Restoring complex vegetation in urban settings: The case of tidal freshwater marshes

Tidal freshwater marshes have diverse plant communities that vary spatially and temporally due to hydrology, animal activity, and other factors. Development of urban centers along rivers of the U.S. Atlantic coast has reduced the historic extent and quality of these and other coastal wetlands. Because the vegetation of these wetlands is more complex than that of salt and brackish marshes (where restoration of vegetation typical of natural systems has sometimes been successful), restoration of tidal freshwater marsh vegetation is likely to be more difficult, particularly in urban areas. Watershed urbanization alters hydrology, sediment load, propagule availability and composition, nutrient status, and other variables that together create an environment different from that of wetlands in less developed areas, possibly precluding restoration of typical marsh vegetation. Tidal freshwater wetlands were historically extensive along the Anacostia River in Washington, DC, but most of these were lost due to filling, dredging, or hydrologic alteration. Over the last decade, the U.S. Army Corps of Engineers has implemented projects designed to restore tidal freshwater wetlands along the Anacostia, which involved increasing elevation with dredged river sediment and planting native vegetation. To illustrate some of the mechanisms affecting vegetation development in restored tidal freshwater marshes in urban areas, I present a case study on one of these wetlands, Kingman Marsh, that also includes research at another restored wetland and two natural reference sites. Studies by my research groups indicate that the restored wetlands undergo essentially a planting-modified process of primary succession. Low densities of seeds are initially present in the substrate, and prolific seed dispersal into the restored sites results in high initial plant diversity comprised of plantings and ruderal (i.e. weedy) natives and exotics. Seed banks develop rapidly at the restored sites, probably due to colonization and early reproduction by ruderal species. Hydrology and disturbance by non-native animals (including resident Canada goose) are important variables controlling establishment of vegetation in these systems. Recent literature and the case study indicate that the environmental conditions of urban settings impose constraints in restored wetlands that result in plant communities more like those of urban natural wetlands than those of wetlands in less urbanized watersheds. This suggests that rather than design wetland restoration projects with the goal of creating pristine wetland vegetation, restorationists must identify, accept, and if possible capitalize on the ecological constraints of the urban environment in setting achievable and desirable restoration goals.     

Relationships between urban parks and bird diversity in the Bangkok metropolitan area,Thailand

An analysis of the birds in Bangkok’s urban parks and landscapes provided guidance in designing healthy urban ecosystems. This research studied the relationships between bird diversity, park size, distance to the nearest main park, and habitat compositions in 10 urban parks in the Bangkok metropolitan area between January and August in 2013. Thirty sampling points per park were used to observe the number and species of birds in each urban park. A total of 50 bird species were found. Phutthamonthon, the largest urban park (400 ha), contained the greatest number of species (39 species), followed by Suan Luang Rama IX (80 ha and 34 species) and Wachirabenchatat (60 ha and 29 species). Moreover, the diversity index (H′) was highest in Phuttamonthon (1.17), followed by Thawiwanarom (1.08), and Wachirabenchatat (1.04). Larger urban parks and parks closer to the largest urban park had higher species richness than smaller parks and parks further from the largest urban park. The large parks contain higher habitat compositions than small parks. These findings can be applied to future urban ecosystem planning to combine the importance of park size (island size, and its proximity to a large park) and its arrangement, including features such as wetland, forest, buildings and grassland; and provide basic advice for future urban park design, as well as re-design of current urban parks.

     

The seed bank of a restored tidal freshwater marsh in Washington,DC

The species composition of seed banks may be a useful indicator of vegetation structure and dynamics, but seed bank studies have rarely been applied to monitoring of wetland restoration projects. We studied the seed banks and vegetation of three distinct sites within a restored tidal freshwater marsh and of two nearby natural marsh sites. Surface soil samples were collected and subjected to flooded and nonflooded conditions in a greenhouse for enumeration of emerging seedlings. Percent coverage of vegetation was estimated in permanent 1-m² plots at each soil sampling location.Species composition of the seed bank and vegetation differed considerably; only 43% of the species observed were common to both. The seed bank of restored marsh sites had higher species richness and seed density than the natural marsh sites, but both had similar species diversity. Annual species were more important in the seed bank and less important in the vegetation of restored sites than reference sites. Flooding significantly reduced the species richness, diversity, and density of emerging seedlings. Most species planted at the site were rare in the seed bank, with Leersia oryzoides being an important exception. Other species abundant in the seed bank included Cyperus odoratus, Juncus effusus, and the nonindigenous Lythrum salicaria. A possible mechanism explaining the higher densities of seeds in restored areas is that ruderal vegetation colonized the restoration site, reproduced, and set seed shortly following placement of dredge material. Perennial species subsequently colonized and were planted, and expanded to reduce the abundance of annuals in restored marsh vegetation. Our study suggests that the plant regeneration dynamics of the restored marsh sites are considerably different from those of natural marshes. Additionally, we suggest that seed bank studies are a useful technique for assessing the community structure and vegetation dynamics of restored wetlands.     

Restoration of urban salt marshes: Lessons from southern California

Extensive restoration efforts in southern California coastal wetlands highlight several challenges for urban salt marsh restoration, including: habitat isolation and fragmentation, impacts from exotic species, the loss of transitional upland habitats, and other alterations to hydrologic and sediment dynamics. Habitat isolation impairs colonization by dispersal-limited plants, so planting becomes essential to achieve diverse salt marshes. Low species richness slows the development of salt marsh functions (e.g., biomass and nitrogen accumulation) in southern California. A variety of exotic species have invaded the upper reaches of salt marshes in southern California, most commonly in marshes with hydrological modifications. The replacement of gradual slopes between wetlands and uplands by sharp transitions abutting urban development limits our ability to restore rare plant and animal populations. Where hydrologic connections are impaired by roads and other structures, the natural migration of channels is constrained, and sediment dynamics often lead to lagoon mouth closure.A case study from Tijuana River National Estuarine Research Reserve (hereafter, Tijuana Estuary) further illustrates a specific lesson for urban salt marsh restoration concerning watershed issues and sediment dynamics. In the south arm of Tijuana Estuary, watershed urbanization, along with local climate, topography, and soils, has resulted in extreme rates of sediment accumulation. Sedimentation rates in a salt marsh in the south arm of the estuary ranged from 10 to 30 cm over a single winter (1994–95), substantially greater than historic sedimentation rates in the estuary or rates from other coastal wetlands with storm sedimentation. Sediment buried salt marsh vegetation in place and is converting intertidal salt marsh to uplands. These impacts illustrate the need to consider watershed issues and sediment control in managing and restoring urban salt marshes.     

Kooragang Wetland Rehabilitation Project: opportunities and constraints in an urban wetland rehabilitation project

This paper describes the Kooragang Wetland Rehabilitation Project (KWRP) in Newcastle, New South Wales, Australia. The area's wetlands have been degraded over the past two hundred years by resource extraction, alterations to hydrology, clearing for agriculture, cattle grazing, and industrial development. KWRP objectives include (1) habitat rehabilitation at three sites totaling 1560 ha, (2) involving the community with rehabilitation, and (3) developing wetland management models through a research program. Rehabilitation in an urban setting is accompanied by various constraints and opportunities. Constraints experienced by KWRP include requirements to (1) avoid disturbance of urban infrastructure, (2) demonstrate that rehabilitation will not increase flood risks to populated areas, and (3) develop methods of increasing wetland habitat without aggravating an existing mosquito problem. Opportunities include (1) availability of financial sponsors and skilled personnel, and (2) close proximity to a university, which allowed establishment of a research partnership. By conducting wetland rehabilitation in a densely populated area, KWRP exposes a large number of people to the challenges associated with ecosystem rehabilitation and the importance of preserving wetland resources.     

Urban and wildland herpetofauna communities and riparian microhabitats along the Salt River, Arizona

Metropolitan areas are continually expanding, resulting in increasing impacts on ecosystems. Worldwide, riverine floodplains are among the most endangered landscapes and are often the focus of restoration activities. Amphibians and reptiles have valuable ecological roles in ecosystems, and promoting their abundance and diversity when rehabilitating riparian systems can contribute to reestablishing degraded ecosystem functions. We evaluated the herpetofauna community by measuring abundance, richness, diversity, and species-habitat relations along three reaches (wildland, urban rehabilitated, and urban disturbed reaches) varying in degree of urbanization and rehabilitation along the Salt River in central Arizona. We performed visual surveys for herpetofauna and quantified riparian microhabitat along eight transects per reach. The wildland reach had the greatest herpetofauna species richness and diversity, and had similar abundance compared to the urban rehabilitated reach. The urban disturbed reach had the lowest herpetofauna abundance and species richness, and had a similar diversity compared to the urban rehabilitated reach. Principal Component Analysis reduced 21 microhabitat variables to five factors which described habitat differences among reaches. Vegetation structural complexity, vegetation species richness, densities of Prosopis (mesquite), Salix (willow), Populus (cottonwood), and animal burrow density had a positive correlation with at least one herpetofauna community parameter, and had a positive correlation with abundance of at least one lizard species. Rehabilitation activities positively influenced herpetofauna abundance and species richness; whereas, urbanization negatively influenced herpetofauna diversity. Based on herpetofauna-microhabitat associations, we recommend urban natural resource managers increase vegetation structural complexity and woody debris to improve herpetofauna habitat when rehabilitating degraded riparian systems.     

Developing habitat models for waterbirds in urban wetlands: a log-linear approach

Up to 95% of wetlands in southwestern Ontario, Canada, have been drained and converted to other land uses since the mid-1800s. Remaining wetlands now exist within a mosaic of urban and agriculture land cover and may resemble “islands” from the point of view of species that need this habitat. We investigated the relationships between waterbirds and wetland size, isolation, and adjacent forest cover and roads in 19 wetlands within and adjacent to London, Ontario. Waterbirds were grouped into resource-based guilds: Dabblers, Divers, Waders, and Gulls and Terns (because of small samples, the Passerine and Raptor guilds were dropped from the statistical analyses). Because of the high degree of multicollinearity between variables, we used log-linear analysis to develop models that explained variations in species richness in the waterbird guilds. The log-linear technique provided quantification of environmental effects in a richer way than previous research as the interplay between biophysical factors found in reality are partially captured by the inclusion of interaction in the habitat models. All of the models incorporated the biophysical variables of wetland size and adjacent wetland area, forest cover, and roads. Waterbirds in these urban and near-urban landscapes appear to be using all wetlands available to them, no matter how small or how disjunct the wetland. This has implications for wetland evaluations that may not rate wetlands in human-dominated landscapes highly enough to be protected from development.     

Patterns of human disturbance and response by small mammals and birds in chaparral near urban development

We report on the extent of disturbance (including habitat alteration and road and trail proliferation) in chaparral near urban development and analyze the effects of disturbance on small mammal and resident bird species. Disturbance patterns were evaluated in a 6700 ha study area in southern California: effects on mammals and birds were investigated by analyzing relationships between vegetation structure and animal species richness and abundance. Disturbance was prevalent throughout the study area and included extensive human-altered habitat (from past human activities such as vegetation clearing, human-caused fires, refuse dumping, and vegetation trampling) and 157 km of roads and trails. A nonsignificant trend was found between human-altered habitat and proximity to development, but human-altered habitat was significantly associated with roadway proximity. Trails were also more frequent near urban development and roads. Small mammals responded strongly to disturbance-related vegetation changes, while birds showed little or no response. Mammals endemic to chaparral vegetation were less diverse and abundant in disturbed sites, whereas disturbance-associated species increased in abundance. Close proximity of urban development to natural areas resulted in alteration of natural habitat and proliferation of roads and trails. Variation in life history traits between birds and mammals may affect response to disturbance and influence persistence if disturbance continues. Conservation efforts must recognize the potential for habitat damage and associated declines in native animal species caused by disturbance near urbanization and implement strategies to reduce these threats.     

Predicting tree species richness in urban forests

There has been an increasing interest in urban forests and the levels of biodiversity they contain. Currently there are no spatially explicit maps of tree species richness in urban areas. This research tests and identifies GIS and remote sensing metrics (climate, area, productivity, three-dimensional structure) hypothesized to be associated with species richness in native forests and identifies methods that can be applied to predict and map tree species richness in cities. We quantified tree species richness, floristic composition, and structure in 28 1-ha plots in the city of Los Angeles. Climate and remote sensing metrics from high-resolution aerial imagery (10 cm), QuickBird (60 cm), Landsat (30 m), MODIS (250 m), and airborne lidar (2 m) were collected for each plot. There were 1208 individual stems and 108 trees identified to species. Species richness ranged from 2 to 31 species per ha and averaged 17 species per ha. Tree canopy cover from QuickBird explained the highest portion of variance (54%) in tree species richness followed by NDVI from Landsat (42%). Tree species richness can be higher in residential urban forests than native forests in the United States. Spatially explicit species richness maps at 1 ha can be created and tested for cities in order to identify both hotspots and coldspots of tree species richness and changes in species richness over time.     

Connectivity of public urban grasslands: implications for grassland conservation and restoration in cities

An important limitation of studies on the ecological value of urban habitats is the question of habitat connectivity. While connectivity allows spread and genetic exchange of species, isolation can lead to the extinction of populations through inbreeding and loss of genetic diversity. However, while practitioners already start improving urban habitat patches by means of restoration, issues of connectivity have not been taken in account although being crucial for a self-sustaining habitat network. In our study, we evaluate the connectivity of public urban grasslands such as lawns, grasslands in residential areas, playgrounds or parks in the city of Münster, Germany. Employing a graph theory approach, which uses a map (graph) of habitat patches to calculate functional connectivity measures using patch area size and patch connectivity, we studied four groups of different plant dispersal distances (2 m, 20 m, 44 m and 100 m). This approach can be recommended for planning issues due to the output of different indicator values and comparably low data demands. Our results show for the first time, that connectivity of urban grasslands is extremely low for species of short-distance dispersal but slightly increases for long-distance dispersal. Except two larger conglomerations of well-connected patches, urban grasslands were found to be mostly sparsely connected. Thus, future research should focus on options to improve connectivity and to prioritize patches for ecological improvement. The graph theory approach turned out to be a useful tool to analyse urban habitat connectivity but also to illustrate results obtained.

     

Occurrence of breeding bird species in urban parks: Effects of park structure and broad-scale variables

Occurrences of breeding bird species in 54 urban parks were investigated in the city of Oulu in northern Finland. Park area, human activity, habitat, and landscape structure within a 9-ha square surrounding the study park were related to the bird species richness and occurrence of individual bird species. A total of 22 species was observed. The area of the park explained 39% of the variance of species richness. Seven species (wheatear [Oenanthe oenanthe], common rosefinch [Carpodacus erythrinus], garden warbler [Sylvia borin], lesser whitethroat [Sylvia curruca], linnet [Acanthis cannabina], redpoll [Carduelis flammea], and yellowhammer [Emberiza citrinella]) were not detected in parks of >0.75 ha. Species with lower area demands occurred closer to the town center than species with greater area requirements. Ground-nesting species were poor colonizers of urban parks, whereas high numbers of nest boxes in urban parks attracted many cavity-nesting species. The willow warbler (Phylloscopus trochilus) and the magpie (Pica pica) bred more often in unmanaged than in managed parks, probably because of the greater vegetation cover in unmanaged parks. Park structure variables were entered into models for 7 of the 12 most common bird species, whereas broad scale variables were entered into models for 6 of the 12 species. The number of adjacent buildings had a negative affect on three bird species (the willow warbler, hooded crow [Corvus corone cornix], and spotted flycatcher [Muscicapa striata]). The occurrence of breeding species in urban parks depends on the size of the park, park structure, and landscape structure outside the park.     

Which traits influence the frequency of plant species occurrence in urban habitat types?

Plants in cities must cope with various anthropogenic environments that differ from surrounding landscapes. Moreover, the differences in biotic and abiotic conditions among these habitats filter species with suitable traits and niche requirements. Here we aim to identify those attributes that promote species occurrence across and within urban habitat types of large cities. Species composition of spontaneously occurring vascular plant species was recorded in 1-ha plots in seven different urban habitat types in each of 32 European cities. Each species was characterized in terms of dispersal type, growth form, height, seed bank longevity, seed mass, selected leaf traits and ecological indicators including Ellenberg indicator values, Grime’s life strategies, and immigration pathways using information from available species-trait databases. For each species, total frequency of occurrence across all plots and habitat frequency of occurrence across plots of given habitat types were calculated and regression trees were used to relate them to traits and ecological indicators. The most frequently occurring species in the cities tended to be human-dispersed, nutrient-demanding plants that prefer drier to mesic soil conditions. These species do not possess the S-strategy and usually produce seeds of low mass forming short-term persistent seed banks. Habitat-specific responses were also revealed, indicating the effects of between- and within-habitat heterogeneity on trends in species performance in cities. Such patterns can be overlooked when differences in species occurrences in particular urban habitat types are not considered; thus, habitat-specific responses can resolve inconsistencies found when whole urban floras are analysed as a whole.     

Urban areas may serve as habitat and corridors for dry-adapted,heat tolerant species; an example from ants

We collected ants from six urban and one forest land-use types in Raleigh, NC to examine the effects of urbanization on species richness and assemblage composition. Since urban areas are warmer (i.e., heat island effect) we also tested if cities were inhabited by species from warmer/drier environments. Species richness was lower in industrial areas relative to other urban and natural environments. There are two distinct ant assemblages; 1) areas with thick canopy cover, and 2) more disturbed open urban areas. Native ant assemblages in open environments have more southwestern (i.e., warmer/drier) distributions than forest assemblages. High native species richness suggests that urban environments may allow species to persist that are disappearing from natural habitat fragments. The subset of species adapted to warmer/drier environments indicates that urban areas may facilitate the movement of some species. This suggests that urban adapted ants may be particularly successful at tracking future climate change.     

Emerging dragonfly diversity at small Rhode Island (U.S.A.) wetlands along an urbanization gradient

Natal habitat use by dragonflies was assessed on an urban to rural land-use gradient at a set of 21 wetlands, during two emergence seasons (2004, 2005). The wetlands were characterized for urbanization level by using the first factor from a principal components analysis combining chloride concentration in the wetland and percent forest in the surrounding buffer zone. Measurements of species diversity and its components (species richness and evenness) were analyzed and compared along the urbanization gradient, as were distributions of individual species. Dragonfly diversity, species richness, and evenness did not change along the urbanization gradient, so urban wetlands served as natal habitat for numerous dragonfly species. However, several individual species displayed strong relationships to the degree of urbanization, and most were more commonly found at urban sites and at sites with fish. In contrast, relatively rare species were generally found at the rural end of the gradient. These results suggest that urban wetlands can play important roles as dragonfly habitat and in dragonfly conservation efforts, but that conservation of rural wetlands is also important for some dragonfly species.     

Legacy effect of trees in the heritage landscape of a peri-urban golf course

Negative environmental impacts of golf courses have received more attention than positive ecological contributions. We studied the mature tree communities and their legacy effect in a historical urban-fringe golf-course site in Hong Kong covering 170-ha with well-managed natural-cum-cultural landscape. Some 44.3 % of the site is covered mainly by large trees forming a mature peri-urban forest. The 94 species in 35 families offer a high species diversity exceeding local secondary and climax fengshui woodlands with notable rare and protected species. Tree species composition, richness and legacy effects brought by anthropogenic and natural factors were investigated by three habitats with varying naturalness and three golf courses with different age. Landscape zone is remarkably heterogeneous versus other microhabitats (fairway and woodland) and the heterogeneity of tree communities amongst the three courses is relatively weak. Synergistic operation of natural regeneration (natural legacy effect) and anthropogenic management (anthropogenic legacy effect) has fostered diversity accumulation. On the one hand, temporal changes in landscape fashion through a century and variations in site management have driven and maintained species diversity. On the other hand, the founder effect of inherited and cultivated species, as well as successful invasion and establishment of native species, have imposed floristic imprint and inertia on woodland habitat. The findings suggested that urban golf courses can serve as potential hotspots for biodiversity conservation within urban ecosystems.     

Influence of urban landscape structure on bird fauna: a case study across seasons in the city of Valencia (Spain)

Studies on bird fauna of urban environments have had a long history, but the potential of studies mapping the distribution of birds in cities probably has not fully developed. The bird fauna of the municipality of Valencia (Spain) was studied to determine the influence of urbanization on bird species richness and abundance. Birds were censused during winter and the breeding season of years 1997–1998 in 197 squares measuring 49 ha each from a rural and an urbanized area. Across seasons the number of species decreased around 40% in the city compared with the rural landscape surrounding it. Such pattern could be attributed to the low number of farmland species capable to use the habitats inside the city, and the limited ability of urban parks in attracting woodland species. In the urban landscape, the influence of the dimensions and spatial arrangement of habitat patches was outweighed by the amount of each habitat per square. Bird richness and the abundance of most species were negatively related with the amount of built-up habitat per square and positively with the amount of urban parks, and of habitat diversity. Conversely, bird fauna was largely independent of mean park size per square especially during winter, indicating that at the landscape scale even small patches of habitat could play an ecological role. Conservation of urban bird diversity could benefit of two complementary strategies: (i) the protection of the surrounding rural landscape from urban development; (ii) habitat enhancement within the city. Particularly, a proper design and habitat management of urban parks could improve their suitability for urban bird fauna.     

Urban landscape matrix affects avian diversity in remnant vegetation fragments: Evidence from the Phoenix metropolitan region, USA

Biodiversity conservation in urban areas has become increasingly important as cities have expanded to cover larger proportions of landscapes across the world. The careful planning of habitat reserves within urbanized areas has the potential to make significant contributions to regional biodiversity. We surveyed the passerine community in 15 habitat reserves within the Phoenix metropolitan region and explored the relationships between community composition and urban land uses surrounding the reserves. Diversity of different guilds was affected in substantially different ways by reserve characteristics and surrounding urban land use. Guilds responded to land use at all three scales included in the study ?C 200 m, 1000 m and 2500 m. The responses of four guilds, synanthropic, non-synanthropic, insectivore and feeding generalist, were well predicted by the factors considered here. Reserve characteristics (area, shape, isolation), particularly area, had effects on all four of these guilds with non-synanthropic and insectivore species responding positively to area, while synanthropic and feeding generalist species responded negatively. Land use type surrounding the reserves had significant effects on all of these guilds, except for feeding generalists. High density, high diurnal activity land uses decreased diversity, while medium density, low diurnal activity uses increased the diversity of some guilds, particularly insectivores, probably by providing supplemental habitat. This study provides new evidence from an arid urban landscape that not only reserve characteristics, but also surrounding urban land use should be considered during conservation planning, especially if non-synanthropic or insectivore species are among the targeted species.     

Determining the effect of urbanization on generalist butterfly species diversity in butterfly gardens

This study investigates the effects of urbanization on local butterfly populations and the role of butterfly gardens in preserving regional butterfly diversity. Data are from 135 butterfly gardens of varying size, location, and number of blooming plants in the Washington DC metropolitan area observed during 2001 and 2002. We investigated the species diversity for comparable gardens in rural, suburban, and urban locations to determine whether the landscape matrix surrounding otherwise suitable habitat affects the diversity found in the habitat. We hypothesized that, once factors such as garden size and number of blooming plant species were taken into account, butterfly diversity for 12 generalist species would decrease as urbanization increased. We found that there were systematic decreases (with one exception) in diversity from rural to suburban to urban gardens only for medium-sized gardens (0.10 to 0.20 ha) with one to ten types of blooming plants, and large gardens (>0.20 ha) with over 20 types of blooming plants. Gardens of other sizes or plant communities showed some decreases in diversity from rural to suburban to urban sites, but these differences were not consistent across the urban/rural gradient. Results of this study indicate that local butterfly diversity is negatively affected by increasing levels of human population, but that the matrix is just one factor determining generalist species diversity.     

Bird diversity of greenspaces in the densely developed city centre of Taipei

Urban greenspaces harbouring many species in cities are vital planning objects for enhancing biodiversity. Seeking to optimise ecological values of urban greenspaces, this paper explores 1. Bird composition by feeding and foraging characteristics in urban greenspaces located in densely developed central districts of Taipei City; and 2. Important features of greenspaces and underlying built environments that influence bird abundance, species richness, and diversity. Results show that the majority of birds found in the study sites are omnivorous and ground foragers; whereas birds relying on water/wetland habitats for feeding and foraging are relatively small in population and species richness. This suggests water/wetland associated environments and birds might be negatively impacted by urbanisation. Secondly, bird richness and diversity increase in accordance with greenspace size, water area, and habitat heterogeneity, but little relationship is found with greenspace structure, such as greenspace shape, distance to nearest greenspaces, and proximity to source patches of mountains and rivers. Also, no significant influence is observed from development intensity, which is measured by NDBI, and building height at greenspace surroundings. According to this result, this study suggests conservation of large greenspaces as a priority strategy for enhancing urban biodiversity. The development of land should take its potential ecological value into account while assessing environmental impact. For enhancing habitat quality of existing urban greenspaces, creating water bodies and increasing habitat types can be effective methods. Yet current planning strategies to increase street greenery and to connect urban greenspaces with surrounding mountains and rivers might only benefit specific urban exploiters or adaptors and result in little overall effect on richness and diversity.

     

Annual and seasonal habitat use of Columbian black-tailed deer in urban Vancouver, Washington

We investigated habitat use of Columbian black-tailed deer in urban Vancouver, Clark County, Washington, at 3 spatial scales: (1) placement of the annual home range within the landscape mosaic, (2) annual and seasonal locations of deer within the annual home range, and (3) short-term use of critical habitats (fawning areas) within seasonal ranges. Annual home range sizes of deer were 162 ha (SD = 133; 95% minimum convex polygon; MCP) and 266 ha (SD = 228; 95% adaptive kernel; AK) for does, and 756 ha (SD = 290; MCP) and 1,235 ha (SD = 382; AK) for bucks. Home range composition of does did not differ from the study area; home ranges of bucks contained more Natural ecological land-use cover types (ELUs) than did the study area. Within home ranges, both does and bucks used Natural ELUs more often than expected by their occurrence in the home range, both annually and seasonally. During the fawning season, does were also found in Natural ELUs more often than expected. Clark County-designated habitat corridors differed from both the study area and deer home ranges in habitat composition, primarily by containing more Natural and other undeveloped ELUs. Deer were located in habitat corridors more than expected. Deer in urban areas appear to use undeveloped habitat types for security. Management that maintains Natural ELUs, such as establishment of wildlife corridors, can provide important habitat components for black-tailed deer in urban habitats.