Responses of Grass Species to Elevated CO2 – A Review of Three Decades of Research and Future Direction

Abstract

Rising atmospheric carbon dioxide accelerates growth and modifies physiological responses in plants. Over the last 40 years, the global scientific community had taken up initiatives to make out the role of plants in capturing and storing atmospheric carbon dioxide. This review consolidates the research of the past three decades on the responses of grass species to elevated levels of CO2. An enhancement in intercellular CO2 concentration, water use efficiency, photosynthesis, total non-structural carbohydrates, and total biomass was noticed in grass species under controlled growth systems supplied with varying levels of CO2. Each of these responses reflects the potency of grasses to survive and store ample carbon in CO2-enriched environments. Reduction in stomatal conductance, transpiration rate, and total nitrogen concentration was in effect positive responses, in connection with the acclimatization of plants at CO2-enriched environments. This review ascertains that in experimental microclimatic environments with varying CO2 regimes or varying treatment duration, grasses show positive growth responses. Thus it illustrates the efficient atmospheric carbon sequestration of grasses irrespective of their photosynthetic pathway (whether C3/C4).

Keywords

• elevated co2, photosynthesis, stomatal conductance, water use efficiency, biomass, grass species