六盘山叠叠沟华北落叶松人工林地上生物量的坡面变化  

Variation of Aboveground Biomass of Larix principis-rupprechtii Plantation along Slopes in the Diediegou Watershed of Liupan Mountains

作　　者：韩新生[1,2,3] 邓莉兰[1] 王彦辉[2] 熊伟[2] 李振华[2] 刘千[2] 王艳兵[2] 孙浩[2] 

机构地区：[1]西南林业大学林学院,昆明650224 [2]中国林业科学研究院森林生态环境与保护研究所国家林业局森林生态环境重点实验室,北京100091 [3]宁夏农林科学院荒漠化治理研究所,银川750002

出　　处：《林业科学》2015年第3期132-139,共8页Scientia Silvae Sinicae

基　　金：国家自然科学基金项目(41230852;41390461);科技部"十二五"农村领域国家科技计划(2012BAD22B030102);宁夏科技支撑重点项目"宁南山区生态产业培育技术集成与示范"(2012ZZS50);云南省风景园林高校科技创新团队基金(23002802);国家林业局宁夏六盘山森林生态站资助

摘　　要：【目的】在降水有限、水分再分配明显的半干旱区山地坡面上,森林生物量通常表现出明显的坡向、坡位差异。便捷、精确地测算整个坡面的森林生物量目前还很困难。本研究旨在定量描述森林生物量的坡面变化规律及其空间尺度效应,为提高森林经营水平和实施精细化管理提供技术支持。【方法】在宁夏六盘山半干旱区的叠叠沟小流域,选择生长华北落叶松人工林的半阴坡和阴坡2个坡面,按坡位从上到下各设置了6块20 m×20 m的样地,调查各样地的立地条件及林分特征后,采用烘干法及六盘山区建立的生物量经验公式计算地上生物量;以"离开坡顶的水平距离"为尺度变量,定量描述地上生物量随坡面空间尺度增加而变化规律,及坡面上任意坡位处样地的地上生物量与坡面平均值的关系。【结果】研究区坡面上森林植被地上生物量存在明显的坡向、坡位差异;水分条件较差的半阴坡上的平均地上生物量(52.36 t·hm-2)比水分条件较好的阴坡低18.16%,但半阴坡上生物量的坡位间变幅(42.50 t·hm-2)比阴坡高14.71%,这说明半阴坡的坡面效应强于阴坡,并与土壤厚度及土壤水分条件差异有关;地上生物量的坡位变化在不同坡面上大致遵循相同的规律,都是由坡顶向下逐渐增大,至下坡处(半阴坡)或中下坡处(阴坡)达到最大,之后又逐渐减小,这主要受土壤水分在坡面上的再分配格局影响;研究区坡面上森林植被地上生物量(y,t·hm-2)随坡面空间尺度(x,m)增加而变化,阴坡表现为y=-2×10-7x3-8×10-5x2+0.121 9x+40.875(R2=0.999 8),半阴坡表现为y=2×10-7x3-7×10-5x2+0.067 5x+30.838(R2=0.995 7);距坡顶的水平距离每增加100 m,阴坡上的地上生物量坡段滑动平均值升高4.92 t·hm-2,半阴坡上为6.28 t·hm-2,即地上生物量的空间尺度效应在水分条件较差的半阴坡上要强于水分条件较好的阴坡;研究区坡面上任意给定坡位(X,【Objective】In general,forest biomass shows a notable variation with slope variables,such as slope direction and slope position,etc.,especially in the arid or semi-arid regions where the precipitation is limited and the redistribution of soil water is remarkable. Up to now,it is hard to conveniently and accurately measure the biomass for the whole slope.In this study,the emphasis was placed on quantification of the variation of forest biomass along the slope and its spatial pattern. And considering the scale effect,a method of assessing forest biomass of a whole slope up-scaling from a certain plot was derived,providing technical support for improving forest management and implementing intensive tending.【Methods】Methods To achieve the objectives,two representative slopes（ a half-shady slope and a shady slope） covered by 27-year-old Larix principis-rupprechtii plantation were chosen in the small watershed of Diediegou within the semi-arid region of Liupan Mountains,Northwest China. On each slope,six plots each with an area of 20 m × 20 m were set up along the slope topdown. The aboveground biomass was measured in mid-July of 2012. In the analysis,the ＂horizontal distance from the slope top＂was used as a variable to quantify the variation of the forest biomass along the slope,and also the relationship between the biomass of a certain plot and the average of the whole slope. 【Results 】The average aboveground biomass was 52. 36 t · hm^-2on the half-shady slope,18. 16% lower than that on the shady slope. The variation range was 42. 50 t·hm^-2on the half-shady slope,14. 71% higher than that on the shady slope,indicating a stronger impact on half-shady slope than on the shady slope. On the other hand,the variation trend of aboveground biomass was similar on both slopes,i. e.,the aboveground biomass increases gradually from top down,reaches the maximum at the lower part（ half-shady slope） or middle-lower part（ shady slope）,and thereafter decreases till the slope foot. This is probably due to

关 键 词：华北落叶松 地上生物量 坡面变化 尺度效应 水分条件 六盘山 

分 类 号：S718.553[农业科学—林学]