Wild specimens of Vanilla planifolia represent a vital part of this resource primary gene pool, and some plants have only been reported in Oaxaca, Mexico. For this reason, we studied its geographical distribution within the state, to locate and describe the ecological characteristics of the areas where they have been found, in order to identify potential areas of establishment. The method comprised four stages: 1) the creation of a database with herbarium records, 2) the construction of the potential distribution based on historical herbarium records for the species, using the model of maximum entropy (MaxEnt) and 22 bioclimatic variables as predictors; 3) an in situ systematic search of individuals, based on herbarium records and areas of potential distribution in 24 municipalities, to determine the habitat current situation and distribution; 4) the description of the environmental factors of potential ecological niches generated by MaxEnt. A review of herbarium collections revealed a total of 18 records of V. planifolia between 1939 and 1998. The systematic search located 28 plants distributed in 12 sites in 95 364 Km2. The most important variables that determined the model of vanilla potential distribution were: precipitation in the rainy season (61.9 %), soil moisture regime (23.4 %) and precipitation during the four months of highest rainfall (8.1 %). The species potential habitat was found to be distributed in four zones: wet tropics of the Gulf of Mexico, humid temperate, humid tropical, and humid temperate in the Pacific. Precipitation oscillated within the annual ranges of 2 500 to 4 000 mm, with summer rains, and winter precipitation as 5 to 10 % of the total. The moisture regime and predominating climate were udic type I (330 to 365 days of moisture) and hot humid (Am/A(C) m). The plants were located at altitudes of 200 to 1 190 masl, on rough hillsides that generally make up the foothills of mountain systems, with altitudes of 1 300 to 2 500 masl. In natural conditions, distribution of the species is not limited to high evergreen forests, since it was also found in mountain mesophyll and tropical evergreen forests. The location of new specimens of V. planifolia in its wild condition reduces the potential distribution area by 66 %. This area is fragmented into three geographically separated areas. Habitat reduction was due to the increased number of located plants that define the environmental conditions into a more accurate level. Conservation actions can thus be designed and implemented, focusing on more specific areas within the state of Oaxaca, Mexico.

En la interfase ciudad-comunidades rurales del área metropolitana del Valle de Puebla se tienen establecidas siete áreas naturales protegidas periurbanas. El objetivo de esta investigación fue tener un diagnóstico exploratorio de su condición actual y de los factores que inciden en su pérdida territorial y deterioro ecológico. Estas áreas no están funcionando como estrategias de conservación debido a que carecen de una delimitación espacial precisa y de un plan de manejo, son desconocidas por la mayoría de los habitantes del área, carecen de un presupuesto para su gestión, hay venta de tierras y persisten las actividades productivas y extractivas.

EVALUACIÓN DE LA CONDICIÓN ECOLÓGICA DEL RÍO ZAHUAPAN

Con el objetivo de evaluar el grado en que los sistemas de producción de ovinos son competitivos y presentan ventajas comparativas, se entrevistaron a 139 productores, y se dio seguimiento a seis rebaños de tres sistemas de producción durante siete meses, en la región de Libres, Puebla. Se registró información de costos, infraestructura, actividad agrícola, mano de obra, producción y venta de ovinos. Para determinar la rentabilidad y la competitividad se utilizó la Matriz de Análisis de Política. El sistema de producción con alimentación en corral fue el más rentable y competitivo de acuerdo con los indicadores de rentabilidad privada, Relación del Costo Privado, Coeficiente de Rentabilidad Privada y la Relación del Costo-Beneficio Privado. El costo de los factores de producción fue mayor en el sistema de producción de corderos en pastoreo y fue el de menor competitividad. La Relación Costo-Beneficio Social indicó ineficiencia para reemplazar las importaciones. La producción de ovinos tuvo una estructura de mercado oligopsónica, producto de las deficiencias institucionales y ausencia de políticas de protección. Los productores utilizaron como criterio de venta el peso adulto, aunque la venta de los corderos inició entre los 30 y 90 días. Es recomendable realizar el análisis de la función de producción, para determinar la viabilidad de la venta de cordero destetado, como una opción para aumentar las ganancias de los productores y la competitividad de estos sistemas.

Background: Fruit yield in vanilla cultivation depends on climatic and genetic factors and management practices; however, studies on the influence of the environment on management systems for vanilla production are still limited. Objective: To evaluate the yield of vanilla fruit in three different management systems in correlation with their climate parameters. Methodology: 16 fruit yield components were evaluated in at least 10 repetitions; in addition, temperature, relative humidity, photosynthetically active radiation, and accumulated precipitation were recorded during the production cycle. The analysis of variance, Tukey´s test (α=0.05), and canonical correlation between yield components and climate parameters were performed under a randomized complete block design. Results: Vanilla fruit yield was influenced by the management system. The intensive system in shade mesh with an inert tutor (Barriles) had the highest yield of three evaluated sites, however, its fruits had lower weight and size than the system in acahual (20 Soles) and shade mesh with a living tutor (Solteros de Juan Rosas). The acahual system had a middle yield and the largest and heaviest fruits. The cultivation in shade mesh with living tutors in Solteros had low yield, attributable to high relative humidity and low photosynthetically active radiation during the cultivation cycle due to excessive shading of living tutors that as a whole could cause low floral induction and environmental stress promoting the development of diseases and premature fruit drop. Nevertheless, the fruits harvested in Solteros had physical characteristics similar to those of acahual (20 Soles). The effect of climate parameters was mainly reflected in inflorescences and fruit density. Implications: The incorporation of more study sites and cultivation cycles are necessary to extend the research, however, the information provided may be useful for producers to modify some of their management practices. Conclusions: The yield and size of vanilla fruits is influenced by the management system, since the highest yield occurred in the intensive system of shade mesh with inert tutors. The presence of diseases is a factor that could influence low fruit yield. Relative humidity and photosynthetically active radiation are the climate parameters with the greatest influence on fruit yield, particularly on fruits and inflorescences density in vanilla cultivation.

Vanilla pompona is the third most important commercial species of the genus Vanilla, but the morphometric variation of its flowers is not well known. In orchids, infraspecific variation is expressed in the labellum. This study had the objective of analyzing the floral variation of V. pompona collections from the localities in Veracruz, Puebla, Jalisco and Oaxaca, in Mexico. During the flowering period, we obtained 55 collections of V. pompona flowers, and the labellum of each flower was dissected. We used ImageJ to measure and portray 54 lines and 7 angles in these labella. With the data obtained, we performed an analysis of variance, principal component analysis and cluster analysis. The results showed significant differences among the collections and localities in the means of the lines of the basal, middle, and apical regions of the labellum. Also, six morphotypes were obtained, and we found that variation was associated with factors such as the environment, geographic barriers, and pollinator pressure. Moreover, we observed variation in flowering periods in one locality of Veracruz. We concluded that there is infraspecific variation within and between the collection localities of V. pompona in the Atlantic region (Puebla and Veracruz) and the Pacific region (Jalisco and Oaxaca), Mexico.