Doctoral Dissertation Research: Biotic and Abiotic Variability Across Forest-Field Edges in Southern Sweden: Effects of Management and Acidic Deposition

博士论文研究：瑞典南部林地边缘的生物和非生物变异：管理和酸性沉积的影响

• 批准号: 0117202
• 负责人: Susan Beatty
• 金额: $ 1万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-08-01 至 2004-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0117202&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Biotic; Abiotic

The boundaries between community types, which are rich sources of spatial heterogeneity, are related to a wide variety of biotic and abiotic edge effects. The prevalence of boundaries in modern landscapes emphasizes the need to understand their ecological function. In order to understand boundary function, improved knowledge is needed regarding how environmental factors and vegetation vary under human influence and across multiple scales. Measuring and understanding multi-scale influences is a significant challenge in many fields. This doctoral dissertation research project focuses on evaluating the relative influence of aspect (local scale), management regime (landscape scale), and atmospheric deposition (regional scale) on the character of forest-field edges in southern Sweden. More intensive management, especially increased fertilizer application, and greater atmospheric deposition have increased soil acidity and nitrogen availability in northern Europe's forest and grassland communities, which generally are quite nutrient-poor. These trends have led to marked changes in species composition and declines in plant diversity. Such interactions have likely been intensified across forest-field edges because of their ecological function as 'sinks' (areas where matter has accumulated). This project study will evaluate the general hypothesis that the biotic edge is directly related to abiotic controls and conditions that vary with respect to location and management regime. Specific objectives of this study are to determine abiotic and biotic variation across forest-field edges, to assess relationships between abiotic and biotic variables, and to identify edge characteristics and functions that differ with respect to location at the local, landscape, and regional scale. The study will be conducted in the southwest and east-central regions of Sweden. Locations of sampling sites reflect the regional gradient from high to low deposition. In each region, replicate sites will be located under each of two management regimes: traditional (non-fertilized) and intensively managed (fertilized) meadows. For each management regime, replicate sites will be sampled across a southwest-facing and a northeast-facing edge. Field research will consist of sampling vegetation and environmental characteristics (such as air and soil temperature, relative humidity, soil pH, and soil moisture tension) along forest-field edge gradients. Soil samples will be collected at a sub-set of sites for laboratory analyses.The results of this project will have both theoretical and management implications. Despite its often-cited importance, multi-scale complexity across edges is not well understood. The project will explore a method for measuring and quantitatively examining the relative influence of processes operating at different scales across landscape boundaries. Results therefore will provide scientists and resource managers with important insights regarding the relationship between regional- and local-scale processes in a culturally fragmented landscape. In addition, by examining change in microclimate, soil conditions, and vegetation across forest-field edges under varying rates of acidic deposition and fertilization, a better understanding can be gained of how boundaries function under human-induced environmental change. Such environmental changes may have a direct effect on forestry, agriculture, water quality, and biodiversity. Findings from this study therefore can be used in land-use planning and environmental policy formation. The project should provide empirical support for the nature of forest-field boundaries in northern Europe as well as provide information about anthropogenic effects at multiple scales. As a Doctoral Dissertation Research Improvement award, this award also will provide support to enable a promising student to establish a strong independent research career.

群落类型之间的边界是空间异质性的丰富来源，与多种生物和非生物边缘效应有关。 现代景观中边界的普遍存在强调了了解其生态功能的必要性。 为了了解边界功能，需要更好地了解环境因素和植被如何在人类影响下和跨多个尺度变化。 测量和理解多尺度影响是许多领域的一项重大挑战。 本博士论文研究项目的重点是评估坡向（局部尺度）、管理制度（景观尺度）和大气沉降（区域尺度）对瑞典南部林地边缘特征的相对影响。 更加集约化的管理，特别是增加施肥和增加大气沉降，增加了北欧森林和草原群落的土壤酸度和氮素利用率，而这些地区的养分通常相当贫乏。 这些趋势导致物种组成的显着变化和植物多样性的下降。 由于林地边缘具有“汇”（物质积累的区域）的生态功能，这种相互作用可能会加强。 该项目研究将评估一般假设，即生物边缘与非生物控制和条件直接相关，而非生物控制和条件随位置和管理制度而变化。 本研究的具体目标是确定林地边缘的非生物和生物变异，评估非生物和生物变量之间的关系，并确定因局部、景观和区域尺度的位置而异的边缘特征和功能。 该研究将在瑞典西南部和中东部地区进行。 采样点的位置反映了从高到低沉积的区域梯度。 在每个区域，复制地点将位于两种管理制度下：传统（未施肥）和集约管理（施肥）草甸。 对于每个管理制度，将在西南和东北边缘对复制地点进行采样。 实地研究将包括沿林地边缘梯度采样植被和环境特征（例如空气和土壤温度、相对湿度、土壤 pH 值和土壤湿度张力）。 将在部分地点收集土壤样本以进行实验室分析。该项目的结果将具有理论和管理意义。 尽管其重要性经常被提及，但跨边缘的多尺度复杂性尚未得到很好的理解。 该项目将探索一种测量和定量检查跨景观边界不同尺度运行过程的相对影响的方法。 因此，研究结果将为科学家和资源管理者提供有关文化碎片化景观中区域和地方规模进程之间关系的重要见解。 此外，通过检查在不同的酸沉降和施肥率下林地边缘的小气候、土壤条件和植被的变化，可以更好地了解边界在人类引起的环境变化下如何发挥作用。 这种环境变化可能对林业、农业、水质和生物多样性产生直接影响。 因此，这项研究的结果可用于土地利用规划和环境政策的制定。 该项目应该为北欧林地边界的性质提供实证支持，并提供有关多尺度人为影响的信息。 作为博士论文研究改进奖，该奖项还将为有前途的学生建立强大的独立研究生涯提供支持。