Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Not applicable.

This study was conducted in Alturas de Pizarra in the Minas Agroforestry Enterprise, in Cuba, in order to determine its composition and structure of the pine forest vegetation for future management. Two areas were selected: one corresponding to Pinus caribaea and the other to Pinus tropicalis. In each area, 30 circular plots of 15 m radius were established. Three strata were considered in the vegetation in order to quantify the species present and conduct the corresponding analyses. Alpha and beta diversity values were determined, the horizontal structure was evaluated by calculating the index of ecological importance and distribution by diametric classes. The vertical structure was described through the richness of species in each stratum as well as its sociological position. The two pine forests contained 36 families, 47 genera and 61 species of plants, with 42 species in Pinus caribaea area and 36 in the Pinus tropicalis area. Differences were observed in the composition of the accompanying vegetation in their strata. Pinus caribaea attained an importance value of 205.96 and Pinus tropicalis attained 175.59, relative abundance and relative frequency were the parameters that most influenced the index of ecological importance. Plots, according to the composition of species, were divided into groups of four, differing in altitude, tree height, basal area and number of dead trees found in each. By specifying some of the parameters of this vegetation type in Cuba, the results obtained in this study constitute a reference for the management of these pine groves.

In this study, environmental factors that determine the abundance and distribution of commercial pine species in the municipality of Capulálpam de Mendez, Oaxaca, were analyzed. We used information pertaining to tree species abundance in 636 sites established in harvesting areas from the municipal forest inventory conducted in 2013 for the Management Plan 2015-2022, as well as 354 additional sites located in areas with different land use. Data of the spatial distribution and ecological niche analysis of the species were obtained, for which nine climatic and four geographic variables were used. Ten species of pine were recorded, of which Pinus patula showed the highest abundance and P. chiapensis the lowest. Canonical Correspondence Analysis indicated that most of the pine species are more highly associated with the climatic variables than with geographic variables, except for that of latitude. Niche analysis showed that species of the genus Pinus are highly marginal and of low tolerance to processes of environmental change. Minimal alterations to their habitat could restrict or reduce their abundance and distribution, with P. chiapensis being the least tolerant species and P. patula the species that presented the broadest niche.

Hevea brasiliensis Müell. Arg plantations contribute to the reduction of atmospheric carbon dioxide by fixing carbon through photosynthesis and storing it in the tree components (leaves, branches, stems, barks and roots) and by their transformation to stabilized forms of soil organic matter. The objective of this study was to determine the stored carbon in the whole aboveground biomass in 5, 9, 15, 25, 32 and 51-year-old plantations, through a forest inventory and the use of allometric equations in Tabasco, Mexico. The stored carbon was determined using linear regression and mean values were analyzed by the Tukey test (p < 0.05) with the Statistical Analysis System (SAS) program. Results indicated that the carbon concentration varies with age; in 51-year-old plantation the stored carbon in stem was 192.32 Mg ha-1, in branches was 64.75 Mg ha-1 and in the whole tree was 257.07 Mg ha-1, while 5-year plantations had values of 16.65, 9.63 y 26.28 Mg ha-1, respectively. The results indicated that H. brasiliensis plantations can be considered a potential source of mitigation of climate change.

The anatomical characteristics of the wood of Pinus arizonica Engelmann, P. cooperi C. E. Blanco, P. durangensis Martínez, P. herrerae Martínez, P. leiophylla Schlecht. & Cham. and P. teocote Schlecht. & Cham are presented. The study material was obtained from two to four trees per species collected in pine-oak forests in the municipalities of Santiago Papasquiaro, San Dimas and Durango, in the state of Durango, Mexico. To observe the microscopic characteristics, slices of 20 µm in thickness were cut and stained with rapid green-safranin or with astra blue-basic fuchsine and dissociated material stained with Bismarck brown. For the macroscopic characteristics, specimens of 7 cm × 5 cm × 1 cm were produced. The proportion of early-wood is three times greater than that of late-wood in all of the specimens; the values of wall thickness and lumen diameter differed between early and late wood. Radii and axial resin canals presented differences in size and abundance. Pinus herrerae presents the widest rings and P. leiophylla and P. teocote the narrowest. The macroscopic characteristics of the six species studied are generally similar among individuals of the same species, regardless of collection site. Wood color and grain are influenced by the proportions of early and late woods present in each ring and the width of those characteristics. Pinus arizonica and P. cooperi presented differences in color between the sapwood and heartwood. The results are presented in tables and illustrated with photographs.

To effectively conserve and sustainably manage forest resources, it is essential to assess forest biodiversity. Recent policies on biodiversity do not only respond to the loss of biological species but also to its role in the ecological balance of the planet. The objective of this study was to analyze the structural diversity and floristic composition of a forest in Chaco Serrano. Forest biodiversity was analyzed in 16 plots in systematic sampling design in two height levels and four main transects. In tree and shrub strata, number of individuals and total height were monitored. Horizontal distribution patterns and vertical structure were analyzed; indexes of importance, of diversity and phyto-sociological were calculated in order to determinate the ecological importance of each strata. The studied forest is a homogeneous mass in reference to its floristic composition. In the altitudinal gradient, the studied forest did not show significant differences, however in latitudinal one did. Seventy percent of species corresponded to the shrub strata; the index of importance woody (IVIL) showed the highest values for three shrubs: Acacia praecox, Ruprechtia apetala and Ruprechtia triflora; followed by an arboreal species: Caesalpinia paraguarensis. The data series were fitted to the lognormal model, which characterizes large, stable, and in equilibrium communities, in an intermediate successional stage.

In this study, we determined the lifespans of two wood finishing systems, one water-based and another solvent-based, using an accelerated process of weathering. The varnishes used were both of the brand Polyform ® (Hydroform ® and 11000 ®). We applied these to wood of Cedrela odorata L. (red cedar) and Roseodendron donnell-smithii (Rose) Miranda (primavera) from commercial plantations of seven years in the state of Veracruz, Mexico. The lifespans of the varnishes were estimated with the Weibull cumulative distribution function. The varnish Hydroform® lasted 1.02 years on red cedar and 2.18 years on primavera, while the varnish 11000 ® lasted 3.70 years on red cedar and 8.99 years on primavera. According to the lifespans estimated for the two varnishes used in this study, we recommend using the varnish 11000 ® rather than Hydroform® for outdoor uses.

Anatomical and histochemical features of the bark of Cercidium plurifoliolatum Micheli, Ipomea pauciflora Martens & Galeotti, Jatropha andrieuxii Muell. Arg., Lysiloma divaricata (Jacq.) MacBride, Ziziphus amole (Sessé & Mociño) M.C. Johnston from a seasonal dry forest of Oaxaca were analyzed. Transverse, tangential and radial sections were obtained from pieces of bark that included sapwood. The terminology of Trokenbrodt (1990) for anatomical characters was used. Lipids, pectins, calcium pectates, lignin and polyphenols were visualized by histochemical reactions. Two types of rays were observed: the first type form fanlike structures that become tangential bands; in the other type, rays are interrupted by small tangential structures such as axial parenchyma, fibers or groups of sclereids. It is noteworthy the radial array of axial parenchyma in Jatropha. Most cells of all species showed a strong reaction to calcium pectates. The composition of cellular contents shows a great diversity; noteworthy is the strong reaction to polyphenols, calcium pectates and oils in Jatropha’s secretory canals. It is evident a general pattern of lignification from the axial parenchyma outwards. The presence of abundant crystals was observed in the five species analyzed. Differences in the histchemical features of the bark between the species are discussed.

In this work, the CO2Fix dynamic model for Windows Ver. 1.2 was utilized to obtain the potential carbon sequestering in the community Nuevo San Juan. Total carbon estimated in the long run (250 years) was 217 tC/ha; the biomass (aerial and subterranean) with 74 tC/ha, products with 49 tC/ha and soil with 94 tC/ha. It was estimated that in the same time span, there is a potential for carbon sequestering in the community forest of 1.9 MtC in tis 8,870 ha. At the same time, sensitivity analyses were carried out with three parameters to identify the potential difference in carbon sequestering (life time of the wood products, humification and decaying rates ±30 % of the original value). Finally, the importance of using the CO2Fix model as a tool for forest management is highlighted especially for forest plantations. The simulation was based, as feasible, in data available locally: (a) area surface in study; (b) forest management: thinning cycles, regeneration and liberation cuttings ; actual standing volume and volume extracted; (c) tree growth: current annual increment, diameter, height, age and annual average increment and, (d) manufactured products as: paper, packaging, construction lumber, wood for furniture, fire wood and dead wood.

Buddleja L. comprises nearly 100 species with pantropical distribution, varying from small shrubs to trees 20 to 30 meters high and few lianas. In this study wood anatomical characteristics of Buddleja are presented based on the study of 41 species, of those 10 are described for the first time, and 15 synthesized from the literature. Also the wood features for 41 species of the genus were analized through a phenetic analysis. The genus showed ring to diffuse porosity, simple perforation plates, alternate intervascular pits, and helical thickenings in vessel elements and vascular tracheids; libriform fibers, with septa in some species; axial parenchyma scanty or rare; heterogeneous rays type IIB and 35% of the species contain prismatic crystals of different size in their ray cells. Phenetic analysis showed that several species are anatomically identical. However, most species conformed two large groups based on qualitative and quantitative wood features. Moreover, other species are distinctive based on the presence of unique qualitative characters. Finally, some taxonomic considerations on Buddleja position within the Scrophulariales order are discussed.