Tree species richness affects litter production and decomposition rates in a tropical biodiversity experiment
Tree species richness affects litter production and decomposition rates in a tropical biodiversity experiment
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DOI：
10.1111/j.2007.0030-1299.16065.x
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发表时间：
2007-12
期刊：
影响因子：
3.4
通讯作者：
M. Scherer‐Lorenzen;J. L. Bonilla;C. Potvin
中科院分区：
文献类型：
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作者：
M. Scherer‐Lorenzen;J. L. Bonilla;C. Potvin
我们报告了巴拿马热带地区树木操纵性生物多样性实验的树叶凋落物产生和分解的数据，该实验旨在探索树木多样性和生态系统功能之间的关系。2001年共建立了24块土地(2025平方米)，使用6种本地树种，其中有1种、3种和6种混合树种。我们使用垃圾捕捉器估计了2005年旱季期间的垃圾产生量；在接下来的雨季用垃圾袋方法评估了分解情况。在旱季期间，枯枝落叶产量在不同树种之间差异很大。树木多样性显著影响枯枝落叶产量，大多数中间多样性混交林的枯枝落叶产量高于单一栽培的预期产量。相比之下，高度多样化的混交林在凋落物产量上并没有表现出如此的超产。凋落物分解速率也具有高度的物种特异性，并与凋落物质量的各种指标(C/N、木质素/N、纤维含量)有关。如果对整个凋落物混合物进行分析，我们没有发现凋落物多样性的总体效应，即混合物种导致了纯粹的加性效应，观察到的分解率与预期的分解率没有差异。然而，个别物种根据混合凋落物的多样性改变其分解模式，即对混合凋落物有物种特有的反应。凋落物混合体内的时间C和N动态分析仅为不同质量的凋落物之间的养分转移提供了有限的证据。在我们的树木多样性实验的早期阶段，树种丰富度对凋落物的产生和分解没有一致和普遍的影响。因此，在生物多样性-生态系统功能关系的范围内，我们的结果突出了多样性可能产生的特定过程的影响。此外，物种对生态系统过程及其时间动态的特定影响是重要的，但这种影响可能会随着树木多样性的梯度而变化。
We report data on leaf litter production and decomposition from a manipulative biodiversity experiment with trees in tropical Panama, which has been designed to explore the relationship between tree diversity and ecosystem functioning. A total of 24 plots (2025 m2) were established in 2001 using six native tree species, with 1-, 3-, and 6-species mixtures. We estimated litter production during the dry season 2005 with litter traps; decomposition was assessed with a litter bag approach during the following wet season. Litter production during the course of the dry season was highly variable among the tree species. Tree diversity significantly affected litter production, and the majority of the intermediate diverse mixtures had higher litter yields than expected based on yields in monoculture. In contrast, high diverse mixtures did not show such overyielding in litter production. Litter decomposition rates were also highly species-specific, and were related to various measures of litter quality (C/N, lignin/N, fibre content). We found no overall effect of litter diversity if the entire litter mixtures were analyzed, i.e. mixing species resulted in pure additive effects and observed decomposition rates were not different from expected rates. However, the individual species changed their decomposition pattern depending on the diversity of the litter mixture, i.e. there were species-specific responses to mixing litter. The analysis of temporal C and N dynamics within litter mixtures gave only limited evidence for nutrient transfer among litters of different quality. At this early stage of our tree diversity experiment, there are no coherent and general effects of tree species richness on both litter production and decomposition. Within the scope of the biodiversity-ecosystem functioning relationship, our results therefore highlight the process-specific effects diversity may have. Additionally, species-specific effects on ecosystem processes and their temporal dynamics are important, but such effects may change along the gradient of tree diversity.