As a structurally and functionally important component in forest ecosystems, plant debris plays a crucial role in the global carbon cycle. Although it is well known that plant debris stocks vary greatly with tree species composition, forest type, forest origin, and stand age, simultaneous investigation on the changes in woody and non-woody debris biomass and their carbon stock with forest succession has not been reported. Therefore, woody and non-woody debris and carbon stocks were investigated across a subalpine forest successional gradient in Wanglang National Nature Reserve on the eastern Qinghai-Tibet Plateau. Plant debris ranged from 25.19 to 82.89 Mg∙ha− 1 and showed a global increasing tendency across the subalpine forest successional series except for decreasing at the S4 successional stage. Accordingly, the ratios of woody to non-woody debris stocks ranged from 26.58 to 208.89, and the highest and lowest ratios of woody to non-woody debris stocks were respectively observed in mid-successional coniferous forest and shrub forest, implying that woody debris dominates the plant debris. In particular, the ratios of coarse to fine woody debris stocks varied greatly with the successional stage, and the highest and lowest ratios were found in later and earlier successional subalpine forests, respectively. Furthermore, the woody debris stock varied greatly with diameter size, and larger diameter woody debris dominated the plant debris. Correspondingly, the carbon stock of plant debris ranged from 10.30 to 38.87 Mg∙ha− 1 across the successional series, and the highest and lowest values were observed in the mid-coniferous stage and shrub forest stage, respectively. Most importantly, the carbon stored in coarse woody debris in later successional forests was four times higher than in earlier successional forests. The stock and role of woody debris, particularly coarse woody debris, varied greatly with the forest successional stage and dominated the carbon cycle in the subalpine forest ecosystem. Thus, preserving coarse woody debris is a critical strategy for sustainable forest management.

中文翻译：

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亚高山森林演替系列中植物残骸和碳储量的变化

作为森林生态系统结构和功能上的重要组成部分，植物残骸在全球碳循环中起着至关重要的作用。虽然众所周知，植物残骸储量随树种组成、森林类型、森林起源和林龄变化很大，但尚未有同时调查木质和非木质残骸生物量及其碳储量随森林演替变化的报道。 . 因此，在青藏高原东部王朗国家级自然保护区的亚高山森林演替梯度上调查了木质和非木质碎屑和碳储量。植物残骸的范围为 25.19 至 82.89 Mg∙ha− 1，除了在 S4 演替阶段减少外，整个亚高山森林演替系列均呈全球增加趋势。因此，木本与非木本残骸存量的比例为26.58～208.89，木本与非木本残骸存量比例最高和最低分别出现在针叶林和灌木林中，表明木本残骸在植物中占主导地位碎片。特别是粗、细木屑种群的比例随演替阶段变化很大，最高和最低的比例分别出现在演替后期和早期的亚高山森林中。此外，木屑存量随直径大小变化很大，较大直径的木屑以植物残骸为主。相应地，植物残体的碳储量在演替序列中范围为 10.30 至 38.87 Mg∙ha−1，最高和最低值出现在中针叶阶段和灌木林阶段，分别。最重要的是，后期演替森林中粗木屑中储存的碳是早期演替森林的四倍。木质碎屑，特别是粗木质碎屑的存量和作用随森林演替阶段变化很大，主导了亚高山森林生态系统的碳循环。因此，保护​​粗木屑是可持续森林管理的关键战略。