Mediterranean ecosystems are significant carbon sinks and are particularly sensitive to climate change. However, the carbon dynamics in such ecosystems are still not fully understood. An improved understanding of the drivers of carbon fixation by vegetation is needed to better predict how these ecosystems will respond to climate change. In this study, a large dataset collected through the FLUXNET network is used to estimate how the gross primary production (GPP) of different Mediterranean ecosystems was affected by air temperature and precipitation between 1996 and 2013. We showed that annual precipitation and temperature were not significant drivers of annual GPP. However, inter-annual variations of GPP seemed largely controlled by the precipitation during early spring (March–April). Late spring and early summer temperature also had a positive effect on annual GPP. We furthermore show that GPP may also have been influenced by both summer rainfall pulses and abiotic emissions due to carbonates precipitation/dissolution. Finally, the sensitivity of GPP in the Mediterranean region to climate drivers seemed not to be ecosystem-type dependent. Our results can provide general information for modeling exercises and improve future biomass projections on a regional scale.

中文翻译：

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降水、气温和非生物排放对欧洲地中海生态系统初级生产总值的影响

地中海生态系统是重要的碳汇，对气候变化特别敏感。然而，此类生态系统中的碳动态仍未完全了解。需要更好地了解植被固碳的驱动因素，以更好地预测这些生态系统将如何应对气候变化。在这项研究中，通过 FLUXNET 网络收集的大型数据集用于估计 1996 年至 2013 年间不同地中海生态系统的初级生产总值 (GPP) 如何受气温和降水的影响。我们表明年降水量和温度并不显着年度 GPP 的驱动因素。然而，GPP 的年际变化似乎在很大程度上受早春（3 月至 4 月）降水的控制。春末夏初气温也对年度 GPP 产生了积极影响。我们进一步表明，由于碳酸盐沉淀/溶解，GPP 也可能受到夏季降雨脉冲和非生物排放的影响。最后，地中海地区 GPP 对气候驱动因素的敏感性似乎与生态系统类型无关。我们的结果可以为建模练习提供一般信息，并在区域范围内改进未来的生物量预测。