冀西北地区4种纯林枯落物及土壤水文效应

为改善冬奥会赛区(张家口市崇礼区清水河流域)水生态环境,提高(崇礼)赛区森林涵养水源功能,以崇礼区和平林场的云杉、白桦、山杨和华北落叶松4种纯林为研究对象,布设50m×50m样地,枯落物水文效应测定采用浸泡法,土壤层水文效应测定采用环刀法。结果表明:(1)枯落物总蓄积量最大为云杉林(38.46t/hm~2),各林分半分解层的蓄积量均大于未分解层;(2)枯落物最大持水量云杉林(3.03t/hm~2)最大,有效拦蓄量云杉林(2.57t/hm~2)最大,最大持水率山杨林(384.22%)最大,枯落物持水量与持水时间呈对数关系,枯落物吸水速率与持水时间呈幂函数关系;(3)土壤容重华北落叶松林(1.00g/cm~3)最大,山杨林(0.67g/cm~3)最小,土壤总孔隙度白桦林(67.14%)最大,山杨林(58.77%)最小。土壤入渗速率与入渗时间呈明显的幂函数关系。(4)林地总持水能力排序为:白桦林(887.45t/hm2)华北落叶松林(840.94t/hm~2)云杉林(800.03t/hm~2)山杨林(768.58t/hm~2),土壤层的持水能力占99%以上。综合分析得知,阔叶林涵养水源功能优于针叶林,土壤层的持水能力强于枯落物层。

Hydrological Effects of Litter in Four Pure Forests and Soils in Northwest of Hebei Province

For the improvement of the water ecological environment and the ability of water conservation of forest in Chongli area (Qingshui River valley in Zhangjiakou),which is one of venues of Winter Olympic Games,we took four kinds of pure stands in Chongli peace forest,including Picea wilsonii,Betula platyphylla,Pobulus davidiana and Larix principis-rupprechtii,as the research objects.We set up 50 m × 50 m sample plots in which litter of plots was adopted by soaking method,and hydrological effects of soil layer by cutting ring method.We carried out quantitative study of litter layer and soil layer hydrological effect.The results showed that:(1) among total amount of litter,the largest was Picea wilsonii (38.46 t/hm2) in which the accumulation amount of the semi decomposed layer of each stand was higher than that of the non decomposed layer;(2) the maximum water holding capacity of litter was Picea wilsonii (3.03 t/hm2) and the maximum effective retaining content was Picea wilsonii (2.57 t/hm2);the maximum water holding capacity of litter was Pobulus davidiana (384.22％) and it showed a logarithmic relation between the water holding capacity and water holding time;water absorption rate and moisture time of litter showed power function relationship;(3) the largest soil bulk density was Larix principis-rupprechtii (1.00 g/cm3);the smallest was Pobulus davidiana (0.67 g/cm3);the largest total porosity of soil was Betula platyphylla (67.14％) and the smallest was Pobulus davidiana (58.77％).The relationship between soil infiltration rate and infiltration time was power function relationship;(4) the order of total water holding capacity of forest land was Betula platyphylla (887.45 t/hm2)＞Larix principis-rupprechtii (840.94 t/hm2)＞Picea wilsonii (800.03 t/hm2) ＞Pobulus davidiana (768.58 t/hm2);the water holding capacity of the soil layer accounted for more than 99 ％.In conclusion,the ability of broad leaved forest to conserve water and soil was stronger than that of coniferous forest;the water holding capacity of the soil layer was stronger than that of the litter layer.