Doctoral Dissertation Research: Simulating Compositional and Structural Change in a Near Boreal Forest

摘要本博士论文研究将探讨气候条件、土地利用和火灾等竞争因素对上五大湖地区近北方森林结构和组成变化的影响。这项研究将使人们更好地了解植被对这些影响的反应，从而促进森林的长期可持续性和复原力。增强的森林景观模拟模型将提供关于植被和环境动力学的新见解，并更全面地了解干扰对生态系统的影响。这项研究的结果将为土地资源管理者和利益相关者提供潜在的未来森林状况情景，使他们能够做出明智的、基于结果的环境管理决策。更好的管理不仅可以保护生态系统，还可以促进该地区的娱乐和经济活动。该项目包括为来自代表性不足群体的本科生提供教育和培训机会，以丰富他们的研究经验。作为博士论文研究改进奖，该奖项将为有前途的学生提供支持，使他们能够建立强大的独立研究事业。在欧美人定居后的一个世纪里，上五大湖附近的北方森林经历了深刻的成分、结构和功能变化。红松在该地区的历史优势代表了火灾在景观上的印记，然而，20世纪的土地利用改造通常排除了整个景观中的火灾，减少了弹性物种的优势，并可能增加区域森林对未来环境变化的易感性。该奖项支持的研究将集中在三个核心问题上：(1)在上大湖地区是否有足够数量的雷击火灾来维持红松林？(2)如果没有20世纪的景观改造，现代景观的组成和结构会有什么不同？(3)未来环境变化将如何影响火情和随后的植被格局？利用景观扰动和演替模型LANDIS-II模拟森林的组成和结构变化。将模拟四种情景，时间范围从人类定居前到公元2300年，模拟森林变化对不同火灾、气候和土地情景的响应。

NATIONAL SCIENCE FOUNDATIONGEOGRAPHY SPATIAL SCIENCES (GSS) PROGRAMABSTRACTThis doctoral dissertation research will investigate the influences of competing factors such as climate conditions, land use, and fire that drive structural and compositional change in the near Boreal forests of the Upper Great Lakes region. The research will provide an improved understanding of the response of vegetation to these impacts in order to promote long-term forest sustainability and resilience. Enhanced forest landscape simulation modeling will provide new insights regarding vegetation and environmental dynamics, and a more holistic understanding of the impacts of disturbances on the ecosystem. Outcomes from this research will provide land resources managers and stakeholders with potential future forest conditions scenarios enabling them to make informed, outcome-based environmental management decisions. Better management efforts will not only protect the ecosystem but also enhance recreational and economic activities in the region. The project includes education and training opportunities for undergraduate students from underrepresented populations to enrich their research experiences. As a Doctoral Dissertation Research Improvement award, this award will provide support to enable a promising student to establish a strong independent research career.The near boreal forests of the Upper Great Lakes have undergone profound compositional, structural, and functional changes during the century following Euro-American settlement. The historical dominance of red pine in the region is representative of fire's imprint on the landscape, however, 20th century land-use modification has generally excluded fire across the landscape, reducing dominance of resilient species and potentially increasing susceptibility of the regional forests to future environmental change. The research supported by this award will focus on three core questions: (1) Are there an adequate number lightning fires to maintain red pine stands in the Upper Great Lakes region? (2) How would the modern-day landscape composition and structure differ in the absence of 20th century landscape modification? (3) How will environmental changes influence fire regimes and subsequent vegetation patterns in the future? The doctoral student will use the landscape disturbance and succession model, LANDIS-II to simulate forest compositional and structural change. Four scenarios will be simulated, ranging temporally from pre-settlement times to AD 2300, to model forest changes in response to varying fire, climate, and land scenarios.