Termites amplify the effects of wood traits on decomposition rates among multiple bamboo and dicot woody species
Termites amplify the effects of wood traits on decomposition rates among multiple bamboo and dicot woody species
复制标题
DOI：
10.1111/1365-2745.12427
复制
发表时间：
2015-09-01
影响因子：
5.5
通讯作者：
Cornelissen, Johannes H. C.
中科院分区：
文献类型：
--
作者：
Liu, Guofang;Cornwell, William K.;Cornelissen, Johannes H. C.
木材分解是陆地碳循环中的一个关键过程，它通过对气候的反馈来控制碳储量。在(亚热带)森林中，白蚁是木材分解的主要参与者，但它们相对于微生物分解者的作用和不同树种的木材特性知之甚少。目前的文献对双子叶树的分解也有很大的偏向，而丰富的木本单子叶植物，特别是竹子，也对(亚)热带碳循环有很大贡献。在这里，我们提出了第一个实验来解开枯木性状和白蚁活动对66种被子植物分解的影响：31种竹子，8种非竹科植物，18种桉树和9种木兰科植物。我们在热带的S中国的一个普通花园里孵化了每个物种最多4个尺寸级的死茎。我们检验了这样的假设：(I)竹(单子叶)枯木比桉树或木兰素的枯木更难分解；(Ii)微生物和白蚁驱动的分解都与初始木材密度和干物质含量呈负相关。竹材的分解一般比双子叶木材慢，但在给定的木材密度或直径时，仅略慢。竹子和双子叶中的木材分解均随木材密度或干物质含量的增加而降低。白蚁对这一格局的贡献率较大，可解释53.4%的木材分解变异，并优先攻击初始密度较低的枯木，这与竹种较厚的外壁相对应。因此，白蚁强烈地加强了物种的木材特征和微生物活动驱动的凋落物分解之间的关系。这些未知的枯木质量、直径、白蚁和木本单子叶和双子叶植物分解微生物之间的关系将有助于我们理解(亚热带)木材分解的驱动机制及其对全球碳循环的贡献。
Wood decomposition is a key process in the terrestrial carbon cycle, controlling carbon storage with feedback to climate. In (sub) tropical forest, termites are major players in wood decomposition, but their role relative to that of microbial decomposers and wood traits of different tree species is poorly understood. The current literature also has strong bias towards dicot tree decomposition, while abundant woody monocots, particularly bamboos, also contribute greatly to (sub) tropical carbon cycling. Here, we present the first experiment to disentangle effects of dead wood traits and termite activity on decomposition of 66 angiosperm species of wide-ranging phylogenetic position: 31 bamboos, eight non-bamboo Poaceae, 18 eudicots and nine magnoliids. We incubated dead stems of up to 4 size classes per species in a common garden' in tropical S China. We tested the hypotheses that (i) dead wood of bamboo (monocots) is less decomposable than dead wood of eudicots or magnoliids; (ii) both microbial- and termite-driven decomposition show negative relationships with initial wood density and with dry matter content. Bamboo wood generally decomposed more slowly than dicot wood but only slightly slower at given wood density or diameter. Wood decomposition in both bamboo and dicot clades decreased with wood density or dry matter content. Termites contributed greatly to this pattern, explaining 53.4% of the variance in wood decomposition and preferentially attacking dead wood of lower initial density, which corresponded with thicker outer culm walls in the case of bamboo species. Thus, termites strongly strengthen the relationship between species' wood traits and litter decomposition as driven by microbial activity.Synthesis. These previously unknown relationships among dead wood quality, diameter, termites and decomposing microbes of both woody monocots and dicots will advance our understanding of the driving mechanisms of (sub) tropical wood decomposition and its contribution to the global carbon cycle.