第2代杉木人工林营养元素积累的动态特征  

Dynamic Characteristics of Nutrient-element Accumulation In Second-rotation Chinese fir Plantations

作　　者：陈玉萍[1] 何斌[1] 蒙跃环 曹明 韦家国 荣薏[1] 

机构地区：[1]广西大学林学院,广西南宁530004 [2]广西南丹县山口林场,广西南丹547200

出　　处：《中南林业科技大学学报》2009年第3期16-20,共5页Journal of Central South University of Forestry & Technology

基　　金：广西"十五"林业科学研究项目(2001-27);广西科学基金项目(桂自0640018)

摘　　要：对第2代杉木人工林N、P、K、Ca和Mg等5种营养元素含量、积累量、年净积累量与分配及其随林分年龄的变化趋势进行了研究.结果表明:8年生、11年生和14年生林分营养元素积累量依次为325.18、343.55和482.61 kg/hm2,其中乔木层分别占78.31%、89.15%和85.64%,灌草层分别占10.90%、2.77%和5.28%,地表现存凋落物层分别占10.79%、12.13%和9.08%;乔木层均以N或Ca积累量最多,其次是K和P,Mg最小;不同组分营养元素积累量的分配随林分年龄的增长发生变化,由8年生和11年生以树叶和树枝为主,逐渐转移到14年生以干材、树根和树皮为主;林分营养元素年净积累量分别为31.83、27.84和29.52 kg/(hm2.a),林木中同一组分各营养元素年净积累量与各组分营养元素积累量变化顺序一致,即为N、K或Ca>P>Mg,3个林分年龄杉木林每积累1 t干物质需要的营养元素总量分别为7.12、5.56和5.45 kg,其中对N或Ca的需求量最大,其次是K和P,Mg最小.因此,在杉木林的经营管理中,保护和恢复林下植被将有利于维持林地持久生产力.This paper conducted a study of the contents, accumulation, annual net accumulation and distribution of five nutrient elements （N, P, K, Ca and Mg） in second-rotation Chinese fir plantations with three stand ages （8 years, 11 years and 14 years）. Results show that the total nutrient accumulation at the different stand ages is respectively 325. 18 kg/hm2, 343.55 kg/hmz and 482.61 kg/hmZ ; that of the total storage of nutrients, 78. 31% ～89.17 % is distributed to the arbor layer, 2.770%～10. 90% to the herb and shrub layer, 9.08%--12.13% to the standing litter layer; that among the five elements, N accumulation in the arbor layer is the largest while Mg is the lowest ; that the accumulation of nutrients in Chinese fir varies with different stand growing stages： most elements accumulate in leaves and branches at the age of 8 and 11 and then gradually move to stem, root and bark at the age of 14; that annual net accumulation of nutrients at the three stand ages is respectively 31.83 kg/（hm^2· a）, 27.84 kg/（hm^2· a） and 29. 52 kg/（hm^2· a） and its change in the same component is similar to that in each of the other components, namely, N, Ca or K P 〉 Mg; and that the total amount of nutrients needed for the accumulation of one ton of organic matter at the three stand ages is respectively 7.12 kg, 5.56 kg and 5.45 kg, the order of its demand to them being N or Ca 〉 K 〉 P 〉 Mg. Therefore, protection and restoration of undergrowth vegetation is beneficial to the maintenance of site productivity in managing Chinese fir plantations.

关 键 词：森林生态学 第2代杉木人工林 营养元素 积累与分布 

分 类 号：S718.5[农业科学—林学]