Increased litterfall in tropical forests boosts the transfer of soil CO2 to the atmosphere.
Increased litterfall in tropical forests boosts the transfer of soil CO2 to the atmosphere.
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在热带森林中增加的垃圾量增加了土壤二氧化碳向大气的转移。
DOI：
10.1371/journal.pone.0001299
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发表时间：
2007-12-12
期刊：
影响因子：
3.7
通讯作者：
Tanner, Edmund V. J.
中科院分区：
文献类型：
--
作者：
Sayer, Emma J.;Powers, Jennifer S.;Tanner, Edmund V. J.
由于大气中二氧化碳浓度升高、气温上升和降雨模式改变，森林中的地面垃圾可能会增加。由于凋落物代表了从植被到土壤的主要碳通量，凋落物输入的变化可能对土壤碳动态产生广泛的影响。这种对碳平衡的干扰在热带地区可能特别重要，因为热带森林储存了全球土壤碳的近30%，使其成为全球碳循环的重要组成部分;然而，对地上凋落物增加对地下碳动态的影响知之甚少。我们使用长期的，大规模的每月凋落物清除和添加处理在低地热带森林，以评估增加凋落物对地下CO2生产的后果。在第二至第五年的治疗，凋落物增加土壤呼吸比凋落物去除减少它，土壤呼吸平均降低20%，在凋落物去除和43%的凋落物添加处理相比，控制，但凋落物添加没有改变微生物生物量。我们预测增加9%的土壤呼吸在凋落物添加地块，减少20%的凋落物去除地块和减少11%的基础上，由于较低的细根生物量在凋落物添加地块。因此，土壤呼吸增加43%，比预测的高34%，这可能是“额外的”CO2是引发效应的结果，即通过添加新鲜有机物刺激旧土壤有机质的分解。我们的研究结果表明，由于全球变化而导致的地上凋落物产生的增加有可能导致热带森林土壤碳大量流失到大气中。
Aboveground litter production in forests is likely to increase as a consequence of elevated atmospheric carbon dioxide (CO2) concentrations, rising temperatures, and shifting rainfall patterns. As litterfall represents a major flux of carbon from vegetation to soil, changes in litter inputs are likely to have wide-reaching consequences for soil carbon dynamics. Such disturbances to the carbon balance may be particularly important in the tropics because tropical forests store almost 30% of the global soil carbon, making them a critical component of the global carbon cycle; nevertheless, the effects of increasing aboveground litter production on belowground carbon dynamics are poorly understood. We used long-term, large-scale monthly litter removal and addition treatments in a lowland tropical forest to assess the consequences of increased litterfall on belowground CO2 production. Over the second to the fifth year of treatments, litter addition increased soil respiration more than litter removal decreased it; soil respiration was on average 20% lower in the litter removal and 43% higher in the litter addition treatment compared to the controls but litter addition did not change microbial biomass. We predicted a 9% increase in soil respiration in the litter addition plots, based on the 20% decrease in the litter removal plots and an 11% reduction due to lower fine root biomass in the litter addition plots. The 43% measured increase in soil respiration was therefore 34% higher than predicted and it is possible that this ‘extra’ CO2 was a result of priming effects, i.e. stimulation of the decomposition of older soil organic matter by the addition of fresh organic matter. Our results show that increases in aboveground litter production as a result of global change have the potential to cause considerable losses of soil carbon to the atmosphere in tropical forests.
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影响因子：
5.5
作者：
ANDERSON, JM;PROCTOR, J;VALLACK, HW
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