Open space system as an armature for urban expansion: evaluation of landscape ecological spatial concepts as a model for improving resilience in urban systems

Urbanization alters several attributes of natural resources, degrading ecosystems and causing them to lose their ability to maintain their structure and function. As a result, native ecosystems in territories subject to urban expansion lose qualities important to their self-organization and may, in certain cases, disappear altogether. Actions that protect or strengthen the resilience of these native ecosystems in the face of urban development may offer increased capacity for these native ecosystems to survive and endure. Landscape ecology aims to understand the relationship between spatial patterns and ecological processes across scales (Wu, 2008) considering the interaction with human activities (Naveh & Lieberman, 1984). A landscape is a kilometers-wide area (Forman & Godron, 1981), comprising a heterogeneous area where ecosystems are repeated in similar form and interact (Forman, 1995b; Forman & Godron, 1986; Forman & Godron, 1981). Wu argues that a landscape ecological perspective is more comprehensive than other approaches for a number of reasons: consideration of operational scales (watershed or metropolitan area); hierarchical and integrative ecological basis; trans and interdisciplinary approaches to study nature-society interactions; theories and methods for studying relationships between spatial pattern and biophysical and socioeconomic processes; methods and metrics to asses sustainability; and “theoretical and methodological tools for dealing with scaling and uncertainty issues” (Wu, 2008). My concern is primarily with how the spatial arrangement of urban land use and land cover influences the survival of ecosystems as cities expand. I propose to address one over-arching question, with two sub-questions within it. The overarching question is: Does applying landscape ecological spatial concepts in the design of urban open space systems have an effect on resilience of ecosystems as they experience urbanization? Urban open space system is defined here as the network of areas in a city that provide habitat for native wildlife and the connections among them; comprised of riparian forests, patches of native vegetation, and woodlots. As urban places, these areas also offer opportunities for people. They provide recreational opportunities and amenities; include parks, plazas, and streets. There is a biophysically-related sub-question: What are the key biophysical processes that are important to address to minimize loss of native biodiversity in urban open spaces? There is also a culturally-related sub-question: What are the urban expansion policies and actions that, if applied to open space planning, will minimize loss of the patterns and processes necessary for native ecological processes to endure in the face of urbanization? This article is a first step to answer the second question. First, it presents a review of landscape ecological approaches as have been investigated and applied in landscape planning and an examination at how spatial solutions have been proposed for landscape planning. Second, a case study is chosen; a review of state of Oregon’s and Portland Metro’s approach to managing urban expansion. The study area is an urban reserve in the Portland Metro region created through application of Oregon Senate Bill 1011, which determines that Metro Portland and Clackamas, Multnomah, and Washington counties define together “which lands outside the current urban growth boundary are best suited to accommodate urban development over the next 40 to 50 years and which lands should be off limits to development in order to protect their values as farms, forests and natural areas during that same period” (Metro) (Figure 4 and Figure 5)

Corredores verdes urbanos: estudo da viabilidade de conexão das áreas verdes de Vitória

Urban planning professionals have applied sustainability principles, reflected on the increase of green space, parks, plazas, street trees etc. This research aims to explore the viability to create urban green corridors in Vitoria (ES), establishing a network of connections between its open spaces making use of its streets and avenues. The proposed corridors aim to improve urban ecology and landscape and the circulation of pedestrians and bikers. The study is based on landscape ecology concepts, for which the landscape is formed by fragments, corridors and matrix. An area was chosen as a test for the methodology adopted, which includes desk studies, mapping of green areas, selections of streets to create corridors, evaluation of street potential as green corridor, site inventory and analysis, definition of guidelines, design of scenarios, and establishment of a green corridor network for Vitória. As a result, it was verified that it is possible to create corridors with small changes on streets and sidewalks to allow continuous tree canopy and bikeways, with direct consequences (microclimates, image, attractiveness to small mammals and birds, incentive to use of bikes) and indirect (reduction of pollution and noise levels, consumption of fuel, etc.)Grande parte dos profissionais de planejamento urbano tem buscado melhorar a qualidade de vida da população e a aplicação de princípios de sustentabilidade, que se refletem, na maioria dos casos, na busca de ampliação das áreas verdes, sejam na forma de parques, praças, arborização de vias ou mesmo incentivo aos jardins particulares. Esta pesquisa apresenta o resultado do estudo de viabilidade de criação de corredores verdes urbanos na cidade de Vitória, estabelecendo uma rede de conexões utilizando-se de sua malha viária, visando incrementar as condições ecológicas e paisagísticas urbanas e melhores condições de circulação de pedestres e ciclistas. Está alicerçada nos conceitos desenvolvidos pela ecologia da paisagem, baseada em fragmentos, corredores e matriz. A metodologia adotada foi aplicada em uma área teste, onde foram realizados levantamentos preliminares, mapeamento das áreas verdes, seleção de vias para implantação de corredores, avaliação dos possíveis corredores, inventário e análise das vias, diretrizes para estabelecimento dos corredores, ensaio projetual e criação de uma rede de corredores verdes. Dentre os principais resultados, verificou-se a possibilidade de criação de corredores com pequenas modificações nos perfis de vias que permitiriam a inserção de vegetação contínua, calçadas e ciclovias com consequências diretas (otimização das condições microclimáticas, melhoria na paisagem, atratividade para pequenos animais, incentivo ao percurso não motorizado, entre outros) e indiretas (redução das partículas em suspensão, redução dos níveis de ruído e do consumo de combustíveis etc.)

Effects of open space configurations and development patterns on future urban wildlife habitats and populations

The viability of wildlife populations in cities is strongly associated to the qualities of urban open spaces and development patterns. Open space systems can serve as armatures to address adverse effects of urbanization on biodiversity. Landscape planners and designers use spatial concepts to translate principles of landscape ecology into working diagrams of land use and land cover to anticipate ecological effects. This paper investigates the consequences of adopting different open space spatial concepts (corridors, patches, and network) in combination with development patterns (compact and dispersed), simulated in eight alternative future scenarios with computer model Envision. Two approaches were used to quantify the effects of the different spatial concepts and urban patterns on Red-legged frog (RLF), Western meadowlark (WML), and Douglas squirrel (DSQ) habitats and populations in an area of urban expansion. First, the amount of habitats was assessed for the initial landscape (ca. 2010) and for the eight future scenarios (year 2060). Second, using the Individual-Based Model (IBM) HexSim, populations of the three species were quantified. All scenarios had increased sums of habitat area, but results showed that differences in open space spatial concepts played a greater role in determining population sizes and were more influential than different development patterns. Network scenarios presented more habitats and the largest populations of RLF. Park and network scenarios showed the most habitats and populations for the WML. No open space and greenway scenarios did not have enough habitats for the WML, but presented the best results for the DSQ. Populations in compact development scenarios showed a small advantage over most dispersed development scenarios. However, in park and network scenarios, dispersed development showed a large influence in the increase of WML population. The study shows that the adopted framework is useful to predict the consequences of landscape plans on wildlife species populations, evaluate trade-offs, and inform planning decisions

Open space as an armature for urban expansion: A future scenarios study to assess the effects of spatial concepts on wildlife populations

Urbanization is one of the biggest threats to biodiversity. To address this problem, landscape planners have increasingly adopted landscape ecology as a theoretical basis for planning. They use spatial concepts that express principles of landscape ecology in diagrammatic form to create frameworks for planning. This dissertation presents a quantitative approach to evaluate the application of spatial concepts developed to create an armature of open space in areas subject to urbanization. It focuses on the predicted urban expansion of Damascus, Oregon, as a case study. An alternative futures study was used to test three open space spatial concepts for patches, corridors and networks in combination with compact and dispersed urban development patterns. The resulting eight scenarios of land use and land cover were then modeled for the year 2060 to evaluate their effects on habitat quantity, quality and configuration and to identify tradeoffs between urban development and conservation for three focal wildlife species: Red-legged frog, Western meadowlark, and Douglas squirrel. Open space spatial concepts strongly influenced habitat quantity and quality differences among future scenarios. Development patterns showed less influence on those variables. Scenarios with no landscape ecological spatial concept provided the most land for urban development but reduced habitat quantity and quality. Greenway scenarios showed habitat increases but failed to provide sufficient habitat for Western meadowlark. Park system scenarios showed habitat increases, but high-quality habitats for Western meadowlark and Red-legged frog decreased. Network scenarios presented the best overall amount of habitats and high-quality habitats for the three species but constrained urban development options. Next, I used an individual-based wildlife model, HexSim, to simulate the effects of habitat configuration and to compare and contrast resulting wildlife population sizes among the eight future scenarios with the ca. 2010 baseline landscape. Network scenarios supported the largest number of Red-legged frog breeders. Park scenarios performed best for meadowlarks, while greenway scenarios showed the largest populations of squirrels. Four of the eight scenarios sustained viable populations of Western meadowlarks. Compact development scenarios performed best for most indicators, but dispersed development scenarios performed better for Western meadowlarks. This dissertation includes both previously published and unpublished material

Corredores verdes urbanos: estudo da viabilidade de conexão das áreas verdes de Vitória

Grande parte dos profissionais de planejamento urbano tem buscado melhorar a qualidade de vida da população e a aplicação de princípios de sustentabilidade, que se refletem, na maioria dos casos, na busca de ampliação das áreas verdes, sejam na forma de parques, praças, arborização de vias ou mesmo incentivo aos jardins particulares. Esta pesquisa apresenta o resultado do estudo de viabilidade de criação de corredores verdes urbanos na cidade de Vitória, estabelecendo uma rede de conexões utilizando-se de sua malha viária, visando incrementar as condições ecológicas e paisagísticas urbanas e melhores condições de circulação de pedestres e ciclistas. Está alicerçada nos conceitos desenvolvidos pela ecologia da paisagem, baseada em fragmentos, corredores e matriz. A metodologia adotada foi aplicada em uma área teste, onde foram realizados levantamentos preliminares, mapeamento das áreas verdes, seleção de vias para implantação de corredores, avaliação dos possíveis corredores, inventário e análise das vias, diretrizes para estabelecimento dos corredores, ensaio projetual e criação de uma rede de corredores verdes. Dentre os principais resultados, verificou-se a possibilidade de criação de corredores com pequenas modificações nos perfis de vias que permitiriam a inserção de vegetação contínua, calçadas e ciclovias com consequências diretas (otimização das condições microclimáticas, melhoria na paisagem, atratividade para pequenos animais, incentivo ao percurso não motorizado, entre outros) e indiretas (redução das partículas em suspensão, redução dos níveis de ruído e do consumo de combustíveis etc.)