Zeri Marcelo, Sá Leonardo D A, Manzi Antônio O, Araújo Alessandro C, Aguiar Renata G, von Randow Celso, Sampaio Gilvan, Cardoso Fernando L, Nobre Carlos A
Centro de Ciência do Sistema Terrestre, Instituto Nacional de Pesquisas Espaciais, Cachoeira Paulista, SP, Brazil.
Centro Regional da Amazônia, Instituto Nacional de Pesquisas Espaciais, Belém, PA, Brazil.
PLoS One. 2014 Feb 18;9(2):e88130. doi: 10.1371/journal.pone.0088130. eCollection 2014.
The carbon and water cycles for a southwestern Amazonian forest site were investigated using the longest time series of fluxes of CO2 and water vapor ever reported for this site. The period from 2004 to 2010 included two severe droughts (2005 and 2010) and a flooding year (2009). The effects of such climate extremes were detected in annual sums of fluxes as well as in other components of the carbon and water cycles, such as gross primary production and water use efficiency. Gap-filling and flux-partitioning were applied in order to fill gaps due to missing data, and errors analysis made it possible to infer the uncertainty on the carbon balance. Overall, the site was found to have a net carbon uptake of ≈5 t C ha(-1) year(-1), but the effects of the drought of 2005 were still noticed in 2006, when the climate disturbance caused the site to become a net source of carbon to the atmosphere. Different regions of the Amazon forest might respond differently to climate extremes due to differences in dry season length, annual precipitation, species compositions, albedo and soil type. Longer time series of fluxes measured over several locations are required to better characterize the effects of climate anomalies on the carbon and water balances for the whole Amazon region. Such valuable datasets can also be used to calibrate biogeochemical models and infer on future scenarios of the Amazon forest carbon balance under the influence of climate change.
利用该地点有史以来最长的二氧化碳和水汽通量时间序列，对亚马逊西南部一个森林地点的碳循环和水循环进行了调查。2004年至2010年期间包括两次严重干旱（2005年和2010年）以及一年的洪水期（2009年）。在通量的年度总和以及碳循环和水循环的其他组成部分，如总初级生产力和水分利用效率中，都检测到了这种极端气候的影响。采用了填补缺口和通量划分的方法来填补因数据缺失而产生的缺口，误差分析使得推断碳平衡的不确定性成为可能。总体而言，该地点的净碳吸收量约为5吨碳/公顷·年，但2005年干旱的影响在2006年仍然可见，当时气候扰动导致该地点成为大气碳的净源。由于旱季长度、年降水量、物种组成、反照率和土壤类型的差异，亚马逊森林的不同区域对极端气候的反应可能不同。需要在多个地点测量更长时间序列的通量，以便更好地描述气候异常对整个亚马逊地区碳平衡和水平衡的影响。这些宝贵的数据集还可用于校准生物地球化学模型，并推断气候变化影响下亚马逊森林碳平衡的未来情景。
