Evaluation of Bioenergy Crops Impacted by Climate Change and Agricultural Practices

Christina Nicole Kieffer, Tennessee State University


Switchgrass is considered a model bioenergy crop that has traditionally served as a forage feedstock in the U.S. and has a strong tolerance of environmental stresses. However, the impacts of current and future climate variation on switchgrass ecophysiology have not been well established. To accomplish this, we conducted three experiments on switchgrass. The first experiment we looked at a comparable bioenergy crop, eastern gamagrass, to evaluate eastern gamagrass’ ability as a bioenergy and forage feedstock in comparison to switchgrass. Both grasses were grown with varying nitrogen applications and cover crops. Our results showed that switchgrass produced more biomass by 29.5%, however forage quality measurements were higher in eastern gamagrass. The second experiment we looked at how different precipitation patterns effects switchgrass’ leaf photosynthesis with changes in light levels and CO2 concentrations. Increasing light levels enhanced the response of leaf photosynthesis in the +50% precipitation treatment. Increasing CO2 concentrations increased net photosynthetic rate until 600 ppm CO2 was reached, were it started to level off. In the same experiment we evaluated different models to determine their prediction accuracy for light and CO2 response curves for switchgrass. Lastly, in our final field experiment we evaluated switchgrass’ leaf ecophysiology under constant elevated temperatures. Ambient temperatures of switchgrass stands were increased by 1-3.3 ºC. Leaf photosynthesis and chlorophyll content measurements were taken. Constant heat stress caused photosynthesis to be reduced as well as chlorophyll content. Overall, we showed the potential benefits of the use of biofuels and how they are affected by climate change.

Subject Area

Ecology|Biology|Climate Change|Plant sciences

Recommended Citation

Christina Nicole Kieffer, "Evaluation of Bioenergy Crops Impacted by Climate Change and Agricultural Practices" (2023). ETD Collection for Tennessee State University. Paper AAI30695549.