不同林龄杉木组织迁移养分的再利用  

Reuse of retranslocated nutrients in tissues of Chinese fir in plantations of different ages

作　　者：吕中诚[1,4] 康文星[1,2,3] 黄志宏 赵仲辉[1,2,3] 邓湘雯 Lü Zhong-Cheng;KANG Wen-Xing;HUANG Zhi-Hong;ZHAO Zhong-Hui;DENG Xiang-Wen(Central South University of Forestry and Technology,Changsha 410004,China;National Engineering Laboratory for Applied Technology of Forestry&Ecology in South China,Changsha 410004,China;Huitong National Field Station for Scientific Observation and Research of Chinese Fir Plantation Ecosystem,Huitong,Hunan 418307,China;Hunan Police College,Changsha 41013,China)

机构地区：[1]中南林业科技大学,长沙410004 [2]南方林业生态应用技术国家工程实验室,长抄410004 [3]湖南会同杉木林国家重点野外科学观测研究站,湖南会同418307 [4]湖南警察学院,长沙410138

出　　处：《植物生态学报》2019年第5期458-470,共13页Chinese Journal of Plant Ecology

基　　金：国家林业公益性行业科研专项(201104009);科技部公益性研究项目(2007-04-15);国家野外科学观测研究站项目(20080615)~~

摘　　要：为了清楚了解不同林龄杉木(Cunninghamialanceolata)组织迁移养分(氮、磷、钾、钙、镁)再利用特征,为人工林丰产的经营管理提供科学依据,该文利用湖南会同杉木林不同林龄段的活的枝叶与枯死枝叶养分浓度及其差异和枝叶枯死量,估算枝叶枯死前的养分迁移量。用某林龄段开始和结束时的杉木器官的养分浓度差异,估算那些在某林龄段开始前林分生产的,在林龄段结束时仍存活的器官(干、皮、枝、叶、根),即仍存活物质,在该林龄段的养分迁移量。将枝叶枯死前迁移的养分和这些仍存活物质中转移的养分与从土壤中吸收的养分相结合,根据森林生产的生物量,综合分析森林物质生产的养分利用特征。研究表明:1–7年生林分,利用枝叶枯死前迁移的养分生产的生物量及占总生产生物量的比例,分别为217 kg·hm^-2·a^-1和3.52%;20^-25年生林分则分别上升到2 540 kg·hm^-2·a^-1和17.50%。枝叶枯死前迁移的养分生产的生物量及占总生产生物量的比例都随林龄增加而增大。林分在12–16、17^-20、21^-25年林龄段,由这些仍存活物质中迁移出的养分生产的生物量分别为385、561和450 kg·hm^-2·a^-1,分别占总生产生物量的3.40%、3.40%和3.11%。这些仍存活物质中迁移出的养分量随林龄增加呈现先上升后下降的变化,由这些养分生产的物质量占总生产物质量的比例随林龄增加呈下降趋势。结果显示,只要有枝叶枯死发生,就有枝叶枯死前迁移出养分用于物质再生产。林分郁闭后,才会发生这些仍存活物质中迁移出的养分再利用。杉木体内养分再分配及贮备机制、杉木生长规律和不同生长发育阶段对养分的需求和利用效率等,共同调节控制着枝叶枯死前迁移的和这些仍存活物质中迁移出的养分再利用的年变化。Aims The purpose of this study is to investigate the reuse characteristics of nutrients(Nitrogen, Phosphorus, Potassium, Calcium, Magnesium) in Cunninghamia lanceolata with different ages, and therefore provide scientific support for better management of the high-yield plantations in China. Methods We estimated the nutrient retranslocation from dying branches and leaves according to nutrient concentration differences between living and dead, and the amount of dead branches and leaves in Chinese fir forests of different age classes in Hunan Huitong. Based on the difference in the nutrient concentrations of Chinese fir organs at the beginning and end of each age class, the nutrient transport amount from "biomass produced before the beginning of a given age class, which is still alive at the end of the age class"(referred as "biomass-still-alive" hereafter) was estimated for the age class. The nutrient utilization characteristics in forest production were comprehensively analyzed by combining the nutrients transferred from dying branches and leaves with those transferred from the biomass still alive and absorbed from the soil. Important findings The results showed that the annual biomass produced by the retranslocated nutrients of dying branches and leaves and their proportion in the total biomass were 217 kg·hm^-2·a^-1 and 3.52%, respectively, for forests 1–7 years old, and increased to 2 540 kg·hm^-2·a^-1 and 17.50%, respectively, when forests reached20^-25 years old. The biomass produced by the retranslocated nutrients of dying branches and leaves and its proportion in the total biomass increased with the increase of forest age. The average annual biomass produced by the biomass-still-alive in stands of 12–16, 17^-20 and 21^-25 years old was 385, 561 and 450 kg·hm^-2·a^-1, accounting for 3.40%, 3.40% and 3.11% of the total biomass production, respectively. The nutrient retranslocation from the biomass-still-alive first increased and then decreased with the increase of forest age, and the proportion of t

关 键 词：杉木 人工林 养分迁移 养分再利用 物质生产 

分 类 号：S71[农业科学—林学]