Chen Zhi, Yu Guirui, Ge Jianping, Wang Qiufeng, Zhu Xianjin, Xu Zhiwei
Synthesis Research Center of Chinese Ecosystem Research Network, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
Synthesis Research Center of Chinese Ecosystem Research Network, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, China.
PLoS One. 2015 Apr 30;10(4):e0125265. doi: 10.1371/journal.pone.0125265. eCollection 2015.
Climate, vegetation, and soil characteristics play important roles in regulating the spatial variation in carbon dioxide fluxes, but their relative influence is still uncertain. In this study, we compiled data from 241 eddy covariance flux sites in the Northern Hemisphere and used Classification and Regression Trees and Redundancy Analysis to assess how climate, vegetation, and soil affect the spatial variations in three carbon dioxide fluxes (annual gross primary production (AGPP), annual ecosystem respiration (ARE), and annual net ecosystem production (ANEP)). Our results showed that the spatial variations in AGPP, ARE, and ANEP were significantly related to the climate and vegetation factors (correlation coefficients, R = 0.22 to 0.69, P < 0.01) while they were not related to the soil factors (R = -0.11 to 0.14, P > 0.05) in the Northern Hemisphere. The climate and vegetation together explained 60% and 58% of the spatial variations in AGPP and ARE, respectively. Climate factors (mean annual temperature and precipitation) could account for 45-47% of the spatial variations in AGPP and ARE, but the climate constraint on the vegetation index explained approximately 75%. Our findings suggest that climate factors affect the spatial variations in AGPP and ARE mainly by regulating vegetation properties, while soil factors exert a minor effect. To more accurately assess global carbon balance and predict ecosystem responses to climate change, these discrepant roles of climate, vegetation, and soil are required to be fully considered in the future land surface models. Moreover, our results showed that climate and vegetation factors failed to capture the spatial variation in ANEP and suggest that to reveal the underlying mechanism for variation in ANEP, taking into account the effects of other factors (such as climate change and disturbances) is necessary.
气候、植被和土壤特征在调节二氧化碳通量的空间变化中发挥着重要作用，但其相对影响仍不确定。在本研究中，我们汇编了北半球241个涡度协方差通量站点的数据，并使用分类与回归树以及冗余分析来评估气候、植被和土壤如何影响三种二氧化碳通量（年总初级生产力（AGPP）、年生态系统呼吸（ARE）和年净生态系统生产力（ANEP））的空间变化。我们的结果表明，在北半球，AGPP、ARE和ANEP的空间变化与气候和植被因素显著相关（相关系数，R = 0.22至0.69，P < 0.01），而与土壤因素无关（R = -0.11至0.14，P > 0.05）。气候和植被共同分别解释了AGPP和ARE空间变化的60%和58%。气候因素（年平均温度和降水量）可解释AGPP和ARE空间变化的45 - 47%，但气候对植被指数的限制约解释了75%。我们的研究结果表明，气候因素主要通过调节植被属性来影响AGPP和ARE的空间变化，而土壤因素的影响较小。为了更准确地评估全球碳平衡并预测生态系统对气候变化的响应，未来的陆面模型需要充分考虑气候、植被和土壤的这些不同作用。此外，我们的结果表明，气候和植被因素未能捕捉到ANEP的空间变化，并表明要揭示ANEP变化的潜在机制，有必要考虑其他因素（如气候变化和干扰）的影响。
