【摘要】 为探究青海高寒山区典型退耕林地土壤水分与林下植被及其相互间关系。以青海大通县青海云杉林、华北落叶松林、祁连圆柏林3种典型人工林分为研究对象,原生荒草地为对照,通过实地调查和室内实验,研究不同林地类型林下植被和0～200 cm土层土壤水分及其相互间关系。结果表明:1)该研究区林地内土壤水分相对缺乏,林下草本多为披碱草、白莲蒿、早熟禾等旱生植物占明显优势。华北落叶松林下草本的丰富度和多样性最好,青海云杉林次之,祁连圆柏林下植被与荒草地较为接近。2)不同林地类型与荒草地土壤平均含水量由大到小顺序为青海云杉林(23. 79%)、荒草地(21. 29%)、祁连圆柏林(19. 02%)、华北落叶松林(16. 93%)。3)对表层土壤(0～20 cm)而言,林地的持水能力均优于荒草地,在20～60 cm土层时青海云杉林地持水能力最好,华北落叶松林地持水能力最差。4)林下植被物种多样性与其生物量和林地土壤含水量分别呈显著正相关和负相关关系(P <0. 05)。且其相互的影响程度随着土层深度的增加不断减小,但其作用主要集中于0～120 cm土层土壤水分情况。综上所述,青海云杉可作为营造水源涵养林的主要造林树种,华北落叶松可作为在土壤水分相对缺乏地区营造水土保持林的主要营林树种,祁连圆柏林下植被与荒草地较为接近,可以有效的形成林草复合结构体系;因此,可将华北落叶松和祁连圆柏作为该地区植被建设的主要树种,同时兼顾对本地物种的引入,从而加快植被恢复的进程,有助于实现通过植树造林维持生态系统良性循环,完善生态系统服务功能的目标。更多还原

【Abstract】 [Background] This work is to explore the characteristics of soil water and understory vegetation and their relationship with each other in typical deforestation forests in the alpine region of Qinghai. [Methods] The three typical plantations of Picea crasslia forest,Larix principis-rupprechtii forest and Sabina przewalskii forest in Datong county of Qinghai province were selected as research objects,and the original grassland was used as the control. The characteristics of understory vegetation and the soil moisture characteristics of 0-200 cm soil layer and their relationship with each other were studied through field investigation and laboratory experiments. [Results] 1) The soil moisture in the forest lands of the study area was relatively scarce,and the herbaceous plants under the forests were dominated with dry-land plants such as the Elymus dahuricus,Artemisia sacrorum,Poa annua,etc. The richness and diversity of herbs under the L. principis-rupprechtii forest was the best,followed by the P.crasslia forest. The vegetation characteristics of the S. przewalskii were similar to those of the grassland.2) The average moisture content of different forest types and grassland was in descending order P.crasslia forest( 23. 79%),grassland( 21. 29%),S. przewalskii forest( 19. 02%),and L. principisrupprechtii forest( 16. 93%). 3) For topsoil( 0-20 cm),the water-holding capacity of forest land was better than that of barren grassland. In 20-60 cm soil layer,the water-holding ability of P. crasslia forest land was the best,and the water-holding capacity of L. principis-rupprechtii forest land was the worst. The effect of vegetation types on soil water-holding capacity increased with increasing soil depth.4) There was a significantly positive correlation and negative correlation between the species diversity of understory vegetation and biomass and the soil moisture content of the forest( P < 0. 05),respectively.And the degree of mutual influence decreased with the increase of soil depth,but its effect was mainly concentrated on the soil moisture of 0-120 cm soil layer. [Conclusions]P. crasslia can be used as the main afforestation species for constructing water conservation forests; L. principis-rupprechtii can be used as the main forest tree species for constructing soil and water conservation forests in areas where soil moisture is relatively scarce; the vegetation characteristics of S. przewalskii are close to wild grassland,then S. przewalskii can effectively form a forest and grass composite structural system. L. principisrupprechtii and S. przewalskii can be used as the main tree species for vegetation construction in the region,and the introduction of local species can be taken into account,thus accelerating the process of vegetation restoration,helping to maintain a virtuous cycle of ecosystems through afforestation and improving the ecosystem of the goal of the service function.更多还原