水資源緊缺地區土壤水資源利用限度

Soil Ware Resource Use limit by Plants in Water-Limited Regions

Environment and Resource / 2019,1(1)：11-30 / 2019-10-08 5907 8725

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• 作者： 郭忠升12     
• 單位：

  1 西北農林科技大學水土保持研究所，楊凌
  2 中國科學院教育部水土保持與生態環境研究中心，楊凌

• 關鍵詞： 土壤水分；水資源緊缺地區；土壤水資源；土壤水資源利用限度；植被類型；立地條件
• Soil water; water-limited regions; plant growth; soil water resources utilization limit by plants; vegetation type; site condition
• 摘要： 土壤水分只能被植物根系吸收和利用，但是在大部分水資源緊缺地區，根系吸收利用土層的水分主要來自天然降水，由于降水不充分，且年際和季節變化較大，地下水埋藏較深，無灌溉條件，導致該層土壤水分供應不充足，常引發嚴重土壤旱化、導致土壤退化，植被衰敗，果品或農作物絕收。為了實現土壤水資源可持續利用，森林可持續發展，果品或農作物可持續生產和可持續發展，就需要依據土壤水資源利用限度和土壤水分植被承載力對植物生長和土壤水分關系進行調控。因此在大部分水資源緊缺地區，植物對土壤水分的吸收和利用應該有一個控制限，這個限度即植物利用土壤水資源的限度，簡稱土壤水資源利用限度，它是指當最大入滲深度范圍內所有土層的土壤水分含量等于指示植物萎蔫系數時的殘留土壤儲水量。采用二線法確定次降水入滲深度和土壤水分補給，采用系列二線法確定最大入滲深度。天然植被的指示植物為植物群落的建群種，人工植被為主要樹種或目的樹（草）種。土壤水資源利用限度是植被類型和立地條件的函數，是判斷植物是否過度利用土壤水資源，確定植物水關系調控起始期和樹草種選擇的理論依據。
• Soil moisture can only be absorbed and utilized by plant roots, but in most areas where water resources are scarce, the soil moisture absorbed and utilized by the roots is mainly due to natural precipitation. Due to insufficient precipitation with a big season and yearly change, deep groundwater storage and no irrigation conditions, the soil water supply in the root layer is insufficient, resulting in soil drought, soil degradation, vegetation decay, fruit and crop failure. In order to realize the sustainable utilization of soil water resource and sustainable management of forest and sustainable production of fruit and crop, it is necessary to regulate the relationship between plant growth and soil moisture according to the soil water resource utilization limit by plants and soil water carrying capacity for vegetation. So，in this area, there should be a control limit for the absorption and utilization of soil water by plants. That is, the soil water resources utilization limit for plants. It refers to the residual soil water storage in maximum infiltration depth when the soil moisture content of the soil layer is equal to the wilting coefficient. The infiltration depth and soil moisture supply for one rain event were determined by two-line method, and the maximum infiltration depth was determined by a series of two-line method. The indicator plant for natural vegetation is constructive species of the plant community, and the non-native vegetation is the main tree species or target tree (grass) species. Soil water resource utilization limit by plants is the function of vegetation type and site condition and the theoretical basis for judging whether plants overuse soil water resources and determining the starting period of plant water relationship regulation and the selection of tree and grass species.
• DOI： https://doi.org/10.35534/er.0101002
• 引用： 郭忠升．水資源緊缺地區土壤水資源利用限度［J］．環境與資源，2019，1（1）：11-30．
  https://doi.org/10.35534/er.0101002