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

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

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.