Agroforestry definitions, concepts and characteristic and the importance and perspectives in Mexico are presented. Also, it is described some of the most important systems in the temperate, tropical and arid regions of Mexico. Likewise, it is exemplified with some practices product of the recent investigation applied in the tropical region of Puebla and Veracruz and in the temperate area of the State of Mexico. Likewise, the application of the agrosilvopastoral systems is emphasized in the small producers farms in the tropic of Mexico.

In the peruvian Amazonia and during the second semester of 2000, we evaluate the volumes of carbon secuestrated by six agroforestry systems and/or land use systems: primary forest, regeneration forest, coffee+shade, pasture+trees, pasture and homegarden. In three ecological situations (blocks). We had consider for the total sample, a) tree biomass, b) herbaceous and arbustive biomass, c) litter and d) soil. About the total carbon, the parameter primary forest, stored 465,8 tC·ha-1, overcomes in 58 % to the treatments: homegarden and coffee+shade, in 74.3 % to the fourth: pasture+trees and 80 % to the other parameter, pasture. However, those ones plus regeneration forest are statistically similar and less than the primary forest (P

In recent years many novel and highly potent lipoid signaling molecules have been recognized. These comprise lipophilic compounds not derived fron lipids, such as the triterpenoid brassinoesteroids, others that are partly of lipid origen such as the lipo-oligosaccharides, nodulation factors of Rhizobium species that may have relatives endogenous to plants, and a third group, the octadecanoids, whose structures are derived from plant fatty acids. Lipid-mediated signals is an important aspect of plant life and a rapidly growing area of research.

The Corixidae are water bugs of economic importance, used as human food, for fish, waterfowl, cage birds, and others. The ecological aspects in Mexico are scarce. The objective is to point out some of them. Were carried out eleven samplings monthly from October 1995 to August 1996 in the piscicole pond “JC” in the State of Mexico. Two sampling stations were located and in each it was measured depth, transparency, temperature, oxygen, pH, conductivity, hardness and alkalinity. The corixids were captured with a sweep-net of rectangular form. Four species were registered: Trichocorixella mexicana, Graptocorixa abdominalis, Krizousacorixa femorata and Corisella edulis. The specie T. mexicana was increased their density by the transparency (0.27 m), the depth (0.78 m) and the oxygen (7.03 mg⋅L-1) and affected by a descent in the depth (0.17 m) and an increment in the temperature (20.7 °C). G. abdominalis increased their density by the transparency (0.28 m); descending for the pH (9.0), the conductivity (132.5 (μmhos⋅cm-1), the depth (0.01 m), the temperature (13.4 °C) and the oxygen (8.72 mg⋅L-1). K. femorata increased their density by the same parameters that T. mexicana and their descent was due to the increment in the hardness (100 mg CaCO3⋅L-1). C. edulis was only presented when the pH was lightly acid (6.9). The density of the Corixidae is in relation with the fluctuations of the environmental parameters of the “JC.” pond

Mankind since it´s beginning has been interested on insects, first observing their variety and abundance, then understanding their role in environment. As a consequence, cultural aspects have created surrounding these organisms, odonata haven´t been the exception; nevertheless their relevance comparing them with other insects groups, that´s why this writing´s objetive is to know different cultural views in wich these insects have been considered, doing a bibliographical research. Several cultural expressions have been found, which topic is odonata, from their common names to literature, going through traditions and believes we have, regarding these insects.

This research was aimed at to fit species diversity indices on the tree strata and to analyse the ecological parameters using different sizes of quadrants and transects as sampling schemes. The ecological parameters of abundance, dominance, frecuency and relative importance value were investigated. The results showed that more than 30 tree species were found growing in a mixed uneven-aged forest with a density of over 1000 trees per ha. The difference between two methods of sampling (i.e. quadrant and transect) for diversity estimats is significant at 95% confidence level. The transects provided better estimates for the average diversity of the both study areas in less sampling surface. Several diversity indices were different significantly with different sizes of quadrants and transects. The indices of Shannon, Margalef and Mcltosh were more sensitive to both sampling schemes and to different sizes of quadrants and transects. The analysis of the ecological parameters revealed that Quercus sartorii, Liquidambar styraciflua and Carya ovata had the higher ecological importance in this community.

Nine models to estimate commercial volume functions with and without bark for purpleheart (Peltogyne mexicana Martínez) were adjusted. For this, dasometric information was taken from 65 wild trees to 20 cm as minimum commercial diameter of the main trunk and/or branches. Results showed that the Combined Variable (ordinary) Equation was the best to estimate both volumes. These were: vcc=0.021015+0.000027435(d2 h) vsc=0.017627+0.000025916(d2 h) Of this equation, the volume commercial tables with and without were generated for this specie.

At south of the Orinoco River, in Venezuela, there are more than three million hectares with most important biodiversity if compared with Europe. Enormous mineral resources, gold and diamonds especially, 530 km of bordering margin with Guyana and native peoples treasure harbored from pre colonial times, are the others peculiarities in the Imataca Forest Reserve. Those factors cause a situation for its narrow relationship with the economic and social development of the country. It is necessary to classify importance concerning some factors as biodiversity, indigenous cultures, wood resources, mining abundance and national frontier. A preliminary diagnosis was well thought-out as starting point for the identification of tendencies and against main objective formulation in order to achieve Imataca Forest Reserve sustainability. To accomplish this objective, efforts are based on the precision about the territory current uses, their problems and potentialities and the promising strategy of territorial uses classification. The purpose of this work is to disclose information about activities development in the Imataca Forest Reserve to facilitate debates directed to achieve the trilogy of the sustainable development: sustainability of the atmosphere, economic benefit and social welfare.

The lack of Knowledge about no wood forestry products has permitted to diminish the economic importance of it fox the national market as for the international one. Investigations of the area suggest that the fatal economic value of the woody Products and Its Improvement could grow greatly without harmful environmental effect the use of them as row material for the electric industry has permitted the Production of an electroaisvlanting varnish, which has a main objective to protect the transformation and electromotor rolling from the humidity and externd agressive element that exert influence upon then, also they can give them a mare everlasting life.

This study was conducted to determine the efficiency of seven antisapstain products that are sold in Mexico to control the fungus that stains Ceratocystis sp. on lumber of rubber (Hevea brasiliensis), by means of the method of the disks jointly with the norm ASTM D 4445-91. Three of these products, Osmotox, Pentatox and Biotox, are made from sodium-pentachlorophenate, three more are made of methylene-bis-thiocyanate and 2-thiocyanomethylthio benzothiazole: Busan 1009, Busan 1450 and Busan 1071, and the seventh, Busan 1118, only contains 2-thiocyanomethylthio benzothiazole. The minimum effective concentration needed to prevent sapstaining for a four-week exposure to the chemicals was estimated to be 4.68 % Osmotox, 2.82 % Pentatox, 3.24 % Biotox and 2.00 % Busan 1118. In contrast, no sapstain occurred with methylene bistiocyanate and 2-thiocyanomethylthio benzothiazole, even with the smallest tested concentration; it is estimated that the concentration required is less than 0.25 %. Considering the commercial cost of each product and the lowest effective concentration for zero growth, Busan 1071 is the most economical and effective product.