Soil autotrophic and heterotrophic respiration respond differently to land-use change and variations in environmental factors
Soil autotrophic and heterotrophic respiration respond differently to land-use change and variations in environmental factors
复制标题
土壤自养和异养呼吸对土地利用变化和环境因素变化的反应不同
DOI：
10.1016/j.agrformet.2018.01.003
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发表时间：
2018-03-15
影响因子：
6.2
通讯作者：
Lin, Ziwen
中科院分区：
文献类型：
--
作者：
Hu, Shuaidong;Li, Yongfu;Lin, Ziwen
将天然林转变为集约化管理的人工林显著改变了土壤碳(C)动态。然而，这种土地利用变化对土壤呼吸（R-S）组分的影响尚不清楚。本研究旨在探讨天然常绿阔叶林向集约经营毛竹人工林转变对R-S、自养呼吸（R-A）和异养呼吸（R-H）的影响。利用便携式土壤CO2通量测量系统，对3个阔叶林-竹林对土壤中R-S、R-A和R-H的季节动态进行了研究。结果表明，将常绿阔叶林改造为竹林后，年累积R-S和R-H分别提高了18.8%和20.9%，但对年累积R-A没有影响。土壤温度对常绿阔叶林R-A和R-H的季节变化分别有48%和79%的解释，对竹林R-A和R-H的季节变化分别有68%和79%的解释。土地利用变化增加了R-A的表观温度敏感性（Q(10)），但对R-H的表观温度敏感性没有影响。在不同土地利用类型下，R-A和R-H与土壤水溶性有机碳呈显著正相关，与土壤含水量无显著正相关。常绿阔叶林R-H与土壤微生物生物量C （MBC）呈显著正相关，竹林R-H与土壤微生物生物量C （MBC）无显著正相关。无论何种土地利用类型，土壤MBC与土壤R-A均不相关。因此，土壤R-A和R-H对土地利用变化和环境因子变化的响应不同，表明将R-S划分为不同组分对于阐明土地利用变化引起R-S变化的相关机制和预测不同气候变化情景下的R-S至关重要。
Converting natural forests to intensively managed plantations markedly alters soil carbon (C) dynamics. However, the impact of such land-use change on soil respiration (R-S) components remains unclear. The objective of this study was to examine the effect on R-S, autotrophic respiration (R-A) and heterotrophic respiration (R-H) of converting a natural evergreen broadleaf forest to an intensively managed Moso bamboo (Phyllostachys edulis) plantation. A two-year field study was carried out to assess the seasonal dynamics of R-S, R-A and R-H in three broadleaf forest-bamboo plantation pairs, using a portable soil CO2 flux measurement system. Results showed that converting the evergreen broadleaf forest to the bamboo plantation increased the annual cumulative R-S and R-H by 18.8% and 20.9%, respectively, but did not change the annual cumulative R-A. Soil temperature alone explained 48% and 79% of seasonal variations in R-A and R-H, respectively, in the evergreen broadleaf forest, and 68% and 79%, respectively, in the bamboo plantation. The land-use change increased the apparent temperature sensitivity (Q(10)) of R-A, but did not affect that of R-H. Regardless of the land-use type, both R-A and R-H were positively correlated with soil water soluble organic C, but not with soil moisture content. The R-H was positively correlated to soil microbial biomass C (MBC) in the evergreen broadleaf forest, but not in the bamboo plantation. The R-A was not correlated with soil MBC, regardless of the land-use type. Therefore, soil R-A and R-H responded differently to land-use change and variations in environmental factors, suggesting that partitioning of R-S to different components is essential to elucidate mechanisms associated with changes in R-S induced by land-use change and to predict R-S under different climate change scenarios.