Decomposition of coarse woody debris in a long-term litter manipulation experiment: A focus on nutrient availability
Decomposition of coarse woody debris in a long-term litter manipulation experiment: A focus on nutrient availability
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DOI：
10.1111/1365-2435.13047
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发表时间：
2018-04-01
影响因子：
5.2
通讯作者：
Tanner, Edmund V. J.
中科院分区：
文献类型：
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作者：
Gora, Evan M.;Sayer, Emma J.;Tanner, Edmund V. J.
1.热带森林的大部分地上碳储存在木材中，在粗木质残体分解过程中返回大气。然而，控制木材分解的因素还没有在与此过程的长度相当的时间尺度上进行实验操作。我们假设，木材分解是有限的养分供应和测试这一假设在一个长期的凋落物添加和去除实验在巴拿马的低地热带森林。具体来说，我们量化分解使用15年的时间序列腐烂树干，并测量呼吸速率和养分限制的木材分解者社区。长期的概率，一棵死树完全分解的地块，凋落物被删除，但没有不同的凋落物添加和控制处理。同样，木材分解者社区的呼吸速率较大，在控制处理相对于凋落物清除地块，凋落物添加治疗没有不同的其他治疗。在凋落物去除和添加处理中，氮、磷、钾营养元素的添加增加了呼吸速率，而对照则没有.建立减少凋落物去除地块的土壤养分浓度和增加呼吸速率响应营养物质的增加表明，减少凋落物去除后的木材分解率是由减少养分的可用性。凋落物操作的影响不同方向从以前的短期分解研究在相同的地块，并减少枯枝落叶去除地块的树干分解率没有出现，直到经过6年以上的分解。这些差异表明，凋落物介导的营养动态的影响有复杂的相互作用，随着时间的推移分解。
1. The majority of above-ground carbon in tropical forests is stored in wood, which is returned to the atmosphere during decomposition of coarse woody debris. However, the factors controlling wood decomposition have not been experimentally manipulated over time scales comparable to the length of this process.2. We hypothesized that wood decomposition is limited by nutrient availability and tested this hypothesis in a long-term litter addition and removal experiment in a lowland tropical forest in Panama. Specifically, we quantified decomposition using a 15-year chronosequence of decaying boles, and measured respiration rates and nutrient limitation of wood decomposer communities.3. The long-term probability that a dead tree completely decomposed was decreased in plots where litter was removed, but did not differ between litter addition and control treatments. Similarly, respiration rates of wood decomposer communities were greater in control treatments relative to litter removal plots; litter addition treatments did not differ from either of the other treatments. Respiration rates increased in response to nutrient addition (nitrogen, phosphorus, and potassium) in the litter removal and addition treatments, but not in the controls.4. Established decreases in concentrations of soil nutrients in litter removal plots and increased respiration rates in response to nutrient addition suggest that reduced rates of wood decomposition after litter removal were caused by decreased nutrient availability. The effects of litter manipulations differed directionally from a previous short-term decomposition study in the same plots, and reduced rates of bole decomposition in litter removal plots did not emerge until after more than 6 years of decomposition. These differences suggest that litter-mediated effects on nutrient dynamics have complex interactions with decomposition over time.