排序方式： 共有4条查询结果，搜索用时 109 毫秒
1
1.
Pati&#;o-L&#;pez Ver&#;nica Bravo-Avilez David Vargas-Mendoza Carlos F. Blancas Jos&#; Rend&#;n-Aguilar Beatriz 《Genetic Resources and Crop Evolution》2022,69(2):601-618
Genetic Resources and Crop Evolution - Across the process of domestication, human selection produces changes in target attributes as well as changes that are not necessarily desired by humans due... 相似文献
2.
Mariana Vallejo Alejandro Casas José Blancas Ana I. Moreno-Calles Leonor Solís Selene Rangel-Landa Patricia Dávila Oswaldo Téllez 《Agroforestry Systems》2014,88(1):125-140
In this study we analysed: (1) the biodiversity conservation capacity of Agroforestry Systems (AFS) in temperate highlands of the Tehuacán–Cuicatlán Valley, Central Mexico, (2) human cultural motives and actions for conserving such diversity and (3) problems endangering that capacity. We evaluated the richness and diversity of perennial plant species maintained in AFS through vegetation sampling of 14 agricultural plots and compared their composition with that of natural forests (14 plots of 500 m2 each). We examined the situations among communities of Náhuatl, Ixcatec and Cuicatec people, documenting through interviews the management practices of plant species and the whole system, reasons why people maintain vegetation cover within AFS, and factors influencing changes in decisions favouring agriculture intensification. In the AFS studied we recorded a total of 79 species of trees and shrubs, 86 % of them being native species and representing 43 % of all species of trees and shrubs recorded in the sampling of the natural forests the AFS derive from. People leave standing on average a total of 40 individual trees and shrubs per agricultural plot. Reasons for leave plant species standing were more frequently associated with their use as fruit trees, firewood, shade, beauty, respect to nature and other environmental benefits. Water availability for irrigation, land tenure, and dependence on agriculture and forest for peasant's subsistence were main decision factors influencing AFS variation in their composition. AFS in temperate zones are important reservoirs of biodiversity and biocultural heritage and should be keystones for conservation policies in the Tehuacán–Cuicatlán Valley. 相似文献
3.
A. Moreno-Calles A. Casas J. Blancas I. Torres O. Masera J. Caballero L. Garcia-Barrios E. Pérez-Negrón S. Rangel-Landa 《Agroforestry Systems》2010,80(3):315-331
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; (ii) “jiotillal” dominated by Escontria chiotilla; and (iii) “garambullal” dominated by Myrtillocactus schenckii. Our information on genetic variation of dominant arboreal species in the study sites was reviewed and included in the analysis.
Factors influencing household’s decisions to maintain vegetation cover were compiled through a survey and interviews and analyzed.
All the samples of the agroforestry systems studied maintained on average nearly 59% plant species and 94% genetic variation
of dominant cacti occurring in the forests, although their ability to preserve endemic rare species is limited. Social factors
favoring maintenance of perennial species in agricultural plots include collective rules, households traditions, use of the
plants maintained in the systems, and the environmental information gathered from NGOs, the local Biosphere Reserve, and researchers.
However, agroforestry systems are losing their capability to maintain vegetation cover, mainly because of (i) decreasing amount
of land managed by households, determined by a progressive fragmentation of the land area given to new families, (ii) adoption
of technologies to intensify agriculture, and (iii) governmental programs penalizing the presence of vegetation patches within
agricultural lands since they are considered “useless” areas. Necessary policies to stop degradation of the agroforestry systems
and to improve their conservation capacity are discussed. 相似文献
4.
Morales J de Aluja AS Martínez JJ Hernández M Rosas G Villalobos N Hernández B Blancas A Manoutcharian K Gevorkian G Cervantes J Díaz A Fleury A Fragoso G Larralde C Sciutto E 《Veterinary parasitology》2011,176(1):53-58
This paper provides macroscopic and histological evidence on the statistically significant protective effects of S3Pvac-phage vaccination against porcine cysticercosis and hydatidosis. The study included 391 rustically bred pigs (187 vaccinated and 204 controls). Vaccination significantly reduced the prevalence of cysticercosis by 61.7%. Vaccination also significantly reduced by 56.1% the prevalence of hydatidosis caused by Echinococcus granulosus in pigs. The presence of the vaccine epitopes in both cestodes is probably involved in the cross-protection observed. Increased inflammation was found in 5% of cysticerci recovered from controls, versus 24% from vaccinated pigs (P<0.01). Hydatid cysts were non-inflammatory in either group. Vaccination was effective to prevent one single disease, but it failed to prevent the simultaneous infections with both parasites in a same pig. The widening of the S3Pvac-phage vaccine protective repertoire to include hydatidosis is a convenient feature that should reduce the prevalence of two frequent zoonoses that affect rustic porcine breading with a single action. Thus, the costs of two different vaccination programs would be reduced to a single one with significant reduction in both zoonoses. 相似文献
1