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Victoria de Durango, Mexico

Navar J.,Technological Institute of Ciudad Victoria | Dominguez-Calleros P.A.,Universidad Juarez del Estado de Durango | Rodriguez-Flores F.J.,Technical University Durango | Lizarraga-Mendiola L.,Autonomous University of the State of Hidalgo | de Hoogh R.,International Agricultural Center
Mathematical and Computational Forestry and Natural-Resource Sciences | Year: 2016

The aim of this research was to develop a growth and yield model for predictions of the basal area and timber volume of reforested stands in degraded, arid, semi-arid and dry-temperate lands of northern Mexico. In total, 124 forest stands (chronosequences) were sampled for allometric features (basal and breast height diameter, canopy height and canopy cover); data from 75% of the stands were used for model tting and data from the remaining 25% of the stands were used for the model validation. The potential timber volume and basal area growth were determined for each reforested species. The growth rates of reforested native coniferous species in the states of Durango (P. durangensis Martinez, P. cooperi C.E. Blanco, and P. engelmannii Carriere) and Nuevo Leon (P. pseudostrobus Lindl.) were higher than those of pine species not native to south Central Durango (P. arizonica Engelmann), eastern Nuevo Leon (P. cembroides Zucc., P. pinceana Gordon, and P. nelsonii Shaw) and Coahuila (P. halepensis Mill.). Because forest stands are often reforested at high seedling densities, the productivity is higher than that of pre-existing native forests communities. Therefore, this practice is recommended in order to increase timber stocks and the productivity of Mexico's degraded temperate and semi-arid forests. © 2016 Publisher of the Mathematical and Computational Forestry & Natural-Resource Sciences. Source

Navar J.,National Polytechnic Institute of Mexico | Rodriguez-Flores F.D.J.,Technical University Durango | Dominguez-Calleros P.A.,Universidad Juarez del Estado de Durango | Perez-Verdin G.,National Polytechnic Institute of Mexico
International Journal of Ecology | Year: 2014

This research examines the diversity-productivity relationship in a semiarid scrubland, initially under late successional conditions and subsequently under early successional conditions created by experimental clearing, to explore the roles that productivity and stochastic mortality play in species exclusion in this environment. A total of fifteen plots were studied by measuring environmental conditions and biomass components of shrubs and seedlings. These stands were distributed along a productivity gradient across five different landforms. A hypothesis about the stochastic self-thinning mortality model along the gradient was evaluated with the diversity- productivity-environment data. The diversity-productivity relationship was linear and reversed between the early and late succession stages. The hypothesis of stochastic mortality of species exclusion was rejected in the early stages of succession and partially accepted in the mature stage of succession. Species exclusion was negatively related to productivity gradients, suggesting that strong interspecific competition occurs in high productivity plots and that a larger number of species can survive in higher abiotic stress landscapes. Further research is needed to understand the temporal and spatial variations of the ecological interactions that shape this plant community. © 2014 Jose Navar et al. Source

Rodriguez-Flores F.D.J.,Technical University Durango | Nava J.,Technological Institute of Ciudad Victoria
Tropical and Subtropical Agroecosystems | Year: 2016

Aboveground tree biomass (bole, branches and foliage), M, plays a key role in the conventional and sustainable management of forest communities. The standard approach to assess tree or plot M is harvesting trees, developing and fitting allometric equations to trees or forest inventory plot data. In the absence of local tree allometry, it is usually recommended to fit off site allometric equations to evaluate tree or plot M. This research aims: (a) to develop an updated on site allometric equation (b) to fit available off site allometric equations to destructively harvested trees and (c) to fit available allometric equations to plot M of Mexico's Sinaloan tropical dry forests to understand sources of inherent tree and plot M variability. Results showed that: (a) the improved on site allometric equation increases precision in contrast to the conventional biomass equation previously reported as well as to off site tree M equations, (b) off site allometry projects tree and plot M deviates by close to one order of magnitude. Two tested and recommended approaches to increase tree and plot M precision when fitting off site equations are: (i) to use all available tree allometric functions to come up with a mean equation or (ii) to calibrate off site equations by fitting new, local parameters that can be calculated using statistical programs.These options would eventually increase tree and plot M precision in regional evaluations. Source

de Jesus Rodriguez-Flores F.,Technical University Durango | Dominguez-Calleros P.A.,UJED
Annals of Forest Research | Year: 2013

Taper functions are required in modern forest management in estimation of the end forest products, to be classified for their life time in the environment. Based on a sample of 1640 trees of 10 species measured in volume, biomass and taper project on Mexico's northern temperate, mixed, uneven-aged coniferous forests, 12 stem profile taper functions were fitted in order to select the equation that provides better diameter estimates at commercial tree height. Although several equations fitted better specific tree species, the Newnham (1990) equation consistently yielded better diameter estimates at any length of the stem for all studied species. The confidence intervals on the Newnham (1990) equation parameters showed that each species has an unique stem profile and, therefore, single parameter equations are reported. Because of lack of analytical integration, the recommended taper equation (when numerically integrated) provided compatible, unbiased total bole volume when contrasted to conventional timber volume assessments. Data for 637 circular, 1/10 ha, plots from temperate forests of Central Durango, Mexico estimated a mean of 135 m3 ha-1, of which 18, 59, 30, and 17 m3 ha-1 could be classified as poles, sawn wood, plywood and secondary forest products, respectively. This information can be used for the planning of the forest industry to optimize forest products derived from timber harvesting, as well as for estimating other environmental components. Source

Rodriguez-Flores F.J.,Technical University Durango | Aguirre-Salado C.A.,Autonomous University of San Luis Potosi | Miranda-Aragon L.,Autonomous University of San Luis Potosi
Agrociencia | Year: 2013

The objective of this study was to model the dynamics of annual evaporation (E) during radial growth of Pinus cooperi Blanco, which is economically and ecologically important for northern México. Dendrochronological data were used to identify a model that would, with instrumental records, relate E for the period 1964 to 2010. The correlation and regression analyses showed that E negatively affects growth during the months previous to the growth season and during the summer of the growth year (June and July). E is a significant variable that can explain water stress and that can have implications for management of P. cooperi in the face of climatic variation. Source

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