El Niño Southern Oscillation (ENSO) Enhances CO2 Exchange Rates in Freshwater Marsh Ecosystems in the Florida Everglades
El Niño Southern Oscillation (ENSO) Enhances CO2 Exchange Rates in Freshwater Marsh Ecosystems in the Florida Everglades
复制标题
厄尔尼诺南方涛动 (ENSO) 提高了佛罗里达大沼泽地淡水沼泽生态系统的二氧化碳汇率
作者：
S. Malone;C. Staudhammer;S. Oberbauer;P. Olivas;M. G. Ryan;J. Schedlbauer;H. Loescher;G. Starr
这项研究考察了厄尔尼诺南方涛动(ENSO)、水位、降水模式和佛罗里达大沼泽地淡水湿地生态系统中二氧化碳(CO2)交换速率之间的关系。数据是在为期5年的研究期间(2009-2013年)从位于大沼泽地国家公园的两个不同水文学的淡水沼泽地点获得的。在短水期站点(Taylor Slough；TS)和长水期站点(Shark River Slough；SRS)，降水模式的波动伴随着ENSO位相的变化，这表明极端的ENSO位相改变了大沼泽地的水文，这是已知对生态系统碳动态有重大影响的。ENSO阶段和年净二氧化碳交换率的变化与湿季和旱季的长度和强度的变化同时发生。厄尔尼诺和拉尼娜阶段与CO2交换速率的季节变化相结合，放大了两个站点的季节强度和CO2交换速率。在TS，净CO2吸收速率在旱季较高，而SRS在雨季具有较高的固碳速率。与厄尔尼诺和中性年份(−5至−43.5g CO2 m−2年−1)相比，由于拉尼娜阶段与干旱年和旱季延长同时发生，TS成为每年更大的二氧化碳汇(−11至−110g CO2 m−2年−1)。除与厄尔尼诺阶段有关的一年异常潮湿的年份(−16克二氧化碳m−2年−1)外，SRs每年都是二氧化碳的一个小来源(1.81至80克二氧化碳m−2年−1)。考虑到未来的气候预测表明厄尔尼诺和拉尼娜阶段的频率和强度更高，这些结果表明极端ENSO阶段的变化将显著改变佛罗里达大沼泽地的二氧化碳动态。
This research examines the relationships between El Niño Southern Oscillation (ENSO), water level, precipitation patterns and carbon dioxide (CO2) exchange rates in the freshwater wetland ecosystems of the Florida Everglades. Data was obtained over a 5-year study period (2009–2013) from two freshwater marsh sites located in Everglades National Park that differ in hydrology. At the short-hydroperiod site (Taylor Slough; TS) and the long-hydroperiod site (Shark River Slough; SRS) fluctuations in precipitation patterns occurred with changes in ENSO phase, suggesting that extreme ENSO phases alter Everglades hydrology which is known to have a substantial influence on ecosystem carbon dynamics. Variations in both ENSO phase and annual net CO2 exchange rates co-occurred with changes in wet and dry season length and intensity. Combined with site-specific seasonality in CO2 exchanges rates, El Niño and La Niña phases magnified season intensity and CO2 exchange rates at both sites. At TS, net CO2 uptake rates were higher in the dry season, whereas SRS had greater rates of carbon sequestration during the wet season. As La Niña phases were concurrent with drought years and extended dry seasons, TS became a greater sink for CO2 on an annual basis (−11 to −110 g CO2 m−2 yr−1) compared to El Niño and neutral years (−5 to −43.5 g CO2 m−2 yr−1). SRS was a small source for CO2 annually (1.81 to 80 g CO2 m−2 yr−1) except in one exceptionally wet year that was associated with an El Niño phase (−16 g CO2 m−2 yr−1). Considering that future climate predictions suggest a higher frequency and intensity in El Niño and La Niña phases, these results indicate that changes in extreme ENSO phases will significantly alter CO2 dynamics in the Florida Everglades.