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

干旱对全世界森林的生长和生存产生了负面影响。特别是，在空气和土壤温度上升的地区，由于植物和土壤中水分的过度蒸发，水变得特别有限。在这个项目中，将利用明尼苏达州北部现有的北方森林变暖濒危交错带(B4WarmED)实验，以及新泽西州中部莱德大学新的普通花园和实验室实验，研究气候变暖和干旱对树苗生长和光合作用速率等生理过程的综合影响。这项研究将能够更准确地量化和了解土壤湿度如何影响植物对气候变暖的敏感性，这可能会对森林管理和栖息地恢复产生重大的社会效益。这个项目还将在莱德大学实施一门以课程为基础的本科生研究体验植物生物学课程，这是一所主要是本科生的机构。本课程将通过使用结构化的、基于探究的项目来解决控制植物生长和发育的机制方面的新问题，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生教育和推广活动的主要重点。这项研究将扩大所需的知识和工具，以预测森林物种将如何应对气候变化；特别是树木幼苗的生长、存活和潜在的生理特征将如何受到气候变暖和可用水变化之间的相互作用的影响。很少有操纵性研究直接评估不同温度和降水制度对植物群落的交互影响，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并影响物种。我们将利用明尼苏达州北部正在进行的气候变化实验(B4WarmED)，同时也将这一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B4WarmED实验之前的研究已经观察到气候变暖对植物生理和某些物种(如糖枫、橡树)生长的积极影响，但据预测，减少供水将抵消这些积极影响，并导致更多的负面植物反应。该项目将利用原位和实验室培育的幼苗来量化叶片的生理特性(例如光合作用、水势)，先前的研究表明，这些特性可以高度预测植物在不同环境中的生长策略和/或死亡反应。该项目的成果将发表在学术期刊上，在地区和国际会议上传播，并纳入莱德大学的本科课程。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.