西藏色季拉山主要林型土壤的水文功能

运用典型样地法,对林芝地区的林芝云杉、高山松、方枝柏等6种不同森林类型土壤的水文生态功能进行了初步研究,结果表明:林芝地区不同森林类型凋落物总厚度林芝云杉最大,为8. 55cm;川滇高山栎林总厚度最小,只有2. 52cm;其它各种林分凋落物总厚度介于林芝云杉和川滇高山栎之间。总储量高山松林最高,为82.26t/hm2,川滇高山栎林最低,仅为10. 81t/hm2。林芝地区主要林分中林芝云杉的未分解层、半分解层、已分解层最大持水量最大,分别为52. 44、54. 50、63. 00t/hm2,未分解层川滇高山栎林最低,为5. 82t/hm2,半分解层糙皮桦最低,为9. 52t/hm2,已分解层西藏箭竹最低,为5. 78t/hm2。方枝柏土壤容重最小,为0. 50g/cm3,土层最薄(0. 70m),但总孔隙度和最大持水量最大。森林土壤蓄水能力大小排序为:方枝柏(7 987. 00t/hm2 )>林芝云杉(7 291. 00t/hm2 ) >糙皮桦(6992. 00t/hm2 ) >川滇高山栎(634. 70t/hm2 ) >高山松(5 980. 00t/hm2 ) >西藏箭竹(4 696. 50t/hm2 )。土壤渗透性高山松林最好,林芝云杉最弱;川滇高山栎、方枝柏林A层渗透速度远远大于B层、C层;糙皮桦和西藏箭竹林B层、C层相差不大,但都稍低于A层。

Soil Hydrological Functions of the Main Forests on Sejila Hills in Tibet

The soil hydrological functions of 6 different types of forests of Picea likiangensis (Franch) Pritz. var. linzhiensis Cheng et L. K. Fu, Pinus d ensata Mast, Mouring cypress, etc. in Linzhi were studied by the method of typical sample plot. The result showed that the thickness of litters for Pice a likiangensis forest was the most, which was 8.55cm, while that for Querc us aquifolioides Rehd. et Wils forest was the least, only 2.52cm, and the th icknesses of other forests were intervenient. The cumulation of Pinus densata fo rest was the largest, which reached to 82.26t/hm 2, and Quercus aquifolioid es was the lowest, only 10.81t/hm 2. Among the main forests in Linzhi, the largest water retaining capacities of the un-disintegrated soil, the semi-disint egrated and the disintegrated of Picea likiangensis were the most, which wer e 52.44, 54.50 and 63.00t/hm 2, respectively, and that of the un-disintegrate d of Quercus aquifolioides (5.82t/hm 2) was the lowest, that of the semi- disintegrated of Betula utilis D. Don (9.52t/hm 2) was the lowest, and th at of the disintegrated of Sinarundinaria setosa Yi was the least of 5.78t /hm 2. For Mourning cypress, its soil bulk density was the least of 0.5 0g/cm 3, the soil was the thinnest of 0.70m, but the total porosity an d the largest water retaining capacity were the most. The order of the soil wate r storage was Mourning cypress (7987.00t/hm 2)> Picea likiangensis (7291.00t/hm 2)> Betula utilis (6992.00t/hm 2)> Quercus aquifoli oides (634.70t/hm 2)> Pinus densata (5980.00t/hm 2)> Sinarundina ria setosa Yi (4696.50t/hm 2). For the soil infiltration, Pinus densata forest was the best, Picea likiangensis forest was the weakest; the infil tration rates of A-layer soil of Quercus aquifolioides and Mourning cy press forests were much more than those of B and C layer soil; those of B and C layer for Betula utilis and Sinarundinaria setosa Yi forests were litt le discrepant, but a little lower than that of A layer.