中亚热带植被恢复阶段植物叶片、凋落物、土壤碳氮磷化学计量特征  

Carbon, nitrogen and phosphorus stoichiometry in leaf, litter and soil at different vegetation restoration stages in the mid-subtropical region of China

作　　者：陈婵[1] 张仕吉[1] 李雷达[1] 刘兆丹 陈金磊 辜翔[1] 王留芳 方晰[1,2] CHEN Chan;ZHANG Shi-Ji;LI Lei-Da;LIU Zhao-Dan;CHEN Jin-Lei;GU Xiang;WANG Liu-Fang;FANG Xi(School of Life Science and Technology,Cenral Souh University of Forestry and Technology,Changsha 410004,China;Huitong National Field Slation for Scientfic Observution and Research of Chinese Fir Planlation Ecosystem in Hunan Province,Huitong,Hunan 438107,China)

机构地区：[1]中南林业科技大学生命科学与技术学院,长沙410004 [2]湖南会同杉木林生态系统国家野外科学观测研究站,湖南会同438107

出　　处：《植物生态学报》2019年第8期658-671,共14页Chinese Journal of Plant Ecology

基　　金：国家林业公益性行业科研专项(201504411);国家自然科学基金(31670448)~~

摘　　要：为揭示植被恢复过程中生态系统的养分循环机制及植物的生存策略,根据亚热带森林群落演替过程,采用空间代替时间方法,以湘中丘陵区地域相邻、环境条件基本一致的檵木(Loropetalumchinensis)+南烛(Vacciniumbracteatu)+杜鹃(Rhododendron mariesii)灌草丛(LVR)、檵木+杉木(Cunninghamia lanceolata)+白栎(Quercus fabri)灌木林(LCQ)、马尾松(Pinus massoniana)+柯(Lithocarpus glaber)+檵木针阔混交林(PLL)、柯+红淡比(Cleyera japonica)+青冈(Cyclobalanopsis Glauca)常绿阔叶林(LCC)作为一个恢复系列,设置固定样地,采集植物叶片、未分解层凋落物和0–30 cm土壤样品,测定有机碳(C)、全氮(N)、全磷(P)含量及其化学计量比,运用异速生长关系、养分利用效率和再吸收效率分析植物对环境变化的响应和养分利用策略。结果表明:(1)随着植被恢复,叶片C:N、C:P、N:P显著下降,而叶片C、N、P含量和土壤C、N含量、C:P、N:P显著增加,其中LCC植物叶片C、N含量,土壤C、N含量及其N:P,PLL植物叶片P含量,土壤C:P显著高于其他3个恢复阶段,各恢复阶段植物叶片N:P> 20,植物生长受P限制;凋落物C、N、P含量及其化学计量比波动较大。(2)凋落物与叶片、土壤的化学计量特征之间的相关关系较弱,叶片与土壤的化学计量特征之间具有显著相关关系,其中叶片C、N、P含量与土壤C、N含量、C:N (除叶片C、N含量外)、C:P、N:P呈显著正相关关系;叶片C:N与土壤C、N含量、C:P、N:P,叶片C:P与土壤C含量、C:N、C:P,叶片N:P与土壤C:N呈显著负相关关系。(3)植被恢复过程中,叶片N、P之间具有显著异速生长关系,异速生长指数为1.45,叶片N、P的利用效率下降,对N、P的再吸收效率增加, LCC叶片N利用效率最低, PLL叶片P利用效率最低而N、P再吸收效率最高。(4)叶片N含量内稳态弱,而P含量具有较高的内稳态,在土壤低P限制下植物能保持P平衡。植被恢复显著影响叶片、凋落物�Aims The aims of this study were to explore how vegetation restoration affects leaf, litter and soil C, N, P stoichiometry dynamics and nutrients cycling, and to characterize the homeostasis and nutrient use strategy of plants at different vegetation restoration stages in the mid-subtropical area of China. Methods Four vegetation types representing the successional sequence in the secondary forests were selected using the "space for time substitution" approach in central hilly area of Hunan Province, China, which consists of Loropetalum chinense + Vaccinium bracteatum + Rhododendron simsii scrub-grass-land(LVR), Loropetalum chinense + Cunninghamia lanceolata + Quercus fabri shrubbery(LCQ), Pinus massoniana + Lithocarpus glaber + Loropetalum chinense coniferous-broad leaved mixed forest(PLL), and Lithocarpus glaber + Cleyera japonica + Cyclobalanopsis glauca evergreen broad-leaved forest(LCC). Permanent plots were established in each community. The organic carbon(C), total nitrogen(N) and total phosphorus(P) contents in leaf, undecomposed litter layer and 0–30 cm soil layer were quantified at each stage. The response and nutrient use strategy of plant to environmental changes were estimated by allometric growth, nutrient use efficiency and nutrient reabsorption efficiency. Important findings 1) Along vegetation restoration, the leaf C:N, C:P ratios decreased significantly and the highest values were in LVR. Leaf C, N, P contents, soil C, N contents and soil C:N, C:P, N:P ratios increased significantly, in which leaf C, N contents and soil C, N contents, N:P in LCC were higher than those in LVR, LCQ and PLL, and leaf P content and soil C:N, C:P in PLL were higher than those in LVR, LCQ and LCC. Leaf N:P(>20) indicated that all restoration stages were P limited. C, N, P contents and their stoichiometry of litter fluctuated greatly. 2) The relationships between litter and leaf or soil nutrients and their stoichiometry were weak, and the significant correlations were found in the relationships between leaf and soil

关 键 词：湘中丘陵区 植被恢复 碳氮磷化学计量比 内稳态 养分利用效率 氮磷再吸收效率 

分 类 号：Q948.113[生物学—植物学]