Increased litter in subtropical forests boosts soil respiration in natural forests but not plantations of Castanopsis carlesii
Increased litter in subtropical forests boosts soil respiration in natural forests but not plantations of Castanopsis carlesii
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亚热带森林中凋落物的增加会促进天然林的土壤呼吸，但不会促进卡氏槠人工林的土壤呼吸
DOI：
10.1007/s11104-017-3281-2
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发表时间：
2017-09-01
期刊：
影响因子：
4.9
通讯作者：
Yang, Yusheng
中科院分区：
文献类型：
--
作者：
Liu, Xiaofei;Lin, Teng-Chiu;Yang, Yusheng
背景和目的响应气候变化的净初级生产力的变化可能会影响凋落物输入到森林土壤。然而，在热带和亚热带森林凋落物输入和土壤碳动态变化之间的反馈仍然知之甚少。方法在中国南方米槠天然林和种植园林中，分别设置凋落物处理和不处理，测定相邻样地的土壤呼吸、土壤性质、细根生物量和酶活性。结果凋落物处理后3年，土壤呼吸、土壤细根生物量和酶活性均显著高于对照。在天然林中，凋落物输入增加一倍（+24%）比消除凋落物输入（-15%）的土壤呼吸变化幅度更大，可能是由于土壤有机碳（SOC）分解的正启动效应。快速和强烈的引发效果被证实的酶活性升高的六种酶分析。相比之下，在种植园林中，对凋落物清除的反应（-31%）大于对凋落物添加的反应（1%;不显著）。种植园林正启动作用的缺乏可能与其土壤肥力较低，不能满足土壤微生物的需求，而土壤粘粒含量较高，保护了土壤有机碳免受微生物的侵害有关。在天然林中，正启动效应显著，而在种植园林中则不显著。carlesii也是一致的，在土壤总碳观察到的凋落物后，在天然林，但不是种植园林的显着下降ConclusionsIncreases地上凋落物生产可能会引发效应，随后转移更多的土壤碳到大气中的CO2在天然林，但不是在种植园林低肥力。全球变化驱动因素导致的废弃物投入变化可能对天然林和种植园林产生不同的影响。
Background and aimsChanges in net primary productivity in response to climate change are likely to affect litter inputs to forest soil. However, feedbacks between changes in litter input and soil carbon dynamics remain poorly understood in tropical and subtropical forests. This study aims to test whether the effects of litter manipulation on soil respiration differ between natural and plantation forests.MethodsSoil respiration, soil properties, fine root biomass and enzyme activity were measured in adjacent plots with doubling vs. eliminating litter input in both natural and plantation forests of Castanopsis carlesii in southern China.ResultsAfter only 3 years of litter manipulation, the magnitude of change in soil respiration was greater in response to a doubling of the litter input (+24%) than to the elimination of litter input (−15%) in the natural forest, possibly due to a positive priming effect on decomposition of soil organic carbon (SOC). The quick and intense priming effect was corroborated by elevated enzyme activities for five of the six enzymes analyzed. In contrast, the response to litter removal (−31%) was greater than the response to litter addition (1%; not significant) in the plantation forest. The lack of positive priming in the plantation forest may be related to its lower soil fertility, which could not meet the demand of soil microbes, and to its high clay content, which protected SOC from microbial attack. The positive priming effect in the natural forest but not plantation forest of C. carlesii is also consistent with the significant declines in total soil carbon observed following litter addition in the natural forest but not the plantation forest.ConclusionsIncreases in aboveground litter production may trigger priming effects and subsequently transfer more soil carbon to atmospheric CO2 in the natural forest but not in the plantation forest with low fertility. Changes in litter inputs resulting from global change drivers may have different impacts on natural and plantation forests.