Species for restoration forestry on degraded lands in the tropics are often restricted to a few well-known exotic timber species. This selection frequently leads to failed projects, as local people expect trees to cover a number of uses, not only timber. We studied local knowledge of the usefulness, scarcity and importance for wildlife of native tree species in central Veracruz, Mexico, a region with mainly secondary vegetation and remnants of tropical dry forest. Data were obtained from several workshops, in depth interviews of 40 key informants, field walks with informants, and botanical collections. Analysis included indices for cultural importance, scarcity and wildlife relevance. We documented 76 species in one or more of the categories, from primary, secondary, agroforestry and riparian habitats. Fabaceae was the most important family. All of the species were useful for humans, mainly for rural construction, food, fence posts and fuel. Two-thirds of the species were considered scarce though they were not necessarily rare-some were highly useful, overexploited species with populations insufficient for demand; this category included five of the ten most important species culturally. Also, two-thirds of the tree taxa were considered important for wildlife, especially species of Moraceae. The study shows that the local population is highly aware of the varying functions of trees in the landscape. However, few of the important species are available from regional nurseries. We propose a number of species for restoration forestry, agroforestry systems and enrichment plantings that would be valued by landowners.

Marijuana (Cannabis sativa) is an important annual medicinal plant that belongs to the Cannabaceae family. It contains 421 substances of 18 chemical types-the most significant compound is δ-9-tetrahydrocannabinol, which causes several effects, both in the Central Nervous System and in several peripheral locations in the organism. The objectives of this scientific review are to mention the anatomical distribution, chemical characteristics and biosynthesis of cannabinoids, as well as its actions mechanisms. The endogenous cannabinoid system, the therapeutic properties of C. sativa and its action on the nociceptive control are described. Finally, the modulators of the cannabinoid system in clinical use are indicated, together with marijuana legalization benefits.

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RESUMENEn México, la producción de plantas forestales en contenedores rígidos se realiza utilizando principalmente como medio de crecimiento la turba, la vermiculita y la agrolita (6:3:1, mezcla estándar). El aserrín y la corteza de pino son desechos de la industria forestal que pueden ser usados como sustratos. Este trabajo tuvo como objetivo caracterizar cinco mezclas de sustratos, compuestos de corteza, aserrín, turba, vermiculita y agrolita. La evaluación de las mezclas incluyó la caracterización física (densidad aparente, porosidad y curva de retención de humedad) y química (pH, conductividad eléctrica y capacidad de intercambio catió-nico). La densidad aparente de las mezclas compuestas de corteza y aserrín varió de 0,31 a 0,51 g cm -3 y la estándar fue de 0,15 g cm -3 . La porosidad total de 77% a 91% y la estándar fue de 84%. La porosidad de aireación varió de 8% a 20% y la estándar fue de 8%. El agua fácilmente disponible varió de 4,8% a 9,9% y la estándar presentó un valor más elevado (17,7%). El pH de las mezclas compuestas de corteza y aserrín varió de 4,52 a 7,70 y la estándar fue de 3,87. La conductividad eléctrica de 1,84 a 2,69 ds m -1 y la estándar 1,13 ds m -1 . La capacidad de intercambio catiónico de 43,6 a 89,4 meq/100 g y la estándar 60,4 meq/100 g. La mezcla 4 (20% de corteza + 80% de aserrín) es semejante a la mezcla estándar por sus características físicas, pero no en sus propiedades químicas. Esta mezcla es un sustrato prometedor en la producción de plantas forestales. PALABRAS CLAVES:Aserrín, corteza, propiedades físicas, propiedades químicas, sustratos, turba. ABSTRACTForest nursery production in containers in México mainly uses peat moss, vermiculite and agrolite (standard mixture). Sawdust and pine bark are subproducts of the forest industry which can be used as substrates. The objective of this work was the characterization of five mixtures using pine bark, sawdust, peat moss, vermiculite. Evaluation included physical (bulk density, total porosity, air porosity and easily available water) and chemical (pH, electrical conductivity and cation exchange capacity) characterization. Bulk density varied from 0,31 to 0,51 g m -3 while the standard mixture was 0,15 g m -3 . Total porosity varied from 77 to 91% compared to the standard mixture with 84%. Air porosity varied from 8 to 20% compared to the standard mixture with 8%. Easily available water varied from 4,8 to 9,9% compared to the standard mixture with 17,7%. pH of the mixtures with bark and sawdust varied from 4,52 to 7,70 while the standard mixture was 3,87. Electrical conductivity varied from 1,84 to 2,69 ds m -1 while the standard mixture was 1,13 ds m -1 . Cation exchange capacity varied from 43,6 to 89,4 meq/100 g while the standard mixture was 60,4 meq/100 g. Physical properties of mixture 4 (20% of bark + 80% of sawdust) are similar to standard mixture, but not the chemical properties. This mixture is a promising substrate for forest nursery production.

An ectomycorrhiza is a mutualistic symbiosis of paramount importance in forestry and tree production. One of the selection criteria of ectomycorrhizal fungi that has currently gained importance is their edibility due to the economic, ecological and cultural relevance of edible ectomycorrhizal mushrooms as a non-timber forest product. The effect of the inoculation with three edible ectomycorrhizal mushrooms: Laccaria laccata, Laccaria bicolor y Hebeloma leucosarx, which are widely sold in Mexico, on the growth and nutrient contents of Pinus greggii grown in an experimental substrate and a commercial substrate enriched with a slow-release fertilizer, was evaluated. Two years after sowing, differences in terms of shoot and root biomass and macro and micronutrient contents between inoculated and non-inoculated plants, were recorded independently of the fungal species and the substrate. Despite the fact that plants grown in the commercial substrate had higher growth and nutrient contents, their ectomycorrhizal colonization percentages were smaller than those of the plants grown in the experimental substrate. The differences in the nutrient transfer to the inoculated plant shoots among the evaluated fungal species were recorded. Ca mobilization by L. laccata, Na by L. bicolor and Mn by H. leucosarx were observed in the plants growing in the experimental substrate. It has been demonstrated that the selection of substrates constitutes an important factor in the production of ectomycorrhizal plants and that the three evaluated species of edible ectomycorrhizal mushrooms have an enormous potential in the controlled mycorrhization of P. greggii.

<p><strong>Background. </strong>All of the Pinaceae require the ectomycorrhizal interaction to survive under field conditions. However, their use has not traditionally been considered in the production of forest plants in Neotropical areas.</p><p><strong>Hypothesis.</strong> There will be an increase in plant quality in greenhouse and in survival in the field of <em>Pinus pringlei</em> inoculated with ectomycorrhizal fungi (ECMF).</p><p><strong>Site of study.</strong> The experiment was carried out in Texcoco, Mexico, in two sites: i) greenhouse of the Colegio de Postgraduados; and ii) in the field, in the San Pablo Ixayoc town.</p><p><strong>Methods.</strong> <em>P. pringlei</em> plants, a native species of Mexico, were inoculated with the ECMF: i) <em>Hebeloma alpinum </em>(<em>Ha</em>); ii) <em>Laccaria trichodermophora</em> (<em>Lt</em>); and iii) <em>Thelephora terrestris</em> (<em>Tt</em>). The effect of this inoculation on plant growth and nutritient translocation was evaluated. A morphological and molecular characterization of ectomycorrhizal roots and an evaluation of the seedling field survival were carried out, and compared with non-inoculated plants.</p><p><strong>Results.</strong> <em>Pinus pringlei</em> plants inoculated with ECMF increased their growth and nutrient content. A significant nutritional allocation from root to stem mainly of K, Fe, and Zn was recorded.</p><p>The morpho-anatomical and molecular characterization showed the presence of <em>Ha</em>, <em>Lt </em>and <em>Tt</em> in ectomycorrhizal roots. Two-year old plants mainly inoculated with <em>Ha</em> and<em> Tt</em> showed higher survival in the field than non-inoculated plants.</p><p><strong>Conclusions.</strong> The beneficial effects of ECMF on <em>P. pringlei</em> growth, nutrimental translocation (mainly on K, Fe and Zn), and field survival rates are reported for the first time.</p>

Se estudió la estructura y composición de la vegetación arbórea en las condiciones ambientales (CA) de Arroyo, Cañada y Loma. Se establecieron tres unidades de muestreo (UM) de 20 x 30 m en cada CA, donde se midió diámetro normal (DN), altura total y diámetros de copa de fustales (DN ≥ 2.5 cm). Para latizales (DN < 2.5 cm y altura ≥ 1.3 m) y brinzales (altura < 1.3 m) sólo se consideró la altura. Se calcularon los índices de valor de importancia (IVI), valor forestal (IVF), diversidad de especies (Shannon: H’) y semejanza florística (Sorensen: So). Se encontraron 83 especies arbóreas. Para fustales, las más importantes fueron Lonchocarpus minimiflorus (IVF = 25.9; IVI = 16.8) en Arroyo, Adenaria floribunda (IVF = 17.3; IVI = 14.7) en Cañada, y Guazuma ulmifolia (IVF = 27.6; IVI = 18.5) en Loma. Para latizales, Piper sp. (IVI = 29.1) en Arroyo, Eugenia capulli (IVI = 14.9) en Cañada, y Cassia sp. (IVI = 20.6) en Loma. Para brinzales, L. minimiflorus (IVI = 27.1) en Arroyo, Cassia sp. (IVI = 15.3) en Cañada, y Lantana achyranthifolia (IVI = 26.8) en Loma. La diversidad fue significativamente mayor (p<0.05) en las UM de Arroyo (H’ = 2.21-2.92) y Cañada (H’ = 2.37-2.98) que en las de Loma (H’ = 0.92-2.44). La semejanza florística fue superior entre las UM de Cañada (So = 0.46-0.71) y menor entre las de Arroyo (So = 0.33-0.39). Arroyo y Cañada presentan bosques maduros, mientras que Loma, vegetación en sucesión secundaria temprana.

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