Photosynthetic responses to high temperature

Predicting Photosynthesis at High Temperature: High temperature is known to have a detrimental effect on photosynthesis. When temperatures exceed the optimum for photosynthesis, lower rates of photosynthesis invariably occur (Fig. 19.1). The rapid increase in mean global temperatures and the increased frequencies of temperature extremes and droughts as a result of anthropogenic activities (IPCC, 2007) make understanding supraoptimal temperature effects on photosynthesis crucial because temperature-induced loss of carbon assimilation is likely to become more frequent. In understanding photosynthetic responses to temperature it is often necessary to mathematically describe the response of photosynthesis or some component process to temperature. Temperature responses are typically logarithmic, that is, processes increase by a set proportion for a given increase in temperature. Descriptions of temperature responses have taken many mathematical forms.