阴山北麓不同林分类型枯落物层持水性能研究

Study on the Water Holding Capacity of the Litter Layer Under Different Forest Types in the North Slope of Yinshan Mountain

为了充分了解研究区不同林分类型枯落物的持水能力及对涵养水源和保育土壤的影响,以武川县公益林11种林分类型为研究对象,通过野外观测、室内浸水法对不同林分类型的枯落物蓄积量、最大持水量、最大持水率、吸水速率和有效拦蓄量进行了研究。结果表明:(1)不同林地类型总蓄积量为0.74~5.09 t/hm^2,落叶松林蓄积量最大,樟子松林最小。天然林的蓄积量大于人工林,半分解层蓄积量均大于未分解层。(2)各林分类型的持水量存在显著差异(p<0.05),呈现随时间的变化而先增大后减小的趋势,4 h内持水量变化较大,8 h后持水量变化相对平稳,24 h后各林地枯落物达到最大持水量,落叶松(8.5 t/hm^2)最大,樟子松林(0.99 t/hm^2)最小。(3)各林地枯落物吸水速率趋势相同,天然林吸水速率较大,其次油松人工林,灌木林吸水速率最差。(4)在各林分类型中,落叶松林蓄积量最大,最大持水量最高,对降水的有效拦蓄量也最好(9.051 t/hm^2);油松、山杏混交林(2.847 t/hm^2)次之。综合比较,落叶松等天然林的持水能力最好,油松人工林枯落物的持水能力次之,柠条、山杏灌木林持水能力较弱。

In order to understand the water holding capacity of litter of different forest types in the study area and its impact on water conservation and soil conservation,the combination of field investigation and immersion experiment is used to investigate the different characteristics of 11 types of forests in Wuchuan County,Hohhot City,Inner Mongolia.These characteristics include litter accumulation,maximum water holding capacity,water absorption rate and effective storage capacity.The results show that:(1)the total litter storage capacities of the 11 different forest land types range from 0.74 t/hm^2 to 5.09 t/hm^2,among which the maximum storage is observed in stand of Larixprincipis-rupprechtii,and minimum storage is found in the stand of Pinus sylvestris L.var.mongolica Litv.;the storage of natural forest is greater than that of planted forest,and the storage of semi-decomposed layer is greater than that of undecomposed layer;(2)there is a significant difference in water holding capacity of each forest type(p<0.05),which shows increasing trend first and then decreasing trend over time;the water holding capacity changes significantly within the first 4 hours,and then changes relatively smoothly after 8 hours;after 24 hours,water holding capacity of the litter of each forest land reached the maximum level,with the larch(8.5 t/hm^2)being the highest and the pine forest(0.99 t/hm^2)being the smallest;(3)litter of each forest land has the same water absorption rate,the has a rather high water absorption rate is observed in the natural forest,while the lowest rate is found in Pinus tabulaeformis plantation;(4)among the different forest types,the largest accumulation,the highest water holding capacity and effective storage capacity for precipitation(9.051 t/hm^2)are observed in the larch forest,followed by the mixed forest of Pinus tabulaeformis and Prunus sibirica apricot(2.847 t/hm^2).In conclusion,natural forests such as larch have the high water holding capacity,followed by Pinus tabulaeformis plantations;the water holding capacity of Armenia sibirica and Caragana microphylla shrubs is comparatively weak.