酸雨对中国陆地生态系统土壤呼吸影响的整合分析

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 酸雨对中国陆地生态系统土壤呼吸影响的整合分析 DOI: 10.5846/stxb202110202959 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31901296）；广东省基础与应用基础研究基金项目（2021A1515010652）；广州市基础研究计划项目（202102020289） Effects of acid rain on soil respiration in Chinese terrestrial ecosystems: A meta-analysis Author: Affiliation: Fund Project: This work was supported by the National Natural Science Foundation of China (31901296), the Guangdong Basic and Applied Basic Research Foundation (2021A1515010652), and the Guangzhou Basic Research Program (2021000031). 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:通过整合分析（Meta-analysis）国内外公开发表的81篇模拟酸雨实验论文的2683条有效观测数据，量化了酸雨对中国3个主要陆地生态系统（森林、草地和农田）土壤呼吸（Rs）及其组分（自养呼吸（Ra）、异养呼吸（Rh））的影响。结果表明，酸雨显著降低了Rs （-9.6%）、Rh （-7.7%）和Ra （-11.7%）；酸雨pH越低，Rs及其组分的降幅越大；野外实验对Rh和Ra的负效应大于温室实验。酸雨对Rs的负效应在农田最大（-14.7%），草地次之（-10.8%），森林最小（-8.0%）；森林Rh、Ra对酸雨的响应与Rs一致，不同林型间差异不显著；草地Rh和Ra在酸雨处理下分别显著降低和增加。Rs、Rh与土壤pH显著正相关，与土壤有机碳（SOC）显著负相关；Rh和Ra分别与地上和地下生物量显著正相关。酸雨对Rs和Ra的负效应随纬度的增加而减弱，随年平均温的升高而增强，对Rs的正效应随年平均降水的降低而增强。研究表明，酸雨不仅降低了土壤pH，抑制了植物生长，减少了植物向土壤的碳输入，还降低了微生物活性，减少了Rh，导致SOC分解降低，因而未显著改变土壤碳库。研究结果将为全球变化背景下我国陆地生态系统的碳预算提供科学借鉴。 Abstract:Anthropogenic activities over the last four decades have increased depositions of sulfur dioxide (SO2) and nitrogen oxides (NOx) by three to five fold in China, which resulted in a serious problem of acid rain with adverse effects on terrestrial carbon cycle. Soil respiration (Rs) as the second largest flux for the most terrestrial carbon cycle, and its two components (i.e., autotrophic respiration (Ra) and heterotrophic respiration (Rh)) are extremely sensitive to anthropogenic acid rain due to its detrimental effects on plant growth and soil microbes. Although numerous ecosystem-level manipulative experiments were conducted to explore the underlying mechanisms how acid rain affected Rs, a quantitative synthesis of previous studies on the effects of acid rain on Rs and its two components across different terrestrial ecosystems was scarce. By conducting a meta-analysis of 2683 observations from 81 independent experimental studies, we quantified the directions and magnitudes of the responses of Rs, Ra, and Rh to simulated acid rain (SAR) in three major terrestrial ecosystems (i.e., forest, grassland, farmland) in China. Across all the experimental studies, our results showed that SAR significantly reduced Rs (-9.6%), Rh (-11.7%) and Ra (-11.7%), and the degree of reduction was proportional to the pH of SAR. The negative effects of SAR on Rh and Ra were greater in field experiment than that in pot experiment due to the differences in the intensity of SAR and experimental duration. Among different terrestrial ecosystem types, the negative effect of SAR on Rs was the most negative in farmland ecosystems (-14.7%), followed by grassland (-10.8%) and forest (-8.0%) ecosystems. The responses of Rh and Ra to SAR in forest ecosystems were consistent with that of Rs, and there were no significant differences among different forest types (i.e., coniferous forest, coniferous and broadleaved mixed forest and broadleaved forest). In grassland ecosystems, the response to SAR was negative for Rh, but positive for Ra. Linear-regression analysis showed that Rs and Rh were positively correlated with soil pH, but negatively correlated with soil organic carbon (SOC). Rh and Ra were positively correlated with aboveground biomass (AGB) and belowground biomass (BGB), respectively. Meta-regression analysis indicated that the negative effects of SAR on Rs and Ra were decreased with the increase of latitude, and increased with the increase of mean annual temperature (MAT), whereas the positive effect of SAR on Rs increased with a decrease in mean annual precipitation (MAP). Based on this meta-analysis, we found that SAR not only reduced soil pH, inhibited plant growth, and thus reduced plant carbon input to soil, but also inhibited microbial activities, reduced Rh, and SOC decomposition rate. Therefore, anthropogenic acid rain significantly altered the input and output of SOC, but did not significantly change the content of SOC in terrestrial ecosystems. These results will provide scientific basis for assessing the carbon budget of the Chinese terrestrial ecosystems in response to global change. 参考文献 相似文献 引证文献