土壤增温、氮添加及其交互作用对杉木幼苗细根生产的影响  

Interactive effects of soil warming and nitrogen addition on fine root production of Chinese fir seedlings

作　　者：史顺增 熊德成[1] 邓飞[1] 冯建新[1] 许辰森 钟波元 陈云玉[1] 陈光水[1] 杨玉盛[1] 

机构地区：[1]福建师范大学地理科学学院,湿润亚热带山地生态国家重点实验室培育基地,福州350007

出　　处：《植物生态学报》2017年第2期186-195,共10页Chinese Journal of Plant Ecology

基　　金：国家自然科学基金(31422012);国家重点基础研究发展计划(973计划)(2014CB460602);福建省杰出青年基金(2014J07005)

摘　　要：为了揭示杉木(Cunninghamia lanceolata)人工林地下部分对全球变暖和氮沉降的响应,在福建省三明市开展了杉木幼苗土壤增温和氮添加双因子试验,包括对照、增温、低氮、高氮、增温低氮、增温高氮6个处理,用微根管法探讨试验第1年土壤增温、氮添加及其交互作用对杉木幼苗细根生产量(以每根管细根一年总出生数量作为表征)的影响。结果表明:(1)土壤增温对细根生产量有显著影响;氮添加、土壤增温与氮添加交互作用对细根生产量并没有显著影响。(2)土壤增温、径级、土壤增温和径级的交互作用对细根生产量有显著影响;土壤增温显著增加了0–1 mm径级细根的生产量,表明小径级的吸收根对于增温的响应更具有可塑性。(3)土壤增温、季节、土壤增温和季节的交互作用,以及土壤增温、氮添加和季节三者的交互作用对细根生产量的影响均达到显著水平。春季,土壤增温、土壤增温和氮添加的交互作用对细根生产量有显著的促进作用;而在夏季,土壤增温、氮添加以及两者的交互作用对细根生产量有显著的抑制作用。(4)土壤增温、土层,以及土壤增温和土层的交互作用对细根生产量有显著影响,土壤增温仅对20–30 cm土层的细根生产有显著的促进作用,表明土壤增温促使细根向更深层土壤分布。由此可见:土壤增温促进了杉木幼苗细根生产,但其影响因径级、季节和土层而异;氮添加则对细根生产没有影响;土壤增温和氮添加仅在春季和夏季才存在显著的交互作用。Aims There have been a large number of studies on the independent separate responses of fine roots to warming and nitrogen deposition, but with contradictory reporting. Fine root production plays a critical role in ecosystem carbon, nutrient and water cycling, yet how it responds to the interactive warming and nitrogen addition is not well understood. In the present study, we aimed to examine the interactive effects of soil wanning and nitrogen addition on fine root growth of 1-year-old Chinese fir （Cunninghamia lanceolata） seedlings in subtropical China. Methods A mesocosm experiment, with a factorial design of soil warming （ambient, ＋5 ~C） and nitrogen addi- tion （ambient, ambient ＋ 40 kg＇hrn-2＇a-1, ambient ＋ 80 kg＇hm-2＇a-~）, was carried out in the Chenda State-owned Forest Farm in Sanming City, Fujian Province, China. Fine root production （indexed by the number of fine roots emerged per tube of one year） was measured biweekly using minirhizotrons from March of 2014 to February of 2015. Important findings （1） The two-way ANOVA showed that soil warming had a significant effect on fine root production, while nitrogen addition and soil warming x nitrogen addition had no effect. （2） The three-way ANOVA （soil warming, nitrogen addition and diameter class） showed that soil warming, diameter class and soil warming x diameter class had significant effects on fine root production, especially for the number of fine roots in 0-1 mm diameter class that had been significantly increased by soil warming. Compared with the 1-2 mm roots, the 0-1 mm roots seemed more flexible. （3） Repeated measures of ANOVA （soil warming, nitrogen addition and season） showed that soil warming, season, soil warming ~ season, and soil warming ~ nitrogen addition ~ season had significant effects on fine root production. In spring, the number of fine roots was significantly increased both by soil warming and soil warming x season, while soil warming, nitrogen addition, soil warming x nitrogen addi- t

关 键 词：土壤增温 氮添加 杉木 微根管 细根生产 

分 类 号：S791.27[农业科学—林木遗传育种]