The relationship between the richness, diversity and distribution of fern and lycophyte species and some climatic and soil variables in the mountain cloud forest of the municipality of Tlanchinol, Hidalgo, Mexico, was analyzed. Twenty-four sampling plots of 400 m2 each were established in three elevational ranges between 1,107 and 1,903 m. In each plot, alpha and beta diversity, and the relative importance value (RIV) of the species were estimated. The relationship between richness, diversity, RIV and environmental variables was established by redundancy, linear regression and regression tree analysis. Few species showed high RIV per plot; richness and diversity values showed no statistically significant differences (P < 0.05) with respect to elevation, but did with respect to the minimum temperature of coldest month, precipitation of warmest quarter, orientation and slope. Beta diversity increased with elevation, was low between nearby elevational ranges and was high at the ends of the gradient. Species distribution was positively related to organic matter, isothermality and sodium content, and negatively with precipitation of driest month, annual actual evapotranspiration and actual evapotranspiration in the rainy season.

The center of origin and domestication of Jatropha curcas L. is Mexico. This crop can be affected by several phytopathogenic fungi and insect pests that diminish the quality of the seeds. The aim of this study was to evaluate the antagonistic and enthomopathogenic activity of rhizospheric bacteria (B. subtilis, B. mojavensis, B. thuringiensis and Lysinibacillus sphaericus) against Fusarium verticillioides and Leptoglossus zonatus. The antagonistic activity of rhizobacteria was evaluated against F. verticillioides by dual culture technique on potato dextrose agar. Moreover, the effect of B. thuringiensis and L. sphaericus was evaluated on the mortality and development of L. zonatus. The results demonstrated that rhizobacteria inhibited the mycelial growth (26 to 55 %) and affected the hyphal morphology of F. verticillioides regardless of the culture medium and cultivation time tested. B. mojavensis (40.4 to 54 %), L. sphaericus (39.6 to 55 %) and B. subtilis (38.5 to 50%) caused the highest percentages of inhibition. On the other hand, B. thuringiensis and L. sphaericus showed no enthomopathogenic activity because they did not affect the mortality or development of L. zonatus.

The purpose of this review is to discuss the role of agroforestry systems in providing environmental services, including more diverse and sustainable agricultural production, increased carbon stocks and enhanced biodiversity conservation, plus improved soil fertility, methane emission mitigation, and water and air quality. There is evidence that agroforestry systems have an important role in providing environmental services, as approximately 20 % of the world’s population, primarily in rural and urban areas of developing countries, depends directly on agroforestry products. The adoption of agroforestry contributes to reduced greenhouse gas emissions (carbon dioxide and methane), diminishes the pressure on vulnerable ecosystems, and improves the livelihoods of rural communities.

The aim of this work was to evaluate the effect of rangeland condition on the nest density of escamoles ant (Liometopum apiculatum) in three different range sites, all within a single (escamoles) collecting area divided into two contrasting use and property regimes, communal and private, in the Municipality of Charcas, San Luis Potosi, Mexico. In order to measure the vegetation, a point-centered quarter method along transects was used; in every quadrant the distance from the point to the closest plant was measured for each vegetation stratum, while the distance to the closest nest (if existing) was also recorded. The species recorded were grouped according to their forage value as desirable, less desirable and undesirable, and using their density and volumetric biomass estimations, these groups were compared through a tabular and descriptive statistical analysis. The soil surface state was evaluated with the line intercept method, in its proportion of live and dead (mulch) basal cover, bare soil, stones, ant trails and feces. The highest density of ant nests (14·ha^-1) was recorded in the favorable site of the ranch (best rangeland condition). Marked differences were found in nest density between adjacent rangeland sites, which in turn were severely altered by the condition of these rangelands

We present evidence that climatic change is an ongoing process and that forest tree populations are genetically differentiated for quantitative traits because of adaptation to specific habitats. We discuss in detail indications that the shift of suitable climatic habitat for forest tree species and populations, as a result of rapid climatic change, is likely to cause significant stresses to natural tree populations. Due to the physical limits of natural migration, tree populations will be unable to keep pace with the moving target that their suitable climatic habitat will become. The consequent decoupling between natural populations and the climate for which they are adapted, will likely cause large forest decline, a phenomenon that is already underway in several forests of the world. In order to accommodate climate change, what are our forest management options? What would be the consequences of inaction? We describe and discuss assisted migration, which is the physical realignment of natural populations to the climate for which they are adapted, by reforestation in sites where their suitable climate is predicted to occur in the future, as an active management option with the aim of maintaining healthy tree ecosystems in the future.

Torrefaction and pelletizing were studied in the generation of energy from lignocellulosic residues to increase the energy properties of the biomass. The aim of this study was torrefied sawdust from Gmelina arborea and Dipteryx panamensis at 200 °C in three time period: 0, 15 and 20 minutes. Then with the biomass, pellets of 6 mm diameter were manufactured and their physical properties, calorific value, density and compression force were evaluated. Both species had similar physical characteristics according to the average diameter (0.50 mm), length (21.50 mm), and water absorption rate (6.00 %). The calorific value increased from 9,749 kJ·kg-1 in un-terrified biomass to 18,126 kJ·kg-1 with torrefied biomass. The pellets from D. panamesis had greater density and compression force compared to G. arborea biomass. Based on the results, pellet compression force decreases as the torrefaction time increases. There is positive correlation between bulk density of pellets and compression force. The D. panamensis species has better torrefaction behavior and pelletizing than the wood of G. arborea.

Determining optimum cutting ages including various forest ecosystem values together with wood production is extremely important in forestry now. This study presents the optimum cutting ages in hybrid poplar plantations (Populus x euramericana [Dode] Guinier cv. I-214) including timber production and carbon sequestration values in Turkey. It also evaluates the effects of different discount rates and carbon prices on the optimum cutting ages using net present value approach. The growth and yield curves and biomass/ carbon conversion factors for hybrid poplar plantations with forest plantation costs are used to determine the optimum cutting ages. Results of the case study showed that the integration of carbon sequestration benefits into wood benefits increased the optimum cutting ages of hybrid poplar plantations. Optimum cutting ages decreased from 19 to 14 years depending on the increase in discount rates. When carbon prices increased, the optimum cutting ages also increased from 17 to 20 years. In the presence of carbon sequestration benefits, increasing the optimum cutting age yields net economic benefits of 374 to 1,654 US$·ha-1. Total net present values obtained from wood production and carbon sequestration benefits increased between 6 and 26 % depending on the increase in carbon prices (from 0 to 40 US$·t-1 carbon).

Historically, logging has been the main reason for encouraging forest research. Since 2000, searching information about carbon capture and content has increased through the use of biometric models and remote sensing technology. The aim of this paper was to compile, systematize, and analyze scientific and technological reports related to biometric models that have been used in forest management in a region of central Mexico (Hidalgo). A total of 32 research studies were published from 1976 to 2015 reporting 289 models. These researches emphasize the use of growth, volume, biomass, carbon, site index, density, and mortality models. The growth models have been the most studied models while biomass and carbon models have consistently increased since 2007. Pinus has been the most studied genus, but research on Quercus was practically not found. Five species do not have fitted models, despite their economic importance: Pinus leiophylla, P. michoacana, P. oocarpa, Cupressus lindleyi, and Arbutus xalapensis. The reliability of all published models is based in statistical criteria, but it has not been reported if they have satisfied final user’s demand.

The aim of this research was to estimate the income elasticity of willingness to pay of consumers of environmental services provided by the Basaltic Prisms recreational park in the municipality of Huasca de Ocampo, state of Hidalgo, Mexico. The importance of the study lies in the resulting environmental policy recommendations to make the Basaltic Prisms ecosystem economically sustainable by charging differential entrance fees to it. The methodology used was consumer segmentation with the two-step cluster analysis model. The main finding was the identification of three types of consumers, where low-income consumers have a greater willingness to pay for potential improvements in the park’s recreational services than those with a higher income. The results indicate that, among the three types of consumers, the income elasticity of the willingness to pay for potential improvements in the quality of recreational services is less than unity and greater than zero. That is, recreational services are a normal good. This result is relevant and consistent with those reported in other studies.

Tree species like Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir) are sensitive to climate cycles and show well defined growth rings. The careful selection of dominant trees with circular trunk section allow the analysis of tree growth trajectories. In this study, we used direct measurements of basal area increment (BAI) to explain biological periodicity and forecast basal area growth of Douglas-fir growing in Western Mexico. To remove the age effect on tree growth we also ran the analysis in terms of cambial age. Results showed significant (P < 0.05) correlation between BAI and precipitation from January to July. We found periodicities in tree growth of 7, 21, 27 and 60 years. However, the 60-year period, was determinant to build an ARIMA model (0,1,1), to forecast BAI for the next decades. Tree growth projections suggest reduced BAI in mature dominant trees for the next decades. Decreased tree-growth is an unexpected result, as BAI in dominant trees remains constant up to the biological age. Our finding is concurrent with a general decrement in tree growth in other forests of the world due to water stress, which suggests that the future climatic variability may worsen health conditions of Douglas-fir forests in North Mexico.