金沙江干热河谷适生树种的引种和早期适应性研究

相思(Acacia spp.)类树种类型多,分布广,除欧洲及南极外各大洲均有分布,尤以澳大利亚最多,其次为非洲;该类树种主要生长在干旱半干旱地区,垂直分布在海平面附近至1 500 m以上;该树种生长快,用途广泛,有根瘤,具有强力固氮作用[1,2];生物量大,枯枝落叶多,对土壤有很好的改良作用[3～5];此外,网脉相思(Acacia aneura F.Muell.ex Benth.)、维多利亚相思(A.victoriae Beath.)还能用作饲料,如网脉相思被认为是澳大利亚干旱季节牲口最充足和营养丰富的饲料.20世纪60年代以来,我国已引种了大叶相思(A.auriculaeformis A.Cunn.)、马占相思(A. mangium Willd.)、厚荚相思(A. crassicarpa A.Cunn. ex Benth.)、纹荚相思(A.aulacocarpa A.Cunn ex Benth.)等,这些相思树种在荒山绿化、薪炭林经营、水土保持及公路建设中发挥了重要作用.

Study on the Introduction and Early Adaptability of Adaptable Afforesta tionTree Provenances in Hot and Ar id Va lley, Jinsha jiang River

The growth performances of 17 provenances of 3 Acacia species,2 provenances of Casuarina species,and 2 provenances of Eucalyptus species were analyzed.The results showed that there are very significant differences among provenances in tree height,crown diameter,ground diameter and reserving rate.All the indicators except reserving rate were remarkably different among blocks.For 17 Acacia provenances,the difference in tree height,crown diameter and ground diameter among provenances and blocks were very significant,but no difference existed between the 2 Casuarina provenances in tree growth.By 18 months' analysis and Ducan test,the 21 provenances were divided into 3 groups,in which 2 Casuarina provenances,2 Eucalyptus provenances and 2 Acacia provenances had the best growth performance and could be selected as the optimal provenances to plant in hot and arid valley.