We predicted changes in avian communities that are likely to occur given predicted land cover and land use for 2003, 2015, and 2027 in the Central Puget Sound of western Washington State, USA. The 8,800 km squared study area is undergoing significant urban development and landscape change.  We combined a microeconomic development model of human behavior, UrbanSim, with a land cover change model (LCCM) to predict land use and land cover 28 years into the future. We developed regression models of avian species richness and relative abundance derived from seven years of field studies with over 6,000 point count surveys spread across the urban to exurban gradient. We applied the avian models to the predicted land use and land cover to estimate future avian community measures. We found that observed avian diversity was sensitive to both the amount and pattern of land use and land cover. As the transition zone between landscapes dominated by human development and exurban areas is transformed into dense development, we predict that bird communities will become spatially partitioned and dominated by either adaptable, synanthropic species (in dense developments) and early successional species that can tolerate some human development or resilient native forest birds (in the exurban zone). We expect native forest birds to become increasingly reliant on higher elevation forests because most low elevation forests will be converted to development too dense to sustain populations.  While these findings are not unexpected, the high spatial resolution of our land use and land cover predictions (landscape pattern metrics can be calculated for 1 km2 “windows”) allowed us to explore how the amount and pattern of future development may influence avian communities. These spatially explicit predictions of future land use, land cover, and avian communities provide an integrated picture of how the landscape might look in 28 years. Additionally, the potential impacts of a proposed policy regulating development location, intensity, or configuration can be modeled to show how it may change land use, how that will likely influence land cover, and how both of these will influence avian communities.

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Hepinstall-Cymerman, J. 2011. Ecological modeling in urban environments: predicting changes in biodiversity in response to future urban development. Pp 359-370 in X. Yang, ed. Urban remote sensing: monitoring, synthesis and modeling in the urban environment.

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In this chapter, I am specifically interested in understanding how future urbanization may change the biodiversity of a region. To tackle this question,  I must be able to: 1) develop models that predict future landscapes; 2) develop models that estimate biodiversity; 3) integrate the output from urban growth models into models estimating biodiversity.  None of these steps are trivial on their own, and the integration of multiple models makes this process even more challenging. I will first introduce the major steps required to address this issue and then provide an example drawn from my work in western Washington State, USA.

 

Hepinstall, J.A., J.M. Marzluff, M. Alberti. 2009. Modeling the responses of birds to predicted changes in land cover in an urbanizing region. Pages 625-659 In J.J. Millspaugh and F.R. Thompson III, eds. Models For Planning Wildlife Conservation In Large Landscapes. Elsevier Science. Amsterdam, The Netherlands.

 

We present a unified modeling approach to predict urban development, land cover change, and ecosystem response to landscape change. We focus on predicting the effects of future landscape change on avian communities as a case example of models that produce results useful to conservation planning across large landscapes. The Central Puget Sound of western Washington State, USA, is a 3200 km2 area undergoing significant urban development and resulting landscape change. We used a microeconomic development model of human behavior, UrbanSim, to predict land use change. The land cover change model incorporates output from UrbanSim, existing land cover, and biophysical attributes to predict land cover change every four years 28 years into the future. Land cover and land use predictions are input into models of avian species richness and relative abundance developed from five years of field studies across the urban to wildland gradient.  Avian diversity was sensitive to both the amount and pattern of land cover. The amount of forest was a key determinant of species richness and abundance of native forest birds.  Additionally, aggregation of residential development was important for total species diversity and the diversity of three habitat guilds modeled suggesting that a variety of birds in our region will benefit from aggregating future development.  The richness of future bird communities will increase gradually with distance from development.  As the transition zone between landscapes dominated by human development and wildland areas is transformed into dense development, the region is likely to be composed of spatially partitioned bird communities dominated by either adaptable, synanthropic species (in dense developments) or resilient native forest birds (in the wildland zone). We expect native forest birds to become increasingly reliant on higher elevation forests because most low elevation forests will be converted to development too dense to support viable populations.  With increased development, the location of new development in regards to existing and proposed conservation networks will need to be considered. Conservation and planning agencies can use our models to evaluate proposed policies and conservation strategies. 

 

Hutyra, L., B., B. Yoon, J. Hepinstall-Cymerman, and M. Alberti. 2011. Carbon consequences of land cover change and expansion of urban lands: a case study in the Seattle metropolitan region. Landscape and Urban Planning. 103:83-93. 

 

Understanding the role humans play in modifying ecosystems through changing land cover is central to addressing our current and emerging environmental challenges. In particular, the consequences of urban growth and land cover change on terrestrial carbon budgets is a growing issue for our rapidly urbanizing planet. Using the lowland Seattle Statistical Metropolitan Area (MSA) region as a case study, this paper explores the consequences of the past land cover changes on vegetative carbon stocks with a combination of direct field measurements and a time series of remote sensing data. Between 1986 and 2007, the amount of urban land cover within the lowland Seattle MSA more than doubled, from 1316 km2 to 2798 km2, respectively. Virtually all of the urban expansion was at the expense of forests with the forested area declining from 4472 km2 in 1986 to 2878 km2 in 2007. The annual mean rate of urban land cover expansion was 1 ± 0.6% year−1. We estimate that the impact of these regional land cover changes on aboveground carbon stocks was an average loss of 1.2 Mg C ha−1 yr−1 in vegetative carbon stocks. These carbon losses from urban expansion correspond to nearly 15% of the lowland regional fossil fuel emissions making it an important, albeit typically overlooked, term in regional carbon emissions budgets. As we plan for future urban growth and strive for more ecologically sustainable cities, it is critical that we understand the past patterns and consequences of urban development to inform future land development and conservation strategies.