| 引用本文: | 李倩,高阳,王洪博, 等..温度升高和干旱对农田生态系统水碳交换动态影响的研究进展[J].灌溉排水学报,2021,(12):110-118. |
| LI Qian,GAO Yang,WANG Hongbo, et al.温度升高和干旱对农田生态系统水碳交换动态影响的研究进展[J].灌溉排水学报,2021,(12):110-118. |
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| 摘要: |
| 气候变化是威胁全球农业可持续发展的重要因素之一。温度升高和干旱等极端天气频发是全球气候变化的主要体现方式。温度升高显著影响土壤-作物系统的表现和功能。深入理解温度升高和干旱对农田水碳动态的影响机理，需要揭示农田生态系统功能与环境因子间的互作关系及其尺度转化效应。本文从以下几个方面综述了升温和干旱胁迫对农田生态水碳动态的影响：①全球气候变化及其影响因素分析；②温度升高、干旱胁迫以及其他气候变化因子对农田生态系统水碳动态的影响；③存在问题与未来研究方向。文献显示，世界人口增加、化石燃料燃烧碳排放量增加等致使气候变暖，在此背景下，引发的气温上升以及干旱频率增加都会对农田生态系统水碳动态有一定程度的影响。温度升高改变农田生态系统的生物量积累，同时影响作物生长和水分利用过程。此外，温度升高加快了土壤活性有机碳的转化和固存。干旱条件下会降低植物光合速率、呼吸速率以及蒸腾速率，同时，在极端干旱条件下水分利用效率也会随之降低；干旱还显著影响土壤碳转化过程与排放通量。气候变化也会伴随降水格局变化，进一步会影响土壤呼吸作用，降水增加会抑制土壤呼吸，从而减缓农田水碳循环过程。然而，目前关于增温和干旱条件下农田水碳动态的研究等方面仍存在一些不足，如对单一环境因子的研究较多，而对多重胁迫的研究较少。在今后的研究中，需加强多因素（如水分、温度等）对农田生态系统水碳动态方面的研究，以期为深入认识温度和干旱对农田生态系统的影响机理提供理论支撑。 |
| 关键词: 增温；干旱；生物量；水碳循环；农田生态系统 |
| DOI：10.13522/j.cnki.ggps.2021285 |
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| Changes in Water and Carbon in Farmland Ecosystems Due to the Combined Impact of Temperature Rise and Drought: A Review |
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LI Qian, GAO Yang, WANG Hongbo, et al
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| Abstract: |
| Climate change would increase the frequency of extreme weather events threatening sustainable agricultural production as a warmed atmosphere has significant effects on functions of soil-crop systems. Although moderate drought is known to improve plant water use efficiency (WUE), how warming combined with drought affects terrestrial ecosystems remains largely unknown. Evolutionally, different plants have developed different strategies to facilitate water acquisition, and their physiological and morphological traits respond to drought in different ways. In this paper, we reviewed the combined effects of warming and drought on water and carbon dynamics in cropped lands in three aspects: ①global climate change and its underlying drivers; ②effects of warming, drought and other climate change factors on water/carbon dynamics; ③unknown/known problems and future research directions. Global warming induced by the increased population, carbon emissions from fossil fuel and increase in drought frequency will all pose a significant impact on water and carbon in farmland. Warming will change the amount of biomass thereby affecting crop growth and water use efficiency, in addition to the accelerated soil organic carbon (SOC) loss. In the above-ground, drought will reduce photosynthetic rate and transpiration, while in the below-ground, it will reduce microbial activity and slow down SOC decomposition, thereby inhibiting soil CO2 emissions. Climate change is likely to change the precipitation pattern, which in turn will alter soil respiration. Apparently, there is a lack of studies on water and carbon cycles under combined influence of drought and increasing temperature. This should be strengthened as water and carbon cycles in soil-crop systems are likely to be affected by multiple biotic and abiotic factors including soil water, temperature, carbon and nutrient concentration, in order to provide a mechanistic understanding of their combined effects on functions of farmland ecosystems as well as their feedback interaction with global warming. |
| Key words: global warming; drought; biomass; water and carbon cycle; farmland ecosystem |
