广西不同地区红锥人工林主要营养元素分布及积累量差异研究

Distribution and accumulation of Castanopsis hystrix main nutrients in different regions of Guangxi

对红锥幼林的C、N、P、K营养元素以及积累量差异进行研究,以广西贺州(HZ)、玉林(YL)、崇左(CZ)、来宾(LB)、南宁(NN)的红锥幼林作为研究对象,测定叶、枝、干、根桩和根系等器官的C、N、P、K等营养元素含量以及各营养元素积累量,并计算元素化学计量比,比较各指标在不同地区、不同部位间的差异,为红锥林持续经营管理、红锥林地生态保护与修复提供科学指导。结果表明:①作为红锥同化和代谢的主要器官,叶片中的N、P、K等元素含量在各器官中最高,红锥干由于富含C的多糖物质的结构性质决定了C元素浓度较高;②CZ的红锥生长主要受到N元素的限制,LB、NN、YL和HZ的红锥生长主要受到P元素的限制,故在CZ的红锥林加强N元素的投入,NN、LB、YL和HZ加强P元素的投入,做到精准施肥,运用缓释长效肥料,增加肥效利用率,减少肥料的流失、浪费及环境污染;③CZ地区的营养元素积累量远低于其他研究地区,建议加大经营管理力度和营养物质的投入;④在红锥幼林的经营过程中,应充分考虑养分投入的平衡,根据树体和土壤的元素含量进行N、P、K平衡施肥,促进红锥幼林生长,减少肥料成本,减少肥料对土壤的污染,促进红锥林环境保护与修复。

The differences of C,N,P and K nutrient elements and their accumulation in young Castanopsis hystrix forests were studied.Taking the young Castanopsis hystrix forests in Hezhou(Hz),Yulin(YL),Chongzuo(CZ),Laibin(LB)and Nanning(NN)in Guangxi as the research object,the contents of C,N,P and K nutrient elements and their accumulation in leaves,branches,stems,root piles and roots were measured,and the stoichiometric ratio of elements was calculated,Compare the differences of each index in different regions and parts,so as to provide scientific basis for the sustainable management of Castanopsis hystrix forest and scientific guidance for the ecological protection and restoration of Castanopsis hystrix forest land.The results showed that:①as the main organ of Castanopsis hystrix assimilation and metabolism,the contents of N,P and K in leaves were the highest in all organs.The concentration of C in Castanopsis hystrix trunk was higher due to the structural properties of polysaccharide rich in C,and the content of elements in branches;②The growth of Castanopsis hystrix in CZ is mainly limited by N elements,the growth of Castanopsis hystrix in LB,YL and Hz is mainly limited by P elements,while the growth of Castanopsis hystrix in NN is mainly limited by both N and P elements.Therefore,the input of N elements is strengthened in Castanopsis hystrix forest in CZ,the input of P elements is strengthened in LB,NN,YL and HZ,so as to achieve precise fertilization and use slow-release and long-term fertilizer,Increase fertilizer efficiency utilization rate and reduce fertilizer loss,waste and environmental pollution;③The accumulation of nutrient elements in CZ area is much lower than that in other research areas.It is suggested to strengthen management and nutrient input;④During the management of young Castanopsis hystrix forest,the balance of nutrient input should be fully considered,and balanced fertilization of N,P and K should be carried out according to the element content of tree and soil,so as to promote the growth of young Castanopsis hystrix forest,reduce fertilizer cost,reduce fertilizer pollution to soil,and promote environmental protection and restoration of Castanopsis hystrix forest.