Terrestrial ecosystems are often thought to be effective sinks of anthropogenic CO₂ emissions with biosphere greening considered unequivocal evidence of this process. Increasing atmospheric concentrations of CO₂ along with other greenhouse gases are however, responsible for global warming. As temperature increases, the rate at which biomes sequester CO₂ may decline as the optimum temperature for photosynthetic production is exceeded, thereby reducing their potential to sequester CO₂. Here we present evidence from 3 years of direct measurements of CO₂ exchanges over subtropical coastal ecosystems in eastern Australia that the optimum temperature range for photosynthesis of 24.1°C to 27.4°C is routinely exceeded. This causes a rapid decline in photosynthetic production made worse when soil water content decreases. As climate change continues, both rising temperatures and predicted decline in rainfall will see these coastal ecosystems ability to sequester CO₂ decrease further rapidly. We suggest similar research is needed urgently over other terrestrial ecosystems.

中文翻译：

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确定亚热带沿海生态系统中光合作用的最佳温度：在变暖世界中固存二氧化碳的意义

人们通常认为陆地生态系统是有效的人为CO ₂排放汇，而生物圈绿化被认为是这一过程的明确证据。但是，大气中CO _2的浓度与其他温室气体的浓度升高是造成全球变暖的原因。随着温度升高，随着超过光合作用产生的最佳温度，生物群落螯合CO ₂的速率可能下降，从而降低了其螯合CO ₂的潜力。在这里，我们提供3年直接测量CO _2的证据在澳大利亚东部亚热带沿海生态系统的交换中，通常会超过24.1°C至27.4°C的光合作用的最佳温度范围。当土壤含水量减少时，这会导致光合作用的迅速下降，从而使情况更加恶化。随着气候变化的继续，温度升高和预计降雨减少将使这些沿海生态系统封存CO _2的能力进一步迅速下降。我们建议对其他陆地生态系统迫切需要类似的研究。