Alejandro Casas

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BACKGROUND AND AIMS Ethnobotanical studies in Mexico have documented that Mesoamerican peoples practise systems of in situ management of wild and weedy vegetation directed to control availability of useful plants. In situ management includes let standing, encouraging growing and protection of individual plants of useful species during clearance of(More)
The role of agroforestry systems in biodiversity conservation was investigated in the semiarid Tehuacán Valley, Central México. Richness and diversity of native plant species were compared between agroforestry systems (6 sampling sites) and the following forests (6 sampling sites) dominated by columnar cacti: (i) “chichipera” dominated by Polaskia chichipe;(More)
BACKGROUND Management types and their intensity may vary according to indicators such as: (1) practices complexity, (2) degree of techniques specialization, (3) occurrence and types of social regulations, (4) artificial selection intensity, (5) energy invested, (6) tools types, and (7) amounts of resources obtained. Management types of edible plants were(More)
People of the Tehuacán Valley, Central Mexico utilise the columnar cactus Escontria chiotilla for their edible fruits, gathering them in the wild and in silviculturally managed populations. Silvicultural management consists in sparing and enhancing selectively, in disturbed areas, individual trees producing fruits of the better quality for consumption and(More)
Ethnobotanical information is presented on use, management, folk nomenclature and classification of the “xoconochtli” (Stenocereus stellatus) as well as on the role of this plant in subsistence of the Nahua, Mixtec and Popoloca peoples from the Tehuacán Valley and La Mixteca Baja in Central Mexico. Among all three groups, S. stellatus was used for various(More)
A general overview of the biological knowledge of the floristic province of the Tehuacán-Cuicatlán Valley in central-southern Mexico is presented. Floristic and faunistic richness and endemism, as well as uses of the flora are analyzed and discussed for this area, recently declared a biosphere reserve. The analysis shows that, in approximately 10 000 km2(More)
The columnar cactus Stenocereus stellatus is used in Central Mexico for its edible fruits which are harvested in wild, managed in situ and cultivated populations. Management in situ of wild populations is conducted by selectively sparing and enhancing the abundance of plants with desirable phenotypes when fields are cleared for agricultural use. Cultivation(More)
Levels of genetic variation and genetic structure of 15 wild populations and three domesticated populations of Capsicum annuum were studied by RAPD markers. A total of 166 bands (all of them polymorphic) and 126 bands (125 of them polymorphic) were amplified in wild and domesticated populations, respectively. Mean percentage of polymorphism was 34.2% in(More)
Polaskia chichipe, a columnar cactus, is cultivated for its edible fruits in central Mexico. This study analyzed whether artificial selection has modified its reproduction patterns and caused barriers to pollen exchange between wild, managed in situ, and cultivated populations. Anthesis was diurnal (∼16 h in winter, ∼10 h in spring) as well as partly(More)
In Spain, trichinellosis represents a public health problem, with an average of five outbreaks per year, wild boar meat being the main source of infection. A trichinellosis survey (2007-2008 hunting campaign) was carried out on wild boars in the Toledo Mountains (south-western Spain, EU) in the context of a surveillance programme on wildlife diseases. A(More)