Mapping forest structure and uncertainty in an urban area using leaf-off lidar data

Urban Ecosystems - Forests are important to nutrient cycling, hydrology, climate and aesthetics in urban ecosystems. Effective forest management in urban environments requires detailed data on the...     

The impact of urban forest structure and its spatial location on urban cool island intensity

Urban forest can help decrease land surface temperature (LST) and create urban cooling effect (UCI) to mitigate urban heat island (UHI). However, it is still unclear how urban forest structure and its location affect UCI, particularly under different seasons. In this study, with plot-based urban forest structure and UCI intensity extracted from Landsat-7 Enhanced Thematic Mapper Plus (ETM+) thermal data, we first conducted correlation analyses between UCI and different forest structures (crown closure, tree height, leaf area index, basal area, stem density and diameter at breast height, etc.) and spatial location (distances from buildings and from water bodies and elevation) attributes, and we then carried out quantitative regression analyses between them. Our results indicate that (1) Urban forest could create “urban cool islands”, which were higher in summer than those in autumn.(2) UCI could be significantly affected by urban forest structural attributes, especially by crown closure and LAI. All urban forest structural attributes had positive linear relationships with UCI except for LAI and basal area which had positive non-linear relationships with UCI.; (3) UCI in urban forest could also be affected by its spatial location but not by its elevation. The UCI non-linearly decreased with decreasing distance from buildings and with increasing distance from water bodies. The threshold values of DB for significantly affecting UCI variation is approximately between 100 m and 300 m in summer and autumn, respectively; and (4) the relationships between UCI and urban forest structure and its location attributes were complex and seasonal dependent. Urban forest attributes had greater effects on increasing UCI in summer than those in autumn. These findings would deepen our understanding of interactions between UCI and urban forest attributes and provide urban planners with useful information about how to design urban forest to effectively mitigate UHI effects.     

Urban bird community composition influenced by size of urban green spaces,presence of native forest,and urbanization

Urban Ecosystems - Understanding what determines wildlife species richness and community composition in urban green spaces is important for wildlife management and urban planning. Numerous studies...     

Loss of urban forest canopy and the effects on neighborhood soundscapes

Urban Ecosystems - The urban landscape constitutes a key aspect of human - nature interactions, as more than 60% of the world’s population resides in cities and their suburbs. This study...     

Effects of park size,peri-urban forest spillover,and environmental filtering on diversity,structure, and morphology of ant assemblages in urban park

Urban Ecosystems - Urban parks are likely the last green areas to preserve fauna diversity in urban ecosystems. We predicted that 1) species richness and ant diversity would increase with...     

Conceptualizing social-ecological drivers of change in urban forest patches

Urban Ecosystems - We introduce a conceptual model of the urban forest patch as a complex social-ecological system, incorporating cross-scale interactions. We developed this model through an...     

A relationship between emotional connection to nature and attitudes about urban forest management

Urban Ecosystems - This paper presents research conducted in Oregon, USA that explored the relationship between an emotional connection to nature and attitudes about urban forest management. We...     

Variation in urban forest productivity and response to extreme drought across a large metropolitan region

The growth and survival of urban trees and maintenance of urban forest canopy are important considerations in adaptation of urban regions to climate change, especially in relation to increasing frequency of extreme climatic events such as drought. However, urban forest growth and drought response may vary considerably within large urban landscapes across gradients in land use, urbanization, forest composition and structure, and environmental factors. We quantified urban forest growth and resilience and resistance to extreme drought in the greater Chicago metropolitan region based on patterns of annual basal area production from increment core analysis. We evaluated variation in growth and drought response in relation to a broad urban to rural gradient, land-use categories, local-scale environmental predictors, and forest community characteristics. Urban forest growth varied greatly among land-use classes and major genera. Plot-level variation in productivity was predicted most strongly (R² = 0.53) by total plot-level basal area, canopy height, species composition, soil and ground-cover characteristics, and position within the urban-rural gradient. Urban forest growth was strongly related to regional meteorological drought. In periods of extreme drought conditions growth declined in the year of the drought (i.e., was not resistant to drought effects), but was highly resilient to drought in the subsequent 5 year period. Drought response did not vary consistently across land-use classes or among major genera, and site or community characteristics had little explanatory power in predicting drought response. Improved understanding of factors driving variation in urban forest growth and drought response could help inform adaptation-focused urban forest management strategies.

     

Determinants of microbat communities in urban forest remnants: a rapid landscape scale assessment

Urban Ecosystems - Urbanisation affects fauna in many ways; with some species persisting and going on to dominate urban habitats, while other species decline over time due to habitat disturbance...     

Effects of habitat-patch size and patch isolation on the diversity of forest birds in the urban-forest mosaic of Durban,South Africa

Urban Ecosystems - Loss of habitat area and structural heterogeneity through anthropogenic fragmentation poses a threat to the survival of wildlife, which may be exacerbated by urban pressures....     

The effect of urbanization gradients and forest types on microclimatic regulation by trees,in association with climate,tree sizes and species compositions in Harbin city,northeastern China

Urban Ecosystems - Rapid urbanization and climate change require stronger microclimatic regulation by urban trees, and maximizing their cooling, humidifying, and shading functions requires an exact...     

Urban wildlife ecology and conservation:A brief history of the discipline

Urban wildlife ecology and conservation is a discipline worldwide in scope. Although some attention was given the subject in the early to mid-1900s, most activity in the field is of more recent origin. Many European countries have active programs and activities, including the United Kingdom-Man and the Biosphere (UK-MAB) Urban Forum and The Wildlife Trusts of England, the United Nations Educational, Scientific, and Cultural Organization's MAB Program, and urban ecology research in Germany and Poland. The Netherlands' concept of “ecological landscapes” introduced a new approach to design of urban open space. Durban, South Africa followed with “D'MOSS,” a metropolitan open space system founded on the principles of island biogeography theory. The park connector network of Singapore combines principles of conservation biology and landscape planning. Urban wildlife programs and activities exist in the United States at the federal, state, and local levels as well as in private conservation organizations. The Wildlife Society established an Urban Affairs and Regional Planning Committee in the mid-1970s that later became the Urban Wildlife Committee and then evolved into the Urban Wildlife Working Group. Urban wildlife research is providing knowledge of wildlife and plant populations and communities in urban areas that hopefully will lead to better understanding and greater sustainability of urban ecosystems.     

Urban forest cover of the Chicago region and its relation to household density and income

Urban forests and herbaceous open space play a vital role in the environmental and aesthetic health of cities, yet they are rarely identified in land-use inventories of urban areas. To provide information on urban forests and other vegetative land cover in Illinois cities, Landsat Thematic Mapper (TM) data from June 27, 1988, were classified for the Chicago metropolitan region (9,717 km²). Ten land-cover classes were identified, including two types of forestland (occupying 5.8% of the total area), residential land with trees (14.6%) or without trees (7.8%), cropland (37.5%), two types of grassland (7.7%), urban with impervious surfaces (23.1%), water (1.6%), and miscellaneous vegetation (2.1%). Correlation analyses indicated that household income and household density are strongly related to land covers in the region, particularly those with tree cover and urbanized land. Population changes for 1980–1985 and 1985–2010 (projected) show a pattern of increasing density in the urbanized zone concurrent with continued urban sprawl, primarily into current cropland.     

Urban ecosystems and ecosystem services in megacity Dhaka: mapping and inventory analysis

Urban Ecosystems - Urban ecosystems and ecosystem services have received little research attention in South Asian countries where rapid urban development is currently problematic. We developed a...     

Local and landscape drivers of bird abundance,species richness,and trait composition in urban agroecosystems

Urban Ecosystems - Urban gardens, or spaces that include vegetables, fruit trees, and ornamental plants, can support bird species and communities by providing food and nesting habitat within urban...     

Ecological performance evaluation of urban agriculture in Beijing based on temperature and fractional vegetation cover

Urban Ecosystems - Urban agriculture (UA) is an important socio-ecosystem in the urban–rural ecotone. Previous studies focused on the production and leisure service of UA, ignoring the...     

Landscape Context Influences the Abundance and Richness of Native Lady Beetles Occupying Urban Vacant Land

Urban Ecosystems - Urban insect communities are structured by hierarchical filters including regional processes, human facilitation, and species interactions. We sought to inform future urban...     

Comparing the transpirational and shading effects of two contrasting urban tree species

Urban Ecosystems - Urban trees are getting increasing attention as a tool to mitigate urban heat island effects. A more functional and quantitative view of transpirational and shading effect,...     

Effects of natural and anthropogenic environmental influences on tree community composition and structure in forests along an urban-wildland gradient in southwestern Ohio

Urban Ecosystems - Unprecedented population growth and urban expansion are rapidly transforming natural and agricultural settings into highly modified urban and suburban landscapes in developed...     

An integrated approach to evaluating urban forest functionality

Despite the fact that forests in urban areas play multiple and often conflicting roles, research and management efforts are typically geared towards a single role or purpose. Urban ecology addresses this multiplicity of function by viewing human and natural systems in urban areas not as separate entities, but as interacting components of an integrated whole. We present an interdisciplinary approach for evaluating the different ways that forests are often valued: economically, socially, and ecologically in residential areas of King County, WA. Economic function is measured as the change in housing prices attributed to location on the gradient, using a hedonic price model. For social function we use a survey to measure (1) residents’ use of parks and forests, and (2) satisfaction with their neighborhoods. We measure ecological function as songbird species richness, using bird survey data. Overlaying the curves of economic, social, and ecological function on the common axis of our urban gradient allows for relationships and tradeoffs to be qualitatively evaluated. Each function responds differently to the gradient. The housing price response is strongest at high and low levels of urbanization, with positive premiums in both areas. Satisfaction with neighborhood attributes decreases with increasing urbanization, while the likelihood of mentioning ‘parks’ as an important element of a resident’s neighborhood increases. Songbird richness peaks in less-developed areas. Evaluating the different functions together is an important step in recognizing and understanding the multiple roles forested areas play.