滇西北亚高山典型退化次生林水源涵养能力分析

Analysis of Water Conservation Capacity of Typical Degraded Secondary Forests in Sub-Alpine Areas of Northwest Yunnan Province

为了摸清云、冷杉采伐后森林植被水源涵养能力变化规律,以滇西北亚高山原始冷杉林作为参照,利用浸水法、环刀法对该区域20世纪70年代、80年代、90年代采伐云、冷杉后自然生长的林分进行了水源涵养能力分析。结果表明:不同林分的不同植被层最大持水量具有一定差异,林冠层最大持水量以原始冷杉林最大,其余依次为退化桦木林、稀疏云+冷杉林、退化大果红杉林、退化杜鹃灌丛;灌木层最大持水量以退化高山栎灌丛最大,其余依次为退化杜鹃灌丛、退化大果红杉林、稀疏云+冷杉林、退化桦木林、原始冷杉林;草本层最大持水量以原始冷杉林最大,其余依次为退化桦木林、稀疏云+冷杉林、退化大果红杉林、退化杜鹃灌丛、退化高山栎灌丛;枯落物最大持水量差异很大,以原始冷杉林为最大,其余依次为退化桦木林、退化大果红杉林、退化杜鹃灌丛、稀疏云+冷杉林;植被层最大持水量以原始冷杉林最大,其余依次为稀疏云+冷杉林、退化桦木林、退化杜鹃灌丛、退化大果红杉林、退化高山栎灌丛。说明植被越好、干扰越少的林分,植被的持水量越大,缺乔木树种的林分,植被持水量较小。从对滇西北亚高山云、冷杉不同采伐年代的水源涵养分析来看,采伐干扰越少的林分最大持水能力越强,采伐年代越久的林分,植被最大持水能力也越大。

In order to find out the pattern of forest vegetation and water conservation capacity change after logging of Picea and Abies,taking the original Abies forests in northwestern Yunnan Province as a control,the water conservation capacities of the forests which naturally grew after harvesting Picea and Abies in the 1970 s,1980 s and 1990 s were analyzed using the water immersion method and the ring knife method.The results show that the maximum water holding capacities of different vegetation layers in different forest stands are different;the maximum water holding capacity of canopy layer is the largest in the original Abies forest,followed by degraded Betula forest,sparse Picea+Abies forest,degraded Larix potaninii var.macrocarpa forest,and degraded Rhododendron simsii Planch.Shrub;the maximum amount of water held by the shrub layer is the largest in degraded Quercus semicarpifolia shrub,followed by degraded Rhododendron simsii Planch.shrubs,degraded Larix potaninii var.macrocarpa forests,sparse Picea+Abies forest,degraded Betula forest,and original Abies forest;the maximum amount of water held by the grass layer is the largest in the original Abies forest,and the rest are degraded Betula forest,sparse Picea+Abies forest,degraded Larix potaninii var.macrocarpa forest,degraded Rhododendron simsii Planch.shrub,and degraded Quercus semicarpifolia shrub;the maximum amount of water held by the litter varies greatly,the greatest one is found in the original Abies forest,followed in degraded Betula forest,degraded Larix potaninii var.macrocarpa forest,degraded Rhododendron simsii Planch.shrub,sparse Picea+Abies forest;the maximum water holding capacity in the vegetation layer is the largest in the original Abies forest,followed by sparse Picea+Abies forest,degraded Betula forest,degraded Rhododendron simsii Planch.shrub,degraded Larix potaninii var.macrocarpa forest,and degraded Quercus semicarpifolia shrub.It is indicated that the better the vegetation is,the less disturbance is,the greater the amount of water held by the vegetation is,the less the tree species are,and the less the vegetation holding water is.According to the analysis of water conservation in different logging years of sub-alpine Picea+Abies in northwestern Yunnan Province,the maximum water holding capacity is greater under less logging disturbance.