tailieunhanh - Báo cáo lâm nghiệp: "Ecophysiology of 8 woody multipurpose species from semiarid northeastern Mexico"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp Original article đề tài: Ecophysiology of 8 woody multipurpose species from semiarid northeastern Mexico. | 454s Ann. Sci. For. 1989 46 suppl. 454s-458s Forest Tree Physiology E. Dreyer et al. eds. Elsevier INRA Ecophysiology of 8 woody multipurpose species from semiarid northeastern Mexico H. stienen1 . Smits2 N. Reid3 J. Landa4 and . Boerboom2 Hnstitut Bicontrol GmbH PF 1630 6500 Mainz . Landbouw Universiteit Wageningen Vakgroep Bosteelt Boscecologie The Netherlands Department of Plant Ecology University of New England Armidale Australia and 4Facultad de Ciencias Forestales UANL Linares . Mexico Introduction The Tamaulipan thornscrub is a low dry forest and shrubland complex covering about 20 million hectares of the Gulf coastal plain in northeastern Mexico and southern Texas the region is called the Matorral. The Tamaulipan thornscrub has been grazed by domestic stock for about 4 centuries and is heavily exploited by subsistence farmers for fuel timber and other resources Reid et al. 1989 . In order to prevent further desertification and sustain agricultural livestock and forestry production the Matorral must be conserved and where necessary enriched with desirable multipurpose trees and shrubs MPTS . The Facultad de Ciencias Forestales of the Universidad Autonoma de Nuevo Leon UANL Mexico is applying a holistic agroforestry approach to some of the region s landuse problems Stienen 1989 . Native shrubs and trees have been selected for agroforestry trials to date on the basis of the products and expected productivity. Knowledge of their ecophy-siological characteristics would facilitate selection of the species most apt for silvicultural management under specified conditions. The water use productivity ratio may be a useful be index for screening potential forestry species because drought frequently limits growth. Materials and Methods The study was conducted in the Matorral on the UANL campus 10 km south of Linares 24 47 N 99 32 W in spring and summer 1988. Mean annual rainfall is 749 mm. Droughts occur in midsummer and winter. Annual free evaporation