摘要
[目的]研究大通县退耕还白桦林枯枝落物和土壤持水效应。[方法]基于野外定点观测法和采样试验分析法,以原坡耕地为对照,研究青海大通县退耕还白桦林枯枝落物及土壤持水量随退耕还林年限变化的效应关系。[结果]枯枝落物持水量随退耕还林年限的增加呈增加的态势,退耕15年枯枝落物持水量为12 017.149 0 kg/hm2,比退耕7年的11 845.271 5 kg/hm2增长了1.451 0%;土壤持水量随退耕还林年限的增加也呈增加态势,退耕15年土壤持水量为103 756.000 0 kg/hm2,比退耕7年的103 426.000 0 kg/hm2增长了0. 3191%,而对照耕地土壤持水量维持在26 254.000 0 kg/hm2,稳中有降;退耕还林土壤持水量大于枯枝落物持水量,退耕还林7年、15年土壤持水量分别是枯枝落物持水量的8.73、8.63倍,随着退耕还林年限的增加,枯枝落物比土壤持水量增加快;退耕还林15年枯枝落物和土壤持水量之和为115 773.149 0 kg/hm2,比退耕还林7年的115 271.271 5 kg/hm2增长了0.435 4%,土壤是森林生态系统持水效应的主体,退耕还林7年、15年土壤持水量分别占枯枝落物持水量和土壤持水量之和的89.72%、89.62%,随着退耕还林年限的增加,枯枝落物持水量占总持水量比例在小幅增加,而土壤持水量占总持水量比例在小幅减少;退耕还林15年枯枝落物和土壤中持水量之和是对照耕地持水量的4.41倍,退耕还林7年枯枝落物和土壤中持水量之和是对照耕地持水量的4.39倍;土壤持水量取决于土壤的非毛细管孔隙度大小,而枯枝落物有效持水量取决于枯枝落物层蓄积量及其自然含水率。[结论]该研究对于引导黄土丘陵区大通县生态环境恢复工程建设及其工程绩效考核评价具有重要意义。
[Objective]To study the hydrological-effect of litter mixture and soil on conversion from farmland to Betula platphylla forest at Datong County.[Method]Based on field investigation and experimental data method, contrasted with the original slope land, hydrological effect of litter and soil on conversion from farmland to B. platphylla forest at Datong County was studied and with what about the year of conversion from farmland to forest. [Result]Water capacity of litter mixture increased with the increasing year of conversion from farmland to forest, water capacity of litter mixture of returning farmland to forest for 15 years was 12 017.149 0 kg/hm 2,while that for 7 years was 11 845.271 5 kg/hm 2, the growth rate was 1.451 0%.Water capacity of soil increased with the increasing year of conversion from farmland to forest, water capacity of soil of returning farmland to forest for 15 years was 103 756.000 0 kg/hm 2,while that for 7 years was 103 426.000 0 kg/hm 2,the growth rate was 0.319 1%,at the same time,water capacity of soil of contrasted with the original slope land kept a steady state with a slight decline, that was 25 254.000 0 kg/hm 2.Water capacity of soil was greater than that of litter mixture, water capacity of soil of returning farmland to forest for 7 years,15 years was 8.73, 8.63 times of litter mixture respectively , with the increasing year of conversion from farmland to forest, water capacity of litter mixture increased faster than that of soil.The total water capacity of litter mixture and soil of returning farmland to forest for 15 years was 115 773.149 0 kg/hm 2, that for 7 years was 115 271.271 5 kg/hm 2, the growth rate was 0.435 4%, soil was the main part of forest ecosystem water holding effect, soil water capacity of returning farmland to forest for 7 years,15 years was 89.72%, 89.62% respectively, with the increasing year of conversion from farmland to forest, procedure cache percent of water capacity of litter mixture was a slight increase,but procedure cache percent of soil water capacity was a slight decrease.The water capacity of soil ＆ litter mixture was 4.41 times than that of contrastive plot for returning farmland to forest 15 years, while returning farmland to forest for 7 years was 4.39 times than that of contrastive plot.The soil water holding capacity depended on the non-capillary porosity of the soil, and the effective water holding capacity of the litter depended on the accumulation of the litter layer and the natural moisture content.[Conclusion]This study is of great significance for guiding the ecological environment restoration project construction and engineering performance evaluation of Datong County in the loess hilly region.
作者
张更权
ZHANG Geng-quan(Qinghai Provincial Forest Inventory and Planning Institute,Xining,Qinghai 81000)
出处
《安徽农业科学》
CAS
2018年第31期107-110,共4页
Journal of Anhui Agricultural Sciences
基金
青海省林业厅项目(青海公益林监测QHLYJC20160508)
关键词
大通县
退耕还林
持水效应
枯枝落物
Datong County；Conservation from farmland to forest；Hydrological effect；Litter
