Effects of frequency and intensity of drying-rewetting cycles on Hydrocotyle vulgaris growth and greenhouse gas emissions from wetland microcosms
Effects of frequency and intensity of drying-rewetting cycles on Hydrocotyle vulgaris growth and greenhouse gas emissions from wetland microcosms
复制标题
干燥-再润湿循环的频率和强度对水生植物生长和湿地微观世界温室气体排放的影响
DOI：
10.1016/j.catena.2018.01.006
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发表时间：
2018-05-01
期刊：
影响因子：
6.2
通讯作者：
Yu, Fei-Hai
中科院分区：
文献类型：
--
作者：
Gao, Jun-Qin;Duan, Mu-Ying;Yu, Fei-Hai
干湿循环可以影响生态系统的功能，但很少有人知道如何之间的相互作用的频率和强度的干湿循环影响植物-土壤系统的温室气体排放。我们组装的微宇宙最初每个克隆，湿地植物天胡荽的两个营养个体（分株），并使他们三个频率（6，9和18个周期，每个周期9，6和3天）与三个强度（添加200，400和600毫升水每个周期）的干燥-再润湿循环54天。增加干湿交替频率显著提高了红球藻的生长和净光合速率。小白菜在最低强度的干湿循环下，其干重和干重均有所降低或无影响。增加干湿交替频率显著增加了最低强度下的CO2排放量，降低了最高强度下的CO2排放量，而在中等强度下没有影响。CO2排放量与H.普通的在最低强度下，CH 4排放受频率影响不显著，但在两个较高强度下，最高频率下CH 4排放最高。在最低强度下，N2 O的排放量在最高频率下最高，但在两个较高强度下，N2 O的排放量不受频率的影响。因此，干湿循环的频率和强度可以相互作用，影响植物-土壤系统的温室气体排放。长期干旱（降水频率低）在降水量较低的情况下会减少CO2排放，而在降水量较高的情况下会促进CO2排放。
Drying-rewetting cycles can affect ecosystem functioning, but little is known about how the interaction between frequency and intensity of drying-rewetting cycles affects greenhouse gas emissions from plant-soil systems. We assembled microcosms initially each having two vegetative individuals (ramets) of a clonal, wetland plant Hydrocotyle vulgaris, and subjected them to three frequencies (6, 9 and 18 cycles with 9, 6 and 3 days per cycle) crossed with three intensities (adding 200, 400 and 600 ml water per cycle) of drying-rewetting cycles for 54 days. Increasing frequency of drying-rewetting cycles significantly increased growth and net photosynthesis rate of H. vulgaris under the lowest intensity of drying-rewetting cycles, but decreased them or had no effect under the two higher intensities. Increasing drying-rewetting frequency significantly increased CO2 emission under the lowest intensity and decreased it under the highest intensity, whereas no effect was found under the intermediate intensity. CO2 emission was positively related to growth of H. vulgaris. Under the lowest intensity CH4 emission was not significantly affected by frequency, but under the two higher intensities it was the highest in the highest frequency. Under the lowest intensity N2O emission was the highest in the highest frequency, but it was not affected by frequency under the two higher intensities. Therefore, frequency and intensity of dryingrewetting cycles can interact to affect greenhouse gas emissions from plant-soil systems. Prolonged drought (low frequency of precipitation) can decrease CO2 emission under a lower amount of precipitation, but promote it under a higher amount of precipitation.