岩溶区根系地下生境优势植物及其养分利用特征

Nutrient Utilization Characteristics of Dominant Plants of Root Underground Habitat in Karst Areas

探索岩溶区根系地下生境与植物适应机制,明确优势植物及其养分利用特征,揭示岩溶特殊生境-土壤-植物之间的关系,促进岩溶区的生态恢复与治理。选择贵州中度石漠化区的3种典型根系地下生境类型(白云岩低倾产状生境<类型6>、白云岩中倾产状生境<类型9>、白云岩高倾产状生境<类型11>)为研究对象,调查优势植物,研究不同生境土壤养分含量,优势植物养分含量及其比值、生物吸收系数的变化,并分别对生物吸收系数与土壤养分和植物养分进行RDA排序。3种类型生境均是以白栎(Quercus fabri)为优势种的群落,其重要值分别为39.21%、72.82%、82.45%;其中,类型6土壤养分含量最低,优势植物除P外,对N、K的吸收在此类型生境表现最高;类型11、类型9土壤养分含量最高,优势植物也表现为除P外,对N、K的吸收在此类型生境表现最低;3种类型生境优势植物的生物吸收系数均与土壤有效N、K含量呈显著的负相关关系。白云岩低倾产状生境适合选择养分利用效率高或对养分需求低的优势物种;白云岩中倾产状生境适合选择养分利用效率低或养分需求高的优势物种;白云岩高倾产状生境适合选择养分利用效率及对养分需求一般的优势物种。

To explore the root underground habitat and plant adaptation mechanism in karst areas,identify the dominant plants and their nutrient utilization characteristics,reveal the relationship between special karst habitat,soil and plant,and promote the ecological restoration and governance in karst areas.Choose three typical root underground habitat types as the research object in moderate rocky desertification area of Guizhou(low dipping dolomite habitat<type 6>,middle dipping dolomite habitat<type 9>,high dipping dolomite habitat<type 11>),survey the dominant plants,research the soil nutrient content in different habitats,nutrient content of dominant plant and its ratio,the change of the biological absorption coefficient,and biological absorption coefficient,soil nutrient and plant nutrients by RDA respectively.In the three types of habitats,the dominant plant was Quercus fabri,the important values were 39.21%,72.82%and 82.45%,among them,the soil nutrient content in the type 6 was the lowest,in addition to advantages plant of P,the absorption of N and K by dominant plants was the highest in this type of habitat;type 11 was in the middle.The soil nutrient content was the highest in type 9,in addition to advantages plant of P,the absorption of N and K by dominant plants was the lowest in this habitat.There was a significant negative correlation between the bioabsorption coefficients of the three types of dominant plants and the soil available N and K contents.The low dipping dolomite habitat is suitable for the selection of dominant species with high nutrient utilization efficiency or low nutrient demand.The middle dipping dolomite habitat is suitable for the selection of dominant species with low nutrient utilization efficiency or high nutrient demand.The high dipping dolomite habitat is suitable for the selection of dominant species with general nutrient utilization efficiency and nutrient demand.