不同相思人工林叶片养分化学计量的内稳性特征

Internal Stability Characteristics of Nitrogen,Phosphorus and Potassiumin the Leaves of Different Acacia Plantations

于2018年7月在福建省漳浦县中西国有林场,以厚荚相思(Acacia crassicarpa A.Cunn.ex Benth.)、黑木相思(A.melanoxylon R.Br.)、卷荚相思(A.cincinnata F.Muell.)、直干大叶相思(A.auriculiformis A.Cunn.ex Benth.)和马占相思(A.mangium Willd.)为研究对象,研究其成熟叶片N、P、K及其C∶N、C∶P、N∶P的内稳性特征,以期揭示不同相思树种对环境的生态适应策略。结果表明:不同相思树种叶片各元素内稳性指数存在差异,除黑木相思N的内稳性指数为弱稳态型外,其它4种相思HN均属于敏感型,5种相思P和K的内稳性指数均为敏感型;元素化学计量比的内稳性指数明显高于元素含量,相思树种C∶N内稳性指数均为稳态型,相思树种HC∶P、HC∶K和HN∶P普遍表现为弱稳态或稳态型(直干大叶相思HC∶P、卷荚相思HC∶K和马占相思HN∶P除外)。总之,厚荚相思具有较高的HC∶P和HC∶K,黑木相思具有较高的HN和HN∶P,卷荚相思具有较高的HP和HC∶N,说明不同相思树种对外界环境的适应能力不同,较高内稳性的相思物种对相应土壤养分变异的适应能力更强。

In July 2018,taking plantations of Acacia crassicarpa A.Cunn.ex Benth.,A.me lanoxylon R.Br.,A.cincinnata F.Muell.,A.au riculiformis A.Cunn.ex Benth.,and A.mangium Willd.as research objects in Zhangzhou City of F ujian Province,the homeostasis characteristics of N,P,K and C∶N,C∶P,C∶K and N∶P of their m ature leaves were studied,in order to reveal the ecological adaptation strategi es of different Acacia species.The results show that:there wer e differences in the internal stability index of leaf elements of different Acaciaspecies,exce pt for the N homeostasis index of A.melanoxylon R.Br.,the H N of the other fou r Acacia species belonged to the sensitive type,and the P and K homeostasis ind ices of the five Acacia species were sensitive.The stoichiometr ic ratio of elem ents 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 HN∶Pof Acacia species generally showed weakly stable or steady sta te 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 Nand H N∶P,and A.c incinnata F.Muell.had higher H P and H C∶N,indicating that different Acacia species had different adaptability to the external environment,and Aca cia species with higher homeostasis had stronger adaptability to the correspondi ng soil nutrient variation.