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

干旱对全球森林的生长和生存产生负面影响。特别是在空气和土壤温度升高的地区，由于植物和土壤中的水分过度蒸发，水变得特别有限。在这个项目中，气候变暖和干旱对树木幼苗生长和光合作用速率等生理过程的综合影响将利用明尼苏达州北部现有的北方森林变暖危险过渡带（b4warm）实验，以及新泽西州中部莱德大学（Rider University）新的普通花园和实验室实验进行研究。这项研究将允许更精确地量化和理解土壤湿度如何影响植物对变暖的敏感性，这可能具有与森林管理和栖息地恢复相关的重大社会效益。该项目还将在莱德大学（Rider University）开设一门以课程为基础的本科研究体验植物生物学课程。本课程将通过结构化的、探究式的项目来解决控制植物生长和发育机制的新问题，从而提高本科生的研究技能和专业发展。鼓励来自代表性不足群体的科学家将是本科教育和推广活动的主要重点。这项研究将扩展预测森林物种如何应对气候变化所需的知识和工具；特别是，气候变暖和水分有效性变化之间的相互作用将如何影响树木幼苗的生长、存活和潜在的生理性状。尽管各种模型分析表明，这两个因素将以单因素实验无法预测的方式相互作用和影响物种，但很少有操纵性研究直接评估了不同温度和降水制度对植物群落的相互作用。我们将利用明尼苏达州北部正在进行的气候变化实验（b4warm），同时将这个长期实验的各个方面扩展到新泽西州的莱德大学校园。虽然先前的b4warm实验研究已经观察到变暖对某些物种（如糖枫、黑栎）的植物生理和生长的积极影响，但预计供水量的减少将抵消这些积极影响，并导致更多的消极植物反应。拟议的项目将量化叶片的生理特性（例如，光合作用、水势），使用原位和实验室生长的幼苗，这些在先前的研究中已被证明是高度预测植物生长策略和/或在不同环境下的死亡反应。该项目的成果将发表在学术期刊上，在区域和国际会议上传播，并纳入莱德大学的本科课程。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.