along a riparian altitudinal gradient in Veracruz. A total of eight morphometric characters were evaluated in 1,800 leaves from 15 trees per site, collected at 70, 200, 600 and 1,700 m. Morphometric differences among sites (F (24, 5189) = 21.1, P < 0.05) were determined using a discriminant function analysis. Characters related to length and width of leaves showed significant intrapopulation differences (P ≤ 0.05). Based on Mahalanobis distances, the site located at 70 m is the most distant morphometrically. Cluster analysis showed ten different leaf groups along the altitudinal gradient. Differences in leaf size were observed, the leaves are larger at 70 m and decrease with altitude. The index of leaf symmetry of P. mexicana showed no significant differences (P > 0.05) among sites in the altitudinal gradient of the Colipa river. The results determine the responsiveness of P. mexicana to the environmental heterogeneity along the altitudinal gradient of the Colipa river.

Statistical nonlinear mixed effect models were used to predict relationships between the total height and diameter at breast height of individual trees in Oriental beech (Fagus orientalis Lipsky) stands in Kestel, Bursa, Northwestern Turkey. 124 sample plots were selected to represent various stand conditions such as site quality, age, and stand density. Nine generalized nonlinear height–diameter models were fitted and evaluated based on Akaike’s information criterion, Schwarz’s Bayesian Information Criterion (BIC), Root Mean Square Error (RMSE), Absolute Bias and Adjusted Coefficient of Determination (R2adj). The nonlinear Schnute’s model was selected as the best predictive model. The height–diameter model based on the nonlinear mixed effect modeling approach accounted for 90.6 % of the total variance in height–diameter relationships and root mean square error (RMSE) values of 1.48 m. Various sampling scenarios that differed in sampling design and size of the selected sub-sample trees from the validation data set revealed that four randomly selected sub-sample trees in a given plot produced the best predictive results (43.3 % reduction of the sum of square errors, 98.4 % reduction of absolute bias, and 36.9 % reduction of the RMSE) in relation to the fixed effect predictions.

The aim of this study is to assess the dynamics and processes of change that have occurred in the municipality of Amanalco de Becerra, State of Mexico, through the construction of a spatially explanatory model of land use/cover changes (LUCC). The modeling process was carried out using DINAMICA EGO, a mapping tool. Land use/cover maps for the years 1989, 1997 and 2009, as well as various explanatory physical-geographical, environmental and land tenure proximity variables, were used as map inputs. The LUCC for 2020 were modelled under two scenarios: 1) the trend model, which assumes that the annual change rates for the period 1997-2009 remain unaltered, and 2) the agropastoral model, which assumes that annual deforestation rates increase because of the establishment and development of farming activities. The analysis of the absolute values of the forest category, for each year, shows a trend towards the loss of forest cover; by contrast, the annual rates of change in the forest category show a trend towards recovery-revegetation-reforestation processes, as a result of the implementation of government environmental programs. 

The diameter distribution of 44 permanent plots (conifers and broadleaf trees) was modeled using the three-parameter Weibull and Johnson’s SB probability density functions (PDFs) in Santiago Papasquiaro, Durango. Four different methods of fitting parameters were used: maximum likelihood (ML), moments (MM), non-linear regression by ordinary least squares (ONLS) and percentiles (MP). The best method of fitting parameters for conifers and broadleaf trees was the method of moments. In modeling the Weibull PDFs, it was assumed that the location parameter (e) corresponds to the minimum measurable diameter. The scale parameter (λ) was modeled using the method of prediction parameter (PPM) through a linear regression relating to the quadratic mean diameter and dominant height of the stand. Finally, the shape parameter (γ) was indirectly recovered by the method of moments through prediction of the average diameter of the stand. According to the Kolmogorov-Smirnov test (P= 0.05), 71 % of the plots for the group of conifers and 68 % of the plots for the group of broadleaf species come from a population that follows the fitting distribution function.