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1.
Human-dominated environments are often subjected to increased nutrient and moisture regimes which have the potential to influence the flowering phenology of plants. Protracted flowering periods within urban landscapes may result in increased food resources, in the form of nectar, and this high resource availability may support a high density of nectarivorous birds within cities. In order to determine whether there was a difference in the productivity and flowering period associated with urbanisation, we compared the number of flowers produced and duration of flowering period for three species of native tree that were present in streetscapes, remnant vegetation and continuous forest. We also recorded the presence of nectarivorous parrots at flowering trees to determine if the presence of nectarivores was associated with flower productivity. All three species in streetscapes produced more flowers and flowered for longer than in remnants and continuous forest. The number of flowers per tree significantly predicted the presence of nectarivorous parrots in streetscapes. This study demonstrates that the flowering phenology of plants within streetscapes can differ from continuous forest, with remnants appearing to be intermediate. This increased flower productivity within urban landscapes may be partially responsible for the high abundance of nectarivorous parrots within some cities. 相似文献
2.
Altered resources, disturbance, and heterogeneity: A framework for comparing urban and non-urban soils 总被引:3,自引:2,他引:1
We propose a framework of key concepts useful in understanding how urban soils can contribute to general ecological theory.
The major factors that can cause urban soils to be different from soils in non-urban ecosystems are identified and related
to the familiar state factor approach. We evaluate directly altered resource availability, and the role of stress in mediating
resource availability in urban ecosystems. Modified groundwater and stream flow, and atmospheric deposition of nitrogen and
base cations are particularly important resource fluxes to soils in urban ecosystems. Disturbance can be conceptualized in
the same way in urban as in non-urban ecosystems. However, in addition to biophysical disturbances familiar to ecologists
studying wild lands, demographically and socially mediated changes in ecosystem structure must also be considered. These changes
include human migration and population structure, institutional shifts, and the effects of human health. Finally, spatial
heterogeneity, including fragmentation and differential connectivity, integrates the effects of resources and disturbance,
and has an effect on subsequent resource availability and susceptibility to disturbance. Layers of heterogeneity include not
only the geomorphic template, but urban climate, biotic composition, buildings and infrastructure, and demographic-social
patterns. The complex layering of natural and social factors that constitute urban heterogeneity permit the continuation of
important ecological processes, as well as modify ecological fluxes involving soils. We present a modification of the state
factor approach as an expanded framework for the study of urban soils. The understanding of urban soils can contribute to
general ecological theory by testing the generality of important ecosystem drivers and their linkage with social processes
in an under investigated ecosystem type that is increasing in extent and impact worldwide. 相似文献
3.
针对城市发展出现的4个重大变因,即人口持续增加、污染排放增加、资源短缺加剧和全球气候变化,为优化和改善上海的城市生态、生活环境,提升城市的宜居水平,应从调结构、控规模、谋布局三大战略思路出发,实现城市大数据全覆盖,提供城市安全保障;分散城市核心功能,降低城市生活成本;优化城市用地布局,提升城市生态品质. 相似文献
4.
Loren B. Byrne 《Urban Ecosystems》2007,10(3):255-274
Habitat structure is defined as the composition and arrangement of physical matter at a location. Although habitat structure
is the physical template underlying ecological patterns and processes, the concept is relatively unappreciated and underdeveloped
in ecology. However, it provides a fundamental concept for urban ecology because human activities in urban ecosystems are
often targeted toward management of habitat structure. In addition, the concept emphasizes the fine-scale, on-the-ground perspective
needed in the study of urban soil ecology. To illustrate this, urban soil ecology research is summarized from the perspective
of habitat structure effects. Among the key conclusions emerging from the literature review are: (1) habitat structure provides
a unifying theme for multivariate research about urban soil ecology; (2) heterogeneous urban habitat structures influence
soil ecological variables in different ways; (3) more research is needed to understand relationships among sociological variables,
habitat structure patterns and urban soil ecology. To stimulate urban soil ecology research, a conceptual framework is presented
to show the direct and indirect relationships among habitat structure and ecological variables. Because habitat structure
serves as a physical link between sociocultural and ecological systems, it can be used as a focus for interdisciplinary and
applied research (e.g., pest management) about the multiple, interactive effects of urbanization on the ecology of soils. 相似文献
5.
This paper studies the use of ecological research information in urban planning focusing on Finland. Research questions addressed
the importance and challenges of incorporating ecological information into the planning process, and ways to promote the use
of ecological information. Fifteen key professionals from three representative development approval processes in the Helsinki
Metropolitan Area were interviewed. The interviewed planners and ecologists considered ecological information important for
identifying and preserving valuable urban nature and biodiversity, diminishing negative environmental impacts of construction
and for enabling nature-related experiences and services for urban residents. The identified challenges for the use of the
information included insufficiency, fragmented nature and lack of adequacy of information, as well as problems with the interpretation
and presentation of information. In order to provide more comprehensive ecological information from urbanizing areas in Finland;
there should be more coordinated efforts to produce research information that planners really need, ecologists should be more
active in the process in providing ecological insights for plans, a proper and simple biodiversity valuation method should
be developed, more research on the function on ecological corridors should be conducted, and biodiversity monitoring of implemented
planning projects should be developed. 相似文献
6.
Sean B. Menke Benoit Guénard Joseph O. Sexton Michael D. Weiser Robert R. Dunn Jules Silverman 《Urban Ecosystems》2011,14(2):135-163
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. 相似文献
7.
Urban ecosystems: What would Tansley do? 总被引:1,自引:0,他引:1
The ecosystem concept was introduced in ecology originally to solve problems associated with theories of succession and ecological
communities. It has evolved to become one of ecology’s fundamental ideas, and has proven to be applicable to a wide variety
of research questions and applications. However, there is controversy about whether or how well the ecosystem concept is suited
to urban habitats. By examining Arthur Tansley’s original presentation of the ecosystem concept, and exploring how the ecological
context of the concept has changed, we indicate that the fundamental concept of the ecosystem is well suited to urban ecological
studies. The concept can be clarified for urban use by including a social complex and a built complex to insure that human
social institutions and actions, and the structures and infrastructure they build are explicitly included in the ecosystem
concept. The ecosystem concept is thus seen as clearly robust to use in urban areas.
相似文献
Steward T. A. PickettEmail: |
8.
Does urbanization affect key life-history traits in native organisms? Some studies show that urban areas reduce diversity in certain taxa, but there is little insight into how these environments affect physiological and ecological traits. Urban areas have distinct physical structure and ecological processes compared to original habitats. The environmental changes associated with urban areas can influence the costs and benefits of different traits and behaviors of local organisms. Some of these effects have been explored in groups such as birds, but we might expect stronger effects in animals with reduced mobility, such as amphibians. Importantly, the effects of urban habitats on amphibians have not been explored, in spite that these are the most threatened vertebrate group in the world. Here, we compared three main traits related to the fitness of amphibians in urban and natural habitats: body size, body condition and immune response. To test the generality of our results, we assessed adult males of four amphibian species. We found that the body size was larger in urban environment populations in three of four studied species, while the body condition was better in the urban populations of two aquatic newt species. Finally, we found no effect of urbanization on the immune response of individuals of any species. In conclusion, we show that different species of amphibians may be affected differently by anthropogenic habitat alteration depending on their specific ecology. 相似文献
9.
M. R. McHale I. C. Burke M. A. Lefsky P. J. Peper E. G. McPherson 《Urban Ecosystems》2009,12(1):95-113
Many studies have analyzed the benefits, costs, and carbon storage capacity associated with urban trees. These studies have
been limited by a lack of research on urban tree biomass, such that estimates of carbon storage in urban systems have relied
upon allometric relationships developed in traditional forests. As urbanization increases globally, it is becoming important
to more accurately evaluate carbon dynamics in these systems. Our goal was to understand the variability and range of potential
error associated with using allometric relationships developed outside of urban environments. We compared biomass predictions
from allometric relationships developed for urban trees in Fort Collins, Colorado to predictions from allometric equations
from traditional forests, at both the individual species level and entire communities. A few of the equations from the literature
predicted similar biomass to the urban-based predictions, but the range in variability for individual trees was over 300%.
This variability declined at increasingly coarse scales, reaching as low as 60% for a street tree community containing 11
tree species and 10, 551 trees. When comparing biomass estimates between cities that implement various allometric relationships,
we found that differences could be a function of variability rather than urban forest structure and function. Standardizing
the methodology and implementing averaged equations across cities could be one potential solution to reducing variability;
however, more accurate quantification of biomass and carbon storage in urban forests may depend on development of allometric
relationships specifically for urban trees. 相似文献
10.
Elena D. Concepción Martin K. Obrist Marco Moretti Florian Altermatt Bruno Baur Michael P. Nobis 《Urban Ecosystems》2016,19(1):225-242
Urban growth is a major factor of global environmental change and has important impacts on biodiversity, such as changes in species composition and biotic homogenization. Most previous studies have focused on effects of urban area as a general measure of urbanization, and on few or single taxa. Here, we analyzed the impacts of the different components of urban sprawl (i.e., scattered and widespread urban growth) on species richness of a variety of taxonomic groups covering mosses, vascular plants, gastropods, butterflies, and birds at the habitat and landscape scales. Besides urban area, we considered the average age, imperviousness, and dispersion degree of urban area, along with human population density, to disentangle the effects of the different components of urban sprawl on biodiversity. The study was carried out in the Swiss Plateau that has undergone substantial urban sprawl in recent decades.Vascular plants and birds showed the strongest responses to urban sprawl, especially at the landscape scale, with non-native and ruderal plants proliferating and common generalist birds increasing at the expense of specialist birds as urban sprawl grew. Overall, urban area had the greatest contribution on such impacts, but additional effects of urban dispersion (i.e., increase of non-native plants) and human population density (i.e., increases of ruderal plants and common generalist birds) were found. Our findings support the hypothesis that negative impacts of urban sprawl on biodiversity can be reduced by compacting urban growth while still avoiding the formation of very densely populated areas. 相似文献
11.
Michael L. McKinney 《Urban Ecosystems》2008,11(2):161-176
Many studies have described the effects of urbanization on species richness. These studies indicate that urbanization can
increase or decrease species richness, depending on several variables. Some of these variables include: taxonomic group, spatial
scale of analysis, and intensity of urbanization. Recent reviews of birds (the most-studied group) indicate that species richness
decreases with increasing urbanization in most cases but produces no change or even increases richness in some studies. Here
I expand beyond the bird studies by reviewing 105 studies on the effects of urbanization on the species richness of non-avian
species: mammals, reptiles, amphibians, invertebrates and plants. For all groups, species richness tends to be reduced in
areas with extreme urbanization (i.e., central urban core areas). However, the effects of moderate levels of urbanization
(i.e., suburban areas) vary significantly among groups. Most of the plant studies (about 65%) indicate increasing species
richness with moderate urbanization whereas only a minority of invertebrate studies (about 30%) and a very small minority
of non-avian vertebrate studies (about 12%) show increasing species richness. Possible explanations for these results are
discussed, including the importance of nonnative species importation, spatial heterogeneity, intermediate disturbance and
scale as major factors influencing species richness. 相似文献
12.
The literature on urban farming in Sub-Saharan African cities reveals that most studies have been conducted in Eastern, Southern and Central African cities. A few have focused on West Africa, including Sierra Leone, Guinea Bissau, and Cameroon. In Ghana there is a paucity of information on urban farming. The purpose of this paper is to examine the status of urban cultivation in Accra, Ghana's capital, reviewing existing research, and to present new empirical findings on urban cultivation emphasizing on its history, nature, practices, problems, potentials and urban planning implications. 相似文献
13.
近期城市安全事故的频发及其严重后果引发了一连串巨大的社会负面效应,这对城市安全管理工作提出了新的要求与挑战。有别于传统的城市安全管理研究,本文力图建立全方位安全管理体系,将关键受众、主导机构及合作网络等主体整合在一起,并从城市安全管理的过程着手建立相应的分析框架,最终为相关实践活动提供理论参考。 相似文献
14.
Lewis Emma Phoenix Gareth K. Alexander Paul David John Cameron Ross W. F. 《Urban Ecosystems》2019,22(5):841-854
Urban Ecosystems - Urban green infrastructure, such as gardens, can mitigate some of the consequences of climate change, e.g. reducing flash-flooding or urban heat islands. Green infrastructure,... 相似文献
15.
An integrated approach to evaluating urban forest functionality 总被引:1,自引:0,他引:1
M. David Oleyar Adrienne I. Greve John C. Withey Andrew M. Bjorn 《Urban Ecosystems》2008,11(3):289-308
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. 相似文献
16.
A comparison of soil organic carbon stocks between residential turf grass and native soil 总被引:4,自引:3,他引:1
A central principle in urban ecological theory implies that in urbanized landscapes anthropogenic drivers will dominate natural
drivers in the control of soil organic carbon storage (SOC). To assess the effect of urban land-use change on the storage
of SOC, we compared SOC stocks of turf grass and native cover types of two metropolitan areas (Baltimore, MD, and Denver,
CO) representing climatologically distinct regions in the United States. We hypothesized that introducing turf grass and management
will lead to higher SOC densities in the arid Denver area and lower densities in the mesic Baltimore area relative to native
cover types. Moreover, differences between turf grass soils will be less than differences between the native soils of each
metropolitan region. Within Baltimore, turf grass had almost a 2-fold higher SOC density at 0- to 1-m and 0- to 20-cm depths
than in rural forest soils, whereas there were no differences with soils of urban forest remnants. Moreover, urban forest
remnants had more than 70% higher SOC densities than rural forest soils. Within Denver, turf grass (>25 years of age) had
more than 2-fold higher SOC densities than in shortgrass steppe soils, while having similar densities to Baltimore turf grass
soils. By contrast, the native soils of Baltimore were almost 2-fold higher than the native steppe grass soils of Denver using
SOC densities of remnant forests as representative of native soils in the Baltimore region. These results supported our hypothesis
that turf grass systems will be similar in SOC densities across regional variations in climate, parent material, and topography.
These similarities are apparently due to greater management efforts in the Denver region to offset the constraint of climate,
i.e., anthropogenic factors (management supplements) overwhelmed native environmental factors that control SOC storage. 相似文献
17.
Christopher G. Boone Elizabeth Cook Sharon J. Hall Marcia L. Nation Nancy B. Grimm Carol B. Raish Deborah M. Finch Abigail M. York 《Urban Ecosystems》2012,15(4):795-807
To meet the grand challenges of the urban century??such as climate change, biodiversity loss, and persistent poverty??urban and ecological theory must contribute to integrated frameworks that treat social and ecological dynamics as interdependent. A socio-ecological framework that encapsulates theory from the social and ecological sciences will improve understanding of metropolitan dynamics and generate science for improved, sustainable management of urban ecosystems. To date, most urban ecological research has focused on single cities. A comparative approach that uses gradients within and between cities is a useful tool for building urban ecological theory. We offer five hypotheses that are testable using a comparative, gradient approach: (i) the current size, configuration, and function of larger metropolitan ecosystems predicts the potential trajectory of smaller urban areas; (ii) timing of growth explains the greatest variance in urban ecosystem structure and function; (iii) form and function of urban ecosystems are converging over time; (iv) urban ecosystems become more segregated and fragmented as populations increase; and (v) larger cities are more innovative than smaller cities in managing urban ecosystems. 相似文献
18.
Urbanization is a widespread intense land use that generally results in biodiversity decline. Among the taxa capable to adapt to urban landscapes, bats are particularly ubiquitous. Brazil has one of the world’s largest diversity of bat species and one of the highest urbanization rates of the world. Yet, few studies have synthesized the biology of bats in urban environments, especially in Brazil. To fill this gap, we systematically reviewed the published scientific literature on the bat fauna found in urban areas of Brazil. The knowledge of urban bats is still incipient and heterogeneously spatially distributed, mostly concentrated in the southeastern region of the country. The assembled list of 84 urban species, of which nineteen are new species records for urban areas (including one new family), represents 47% of the bat richness registered in the country. Thirty-one bat species (37%) were captured exclusively inside forest fragments. Moreover, we provide information on the resources used within the urban matrix by summarizing the roosting sites for 38 bat species, as well as 31 plants consumed by at least twelve bat species. Regarding parasitological aspects, we listed eleven zoonotic parasites hosted by 27 bat species and discussed their potential to become a public health threat. Likewise, we considered the different features linked to urbanization, including impacts on immunity, body condition and susceptibility to acquiring parasites, as possible bat conservation issues. Finally, we defined an agenda for bat studies in urban areas of Brazil. 相似文献
19.
CAP LTER focuses on an arid-land ecosystem profoundly influenced, even defined, by the presence and activities of humans and is one of only two LTER sites that specifically studies the ecology of an urban system. In this large-scale project, biological, physical, and social scientists are working together to study the structure and function of the urban ecosystem, to assess the effects of urban development on surrounding agricultural and desert lands, and to study the relationship and feedbacks between human decisions and ecological processes.Our interdisciplinary investigations into the relationship between land-use decisions and ecological consequences in the rapidly growing urban environment of Phoenix are of broad relevance for the study of social ecological systems and cites in particular. Refinements in our conceptual model of social ecological systems focuses our attention on recognizing the scales and periodicities of ecological and human phenomena, understanding the means and impacts of human control of variability in space and time, and finally an evaluation of the resilience of various aspects of socio-ecological systems especially their vulnerabilities and their potential for adaptive learning. 相似文献
20.
Waterbird species were used to assess the consequences of developed habitat on wildlife behaviour in an urban riparian system
along the Rideau River in Ottawa, Canada. Fourteen developed sites and 14 undeveloped sites were surveyed from October 2004
to February 2005. Each site was approached on foot and the first observed behaviour (i.e., fleeing, foraging, resting or swimming)
of each individual was recorded. A total of 10,604 behavioural observations were made across 12 taxa. Overall, the fleeing
behaviour was observed more often at undeveloped sites. Foraging, resting and swimming behaviours were observed more often
at developed sites. We found that seven species fled more often at undeveloped sites, including hooded merganser. This species
was also more abundant at undeveloped sites, suggesting that hooded merganser may be more sensitive to anthropogenic disturbance
in urban environments than other species that are habituated toward humans. For sensitive species, undeveloped shoreline may
serve as a refuge from human disturbance in urban ecosystems. 相似文献