Internal Stability Characteristics of Nitrogen, Pho sphorus and Potassiumin the Leaves of Different AcaciaPlantations

In July 2018,taking plantations of Acacia crassicarpa A.Cunn.ex Benth.,A.melanoxylon R.Br.,A.cincinnata F.Muell.,A.auriculiformis A.Cunn.ex Benth.,and A.mangium Willd.as research objects in Zhangzhou City of Fujian Province,the homeostasis characteristics of N,P,K and C:N,C:P,C:K and N:P of their mature leaves were studied,in order to reveal the ecological adaptation strategies of different Acacia species.The results show that:there were differences in the internal stability index of leaf elements of different Acacia species,except for the N homeostasis index of A.melanoxylon R.Br.,the H_N of the other four Acacia species belonged to the sensitive type,and the P and K homeostasis indices of the five Acacia species were sensitive.The stoichiometric ratio of elements was significantly higher than the elemental content,and the C:N stability indices of Acacia species were all steady-state,The H_C:P,H_C:K,and H_N:P of Acacia species generally showed weakly stable or steady state types (except for H_C:P of A.auriculiformis A.Cunn.ex Benth.,H_C:K of A.cincinnata F.Muell.and H_N:P of A.mangium Willd.).In conclusion,Acacia crassicarpa A.Cunn.ex Benth.had higher H_C:P and H_C:K,A.melanoxylon R.Br.had higher H_N and H_N:P,and A.cincinnata F.Muell.had higher H_P and H_C:N,indicating that different Acacia species had different adaptability to the external environment,and Acacia species with higher homeostasis had stronger adaptability to the corresponding soil nutrient variation.