岩溶生境与降雨间隔对云南松幼苗生长和矿质元素的影响OA

Three karst habitats[rock-free all-soil(S0),low-rock high-soil(S1/4),half-rock half-soil(S1/2)]and three rainfall intervals(I3 d,I6 d,I9 d)were simulated to explore their effects on the growth and mineral element content of 2-year-old Pinus yunnanensis seedlings.The results showed that with the prolongation of the rainfall interval(I3 d and I6 d),the seedling height,ground diameter,needle length,root biomass,stem biomass,leaf biomass,root biomass allocation ratio,and root shoot ratio of P.yunnanensis seedlings all exhibited a trend of first increasing and then decreasing.Both the biomass allocation ratio and the mineral element content of each organ followed the order of leaf>stem>root.In the same karst habitat,the growth indices of P.yunnanensis seedlings and the mineral element content in various organs generally showed similar trends of first increasing and then decreasing as the rainfall interval extended.Correlation analysis revealed that K+content was positively correlated with the biomass of each organ and the content of Ca2+,Na+,and Mg2+(P<0.01).Ground diameter and needle length were positively correlated with root,stem,and leaf biomass(P<0.001).Comprehensive evaluation based on the fuzzy membership function indicated that the optimal treatment group was I6d S1/4.