Consequences of the reduction of plant diversity for litter decomposition: effects through litter quality and microenvironment
Consequences of the reduction of plant diversity for litter decomposition: effects through litter quality and microenvironment
复制标题
DOI：
10.1034/j.1600-0706.2000.900217.x
复制
发表时间：
2000-08-01
期刊：
影响因子：
3.4
通讯作者：
Lawton, JH
中科院分区：
文献类型：
--
作者：
Hector, A;Beale, AJ;Lawton, JH
植物凋落物的分解是生态系统中能量和养分流动的关键过程，可能对生物多样性的丧失敏感。植物多样性的变化可能影响凋落物分解的两种假设机制是（1）通过凋落物物种组成的变化，以及（2）通过改变分解微环境。我们测试了这些与实验植物组合中草本植物凋落物的短期分解相关的想法，这些组合在植物物种的数量和类型以及它们所包含的功能组方面有所不同，以模拟植物多样性的丧失。我们使用不同的垃圾袋实验来区分多样性对分解产生影响的两种潜在途径。我们的两项垃圾袋试验表明，改变植物多样性通过分解微环境的变化与通过凋落物组成的变化对凋落物分解的影响不同。在分解微环境实验中，与植物多样性降低相关的分解速率显着但微弱的下降，但植物组成没有显着影响。凋落物组成实验表明，丰富度没有影响，但组成有显着影响，包括植物种类和功能组之间在凋落物化学和分解速率方面存在巨大差异。然而，对于我们的垃圾混合物的嵌套子集，单物种袋的分解并不能准确预测；垃圾混合会产生积极的、非累加的效果，从而促进分解。我们严格评估了短期垃圾袋试验在预测植物多样性变化对垃圾分解率的长期影响方面的优势和局限性。
Decomposition of plant litter is a key process for the flow of energy and nutrients in ecosystems that may be sensitive to the loss of biodiversity. Two hypothetical mechanisms by which changes in plant diversity could affect litter decomposition are (1) through changes in litter species composition, and (2) by altering the decomposition microenvironment. We tested these ideas in relation to the short-term decomposition of herbaceous plant litter in experimental plant assemblages that differed in the numbers and types of plant species and functional groups that they contained to simulate loss of plant diversity. We used different litterbag experiments to separate the two potential pathways through which diversity could have an effect on decomposition.Our two litterbag trials showed that altering plant diversity affected litter breakdown differently through changes in decomposition microenvironment than through changes in litter composition. In the decomposition microenvironment experiment there was a significant but weak decline in decomposition rate in relation to decreasing plant diversity but no significant effect of plant composition. The litter composition experiment showed no effect of richness but significant effects of composition, including large differences between plant species and functional groups in litter chemistry and decomposition rate. However, for a nested subset of our litter mixtures decomposition was not accurately predicted from single-species bags; there were positive, non-additive effects of litter mixing which enhanced decomposition. We critically assess the strengths and limitations of our short-term litterbag trials in predicting the longer-term effects of changes in plant diversity on litter decomposition rates.