甘南尕海不同湿地类型土壤物理特性及其水源涵养功能

通过对甘南尕海4种湿地类型的土壤物理性状和水源涵养功能的研究,结果表明:不同类型湿地的土壤颗粒组成、土壤容重和土壤孔隙度差异明显,且均随土壤深度的增加呈现波动性变化。土壤平均粗砂粒含量为草本泥炭地(63.00%)>永久性沼泽湿地(46.47%)>高山湿地(37.60%);细砂粒为高山湿地(62.40%)>永久性沼泽湿地(53.53%)>草本泥炭地(37.00%)。永久性沼泽湿地(0.49g/cm3),高山湿地(0.90g/cm3)和亚高山草甸(1.29g/cm3)平均土壤容重约是草本泥炭地(0.22g/cm3)的2,4,6倍。土壤总孔隙为草本泥炭地>永久性沼泽湿地>高山湿地>亚高山草甸,土壤非毛管孔隙度为草本泥炭地>亚高山草甸>高山湿地>永久性沼泽湿地。土壤平均最大蓄水量为草本泥炭地(13 143.94t/hm2)>永久性沼泽湿地(11 640.19t/hm2)>高山湿地(9060.79t/hm2)>亚高山草甸(7 391.80t/hm2),非毛管蓄水量为草本泥炭地(937.67t/hm2)>亚高山草甸(598.50t/hm2)>高山湿地(594.67t/hm2)>永久性沼泽湿地(325.13t/hm2)。土壤排水能力的平均值为亚高山草甸(51.49mm)>永久性沼泽湿地(49.66mm)>高山湿地(43.42mm)>草本泥炭地(22.45mm)。在甘南尕海,草本泥炭地的水源涵养功能最好,而亚高山草甸排水功能最好。

Soil Physical Characteristics and Water Conservation Function for Four Main Wetland Types in Gahai of Gannan

The soil physical properties and water conservation function of 4 types of wetland were studied in Gahai,Gannan.Results indicate that there are great differences in soil particle composition,soil bulk density and soil porosity for the different wetland types,and they are fluctuating changes with the increase in soil depth;the average level of thick sand of soil for herbaceous peats,permanent marsh wetlands and mountain wetlands is 63.00%,46.47% and 37.60% respectively;fine sand for mountain wetlands,permanent marsh and herbaceous peats is 62.40%,53.53% and 33.63%;the average soil bulk density of permanent marsh wetlands(0.49 g/cm3),mountain wetlands(0.90 g/cm3) and subalpine meadows(1.29 g/cm3) is about 2,4,6 times that of herbaceous peats(0.22 g/cm3);the total soil porosity is shown as: Herbaceous peats >permanent marsh wetlands >mountain wetlands >subalpine meadows;the non-capillary porosity is shown as: Herbaceous peats >subalpine meadows >mountain wetlands >permanent marsh wetlands;the average level of maximum water holding quantity of soil for herbaceous peats,permanent marsh wetlands,mountain wetlands and subalpine meadows is 13 143.94 t/hm2,11 640.19 t/hm2,9 060.79 t/hm2 and 7 391.80 t/hm2 respectively;non-capillary water holding quantity of soil for herbaceous peats,subalpine meadows,mountain wetlands and permanent marsh wetlands is 937.67 t/hm2,598.50 t/hm2,594.67 t/hm2 and 325.13 t/hm2 respectively;the average water draught capacity of soil for subalpine meadows,permanent marsh wetlands,mountain wetlands and herbaceous peats is 51.49 mm,49.66 mm,43.42 mm and 22.45 mm respectively.The function of water conservation for herbaceous peats is the best and the function of water draught for subalpine meadows is the best in Gahai of Gannan.