Joaquín Sosa Ramírez

Adaptaciones morfológicas foliares en tomate cultivado en bioespacio de techo retráctil con clima cálido

Microclimatic conditions and indeterminate tomato leaf morphology of two bio-spaces were analyzed: retractable- roof greenhouse and shade-house in Culiacan, Sinaloa, Mexico, during the period 2009 - 2010. The results show that, the retractable-roof greenhouse generates more favorable conditions for photosynthesis, as a result of lower thermal fluctuation within this bio-space, compared with the environment imposed by the shade-house. Extreme temperatures (maximum and minimum) into the retractable- roof greenhouse remained in a range significantly smaller and therefore more favorable for the production and reproductive stability of tomato in the warm weather of Culiacan, compared to shade-houses. This was corroborated by the magnitude of leaf morphological variables analyzed and the differences detected between leaflets developed in both cases. The values of leaf area index, leaf thickness, length of palisade parenchyma and presence of double palisade parenchyma observed in plants grown under retractable-roof made of glass were significantly higher than the values observed in the shade-house. The results suggested that higher tomato yields recently reported retractable-roof greenhouse in warm climates are due in

Diversity, Distribution, and Abundance of Woody Plants in a Dry Tropical Forest: Recommendations for Its Management

Dry tropical forests cover approximately 35% of Mexico’s surface. However, in the past 20 years, a substantial proportion of these forests have been lost, placing this country among the first three with highest deforestation worldwide. In Aguascalientes this type of forest is located mainly in the municipality of Calvillo and is also in a process of degradation. We conducted a phytoecological analysis to document the species richness, their abundances, spatial distribution, and overall diversity. We established 26 sites in the forested area of the Sierra Fria Protected Natural Area. We identified 79 species of trees and shrubs belonging to 45 genera and 14 families. The diversity index H′ varies from 3.49 in the best preserved sites to 2.77 in the most degraded sites. The species richness found in this area (N = 79) is similar to that reported for other areas in the dry tropical forests of Mexico. Management strategies are suggested to conserve biological diversity and ecosystem services associated with this forest, considering the aspirations and well-being of the rural communities that own the land where these forests are located.