Rubio Vanessa E, Detto Matteo
Smithsonian Tropical Research Institute Balboa Panama.
Department of Biological Sciences University of Los Andes Bogota Colombia.
Ecol Evol. 2017 Aug 14;7(17):7104-7116. doi: 10.1002/ece3.3267. eCollection 2017 Sep.
We monitored soil CO effluxes for over 3 years in a seasonally wet tropical forest in Central Panama using automated and manual measurements from 2013 to 2016. The measurements displayed a high degree of spatial and temporal variability. Temporal variability could be largely explained by surface soil water dynamics over a broad range of temporal scales. Soil moisture was responsible for seasonal cycles, diurnal cycles, intraseasonal variability such as rain-induced pulses following dry spells, as well as suppression during near saturated conditions, and ultimately, interannual variability. Spatial variability, which remains largely unexplained, revealed an emergent role of forest structure in conjunction with physical drivers such as soil temperature and topography. Mean annual soil CO effluxes (±) amounted to 1,613 (±59) gC m year with an increasing trend in phase with an El Niño/Southern Oscillation (ENSO) cycle which culminated with the strong 2015-2016 event. We attribute this trend to a relatively mild wet season during which soil saturated conditions were less persistent.
2013年至2016年期间，我们在巴拿马中部一个季节性湿润的热带森林中，通过自动和手动测量对土壤二氧化碳通量进行了长达3年多的监测。测量结果显示出高度的空间和时间变异性。时间变异性在很大程度上可以由广泛时间尺度上的表层土壤水分动态来解释。土壤湿度决定了季节循环、昼夜循环、季节内变异性，如干旱期后降雨引发的脉冲，以及接近饱和条件下的抑制作用，最终还决定了年际变异性。空间变异性在很大程度上仍无法解释，它揭示了森林结构与土壤温度和地形等物理驱动因素共同发挥的重要作用。年平均土壤二氧化碳通量（±）为1,613（±59）克碳/平方米·年，并且随着厄尔尼诺/南方涛动（ENSO）周期呈上升趋势，在2015 - 2016年的强烈事件中达到顶峰。我们将这种趋势归因于相对温和的雨季，在此期间土壤饱和条件持续时间较短。
