This paper analyzes the loss of forest cover in the Monarch Butterfly Biosphere Reserve in the period between 2006 and 2010 using high-resolution SPOT satellite imagery (10 m). The images were calibrated, atmospherically corrected and superimposed with control points. A map of forest and non-forest (with and without apparent tree vegetation) was constructed with each image. The maps were validated using very high-resolution images of the same dates. Within the forest area, the natural boundary between oyamel fir forest (Abies religiosa (Kunth) Schltdl. and Cham.) and pine forest was set based on a supervised classification and an altitude criterion. Comparing the maps allowed us to establish the loss of oyamel fir forest in the period studied, which is estimated at 2,227.00 ha, which corresponds to a deforestation rate of 556.75 ha.year-1. The change map was compared to reports identifying areas affected by pests presented by the National Forestry Commission and the Universidad Autónoma de Chapingo in 2004, and others detailing phytosanitary measures undertaken by the Ministry of Environment and Natural Resources between 2005 and 2009.

A study was conducted to analyze production, mass loss and decomposition rates of leaf litter in agroforestry plots with traditional coffee system (TCS), rustic coffee system (RCS) and medium tropical forest (mtf), in San Miguel, Veracruz, Mexico. In each system, three quadrants were randomly established (1000 m2). The collection of leaf litter produced by the canopy was performed every 15 days, during a calendar year. Leaf litter decomposition was evaluated in litterbags containing 10 g (dry weight) of the dominant species and a representative mixture per system. Litterbags were collected on seven dates during 352 days. The decomposition rate (k) was high for Piper hispidum and leaf litter in RCS, in all sampling dates, indicating a possible effect of microclimate or quality of leaf litter. The lowest k values were obtained in Robinsonella mirandae/Coffea arabica and Mastichodendron capirii, in TCS and mtf. The rest of the leaf litter showed average rates of decomposition; Robinsonella mirandae showed no differences among systems. The study demonstrates the importance of leaf litter quality and production, and the environmental factors in the decomposition of the study systems.

The objective was to study the yearly and monthly trends for the number of positive samples (NPS) and the infestation level (IL) of Varroa destructor in honeybees (Apis mellifera). The study was carried out from 2002 to 2006 at the SAGARPA Bee Identification and Diagnosis Laboratory. Mite detection was performed using the De Jong procedure for V. destructor. Estimates of annual and monthly trends for NPS and IL were obtained through regression analysis. The monthly average for NPS was 47.6 ± 49.3 NMP, with the range varying from 0 to 248 samples per month. The annual trend (-5.69 ± 4.48) for the increase in the number of bee samples tested positive for V. destructor was not different from zero (P = 0.2087). The monthly trend from January to December was 0.91 ± 1.7 (P = 0.6024). The average IL in the positive samples was 3.27 ± 2.6 %, while the monthly average ranged from 0 to 10.06 %. The average annual rate of increase in IL was 0.34 ± 0.23 % (P = 0.2494). The average monthly rate of increase, from January to December, was -0.17 ± 0.1 % (P = 0.1194). The NPS with V. destructor and the IL showed no significant increases for the period studied. There was no effect of seasonality on NPS and IL.

Growth and macro and micronutrient contents of Pinus greggii Engelm. inoculated with the edible ectomycorrhizal mushroom Hebeloma mesophaeum (Pers.) Quél. was evaluated. The experiment consisted of two treatments: plants inoculated with H. mesophaeum and non-inoculated plants. Results showed that shoot and root dry weight, shoot height, stem diameter, and total contents of N, P, K, Ca and Mg were higher in inoculated plants than in non-inoculated plants. P and Mg contents were 6.7 and 6.9 times respectively higher in the shoot of inoculated plants in comparison to noninoculated plants. Additionally, H. mesophaeum originated a high translocation efficiency of P, K and Mg to the shoot. The percentage of mycorrhization was high (79.5 %); more than half of it being observed in the central part of the root ball in the plant containers. Therefore, inoculation with H. mesophaeum has a great potential to be used in the production of P. greggii plants under greenhouse conditions.

Machining quality is different for each species and, as a result, it is necessary to know the characteristics and properties involved in this process, such as the anatomical structure, moisture content, specific gravity, growth rate, number of growth rings per inch, and grain direction. The aim of this study was to determine the machining properties of Pinus oaxacana Mirov. wood in planing, sanding, shaping, turning and boring tests. The test material was obtained in a plantation located on one side of the Universidad Autónoma Chapingo forestry department. Machining tests, defect evaluation and grading were performed as set out by ASTM-D 1666-87, with some modifications in terms of machinery and moisture contents. In general, P. oaxacana wood was graded as having excellent workability, except in the first shaping test cut where it was graded as good. This test result improved in the second cut. Therefore, the species can be used in the manufacture of finished products with higher value added, such as doors, windows, frames, turned parts, moldings, furring and furniture in general.

The yew tree (Taxus spp.) is a dicot gymnosperm belonging to the Taxaceae family and it can be found in America, Europe and Asia. These trees have in their bark and leaves diterpenic alkaloids known as taxoids, which are chemically characterized by the presence of a taxane skeleton and an oxetane ring such as taxol, which is used in the treatment of ovarian, breast, prostate and lung cancer; disease that is currently one of the leading causes of death worldwide. Taxol content is low in trees, so it is necessary to use biotechnology alternatives such as in vitro cultivation of plant tissue to increase the amount of taxoids and preserve the natural resource. The chemical characteristics of taxoids, the mechanism of the biological action and the semi-synthetic organic of taxol were reported in this scientific review; as well as, the biosynthetic pathway of major taxoids and the main enzymes involved in obtaining taxoids at biochemical level and, finally the production of taxoids in vitro cultures is indicated.

A study was conducted to determine the nutritional composition of the diet of white-tailed deer in Pitzotlán, Morelos during three seasons of the year: spring, autumn and winter (including dry and rainy periods). Each season, a diet was simulated based on fecal microhistological analysis. Crude protein (CP), ashes, ether extract, neutral fiber detergent (NFD) and acid detergent fiber (ADF), Ca, P, Se and in vitro digestibility of dry matter were determined. The amount of CP and ADF were lower in winter diet (10.8 and 23.0 %) compared to autumn diet (15.0 and 31.0 %) or spring diet (14.2 and 26.2 %). The digestibility during autumn was the highest (52.4 %) compared to other seasons. Sida sp. was the most consumed plant having the greatest digestibility (67.1 %) and crude protein (17.9), followed by Randia aculeata (13.8 %). Nutritional quality of the diet selected (during autumn and spring) by white tail deer can be considered appropriated based on digestibility and CP content. However, in winter CP was deficient for the requirements of white-tailed deer.

The effect of radial distance from water sources (RDW) on plant volume, hiding cover (HC) and the presence of white-tailed deer was assessed. The study was conducted in the state of Puebla, Mexico. Stratified random sampling was used to select five areas with a RDW of less than 800 m, four between 800-1,600 m and four greater than 1,600 m. Plant volume was estimated in these areas and they were the starting point of transects in which HC and the number of white-tailed deer and coyote fecal pellet groups (PGs) were estimated. The number of white-tailed deer PGs increased as the RDW increased (Tukey; P < 0.05), while coyote PGs remained within the 800-m radius (X2 = 0.004). The RDW did not affect HC (Tukey, P > 0.05). The relationship between RDW, HC and PGs was established using Poisson and polynomial regression. Poisson regression showed that RDW and HC significantly changed (X2; P < 0.0004 and P < 0.0001) the PG number. The polynomial equation showed that HC has a good correlation (R2 = 0.72) with PGs.

Shifting cultivation system, factor in the food sovereignty of the Piaroa indigenous in the Venezuelan Orinoquia, is an anthropocentric activity that has preserved the dynamics of tropical rainforest. Today, the changes caused by globalization processes threaten the sustainability of the system. Therefore, studying in detail the operation of the systems is fundamental for making decisions regarding the management of the tropical forest. This study proposed to determine the relationship between crop species and soil characteristics at the stage of sowing. Therefore, 40 sampling units (soil and vegetation) were placed in 4 Piaroa conucos, in two different periods of time after burning (0 to 2 and 2 to 4 years). Based on the field data, a model was developed to explain the spatial distribution of each grown species according to the soil characteristics. The model used showed different responses depending on the species grown by the Piaroa indigenous. However, this model explains the selection of microsites for sowing through soil physical properties, leaf litter distribution and biomass distribution after the felling and burning stage in the conuco.

The degradation of natural resources worldwide has led to important questions about how to use these resources and the prospects for future development at the pace of current exploitation. In Mexico, forest management is mainly in the hands of ejidos and communities. This research evaluated in 2010 the impact of the Pilot Forest Plan (PFP) established in Quintana Roo in the 1980s. The study examined the socioeconomic and cultural aspects of forest management in two ejidos: Noh Bec and Xhazil. Welfare, natural conditions and the change in social, economic and cultural aspects were analyzed with a well-being index in relation to forest management, which took into account natural, human social, economic and cultural systems. The current well-being status in relation to forestry was medium high and medium for Noh Bec and Xhazil, respectively. Forest management with the strategic PFP guidelines was an adaptive process for both ejidos, which showed significant differences in community organization, marketing, diversification and financial support.