Plant carbon metabolism and climate change: elevated CO₂ and temperature impacts on photosynthesis, photorespiration and respiration

Abstract

Contents Summary 32 I. The importance of plant carbon metabolism for climate change 32 II. Rising atmospheric CO2 and carbon metabolism 33 III. Rising temperatures and carbon metabolism 37 IV. Thermal acclimation responses of carbon metabolic processes can be best understood when studied together 38 V. Will elevated CO2 offset warming-induced changes in carbon metabolism? 40 VI. No plant is an island: water and nutrient limitations define plant responses to climate drivers 41 VII. Conclusions 42 Acknowledgements 42 References 42 Appendix A1 48 SUMMARY: Plant carbon metabolism is impacted by rising CO concentrations and temperatures, but also feeds back onto the climate system to help determine the trajectory of future climate change. Here we review how photosynthesis, photorespiration and respiration are affected by increasing atmospheric CO concentrations and climate warming, both separately and in combination. We also compile data from the literature on plants grown at multiple temperatures, focusing on net CO assimilation rates and leaf dark respiration rates measured at the growth temperature (A and R , respectively). Our analyses show that the ratio of A to R is generally homeostatic across a wide range of species and growth temperatures, and that species that have reduced A at higher growth temperatures also tend to have reduced R , while species that show stimulations in A under warming tend to have higher R in the hotter environment. These results highlight the need to study these physiological processes together to better predict how vegetation carbon metabolism will respond to climate change.

Climate warming and tree carbon use efficiency in a whole‐tree 13CO2 tracer study

“…Respiration and photosynthesis may acclimate to temperature together such that their ratio ( R/A ) is constant. This is consistent with some measurements of an invariant R/A ratio across a wide range of temperatures, but with some additional variation at exceptionally high or low temperatures (Atkin et al ., ; Aspinwall et al ., ; Slot & Winter, ; Crous et al ., ; Dusenge et al ., ). Importantly, several studies indicated that the R/A ratio changed in response to a change in growth temperature, but that a homeostatic R/A ratio was restored following the development of new leaves (Ziska & Bunce, ; Loveys et al ., ; Campbell et al ., ).…”

Origins of abrupt change? Postfire subalpine conifer regeneration declines nonlinearly with warming and drying

“…However, increased CO 2 effects on tree growth remain poorly understood (Dusenge et al. ) and may be less important for seedlings than mature trees (Johnson et al. ).…”

Can leaf net photosynthesis acclimate to rising and more variable temperatures?

“…Therefore, the effects of future changes in air and leaf temperature on plant C balance may alter productivity (Boisvenue & Running, ; Reyer et al, ; Teskey et al, ; Zhao et al, ) and eventually lead to shifts in species ranges and local extinctions (Chen, Hill, Ohlemüller, Roy, & Thomas, ; Loarie et al, ). Given the close coupling between T l and plant productivity, quantifying vegetation responses to climatic changes requires an understanding of leaf‐level responses to temperature and thermal fluctuations (Dusenge, Duarte, & Way, ).…”