Doctoral Dissertation Research: Urban Sprawl in the Front Range, Colorado: Consequences for Above-Ground Net Primary Productivity and Carbon Storage

城市和农业地区极大地改变了地球表面，从而改变了水、能量和养分的储存和流动，这是“计划外的实验”。改变生态系统过程，如地上初级生产力(ANPP)和碳储存，是这些城市化试验的重要组成部分。虽然对土地利用和土地覆盖变化的研究探讨了人类活动对生态过程的影响，但这些研究很少包括城市和郊区占主导地位的土地覆盖类型。除了全球环境变化的问题外，城市化还为探索模式对过程和规模依赖的影响提供了一个独特的机会。这种联系在城市系统中很重要，因为许多生态后果是由于模式的变化而产生的，因为自然区被转换为农业、建筑和景观单元的拼凑。这一博士论文研究项目将探索科罗拉多州前沿地区城市和郊区土地利用和土地覆盖变化的生态和生物地理维度。前沿山脉构成了与落基山脉毗邻的最大的人类住区区域，由城市、农业和草原覆盖类型组成。该项目将侧重于以下问题：城市、郊区和农业环境对ANPP的综合影响是什么？城市、郊区、农业和草原地区的碳储量相比如何？人工和自然系统的空间安排如何在不同的尺度上影响这些过程？ANPP和C-STORAGE的覆盖型特定值将从现场测量和现有数据集的组合中获得。草地、农业和河岸覆盖类型有大量的数据集。这些数据将与在城市和郊区覆盖类型中收集的实地数据结合起来。测量包括地上初级生产力、植被中的碳储量和土壤中的碳储量。将进行分类前和分类后的变化检测分析，以计算20世纪土地覆盖变化的位置、数量和速率。从野外工作和档案研究中获得的数据将与分类地图、光谱混合分析和变化检测产品相结合，以估算区域随时间的ANPP和C-储量。还将检查区域估计的空间和比例关系。通过研究城市和郊区覆盖类型的植被和土壤的生产力和碳储量，这项研究将能够量化ANPP和C储量，因为它们在自然和人为覆盖类型之间存在差异。区域估计的时间序列将说明日益发展的地貌如何改变生态系统生产力和碳储存。空间分析将有助于加深对格局影响生态系统过程这一生态学原理的理解。对人造环境对自然系统的邻近影响的评估将表明发展对一个地区的影响程度。该项目将量化科罗拉多州前线山脉的生产力和碳储量如何变化，因为草原已经转变为一个无序的大都市区。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研究生涯。

Urban and agricultural areas significantly modify the surface of the earth and thereby alter the storage and fluxes of water, energy, and nutrients in "unplanned experiments." Alterations to ecosystem processes such as above-ground primary productivity (ANPP) and carbon storage comprise an important part of these urbanization experiments. Although studies of land-use and land-cover change explore the consequences of human actions upon ecological processes, rarely do these studies include the kinds of land cover that predominate in urban and suburban areas. In addition to the problems of global environmental change, urbanization presents a unique opportunity to explore the effect of pattern on process and scale dependencies. The connection is important in urban systems because many ecological consequences result from changes in pattern as natural areas are converted into a patchwork of agricultural, built, and landscaped units. This doctoral dissertation research project will explore ecological and biogeographic dimensions of urban and suburban land-use and land-cover change in the Front Range of Colorado. The Front Range constitutes the largest area of human settlement adjacent to the Rocky Mountains and is comprised of a matrix of urban, agricultural, and grassland cover types. The project will focus on the following questions: What are the integrated effects of urban, suburban, and agricultural environments on ANPP? How does the C-storage of urban, suburban, agricultural, and grassland areas compare? How does the spatial arrangement of man-made and natural systems influence these processes at a variety of scales? Cover-type specific values for ANPP and C-storage will be acquired from a combination of field measurements and existing data sets. Extensive data sets exist for grassland, agricultural, and riparian cover types. These will be combined with field data collected in urban and suburban cover types. Measurements include aboveground primary productivity, C storage in vegetation, and C storage in soils. Pre- and post-classification change detection analyses will be performed to calculate the location, amount, and rate of land-cover transformation in the 20th century. The data obtained from field work and archival research will be combined with the classified maps, spectral mixture analysis, and change detection products in order to estimate regional ANPP and C-storage through time. The regional estimations will also be examined for spatial and scale relationships. By studying the productivity and C-storage of vegetation and soil in urban and suburban cover types, this study will allow the quantification of ANPP and C-storage as they vary across natural and anthropogenic cover types. A time series of the regional estimates will illustrate how an increasingly developed landscape modifies ecosystem productivity and C-storage. The spatial analyses will add to the understanding of the proposed ecological principle that pattern affects ecosystem process. An assessment of adjacency effects of man-made environments upon natural systems will demonstrate the extent to which development affects a region. This project will quantify how productivity and carbon storage have been changed in Colorado's Front Range as the prairie has been transformed into a sprawling metropolitan area. 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.