With an increase in average global temperatures over the last 200 years (at least 1.1°Csince 1880, with the majority of the warming occurring since 1975 at a rate of roughly0.15 to 0.20°C per decade; NASA’s Goddard Institute for Space Studies (GISS)), it hasbecome imperative to understand the impact of this warming on plants, particularly foodcrops. An important aspect of understanding this impact is studying the variation of leaftemperature and its relationship with a variety of environmental and genetic factors.Studying the thermal dynamics of leaves, which are the food factories of plants, mayallow us to devise methods to control leaf temperature, thus enabling the plant tophotosynthesize at its optimum.Any property of an organism (which, in our study, is leaf temperature) is controlled bytwo aspects—intrinsic or genetic aspects and extrinsic or environmental aspects. Theintrinsic factors affecting leaf temperature may include leaf area, width, length, presenceof appendages, leaf surface texture, and leaf shape. The extrinsic factors affecting leaftemperature may include wind speed, solar radiation, humidity, and water availability.However, there is also a possibility of some factors being influenced by both genes andthe environment.Several past studies have shown that the rate of transpiration and the associatedcooling effect may play a vital role in regulating leaf temperature.Additionally, somestudies suggest that variation in leaf width, area, and shape (marginalcomplexity/dissection) affects its thermal dynamics (A. Leigh, 2017).We designed an experiment that involved both intrinsic parameters (e.g., width, area,length) and an extrinsic parameter (effect of transpiration) as variables and attempted to find causal links between leaf temperature and these variables. Alongside this, we alsoaimed to identify a pattern of leaf temperature variation across four different species.
Pawar et al. (Mon,) studied this question.