Kim Lab

Whole-plant responses to climate change

Carbon allocation and storage in rhizomes of C3 species in response to elevated CO2

Plants have been faced with changes in atmospheric CO2 concentrations throughout their evolutionary history. Plant responses to elevated CO2 are often complicated by other factors such as nitrogen availability, growth habit, morphology, and sink capacity. Our lab is testing the effects of elevated CO2 on allocation of carbon to below-ground storage in rhizomes in highly productive perennial grass species (e.g., reed canary grass [Phalaris arundinacea], giant reed [Arundo donax]). Many rhizomatous perennial grasses are invasive species. Conversely, they are also considered a candidate for energy crop elsewhere for their fast growth and high productivity in less favorable environments. Our research revealed that fructan accumulation in rhizomes was significantly enhanced in P. arundinacea under elevated CO2 with limited nutrient supplies. This has a number of ecological implications because fructans can facilitate overwintering, drought tolerance, and early sprouting in cool season perennial C3 grasses resulting in improved invasiveness or utility as an energy crop (See Kinmonth-Schultz and Kim, 2011).

Significant breakthroughs in the last few decades have improved our understanding of the mechanisms and functions of plant symbiotic interactions with other organisms. We investigate the ecophysiological functions of endophytes and pathogens in regulating the growth and stress responses of the host plants.

Fungal and bacterial endophytes in crops and trees

In collaboration with Doty and Ettl labs in the School, we investigate the mechanisms and functions of nitrogen fixing bacterial endophytes (e.g., Burkholderia vietnamiensis) interacting with the physiology and ecology of trees (e.g., Populus trichocarpa) and field crops (e.g., maize); our lab focuses on the physiological functions, benefits, and costs of the interaction on whole-plant growth, carbon, water, and nitrogen relations. Our team is expanding this research to other crops and tree species of economic and ecological importance. The growth promotion of crops and trees by the N fixing endophytes holds the potential to transform the conventional production practices in agriculture and forestry to reduce their carbon and water footprints and mitigate the impacts of climate change.

Models are an effective tool to synthesize the knowledge in biological and ecological systems. We develop and apply process-based and niche-based models to test hypotheses, make predictions, and develop solultions to problems.

Crop simulation modeling

Mechanistic crop models that are based on solid science can provide critical insights for understanding the linkage among individual components within a complex agroecosystem. These models can also play a central role in developing adaptive solutions and strategies to sustain crop productivity while protecting the environment by optimizing resource management in a changing climate. We develop and apply crop simulation models for field and fruit tree crops (i.e., maize, garlic, apple) with an aim to apply the models for facilitating adaptive policy and management decisions in a changing climate.