文献类型：期刊文献

中文题名：不同立地指数杉木人工林碳、氮、磷化学计量及养分重吸收特征

英文题名：Characteristics of carbon,nitrogen,and phosphorus stoichiometry and nutrient resorption in Chinese fir plantations under different site indexes

作者：余涵[1,2] 吴绍发[3] 蒋科毅[4] 胡兆贵[3] 周本智[1] 吴统贵[1] 童冉[1]

第一作者：余涵

机构：[1]中国林业科学研究院亚热带林业研究所,杭州311400;[2]南京林业大学南方现代林业协同创新中心,南京210037;[3]庆元林场,丽水323000;[4]浙江省公益林和国有林场管理总站,杭州310020

年份：2025

卷号：45

期号：19

起止页码：9606-9614

中文期刊名：生态学报

外文期刊名：Acta Ecologica Sinica

收录：;北大核心:【北大核心2023】；

基金：浙江省省院合作林业科技项目(2025SY10);国家重点研发计划项目(2016YFD0600200)。

语种：中文

中文关键词：立地指数;碳、氮、磷;化学计量;内稳性;植物-凋落物-土壤;杉木

外文关键词：site index;carbon,nitrogen and phosphorus;stoichiometry;homeostasis;plant-litter-soil;Chinese fir

分类号：S791.27

摘要：碳(C)、氮(N)、磷(P)化学计量特征及养分重吸收能力是揭示生物地球化学循环机制及其与生态系统结构、功能和过程关系的重要指标。立地指数则是评价林地立地生产力大小的关键参数。然而,在不同立地指数条件下,森林生态系统各组分(包括植物、凋落物和土壤)的化学计量及养分重吸收特征仍缺乏认识。通过对14、16和18这3个立地指数的杉木人工林进行实地野外调查,分析植物、凋落物和土壤C、N、P化学计量及养分重吸收特征对立地指数变化的响应,揭示杉木生长养分限制状况,探究化学计量内稳性在杉木不同器官间的差异,阐明杉木适应外界环境条件变化的潜在机制。结果表明,随着立地指数增加,细根C含量和碳氮比(C/N)呈减小趋势,枝N、P含量呈增加趋势,C/N、碳磷比(C/P)则呈减小趋势。叶片N、P含量及氮磷比(N/P)的化学计量内稳性指数(H)分别为3.85、3.03和3.13,属于弱稳态型,而枝和细根N、P计量特征多数表现为“绝对稳态”。叶片N/P平均值为16.79,略高于陆地生态系统植物生长P限制阈值(16),凋落叶N、P含量的平均值分别为12.10 g/kg和0.52 g/kg,均属于不完全吸收范围,叶片P重吸收效率显著高于N重吸收效率。与细根、枝相比,叶片能够更为灵活的调控养分计量特征,通过优化养分资源分配更为高效地应对外界环境条件的变化。此外,本研究区杉木生长不受养分限制或受到轻微的P限制。研究结果加深了对人工林植物-凋落物-土壤养分互作关系的认识,并强调在森林经营与养分调控研究中引入立地指数作为关键参数的重要意义。
Carbon(C),nitrogen(N),and phosphorus(P)stoichiometric characteristics and nutrient resorption efficiencies are critical indicators for understanding nutrient cycling and plant adaptation strategies in terrestrial ecosystems.These traits not only reflect the physiological status and nutrient use efficiency of plants but also provide insights into the regulatory mechanisms of biogeochemical processes in relation to ecosystem structure and function.In forest ecosystems,the site index is a widely used quantitative indicator of site productivity,typically based on dominant tree height at a reference age,and effectively reflects the overall capacity of a site to support forest growth.However,the influence of site index variation on stoichiometric traits and nutrient conservation strategies in different ecosystem components,including tree organs,litter,and soil,remains insufficiently explored.This study investigated Chinese fir plantations with site indexes of 14,16,and 18 to examine how changes in site quality affected the stoichiometric characteristics of C,N,and P in tree organs(including leaf,branch,and fine root),litter,and soil.We also explored the differences in stoichiometric homeostasis among tree organs,their potential roles in adapting to environmental changes,and the nutrient limitation conditions that affected tree growth.The results showed that with increasing site index,the C content and the carbon-to-nitrogen ratio(C/N)in fine root exhibited a decreasing trend.However,the N and P content in branch showed an increasing trend,while the C/N and carbon-to-phosphorus ratio(C/P)decreased.The homeostasis indices(H)for leaf N,P content,and nitrogen-to-phosphorus ratio(N/P)were 3.85,3.03,and 3.13,respectively,indicating a weak homeostasis.In contrast,the N and P stoichiometric characteristics in branch and fine root mostly exhibited‘absolute homeostasis’.The mean N/P ratio in leaf was 16.79,slightly exceeding the commonly recognized threshold of 16 for P limitation in tree growth within terrestrial ecosystems.The average contents of N and P in leaf litter were 12.10 g/kg and 0.52 g/kg,respectively,both falling within the incomplete absorption category.The P resorption efficiency in leaf was significantly higher than that of N resorption efficiency.Overall,our findings reveal that Chinese fir exhibits organ-specific stoichiometric responses and nutrient use strategies that vary with site index.Among the organs,leaf is more responsive and plastic in nutrient allocation,facilitating more efficient adaptation to varying environmental conditions.Additionally,the growth of Chinese fir in this study area was either unrestricted or slightly limited by P.These results deepen our understanding of plant-litter-soil nutrient interactions in forest plantations and underscore the importance of considering site index in forest management and nutrient regulation research.