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

群落类型之间的边界是空间异质性的丰富来源，与各种各样的生物和非生物边缘效应有关。 边界在现代景观中的流行强调了理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在人类影响下如何在多个尺度上变化。 测量和理解多尺度影响是许多领域的重大挑战。 这个博士论文研究项目的重点是评估方面（当地规模），管理制度（景观规模）和大气沉积（区域规模）在瑞典南部的森林领域边缘的字符的相对影响。 更密集的管理，特别是增加施肥，以及更多的大气沉降，增加了北方森林和草原社区的土壤酸度和氮的可用性，这些社区通常相当缺乏营养。 这些趋势导致物种组成的显著变化和植物多样性的下降。 这种相互作用很可能在森林-田野边缘得到加强，因为它们具有“汇”（物质积累的区域）的生态功能。 本项目研究将评价生物边缘与非生物控制和条件直接相关的一般假设，这些控制和条件因地点和管理制度而异。 本研究的具体目标是确定非生物和生物变化的森林领域的边缘，评估非生物和生物变量之间的关系，并确定边缘的特点和功能，不同的位置在当地，景观和区域尺度。 这项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沉积到低沉积的区域梯度。 在每个地区，复制网站将位于两个管理制度：传统（非施肥）和集中管理（施肥）草地。 对于每种管理制度，将在西南向和东北向边缘对重复地点进行取样。 实地研究将包括沿沿着林地边缘梯度对植被和环境特征（如空气和土壤温度、相对湿度、土壤pH值和土壤水分张力）进行取样。 我们会在若干地点收集土壤样本，进行化验分析，研究结果会对理论和管理工作产生影响。 尽管其经常被引用的重要性，跨边缘的多尺度复杂性还没有得到很好的理解。 该项目将探讨一种方法，用于测量和定量研究在不同尺度上跨景观边界运行的过程的相对影响。 因此，研究结果将为科学家和资源管理人员提供关于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，通过研究不同速率的酸性沉积和施肥下的小气候、土壤条件和林地边缘植被的变化，可以更好地了解人类引起的环境变化下边界的功能。 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，本研究的结果可用于土地利用规划和环境政策的制定。 该项目应该为北方森林-田地边界的性质提供经验支持，并提供关于多种尺度的人为影响的资料。 作为博士论文研究改进奖，该奖项还将提供支持，使有前途的学生建立一个强大的独立的研究生涯。

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.