BRC-BIO Interactive effects of warming and drought on physiological and growth responses of boreal and temperate tree seedlings: A PUI Research Initiative

Rider University, Lawrenceville NJ

Investigators

Abstract

Drought negatively affects the growth and survival of forests worldwide. In particular, in areas where air and soil temperatures are increasing, water becomes particularly limiting due to excess evaporation of water from plants and soil. In this project, the combined effect of warming and drought on tree seedling growth and physiological processes such as rates of photosynthesis will be investigated using both the existing Boreal Forest Warming at an Ecotone in Danger (B4WarmED) experiment in northern Minnesota, as well as new common garden and laboratory-based experiments at Rider University in central New Jersey. This research will allow for more precise quantification and understanding of how soil moisture affects the sensitivity of plants to warming, which could have significant societal benefits related to forest management and habitat restoration. This project will also implement a course-based undergraduate research experience plant biology class at Rider University, a primarily undergraduate institution. This course will enhance the research skills and professional development of undergraduate students by using structured, inquiry-based projects addressing novel questions about mechanisms that control plant growth and development. Encouraging scientists from underrepresented groups will be a main focus of undergraduate education and outreach activities. This research will expand the knowledge and tools needed to predict how forest species will respond to climate change; in particular, how tree seedling growth, survival, and underlying physiological traits will be affected by the interaction between climate warming and changes in water availability. Few manipulative studies have directly assessed the interactive effects of varying temperature and precipitation regimes on plant communities, despite a variety of model analyses suggesting that these two factors will interact and affect species in ways that are unpredictable from single-factor experiments. We will utilize an ongoing climate change experiment in northern Minnesota (B4WarmED), while also expanding aspects of this long-term experiment to the Rider University campus in New Jersey. While prior research at the B4WarmED experiment has observed positive effects of warming on plant physiology and growth of some species (e.g., sugar maple, bur oak), it is predicted that a reduced water supply will offset these positive effects and lead to more negative plant responses. The proposed project will quantify leaf physiological traits (e.g., photosynthesis, water potential) using both in situ and laboratory-grown seedlings, which have been shown in prior studies to be highly predictive of plant growth strategies and/or mortality responses in different environments. Results from this project will be published in scholarly journals, disseminated at regional and international conferences, and integrated into undergraduate courses at Rider University. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.