Hernandez-Ramos J.,Instituto Nacional de Investigaciones Nucleares |
Garcia-Magana J.J.,Universidad Michoacana de San Nicolas de Hidalgo |
Olvera-Delgadillo E.H.,Comision Nacional Forestal CONAFOR |
Velarde-Ramirez J.C.,Asesoria Tecnica Forestal ATF |
And 2 more authors.
Revista Chapingo, Serie Ciencias Forestales y del Ambiente | Year: 2014
Productivity indices are essential to sustainable forest management planning. Site Index is the primary method used to classify the quality of forest sites. However, this information is not available to aid in the planning of silvicultural interventions for most forest stands and plantations. Therefore, the objective was to estimate the site index for forest plantations of Pinus greggii Engelm., which were already established in the mountainous region of the municipality of Metztitlán, Hidalgo. Schumacher, Chapman-Richards and Weibull functions were fitted to 233 age-height data pairs obtained from stem analysis. Based on the lowest value of the mean square error, the highest R2 value and the distribution of residuals, the Schumacher model was selected for the construction of the guide curve and the families of anamorphic and polymorphic curves. Five site index labels were established for heights of 12, 14, 16, 18 and 20 m with site qualities of V, IV, III, II and I, respectively. A good representation of dominant height growth as a function of age was achieved given that all conditions existing within the plantations were considered in the models. © 2014, Universidad Autonoma Chapingo. All rights reserved.
Henry M.,Food and Agriculture Organization of the United Nations |
Cifuentes Jara M.,Tropical Agriculture Research and Higher Education Center |
Rejou-Mechain M.,French Institute of Pondicherry |
Rejou-Mechain M.,CIRAD - Agricultural Research for Development |
And 25 more authors.
Annals of Forest Science | Year: 2015
Key message: Three options are proposed to improve the accuracy of national forest biomass estimates and decrease the uncertainty related to tree model selection depending on available data and national contexts. Introduction: Different tree volume and biomass equations result in different estimates. At national scale, differences of estimates can be important while they constitute the basis to guide policies and measures, particularly in the context of climate change mitigation. Method: Few countries have developed national tree volume and biomass equation databases and have explored its potential to decrease uncertainty of volume and biomasttags estimates. With the launch of the GlobAllomeTree webplatform, most countries in the world could have access to country-specific databases. The aim of this article is to recommend approaches for assessing tree and forest volume and biomass at national level with the lowest uncertainty. The article highlights the crucial need to link allometric equation development with national forest inventory planning efforts. Results: Models must represent the tree population considered. Data availability; technical, financial, and human capacities; and biophysical context, among other factors, will influence the calculation process. Conclusion: Three options are proposed to improve accuracy of national forest assessment depending on identified contexts. Further improvements could be obtained through improved forest stratification and additional non-destructive field campaigns. © 2015, The Author(s).
Cubbage F.W.,North Carolina State University |
Davis R.R.,The World Bank |
Rodriguez Paredes D.,The World Bank |
Mollenhauer R.,The World Bank |
And 6 more authors.
Journal of Sustainable Forestry | Year: 2015
Community-based forest management, such as Community Forest Enterprises (CFEs), has the potential to generate positive socioenvironmental and economic outcomes. We performed a detailed survey of financial and production parameters for 30 of the approximately 992 CFEs in Mexico in order to estimate costs, income, profits, and sustainability of harvest levels for forest management, harvest, and sawmilling. Fourteen of the 30 CFEs harvested more timber than they grew in 2011, suggesting issues with sustainability, but only two of these had harvest far above annual growth, and five of those were only a fraction more than annual growth. All of the 30 CFEs except one made profits in forest management and timber growing. For timber harvesting, 22 of 30 CFEs made profits, but the losses were small for the other CFEs. For the 23 CFEs with sawmills, 18 made profits and five had losses; the greatest returns for the CFEs accrued to those with sawmills for lumber production. On average, the CFEs surveyed had high costs of production relative to other countries, but the CFEs were still profitable in national lumber markets. If Mexico were to begin importing large amounts of lumber from lower cost countries, this could pose a threat to CFE profitability. Copyright © International Bank for Reconstruction and Development/The World Bank.