The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Tracy A. G. Rittenhouse - One of the best experts on this subject based on the ideXlab platform.
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Stream salamander persistence influenced by the interaction between exurban Housing age and development
Urban Ecosystems, 2019Co-Authors: D. Cristina Macklem, Ashley M. Helton, Morgan W. Tingley, Jenny M. Dickson, Tracy A. G. RittenhouseAbstract:Exurban development is the fastest growing form of land use in the United States and already predominates southern New England. These Housing developments alter stream ecosystems in a predictable manner described as urban stream syndrome. Yet, many stream salamanders are considered ubiquitous in the region. To determine what stream and watershed features enhance long-term population persistence in an exurban landscape, we compared the occupancy and abundance of two stream salamanders, Eurycea bislineata (northern two-lined salamander) and Desmognathus fuscus (northern dusky salamander), in watersheds that differed in Housing Density and time since construction. We estimated E. bislineata occupancy at 100% and found strong support for an interaction between the quadratic of average Housing development age and Housing Density in watersheds influencing abundance. Abundance was sensitive to new and high-Density Housing developments and increased in watersheds that were more than 20 years post-construction when Housing Density was low. In comparison, D. fuscus occupancy was estimated at 18% and best explained by fine-scale stream features including soil temperature, water conductivity, dissolved oxygen, discharge, and sediment distribution. Notably, estimates of D. fuscus relative abundance within watersheds, including watersheds with low Housing densities, were much lower than comparable estimates in the literature. We suggest an adaptive management approach to monitor and manage D. fuscus populations in the region. Future wildlife management decisions in exurban landscapes should consider interactions between Housing age and Density as well as development legacy effects.
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Stream salamander persistence influenced by the interaction between exurban Housing age and development
Urban Ecosystems, 2019Co-Authors: D. Cristina Macklem, Ashley M. Helton, Morgan W. Tingley, Jenny M. Dickson, Tracy A. G. RittenhouseAbstract:Exurban development is the fastest growing form of land use in the United States and already predominates southern New England. These Housing developments alter stream ecosystems in a predictable manner described as urban stream syndrome. Yet, many stream salamanders are considered ubiquitous in the region. To determine what stream and watershed features enhance long-term population persistence in an exurban landscape, we compared the occupancy and abundance of two stream salamanders, Eurycea bislineata (northern two-lined salamander) and Desmognathus fuscus (northern dusky salamander), in watersheds that differed in Housing Density and time since construction. We estimated E. bislineata occupancy at 100% and found strong support for an interaction between the quadratic of average Housing development age and Housing Density in watersheds influencing abundance. Abundance was sensitive to new and high-Density Housing developments and increased in watersheds that were more than 20 years post-construction when Housing Density was low. In comparison, D. fuscus occupancy was estimated at 18% and best explained by fine-scale stream features including soil temperature, water conductivity, dissolved oxygen, discharge, and sediment distribution. Notably, estimates of D. fuscus relative abundance within watersheds, including watersheds with low Housing densities, were much lower than comparable estimates in the literature. We suggest an adaptive management approach to monitor and manage D. fuscus populations in the region. Future wildlife management decisions in exurban landscapes should consider interactions between Housing age and Density as well as development legacy effects.
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black bear recolonization patterns in a human dominated landscape vary based on Housing new insights from spatially explicit Density models
Landscape and Urban Planning, 2017Co-Authors: Michael J Evans, Tracy A. G. Rittenhouse, Jason E Hawley, Paul W RegoAbstract:Abstract Housing development is often intermixed within natural land cover, creating coupled human-natural systems that benefit some species, while eliminating critical habitat for others. As carnivore populations recover and expand in North America, understanding how populations may recolonize human-dominated landscapes is an important goal for conservation. We empirically test whether a population of American black bear ( Ursus americanus ) recolonizing a developed landscape is responding to land cover, Housing Density, or the amount of intermixture between forest and Housing as quantified by the Wildland Urban Interface. Housing Density was the most supported spatially explicit mark-recapture model and indicated that bear Density was highest among exurban Housing densities. Mean estimated bear Density in exurban areas (6–49 houses/km 2 ) was 0.18 individuals/km 2 compared to 0.12 individuals/km 2 in rural areas ( 2 ). Bear densities also declined to zero as development approached 50 houses/km 2 . We also tested for differences in sex ratio between more and less intensely developed areas, using hybrid mixture models. Sex ratios were significantly more male-biased in areas of higher Housing Density. Elevated bear densities provide evidence that exurban land-use can facilitate recolonization of black bears, yet high Housing Density may also limit the recovery of bear populations. Explicit relationships between land-use and bear Density will allow managers to anticipate future population distribution, and areas where bears and people may come into frequent contact.
Volker C. Radeloff - One of the best experts on this subject based on the ideXlab platform.
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long term avian community response to Housing development at the boundary of us protected areas effect size increases with time
Journal of Applied Ecology, 2015Co-Authors: Volker C. Radeloff, Anna M. Pidgeon, Nicholas S. Keuler, Eric M. Wood, David P Helmers, Patrick D Culbert, Curtis H. FlatherAbstract:Summary 1. Biodiversity conservation is a primary function of protected areas. However, protected areas also attract people, and therefore, land use has intensified at the boundaries of these lands globally. In the USA, since the 1970s, Housing growth at the boundaries (<1 km) of protected areas has increased at a rate far higher than on more distant private lands. Here, we designed our analyses to address our central hypothesis that increasing Housing Density in and near protected areas will increasingly alter their avian communities. 2. We quantified the relationship between abundance and richness of protected-area avian species of greatest conservation need, land-cover affiliates (e.g. species associated with natural land cover such as forest breeders) and synanthropes (e.g. species associated with humans) with Housing Density on the boundary of protected areas and on more distant private lands from 1970 to 2010 in three ecoregions of the USA. We accomplished this using linear mixedmodel analyses, data from the US Census Bureau and 90 routes of the North American Breeding Bird Survey. 3. Housing Density at the boundary of protected areas tended to be strongly negatively related with the abundance and richness of species of greatest conservation need and landcover affiliates (upwards of 88% of variance explained) and strongly positively related with synanthropes (upwards of 83% of variance explained). The effect size of these relationships increased in most cases from 1970 to 2010 and was greatest in the densely developed eastern forests. In the more sparsely populated West, we found similar, though weaker, associations. 4. Housing Density on private lands more distant from protected areas had similar, but more muted negative effects. 5. Synthesis and applications. Our results illustrate that as Housing Density has increased along the boundary of protected areas, the conservation benefit of these lands has likely diminished. We urge conservation planners to prioritize the purchase of private-land inholdings in order to maximize the extent of unfragmented natural lands within protected areas. Further, we strongly recommend that land-use planners implement boundary management strategies to alter the pattern of human access to protected areas, cluster development to concentrate the footprint of rural Housing, and establish conservation agreements through local land trusts to buffer protected areas from the effects of development along protected-area boundaries. To maximize the conservation benefit of protected areas, we suggest that Housing development should be restricted within 1 km of their boundaries.
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Systematic Temporal Patterns in the Relationship Between Housing Development and Forest Bird Biodiversity
Conservation biology : the journal of the Society for Conservation Biology, 2014Co-Authors: Anna M. Pidgeon, Susan I. Stewart, Volker C. Radeloff, Curtis H. Flather, Christopher A. Lepczyk, Nicholas S. Keuler, Eric M. Wood, Roger B. HammerAbstract:As people encroach increasingly on natural areas, one question is how this affects avian biodi- versity. The answer to this is partly scale-dependent. At broad scales, human populations and biodiversity concentrate in the same areas and are positively associated, but at local scales people and biodiversity are negatively associated with biodiversity. We investigated whether there is also a systematic temporal trend in the relationship between bird biodiversity and Housing development. We used linear regression to examine associations between forest bird species richness and Housing growth in the conterminous United States over 30 years. Our data sources were the North American Breeding Bird Survey and the 2000 decennial U.S. Census. In the 9 largest forested ecoregions, Housing Density increased continually over time. Across the conterminous United States, the association between bird species richness and Housing Density was positive for virtually all guilds except ground nesting birds. We found a systematic trajectory of declining bird species richness as Housing increased through time. In more recently developed ecoregions, where Housing Density was still low, the association with bird species richness was neutral or positive. In ecoregions that were developed earlier and where Housing Density was highest, the association of Housing Density with bird species richness for most guilds was negative and grew stronger with advancing decades. We propose that in general the relationship between human settlement and biodiversity over time unfolds as a 2-phase process. The first phase is apparently innocuous; associations are positive due to coincidence of low-Density Housing with high biodiversity. The second phase is highly detrimental to biodiversity, and increases in Housing Density are associated with biodiversity losses. The long-term effect on biodiversity depends on the final Housing Density. This general pattern can help unify our understanding of the relationship of human encroachment and biodiversity response.
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Housing growth, forests, and public lands in Northern Wisconsin from 1940 to 2000
Journal of environmental management, 2009Co-Authors: Roger B. Hammer, Susan I. Stewart, Todd J. Hawbaker, Volker C. RadeloffAbstract:Rural, forested areas throughout the United States are experiencing strong Housing growth with potentially detrimental impacts on the environment. In this paper, we quantify Housing growth in Northern Wisconsin over the last sixty years to determine if growth rates were higher near public lands, which may represent an important recreational amenity. We used data from the U.S. Census to produce decadal Housing Density estimates, ‘‘backcasts,’’ from 1940 to 2000 for northern Wisconsin to examine ‘‘rural sprawl’’ in northern Wisconsin and its relationship to forested areas and public lands. We integrated Housing Density estimates with the 1992/1993 National Land Cover Dataset to examine the relationship between rural sprawl and land cover, especially forests. Between 1940 and 2000, private land with
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Assessing Housing growth when census boundaries change
International Journal of Geographical Information Science, 2009Co-Authors: Alexandra D. Syphard, Susan I. Stewart, Roger B. Hammer, Jason Mckeefry, Jeremy S. Fried, Sherry Holcomb, Volker C. RadeloffAbstract:The US Census provides the primary source of spatially explicit social data, but changing block boundaries complicate analyses of Housing growth over time. We compared procedures for reconciling Housing Density data between 1990 and 2000 census block boundaries in order to assess the sensitivity of analytical methods to estimates of Housing growth in Oregon. Estimates of Housing growth varied substantially and were sensitive to the method of interpolation. With no processing and areal-weighted interpolation, more than 35% of the landscape changed; 75-80% of this change was due to decline in Housing Density. This decline was implausible, however, because Housing structures generally persist over time. Based on aggregated boundaries, 11% of the landscape changed, but only 4% experienced a decline in Housing Density. Nevertheless, the Housing Density change map was almost twice as coarse spatially as the 2000 Housing Density data. We also applied a dasymetric approach to redistribute 1990 Housing data into 2000 census boundaries under the assumption that the distribution of Housing in 2000 reflected the same distribution as in 1990. The dasymetric approach resulted in conservative change estimates at a fine resolution. All methods involved some type of trade-off (e.g. analytical difficulty, data resolution, magnitude or bias in direction of change). However, our dasymetric procedure is a novel approach for assessing Housing growth over changing census boundaries that may be particularly useful because it accounts for the uniquely persistent nature of Housing over time.
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Associations of forest bird species richness with Housing and landscape patterns across the USA.
Ecological applications : a publication of the Ecological Society of America, 2007Co-Authors: Anna M. Pidgeon, Volker C. Radeloff, Todd J. Hawbaker, Murray K. Clayton, Curtis H. Flather, Christopher A. Lepczyk, Roger B. HammerAbstract:In the United States, Housing Density has substantially increased in and adjacent to forests. Our goal in this study was to identify how Housing Density and human populations are associated with avian diversity. We compared these associations to those between landscape pattern and avian diversity, and we examined how these associations vary across the conterminous forested United States. Using data from the North American Breeding Bird Survey, the U.S. Census, and the National Land Cover Database, we focused on forest and woodland bird communities and conducted our analysis at multiple levels of model specificity, first using a coarse-thematic resolution (basic models), then using a larger number of fine-thematic resolution variables (refined models). We found that Housing development was associated with forest bird species richness in all forested ecoregions of the conterminous United States. However, there were important differences among ecoregions. In the basic models, Housing Density accounted for ,5% of variance in avian species richness. In refined models, 85% of models included Housing Density and/or residential land cover as significant variables. The strongest guild response was demonstrated in the Adirondack-New England ecoregion, where 29% of variation in richness of the permanent resident guild was associated with Housing Density. Model improvements due to regional stratification were most pronounced for cavity nesters and short-distance migrants, suggesting that these guilds may be especially sensitive to regional processes. The varying patterns of association between avian richness and attributes associated with landscape structure suggested that landscape context was an important mediating factor affecting how biodiversity responds to landscape changes. Our analysis suggested that simple, broadly applicable, land use recommendations cannot be derived from our results. Rather, anticipating future avian response to land use intensification (or reversion to native vegetation) has to be conditioned on the current landscape context and the species group of interest. Our results show that Housing Density and residential land cover were significant predictors of forest bird species richness, and their prediction strengths are likely to increase as development continues.
Roger B. Hammer - One of the best experts on this subject based on the ideXlab platform.
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Systematic Temporal Patterns in the Relationship Between Housing Development and Forest Bird Biodiversity
Conservation biology : the journal of the Society for Conservation Biology, 2014Co-Authors: Anna M. Pidgeon, Susan I. Stewart, Volker C. Radeloff, Curtis H. Flather, Christopher A. Lepczyk, Nicholas S. Keuler, Eric M. Wood, Roger B. HammerAbstract:As people encroach increasingly on natural areas, one question is how this affects avian biodi- versity. The answer to this is partly scale-dependent. At broad scales, human populations and biodiversity concentrate in the same areas and are positively associated, but at local scales people and biodiversity are negatively associated with biodiversity. We investigated whether there is also a systematic temporal trend in the relationship between bird biodiversity and Housing development. We used linear regression to examine associations between forest bird species richness and Housing growth in the conterminous United States over 30 years. Our data sources were the North American Breeding Bird Survey and the 2000 decennial U.S. Census. In the 9 largest forested ecoregions, Housing Density increased continually over time. Across the conterminous United States, the association between bird species richness and Housing Density was positive for virtually all guilds except ground nesting birds. We found a systematic trajectory of declining bird species richness as Housing increased through time. In more recently developed ecoregions, where Housing Density was still low, the association with bird species richness was neutral or positive. In ecoregions that were developed earlier and where Housing Density was highest, the association of Housing Density with bird species richness for most guilds was negative and grew stronger with advancing decades. We propose that in general the relationship between human settlement and biodiversity over time unfolds as a 2-phase process. The first phase is apparently innocuous; associations are positive due to coincidence of low-Density Housing with high biodiversity. The second phase is highly detrimental to biodiversity, and increases in Housing Density are associated with biodiversity losses. The long-term effect on biodiversity depends on the final Housing Density. This general pattern can help unify our understanding of the relationship of human encroachment and biodiversity response.
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Housing growth, forests, and public lands in Northern Wisconsin from 1940 to 2000
Journal of environmental management, 2009Co-Authors: Roger B. Hammer, Susan I. Stewart, Todd J. Hawbaker, Volker C. RadeloffAbstract:Rural, forested areas throughout the United States are experiencing strong Housing growth with potentially detrimental impacts on the environment. In this paper, we quantify Housing growth in Northern Wisconsin over the last sixty years to determine if growth rates were higher near public lands, which may represent an important recreational amenity. We used data from the U.S. Census to produce decadal Housing Density estimates, ‘‘backcasts,’’ from 1940 to 2000 for northern Wisconsin to examine ‘‘rural sprawl’’ in northern Wisconsin and its relationship to forested areas and public lands. We integrated Housing Density estimates with the 1992/1993 National Land Cover Dataset to examine the relationship between rural sprawl and land cover, especially forests. Between 1940 and 2000, private land with
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Assessing Housing growth when census boundaries change
International Journal of Geographical Information Science, 2009Co-Authors: Alexandra D. Syphard, Susan I. Stewart, Roger B. Hammer, Jason Mckeefry, Jeremy S. Fried, Sherry Holcomb, Volker C. RadeloffAbstract:The US Census provides the primary source of spatially explicit social data, but changing block boundaries complicate analyses of Housing growth over time. We compared procedures for reconciling Housing Density data between 1990 and 2000 census block boundaries in order to assess the sensitivity of analytical methods to estimates of Housing growth in Oregon. Estimates of Housing growth varied substantially and were sensitive to the method of interpolation. With no processing and areal-weighted interpolation, more than 35% of the landscape changed; 75-80% of this change was due to decline in Housing Density. This decline was implausible, however, because Housing structures generally persist over time. Based on aggregated boundaries, 11% of the landscape changed, but only 4% experienced a decline in Housing Density. Nevertheless, the Housing Density change map was almost twice as coarse spatially as the 2000 Housing Density data. We also applied a dasymetric approach to redistribute 1990 Housing data into 2000 census boundaries under the assumption that the distribution of Housing in 2000 reflected the same distribution as in 1990. The dasymetric approach resulted in conservative change estimates at a fine resolution. All methods involved some type of trade-off (e.g. analytical difficulty, data resolution, magnitude or bias in direction of change). However, our dasymetric procedure is a novel approach for assessing Housing growth over changing census boundaries that may be particularly useful because it accounts for the uniquely persistent nature of Housing over time.
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Associations of forest bird species richness with Housing and landscape patterns across the USA.
Ecological applications : a publication of the Ecological Society of America, 2007Co-Authors: Anna M. Pidgeon, Volker C. Radeloff, Todd J. Hawbaker, Murray K. Clayton, Curtis H. Flather, Christopher A. Lepczyk, Roger B. HammerAbstract:In the United States, Housing Density has substantially increased in and adjacent to forests. Our goal in this study was to identify how Housing Density and human populations are associated with avian diversity. We compared these associations to those between landscape pattern and avian diversity, and we examined how these associations vary across the conterminous forested United States. Using data from the North American Breeding Bird Survey, the U.S. Census, and the National Land Cover Database, we focused on forest and woodland bird communities and conducted our analysis at multiple levels of model specificity, first using a coarse-thematic resolution (basic models), then using a larger number of fine-thematic resolution variables (refined models). We found that Housing development was associated with forest bird species richness in all forested ecoregions of the conterminous United States. However, there were important differences among ecoregions. In the basic models, Housing Density accounted for ,5% of variance in avian species richness. In refined models, 85% of models included Housing Density and/or residential land cover as significant variables. The strongest guild response was demonstrated in the Adirondack-New England ecoregion, where 29% of variation in richness of the permanent resident guild was associated with Housing Density. Model improvements due to regional stratification were most pronounced for cavity nesters and short-distance migrants, suggesting that these guilds may be especially sensitive to regional processes. The varying patterns of association between avian richness and attributes associated with landscape structure suggested that landscape context was an important mediating factor affecting how biodiversity responds to landscape changes. Our analysis suggested that simple, broadly applicable, land use recommendations cannot be derived from our results. Rather, anticipating future avian response to land use intensification (or reversion to native vegetation) has to be conditioned on the current landscape context and the species group of interest. Our results show that Housing Density and residential land cover were significant predictors of forest bird species richness, and their prediction strengths are likely to increase as development continues.
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Associations of forest bird species richness with Housing and landscape pattern across the United States
Ecological Applications, 2007Co-Authors: Anna M. Pidgeon, Volker C. Radeloff, Todd J. Hawbaker, Murray K. Clayton, Curtis H. Flather, Christopher A. Lepczyk, Roger B. HammerAbstract:In the United States, Housing Density has substantially increased in and adjacent to forests. Our goal in this study was to identify how Housing Density and human populations are associated with avian diversity. We compared these associations to those between landscape pattern and avian diversity, and we examined how these associations vary across the conterminous forested United States. Using data from the North American Breeding Bird Survey, the U.S. Census, and the National Land Cover Database, we focused on forest and woodland bird communities and conducted our analysis at multiple levels of model specificity, first using a coarse-thematic resolution (basic models), then using a larger number of fine-thematic resolution variables (refined models). We found that Housing development was associated with forest bird species richness in all forested ecoregions of the conterminous United States. However, there were important differences among ecoregions. In the basic models, Housing Density accounted for
D. Cristina Macklem - One of the best experts on this subject based on the ideXlab platform.
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Stream salamander persistence influenced by the interaction between exurban Housing age and development
Urban Ecosystems, 2019Co-Authors: D. Cristina Macklem, Ashley M. Helton, Morgan W. Tingley, Jenny M. Dickson, Tracy A. G. RittenhouseAbstract:Exurban development is the fastest growing form of land use in the United States and already predominates southern New England. These Housing developments alter stream ecosystems in a predictable manner described as urban stream syndrome. Yet, many stream salamanders are considered ubiquitous in the region. To determine what stream and watershed features enhance long-term population persistence in an exurban landscape, we compared the occupancy and abundance of two stream salamanders, Eurycea bislineata (northern two-lined salamander) and Desmognathus fuscus (northern dusky salamander), in watersheds that differed in Housing Density and time since construction. We estimated E. bislineata occupancy at 100% and found strong support for an interaction between the quadratic of average Housing development age and Housing Density in watersheds influencing abundance. Abundance was sensitive to new and high-Density Housing developments and increased in watersheds that were more than 20 years post-construction when Housing Density was low. In comparison, D. fuscus occupancy was estimated at 18% and best explained by fine-scale stream features including soil temperature, water conductivity, dissolved oxygen, discharge, and sediment distribution. Notably, estimates of D. fuscus relative abundance within watersheds, including watersheds with low Housing densities, were much lower than comparable estimates in the literature. We suggest an adaptive management approach to monitor and manage D. fuscus populations in the region. Future wildlife management decisions in exurban landscapes should consider interactions between Housing age and Density as well as development legacy effects.
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Stream salamander persistence influenced by the interaction between exurban Housing age and development
Urban Ecosystems, 2019Co-Authors: D. Cristina Macklem, Ashley M. Helton, Morgan W. Tingley, Jenny M. Dickson, Tracy A. G. RittenhouseAbstract:Exurban development is the fastest growing form of land use in the United States and already predominates southern New England. These Housing developments alter stream ecosystems in a predictable manner described as urban stream syndrome. Yet, many stream salamanders are considered ubiquitous in the region. To determine what stream and watershed features enhance long-term population persistence in an exurban landscape, we compared the occupancy and abundance of two stream salamanders, Eurycea bislineata (northern two-lined salamander) and Desmognathus fuscus (northern dusky salamander), in watersheds that differed in Housing Density and time since construction. We estimated E. bislineata occupancy at 100% and found strong support for an interaction between the quadratic of average Housing development age and Housing Density in watersheds influencing abundance. Abundance was sensitive to new and high-Density Housing developments and increased in watersheds that were more than 20 years post-construction when Housing Density was low. In comparison, D. fuscus occupancy was estimated at 18% and best explained by fine-scale stream features including soil temperature, water conductivity, dissolved oxygen, discharge, and sediment distribution. Notably, estimates of D. fuscus relative abundance within watersheds, including watersheds with low Housing densities, were much lower than comparable estimates in the literature. We suggest an adaptive management approach to monitor and manage D. fuscus populations in the region. Future wildlife management decisions in exurban landscapes should consider interactions between Housing age and Density as well as development legacy effects.
Lenore Fahrig - One of the best experts on this subject based on the ideXlab platform.
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Do birds and beetles show similar responses to urbanization
Ecological applications : a publication of the Ecological Society of America, 2011Co-Authors: Sara A. Gagné, Lenore FahrigAbstract:To date, the vast majority of studies in urban areas have been carried out on birds, yet it is not known whether the responses of birds to urbanization are congruent with those of other taxa. In this paper, we compared the responses of breeding birds and carabid beetles to urbanization, specifically asking whether the emerging generalizations of the effects of extreme levels of urbanization on birds (declines in total species richness and the richness of specialist species, increases in total abundance and the abundances of native generalist and introduced species, and community simplification, including increasing similarity) could also be applied to ground beetles. We also directly tested for congruence between birds and ground beetles using correlations between variables describing bird and beetle community structure and correlations between bird and beetle distance matrices describing community dissimilarity between pairs of sampling locations. Breeding bird and carabid beetle community data were collected in Ottawa, Ontario, and Gatineau, Quebec, Canada, in two groups of sites: developed sites representing the predictor variable within-site Housing Density, and forested sites adjacent to development representing the predictor variable neighboring Housing Density (each site was 0.25 km2). Breeding birds and carabid beetles do not respond similarly to increasing within-site Housing Density but do exhibit some similar responses to increasing neighboring Housing Density. Birds displayed strong declines in diversity, compositional changes, and community simplification in response to increasing within-site Housing Density. Forest and introduced species of birds and beetles responded similarly to increasing Housing Density within a site, but responses of overall diversity and open-habitat species richness and patterns of community simplification differed between birds and beetles. Increasing neighboring Housing Density resulted in increases in the abundances of introduced birds and introduced beetles and similar patterns of community simplification in both taxa. To better understand and mitigate the effects of urbanization on biodiversity, we suggest that, in addition to the responses of birds, future research should focus on the responses of other taxa in the urban matrix.
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The trade-off between Housing Density and sprawl area: minimizing impacts to carabid beetles (Coleoptera: Carabidae).
Ecology and Society, 2010Co-Authors: Sara A. Gagné, Lenore FahrigAbstract:Increasing Housing Density has negative effects on native biodiversity. This implies that we should build at low Density to conserve native species. However, for a given human population, low-Density development must cover a large area, resulting in sprawl. A pertinent question is then, at what Housing Density are the impacts of a given human population on native biodiversity minimized? We addressed this question with carabid beetles in Ottawa and Gatineau, Canada. First, we collected beetles at 22 sites representing a range of Housing densities. We then used these data to estimate beetle abundance and species richness in hypothetical development scenarios representing the Housing Density/sprawl area trade-off. Our results suggest that clustering development at a high Housing Density minimizes the impacts of a given human population on carabid beetles. If these results are general across all forest taxa, then planning that favors densification rather than sprawl would minimize urbanization effects on forest biodiversity.
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The trade-off between Housing Density and sprawl area: Minimising impacts to forest breeding birds
Basic and Applied Ecology, 2010Co-Authors: Sara A. Gagné, Lenore FahrigAbstract:Increasing Housing Density is generally assumed to confer negative effects on forest breeding birds. This implies we should build at low Density over the landscape to conserve these species. However, for a given human population, low-Density development must cover a large area, resulting in sprawl. A pertinent question is then: at what Housing Density are the impacts of a given human population on forest biodiversity minimised? For a given human population, it is unclear whether the impacts on forest biodiversity are less where Housing Density is high and sprawl area is small or where Housing Density is low and sprawl area is large. We addressed this question using the abundance, species richness and evenness of forest birds in Ottawa, Ontario and Gatineau, Quebec, Canada. First, we counted breeding birds at 22 sites representing a range of Housing densities. We then used these empirical measurements to estimate forest bird abundance, species richness and evenness in four hypothetical development scenarios representing the trade-off between Housing Density and sprawl area. With the exception of the Undeveloped scenario (i.e., continuous forest), forest birds and forest interior birds were most abundant in the Compact scenario and most speciose in the Semi-compact scenario, whereas forest edge birds were most abundant and speciose in the Dispersed scenario. All three bird groups were most even in the Compact scenario. We conclude that compact Housing development (building at high Density over a small area) minimises the impacts of a given human population on forest breeding birds.