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The use and consumption of wood has always captured the attention of forest researchers, mainly from the point of view of forest management and the sustainable processing of raw materials. For this reason, the wood industry has not only been concerned with the maintenance of forests, but also with efficient processing. The objective was to identify, analyse and discuss the main elements that influence the efficient use of natural timber resources at a global, regional and local level, providing a historical and current perspective of the industrial forestry sector in Mexico. Historically, the wood industries worldwide have been concerned with applying intensive silvicultural treatments in native and artificial forest stands, in search of satisfying the demand of a growing market. In this context, industries evolved as processes needed to be more efficient. Therefore, efforts were made to reduce and take advantage of forest residues, at the same time various historical events generated additional needs. At present, the integration of silviculture and forest transformation allow to increase and improve the quality of the products generated. Through the application of intensive silvicultural treatments, products of a single species are obtained. However, it is possible to direct production to a specific market as the forest mass develops. For its part, selective treatments in uneven-aged forests maintain a constant production of diverse products for different specialized markets. In Mexico, it is imperative to analyse and generate innovative or competitive products derived from wood to improve the efficiency of forest harvesting. [ABSTRACT FROM AUTHOR]

Sectional equations and mathematical volume models are a reliable way to estimate carbon sequestration and storage, which is a key foundation for forest management and conservation. The objective of this study was to assess stem volume and form factor through the classical sectional method to then, using five regression models commonly used for forest management, identify the most suitable mathematical model to estimate the stem volume in a commercial forest plantation (CFP) of Pinus pseudostrobus Lindley in the Comunidad Indígena de Nuevo San Juan Parangaricutiro, Michoacán, in Western Mexico. By using 10, 15 and 20 yr.-old sampling points and two sampling methods (destructive and nondestructive), we found a form factor 0.42, 0.48 and 0.51 and stem volume of 0.098 m3, 0.400 m3 and 0.804 m3 for the three ages assessed, which presented diameter classes (DC), from 10 to 45 cm. The mathematical models identified that age of plantation determines stem volume and form factor, and the models that best fit volume estimation were the Schumacher-Hall model and the Australian model with an R2adj range between 0.89 and 0.99. Estimation of stem volume is of vital importance to assess the income generated by the timber industry, and relevant for forest conservation, management, and carbon sequestration studies. [ABSTRACT FROM AUTHOR]

Copyright of Ecosistemas y Recursos Agropecuarios is the property of Universidad Juarez Autonoma de Tabasco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The pinyon pines, Pinus cembroides and P. nelsonii, offer a unique example of the dendroclimatic potential of semiarid species for reconstructing cyclic low-frequency fluctuations of droughts and pluvials in northeastern semiarid Mexico. This study presents a new ring-width chronology of pinyon pines from Miquihuana, Tamaulipas, in northeastern Mexico, and uses climatic data and comparisons with the El Niño-Southern Oscillation (ENSO) and drought indices to reconstruct a historical precipitation that allows for the examination of the long-term hydroclimatic variability of seasonal rainfall, frequency of droughts and pluvials in this region, and their socio-economic impact. The radial growth of these two pinyon pines was sensitive to precipitation from November of the previous year to July of the current year. During droughts, these pinyon pines showed reduced ring-widths, but in wet years ring-widths were larger. The reconstructed precipitation extends from 1853 to 2018 (166 years) and shows high interannual and multiannual variability of precipitation influenced by ENSO, causing extreme hydroclimatic events each 2 to 4 years. The highly significant association with drought indices reinforces the potential use of pinyon pines as a proxy for determining dominant drought conditions in the region. Evidence from historical documents and dendroclimatic reconstructions from northern and central Mexico validated the main periods of drought and pluvials detected in this reconstruction. Droughts in the tree-ring record coincided with famines, migration of rural population, and warfare. Our results show a wide spectrum of natural variability in precipitation for northeastern Mexico, thus providing insights that could contribute to a better planning for regional water resources. [ABSTRACT FROM AUTHOR]

Copyright of Bosque (03048799) is the property of Facultad de Ciencias Forestales, Universidad Austral de Chile and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Biometric systems are the basis of forest management and consist of a set of equations that describe the relationships between forest attributes and dendrometric variables. A systematic review of the state of the art of biometric systems in Mexico was carried out by a Mexican consortium (10 researchers), covering a period of 50 years ca (1970–2019), using the main scientific literature delivered by a systematic search (WoS, Scopus, Scielo, Redalyc) and a targeted search (theses, technical reports, etc.). A single selection criterion was established for the inclusion of information in the analysis: the document had to present at least one of the equations of interest. We found 376 documents containing 2524 equations for volume (69%), diameter (11%), height (9%) and site index (11%). These equations were developed for forest species mainly from temperate regions (88%), such as pine (66%) and oak (9%). Consequently, the Mexican states with the highest number of equations were Durango (28%), Chihuahua (17%), Hidalgo (13%) and Oaxaca (8%). Although large, the number of equations identified concentrated on a relatively small number of models: Schumacher & Hall and Fang et al. for volume; Chapman-Richards and Schumacher for site index and diameter; and Chapman-Richards and the allometric equation for height. An analysis of model fit, measured through R2, showed that, on average, the volume, diameter and site index models show high fit (R2 = 0.96), although this pattern was more consistent in the volume models. Publication bias was evaluated by means of a funnel plot analysis, with no apparent bias identified. A limitation of our study is that the information obtained is not updated to the present year; however, the 50-year trends allow us to assume that no recent significant changes in the patterns exist. Finally, we highlight the need to assess the predictive ability of the models to ensure accurate estimates to support better forest management decisions. [ABSTRACT FROM AUTHOR]

Copyright of Ecosistemas y Recursos Agropecuarios is the property of Universidad Juarez Autonoma de Tabasco and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A compatible system consisting of stem taper, merchantable-, stem-, branch- and stem and coarse branch tree volume equations was developed for 11 major tropical species in southeast Mexico. A database corresponding to 6187 felled trees was used to develop the system of equations. Iterative seemingly unrelated regression was used to fit the system in two steps: the stem volume, branch volume and stem and coarse branch tree volume equations were first fitted simultaneously and the common estimated parameters were substituted in the stem taper and merchantable volume equations. In the second step, the remaining parameters were estimated by fitting the stem taper and merchantable volume equations simultaneously. Weighted regression and a second order autoregressive model were used in the model fitting to account for heteroscedasticity and autocorrelation. To assess whether the compatible system differs between ecoregions for the same species, a system with the same set of parameters for all the ecoregions was compared with a system with a different set of parameters for each ecoregion. The results of the comparisons indicated the need to fit a different system for each ecoregion and species. The proposed equations can be used to estimate stem-, branch- and merchantable volume at any upper diameter and height, as well as stem and coarse branch tree volume. If classification of the products by merchantable sizes is not required, the stem and coarse branch volume equation is preferred, thereby simplifying the calculations and making it more suitable for practical purposes. [ABSTRACT FROM AUTHOR]

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Foresters in northeastern Mexico currently use height growth curves developed 20 years ago to estimate the dominant height and productivity of Pinus pseudostrobus Lindl. The development of new curves could improve the ability to predict heights and would allow increasingly precise yield projections for this species. Data from stem analysis of 72 P. pseudostrobus dominant trees growing in natural stands in Nuevo Leon, Tamaulipas and Coahuila (northeastern Mexico), were used to evaluate several dynamic site equations derived with the Generalized Algebraic Difference Approach (GADA). All the equations directly estimate dominant height and site index from any dominant height and age. The fittings were carried out using the base-age-invariant nested iterative approach. A second-order continuous-time autoregressive error structure was used to correct the inherent autocorrelation of the longitudinal data used. The GADA formulation derived from the Korf model, by considering the asymptote and the rate parameters as related to site productivity, had the best fit to the data. Therefore, it is recommended for estimating dominant height growth and site index for Pinus pseudostrobus in northeastern Mexico. [ABSTRACT FROM AUTHOR]

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Chapingo Serie Ciencias Forestales is the property of Universidad Autonoma Chapingo and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Foresters may require to estimate the diameter at breast height (d.b.h.) and the volume of trees that have been cut, and may only have available the stumps as an indicator of the size of the trees. In the present study, equations for predicting both d.b.h. and volume from stump diameter inside bark were developed for major pine species in the forest region of El Salto, Durango (Mexico). The d.b.h. was estimated with relatively high accuracy with a simple linear model. The tree volume was also estimated with high precision by use of an allometric equation. Weighted linear and non-linear least squares methods were used to take into account the problem of heteroscedasticity observed in the volume-stump diameter relationships. The results of the non-linear extra sum of squares method and of the F tests indicated that species-based equations for estimating both d.b.h. and volume from stump diameter are required. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Ciencias Agrícolas is the property of Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Studies on functional relationships between relative stem diameter and height to estimate timber yield are useful in the management of commercial forest plantations. With taper analysis data of 42 Pinus pseudostrobus Lindl. trees in the indigenous community of Nuevo San Juan Parangaricutiro , Michoacan, Mexico, six compatible systems for predicting taper (d), merchantable volume (Vm), stem volume (Vs), total tree volume (Vt) and branch volume (Vb) were fitted and evaluated. The compatible taper and merchantable volume equations were based on volume ratio equations. Three Vs equations were tested in each system. In general, the compatible systems presented statistical accuracy in the d, Vm, Vs and Vt components but were less accurate in Vb. Three compatible systems were selected, according to their more efficient goodness-of-fit statistics, and a different total volume equation was incorporated into each system. The compatible systems based on volume ratio equations are simple, reliable tools for estimation of stand timber stocks and product classification of P. pseudostrobus in commercial forest plantations in Mexico. [ABSTRACT FROM AUTHOR]

In sustainable forest management it is essential to conserve and maintain biodiversity, the floristic composition and the mixture of its species. For this purpose, the objective of this study was to evaluate the effect of the selection silvicultural treatment as a function of time, on the horizontal structure of a Pine-Oak Forest in northern Mexico. Nine sampling points were established to analyze the structure of the Initial Condition of the forest in 2012, the Recruitment of 2022 and the Final Condition of 2022. In addition, the Jaccard similarity coefficient and the Margalef wealth index were estimated. Likewise, Shannon true diversity index, the importance value index and the forest value index were calculated for each species. The analysis of variance with a confidence of 95% was used to evaluate the studied variables, multiple comparisons were made with Duncan's test to group the species in ranges of statistical importance. The results indicated that the forest not presented a change in similarity, richness and diversity of species due to the application of the selection silvicultural treatment, without statistical differences according to the mix and distribution of the species in the forest, this indicates that selective logging does not change the composition of forest species. Regarding the indices of true diversity, value of importance and forest value by species, no significant differences were observed in terms of the application of silvicultural treatment. According to these results, it was possible to identify groups of forest importance and value, where Pinus durangensis Martínez was the most representative species. [ABSTRACT FROM AUTHOR]

Introduction: Dendrochronological studies in Mexico have been mainly based on conifers, while hardwood species have been little studied. This has been the case of the genus Quercus, which has a high taxonomic diversity in the country but has not been previously studied for dendrochronological issues, despite the ecological and economic values of oak species. Objective: In the present investigation, the dendroclimatic potential of Quercus sideroxyla in Northwestern Mexico was determined, as well as its relationship with climatic variables such as precipitation and temperature. Methods: The research was carried out in the state of Durango, Chavarría Viejo with coordinates (23°43' N & -105°33' W). Samples of 5 cm to 7cm were collected in two sites under forest exploitation and processed by conventional dendrochronological techniques. Results: A chronology of total ring width was developed, which was composed of 30 samples from 16 trees for the period from 1917 to 2018 (101 years). Inter-series intercorrelation values of 0.43, mean sensitivity of 0.36, signal-to-noise ratio of 3.53 and first-order autocorrelation (0.58) were obtained. Regarding the climate-growth relationship, the ring width index values were correlated with data from the climatic station nearest to the study site, where winter-spring precipitation (January-May) was the variable with the greatest influence on the growth of the species. Conclusions: Based on the dendrochronological parameters, the high potential of the species that were used in dendroclimatic studies in the region has demonstrated that the response of the species to precipitation is similar to that of the conifers with which the Quercus sideroxyla shares its habitat with. [ABSTRACT FROM AUTHOR]

Recent studies have suggested that climatic variations may have implications on ecosystem biogeography. Dendrochronological techniques constitute a useful tool to analyze relationships tree growth-climate. Ring widths usually are standardized before the analysis in order to remove unwanted bias due to individual growth related to stem size and age. This approach produces rings widths indices while retaining climatic signals that are in common among trees into a single chronology. However, in dendroclimatology few papers show their sensitive capacity. As a result its use could be becomes routine practice without considering their implications. The aim of this work was to assess the climate sensitivity responses of three chronologies indexes of Pinus cooperi: Standard (Sd), Residual (Rd), and Arstan. Such series were correlated with historical records of precipitation, temperature and two index El Niño-Southern Oscillation ENSO (Niño3 and MEI).The three chronologies showed similar trends during previous growing months (August to December). Nevertheless, Rd was better associated with current growing months, but showed weaker correlation with ENSO. Comparatively Sd and Ar demonstrated stronger sensibility to large-scale climatic patterns in previous growing months. It is concluded that appropriate selection of dendrochronology index is important, indicating repercussions on climatic scenarios. Neither should be considered substitutes for each other. Combining them with complementary tools would improve the sensitivity capacity of ecological processes in the forest. [ABSTRACT FROM AUTHOR]

The present study evaluated the regeneration of woody species in four abandoned areas with different land-history tenure (extensive production of livestock, intensive production of livestock, agriculture, and clearcutting) in the Tamaulipan thornscrub in northeastern Mexico. These areas regenerated naturally over a period of 21 years (1984-2005). These areas regenerated naturally over a period of 21 years (1984-2005). Four 250-m² plots, each 10 x 25 m, were established in each area for sampling. At each plot, abundance, dominance, mean height of the tallest individuals, species richness, and diversity of the woody species were evaluated. To detect significant differences among the four areas, an analysis of variance (P < 0.05) was used to compare averages of the variables height, abundance, dominance, species richness, and diversity. The analysis of variance showed significant differences for all variables, except height (P > 0.05). The area of intensive production of livestock showed the lowest values for abundance (1,760 ± 704 N/ha), dominance (6.8 m /ha), and species richness (11). In contrast, the area of extensive production of livestock showed the greatest abundance (16,983 ± 3,429 N/ha), dominance (26.1 ± 3.4 m²/ha), and species richness (19). [ABSTRACT FROM AUTHOR]