Page 132 - 《广西植物》2026年第6期
P. 132
6 期 凌雷等: 林龄和密度对洮河流域云杉人工林碳储量的影响 1 0 4 7
Abstract: In the context of global carbon neutrality and regional ecological security requirementsꎬ the optimization of the
carbon sink function of Picea asperata plantations in the Taohe River basin has become increasingly crucial. To explore
the distribution characteristics and influencing factors of its carbon storageꎬ this study focused on P. asperata plantations
within the Taohe River basinꎬ establishing plots with varying stand ages (young and middle forests) and densities (925-
 ̄2
2 800 treeshm ). It systematically measured and comprehensively evaluated the carbon storage and distribution
characteristics of different organs (trunkꎬ branchꎬ leafꎬ barkꎬ root) within the tree layerꎬ the litter layerꎬ and distinct
soil horizons (0- 10 cmꎬ 10- 20 cmꎬ 20- 40 cmꎬ 40- 60 cmꎬ 60- 80 cm). It provided an in ̄depth analysis of the
mechanisms by which stand age and density influenced carbon storage. The results were as follows: (1) The total carbon
 ̄2
storage of P. asperata plantation ecosystem in the Taohe River basin ranged from 336.25 to 512.39 thm . The overall
pattern exhibited a hierarchy of carbon storage: soil layer > tree layer > litter layer. (2) The soil layer constituted the
most fundamental stable carbon reservoir within ecosystemsꎬ holding carbon storage ranging from 256.89 to 300.45 t
 ̄2
hm . This accounted for 69.90% of total carbon storageꎬ with over 60% of soil carbon concentrated within the 0-40 cm
 ̄2
soil layer. (3) The carbon storage in the tree layer ranged from 43.12 to 190.02 thm ꎬ exhibiting pronounced spatio ̄
temporal heterogeneity alongside a significant ‘mid ̄mature forest carbon accumulation peak’. Carbon was preferentially
allocated to the trunk (22.46% - 49.42%) and root (19.39% - 29.35%) among the various organs. Its distribution
strategy was density ̄regulated: biomass in high ̄density stands concentrated in the trunkꎬ while in medium ̄to ̄low ̄density
standsꎬ all organs grew more evenlyꎬ resulting in higher carbon sequestration efficiency. (4) The carbon storage in the
 ̄2
litter layer ranged from 12.53 to 21.92 thm ꎬ accounting for 3.58% to 4.30% of the total carbon storage. Howeverꎬ its
 ̄1
carbon content was remarkably high at 306.04 to 389.32 gkg ꎬ making it a pivotal hub connecting above ̄ground and
below ̄ground carbon flows. This study confirms that stand age and density are the core factors driving carbon
accumulation and distribution within P. asperata plantations ecosystems. By implementing sustainable management
strategies centred on density regulationꎬ the carbon sink potential of P. asperata plantations in this region can be
effectively harnessed. The results provide a crucial theoretical basis and practical guidance for optimizing the carbon sink
function of plantations in the Taohe River basinꎬ safeguarding ecosystemꎬ and achieving regional carbon neutrality
objectives.
Key words: stand ageꎬ densityꎬ carbon storageꎬ synergistic effectsꎬ Picea asperata forests
森林生态系统在陆地碳循环中占主导地位ꎬ 导碳储量的长期动态(Li et al.ꎬ2023)ꎻ密度则通过
其碳储量约占全球陆地总量的 40% ( 刘世荣等ꎬ 改变光、水、养分的竞争格局ꎬ影响生物量分配策略
2024)ꎬ在调节大气 CO 浓度和全球碳循环中发挥 与碳积累效率(Binkley et al.ꎬ2009)ꎮ 例如ꎬ高密度
2
着关键作用( Pan et al.ꎬ2011)ꎮ 人工林作为全球 林分在幼龄期可通过最大化叶面积指数( leaf area
森林资源的关键构成部分ꎬ在增强陆地生态系统 indexꎬLAI)提升碳汇能力(Kassierꎬ2011)ꎬ但随林龄
碳汇功能、缓解区域气候变化及保障生态稳定性 增长ꎬ过度竞争可能导致碳向非结构性器官(如枝
等方 面 均 发 挥 着 关 键 的 战 略 作 用 ( 冯 瑞 芳 等ꎬ 叶)分配的比例增加ꎬ抑制树干生物量积累(Binkley
2006)ꎮ 随着中国林业生态工程的持续推进ꎬ人工 et al.ꎬ2004ꎻThorpe et al.ꎬ2010)ꎮ
林面积已升至全球首位ꎬ中、幼龄林的持续生长预 洮河流域位于青藏高原-黄土高原过渡带ꎬ是
示着 人 工 林 在 未 来 将 具 有 巨 大 的 碳 汇 潜 力 中 国 西 北 重 要 的 生 态 安 全 屏 障 ( Wang et al.ꎬ
(Omosalewa et al.ꎬ2022ꎻZhang et al.ꎬ2023)ꎮ 有效 2015)ꎮ 该 区 域 广 泛 分 布 的 云 杉 林 ( Picea
经营人工林已成为区域生态恢复和碳中和目标实 asperata)在维持区域生态平衡和提供生态系统服
现的重要途径(Chen et al.ꎬ2019)ꎮ 务方面发挥着关键作用ꎮ 目前ꎬ对洮河流域人工
林龄和密度更是调控碳储量分配的核心驱动 云杉林碳储量分布特征及其驱动机制的研究ꎬ仍
因素ꎬ二者共同影响植被碳库的垂直分布格局和周 存在明显不足:一是大多聚焦单一林龄或密度梯
转效率(Kurt & Pregitzerꎬ 2004)ꎮ 已有研究证实ꎬ林 度(Kassierꎬ2011ꎻ冯宜明等ꎬ2023)ꎬ未能涵盖林分
龄通过调控林木生长阶段与生态系统功能发育ꎬ主 发育的动态变化ꎬ难以揭示碳储量的长期积累规

