近日,沈陽農(nóng)業(yè)大學(xué)梁成華教授等幾位學(xué)者在生態(tài)學(xué)期刊《Water》上發(fā)表了題為“Atmospheric and Surface-Condition Effects on CO2 Exchange in the Liaohe Delta Wetland, China”的論文。該論文采用渦度協(xié)方差【1】的方法,研究了遼河三角洲蘆葦濕地CO2的通量。下面是中英文摘要。
摘要
在2012到2015年間,采用渦度協(xié)方差方法,研究了遼河三角洲蘆葦濕地的CO2通量。同時,分析了當(dāng)?shù)丨h(huán)境因子—包括氣象、植被、水文和土壤的變化。結(jié)果表明,在這四年間,該地區(qū)的CO2濃度變化趨勢和全球變化整體趨勢保持基本一致。該地區(qū)平均每年的CO2累積量是2.037kg·CO2·m-2,變化范圍在1.472 到2.297kg·CO2·m-2之間。
該生態(tài)系統(tǒng)CO2通量的季節(jié)特征如下。一般在每年的6月和7月,是CO2在一年中的強吸收期;而每年4月以及9月到10月是一年中的強排放期。在整個觀測期內(nèi),2015年7月是CO2排放量最強的月份。
從2013到2015年間,該生態(tài)系統(tǒng)的平均溫度,高于50年來的平均水平,主要是因為冬季氣溫偏高;平均降水量低于50年來的均值,主要是由于夏季降水的減少;在平均風(fēng)速方面,低于50年來的均值;且日照時數(shù)逐年遞減。
CO2通量和環(huán)境因子在一定程度上存在相關(guān)性。使用偏最小二乘法分析了氣象、植被、水文和土壤對CO2通量的貢獻率。水分和土壤溫度對CO2通量的變異影響顯著。采用顯著貢獻因子,建立了CO2收支的回歸方程。這些因子包括溫度、降水、相對濕度、水位、鹽分和生物量,該模型擬合可解釋CO2通量的70%。
關(guān)鍵詞:濕地;CO2通量;環(huán)境因子;特征;貢獻;預(yù)測
Abstract
The eddy covariance method was used to study the CO2 budget of the Liaohe Delta reed wetland in northern China during 2012–2015. The changes in environmental factors (including meteorology, vegetation, hydrology, and soil) were analyzed simultaneously. The change in the trend of the CO2 concentration in the reed wetland was similar to global changes over the four years. The average annual CO2 accumulation was 2.037 kg·CO2·m-2, ranging from 1.472 to 2.297 kg·CO2·m-2. The seasonal characteristics of the CO2 exchange included high CO2 absorption in June and July, and high emissions in April and from September to October, with the highest emissions in July 2015. The average temperatures from 2013 to 2015 were higher than the 50-year average, largely due to increased temperatures in winter. Precipitation was below the 50-year average, mainly because of low precipitation in summer. The average wind speed was less than the 50-year average, and sunshine duration decreased each year. The CO2 exchange and environmental factors had a degree of correlation or consistency. The contribution of meteorology, vegetation, hydrology, and soil to the CO2 budget was analyzed using the partial least squares method. Water and soil temperature had a greater effect on the CO2 exchange variability. The regression equation of the CO2 budget was calculated using the significant contributing factors, including temperature, precipitation, relative humidity, water-table level, salinity, and biomass. The model fit explained more than 70% of the CO2 exchange, and the simulation results were robust.
Keywords: wetland; CO2 exchange; environmental factors; characteristics; attribute; prediction
源/Jia, Q.; Yu, W.; Zhou, L.; Liang, C.Atmospheric and Surface-Condition Effects on CO2 Exchange in the Liaohe Delta Wetland, China. Water 2017, 9, 806.
延伸閱讀
【1】渦度協(xié)方差是一種原位、直接測定生態(tài)系統(tǒng)與大氣間物質(zhì)與能量通量的方法。其中,以美國LI-COR公司提供的系統(tǒng)解決方案最為高效、穩(wěn)定、完整。
圖1 LI-COR渦度協(xié)方差系統(tǒng)解決方案
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