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Natural resources are important for the development of communities because of the generation of goods, services and jobs. The strategies for protection and exploitation of wildlife at the international level are specified in conventions, agreements and treaty signatures. However, an evaluation and analysis of these is required to understand their effectiveness. The purpose of this study was to carry out a literature review about the conservation strategies during 1970-2010; to this aim, information was sought, organized and analyzed related to scientific articles, legal framework and electronic books elaborated by International Organizations. The information was organized by developed countries (n=7) and developing countries (n=7). In the 113 evidences analyzed it was found that the strategies conclude with the signature, execution of conventions and international agreements; however, only 5 % of the documents are related to the evaluation, analysis of the effectiveness and performance of those programs, highlighting that in their majority they refer to developing countries. This document emphasizes that in order for conservation strategies to be successful, they should be elaborated based on principles, criteria, indicators and verifiers of social, economic, political and ecologic type., Los recursos naturales son importantes para el desarrollo de las comunidades por la generación de bienes, servicios y empleos. Las estrategias de protección y aprovechamiento de la vida silvestre a nivel internacional se especifican en convenios, acuerdos y firma de tratados. Sin embargo, se requiere una evaluación y análisis de estos para conocer su eficacia. El propósito de este trabajo fue realizar una revisión de literatura sobre las estrategias de conservación durante 1970-2010; para ello se buscó, organizó y analizó información relacionada con artículos científicos, marco normativo y libros electrónicos elaborados por Organizaciones Internacionales. La información se organizó por países desarrollados (n=7) y en vías de desarrollo (n=7). En las 113 evidencias analizadas se encontró que las estrategias concluyen con la firma, ejecución de convenios y acuerdos internacionales; sin embargo, solo 5 % de los documentos se relacionan con la evaluación, análisis de la efectividad y desempeño de esos programas, destacando que en su mayoría se refieren a países en vías de desarrollo. Este documento enfatiza que para que las estrategias de conservación tengan éxito estas deberán elaborarse con base en principios, criterios, indicadores y verificadores de tipo social, económico, político y ecológico.

Se estudiaron tres poblaciones silvestres de Jatropha curcas L. en la región sur y centro de Sinaloa en los sitios de Estación Dimas, La Campana y El Quelite. Los objetivos fueron caracterizar morfológicamente las plantas y semillas, evaluar la relación de las variables morfológicas con los factores ambientales y analizar el potencial de distribución de las especies en Sinaloa considerando los factores ambientales registrados en los sitios de estudio. En cada sitio de estudio se realizó el conteo del número de individuos/m2 y se midió la altura, el diámetro de copa, el diámetro basal y el número de ramas. De cada sitio se obtuvo también el número de semillas por kilogramo, color, peso, longitud y ancho de la semilla. La altura de las plantas estuvo en un intervalo de 2.25 a 4.59 m, el diámetro de la copa fue de 2.24 a 4.48 m, el diámetro basal de 18.75-24.81 cm y el número de ramificaciones de 2 a 4. No se observaron diferencias significativas entre las características morfológicas de las plantas de Estación Dimas y el Quelite pero sí con respecto a La Campana. En ambos sitios se observó que la altura de las plantas fue favorecida cuando la temperatura y velocidad del viento fueron menores, y cuando la precipitación y humedad relativa fueron mayores. Las dimensiones de las semillas fueron, ancho 7.41 a 7.9 mm y longitud de 15.1 a 15.9 mm. La humedad de las semillas fue de 3.57 a 4.21%, y el color de las semillas fue de 60.80 a 65.64°Hue. La mayor densidad de individuos se encontró en Estación Dimas (21 ind/ha), pero la utilización del campo con fines agrícolas que se encuentra cercana a este ecotipo amenaza al desarrollo de la vegetación silvestre de este sitio. Por lo que el germoplasma de las poblaciones en estudio puede ser útil para elaboración de planes y manejos de conservación de la especie, además constituye una alternativa para el establecimiento de cultivos en el estado con especies propias de la región y, posiblemente, para otras regiones del país. Por ot, Three wild populations of Jatropha curcas in the central and southern parts of Sinaloa were studied; Estación Dimas, La Campana, and El Quelite. The objectives were to characterize plants and seeds morphologically to assess the relationship between morphological traits and environmental factors and the potential distribution of the species considering environmental factors from the study sites. All individuals/m2 and number of branches were counted, and height, diameter of cup, and basal diameter were measured. The number of seeds per kilogram was obtained, as well as color, weight, and seed length and width. Plant height ranged from 2.25 to 4.59 m; the crown diameter from 2.24 to 4.48 m; basal diameter from 18.75 to 24.81 cm; and branch number 2 to 4. No significant differences were found in morphological characteristics between plants from Estación Dimas and El Quelite but those from La Campana were significantly smaller. Plant height was favored in sites with lower temperature, altitude, and wind speed, and with higher precipitation and relative humidity. Seed length ranged from 7.41 to 7.9 mm and seed width from 15.1 to 15.9 mm. Seed moisture ranged from 3.57 to 4.21%. The seed color ranged from 60.80 to 65.54° Hue. The highest tree density was found in Estación Dimas (21 ind/ha), but agricultural practices threatens the vegetation in this site. The species has a high potential for distribution in the southern and central parts of the state. Germplasm from the studied populations may be useful for plans and management for species conservation; they also constitute an alternative to the establishment of crops in the state of Sinaloa with typical species of the region and possibly other regions of the country. Moreover, it was observed that the species has a high potential for distribution in the state mainly in the municipalities of Sinaloa de Leyva, Guasave, Guamuchil, Culiacan, Elota, San Ignacio, Mazatlan, Villa Union, Concordia, and Escuinapa.

Pastures established using buffelgrass (Cenchrus ciliaris L.) have shown heterogeneous responses in terms of forage production and permanence. A good alternative for determining establishment sites and predict trends in buffelgrass conditions is the use of simulation models. The objectives of this research were to determine the factors that regulate successfulness in buffelgrass pastures and to develop a model to determine suitability in areas managed for buffelgrass pastures, based on environmental, ecological, and management variables. Above ground biomass production was considered to determine suitability in sites with buffelgrass. Eight ranches with different geographic locations, environmental situations, and management conditions were sampled as preliminary study sites to measure and model plant production. The resulting model was used to estimate plant production in the 37 sampling sites of the study areas. Results of the study indicate that basal area is a good modeling parameter to estimate production in buffelgrass plants. I also found that plant production in buffelgrass is negatively affected by population density. I concluded that there exist a positive correlation between pasture management and buffelgrass plant production. Correlation analyses demonstrate that there exist significant correlations between Pasture Condition Index (PCI) and mean annual temperatures, aspect, pasture age, nitrogen and sodium content. However, after performing stepwise regressions, only three variables were significant: pasture age (PA), nitrogen content (N2), and mean annual temperature (MAT); the last two, produce a negative response on PCI.

Remote sensing and geographic information system techniques have proved to be effective tools to detect, analyze, and evaluate land cover and land use changes over time. In this research project, changes in land cover and land use were detected in northwestern Sonora, Mexico between 1972 and 1992 using Landsat MSS imagery. About 40% of the entire land cover in the study area changed during that period of time. Of the six classes assigned to the imagery, cropland had the highest rate of change being modified into riparian areas by more than 60%, more than 20% into plains vegetation, and about 8% into bajadas with vegetation. From the two classification methods utilized in this study, the seeding pixels method yielded an over all accuracy over 96%, while the seeking polygons method generated overall accuracy values smaller than 82% probably to user's error.