浑河源头水源涵养林土壤优先流特征

以浑河源头4种类型水源涵养林为研究对象,采用野外染色示踪和室内理化分析等研究方法,研究不同水源涵养林土壤优先流的形态特征与变化规律,揭示浑河源头水源涵养林保护和治理过程中优先流的形成机理及影响因素。结果表明:4个样地土壤优先流的入渗深度范围为30~38cm,且其深浅与根系的根长密度关系密切;0—10cm土层的土壤优先流染色面积比依次为82.41%,75.44%,91.03%,79.82%,土壤优先流染色面积比随土层深度的增加而减小,4个样地上层土壤显著大于下层土壤染色面积比;土壤优先流染色面积比与土壤容重、总孔隙度、有机质、总根长密度呈极显著或显著正相关,均影响着优先流的发生程度,并且得到土壤优先流染色面积比与其影响指标的多元函数关系;根据各主成分得分及其权重,得到水源涵养林土壤优先流特征综合得分为混交林地(3.134)>落叶松(1.660)>采伐迹地(-1.946)>红松(-2.847)。研究结果可为深入探究浑河源头水源涵养林的生态水文过程及植被建设提供科学依据。

Characteristics of Soil Preferential Flow in Water Conservation Forest at Hunhe River Source

Taking four types of water conservation forests at the Hunhe River source as the research object, the morphological characteristics and change regularity of soil preferential flow in different water conservation forests were studied by field dyeing tracer and indoor physicochemical analysis, to reveal the formation mechanism and influencing factors of preferential flow in the process of protection and management of water conservation forest. The results showed that the infiltration depth of the soil preferential flow ranged from 30 cm to 38 cm in the four plots, and its depth was closely related to root length density. The dyeing area ratios of soil preferential flows in 0 -10 cm soil layer were 82.41%, 75.44%, 91.03% and 79.82%, respectively, and the dyeing area ratio of soil preferential flow decreased with the increasing of soil depth, and the dyeing area ratio of upper soil was significantly larger than that of the lower soil in the four plots. The dyeing area ratio of soil preferential flow was significantly or positively correlated with soil bulk density, total porosity, organic matter and total root length density, which all affected the occurrence degree of preferential flow, and got the multi-function relationship between the soil preferential flow dyeing area ratio and the influence index. According to the score and weight of each principal component, the comprehensive scores of soil priority flow characteristics of water conservation forests were mixed forest land (3.134) > larch forest (1.660) > cutting area (-1.946) > Korean pine forest (-2.847). The results could provide scientific basis for further study on ecological hydrological process and vegetation construction of water conservation forest at Hunhe River source.