George and his memoir, In the Shadow of the Palace were on display, and brief insights on the latter were explained. The students did not miss the opportunity to question Mitchell on the design and construction of the Guyana National Cultural Centre , and the hurdles he had to overcome in completing this iconic Performing Arts Theatre, the largest of its kind in the English speaking Caribbean. Opportunity was taken by Head of the Department — Mr. William Harris, requesting Mitchell to join him in the preparation of a compendium of Architectural Construction Details for students and practioners in the Tropics with special reference to the English speaking Caribbean.
Echoes of sovereignty and National Identity. These categories included disease transmission, genetics, source-sink dynamics, demographic changes, ecological traps, novel predator—prey dynamics, phenology and diversity. Two of the papers fell into multiple categories. The number of studies published per year has increased over time, with only 2 years and yielding no literature on this topic Fig. This increase in studies published over time reflects a broader trend in the increase of publication on urban biodiversity more broadly Magle et al.
Map of study locations based on city or urban area of focus and country from relevant papers in Table 1. Graph depicting the number of relevant studies published in relation to recent years of publication.
- Sustainability of Indian Microfinance Institutions: A Mixed Methods Approach (India Studies in Business and Economics).
- Une vie en échange (BEST-SELLERS) (French Edition)?
- Dynamics of Urban St. George by Norris Mitchell, Paperback | Barnes & Noble®;
Relevant papers are listed in Table 1. Based on taxonomic data found in Web of Science ISI Web of Knowledge, relevant research papers related to the topic of urban spillover covered only 7 8. The 3 groups best represented were Aves birds with 16 papers, Plants Spermatophyta, including Angiospermae and Gymnospermae with 5 papers, and Mammalia mammals with 11 papers Fig. Papers involving studies of viruses, protozoa and birds were over-represented in our group of 29 papers related to urban spillover, when compared with the conservation literature more broadly, with birds being the most over-represented group.
In contrast, plants, invertebrates, reptiles and mammals were under-represented, with plants being the most under-represented group. When we examined the locations where studies related to urban spillover had been conducted, we found that the majority of studies took place in the Northern Hemisphere, with clusters of field sites occurring in northwestern France and northern Finland in Europe. Half 15 of the field sites included locations in North America; the next best represented continents included Europe, with six field locations and South America, with four Fig. Black bars indicate the number of times each of the seven taxonomic groups is included within the 29 papers selected for this review.
Faculty | Geography, Environment & Society | College of Liberal Arts | University of Minnesota
Some of the papers include more than one taxonomic group. The percentage values given at the top of each bar indicate what percentage of the total inclusions is attributable to the corresponding taxonomic group. The gray circles indicate the percentage by which each taxonomic group is under or over-represented within the 29 papers selected for this review, compared with the conservation literature more broadly. None of the 29 papers selected for this review included studies conducted in Asia.
One paper included studies from both Europe and North America. Another study was global in extent. The largest store of papers elucidating urban to wildland spillover effects was found in the disease transmission literature, with seven papers identifying actual or potential urban to wildland pathways for pathogen transmission Table 1. Ecological spillover in this context imagines inter- or intra-specific pathogen flow and potential consequent impacts from urban populations to wildland populations. We found five papers that provide evidence of genetic exchange between urban and wildland populations.
A study by Roy, Butler and Haynie suggests that restored or conserved, yet fragmented, habitat patches within an agricultural or urban context provide sufficient resources to sustain genetically viable populations of the Brownsville common yellowthroat Geothlypis trichas insperata in the Lower Rio Grande Valley of Texas, USA, as fledging individuals maintain little natal site fidelity. Johnson and Galloway found that the pollen of Lobelea cardinalis was able to travel up to 1 km, suggesting that fertilization of wild plants adjacent to horticultural plantings in urban areas is possible.
Finally, Bjorklund, Ruiz and Senar found that parklands within central Barcelona host great tit Parus major populations with a higher degree of genetic diversity than those in adjacent natural habitats, and that gene flow was greater in the urban to wildland direction, but the authors provided no analysis of effects on wildland populations.
We found five studies that examined source-sink dynamics as related to urban spillover. Roe, Rees and Georges found that urban water sources act as drought refugia for the eastern long-necked turtle Chelodina longicallis in Australia, though accessing these desirable urban sites requires individuals from wildland populations to traverse a dangerous urbanized matrix, leading to high mortality and therefore a negative spillover effect on wildland populations.
Kauffman, Pollock and Walton found that coastal populations of peregrine falcons Falco peregrinus anatum in southern California preferentially disperse to urban areas, which may act as a pseudo-sink given that the urban areas are used as sources for relocation efforts. Padilla and Rodewald found evidence that urban areas may be acting as sinks for avian species in riparian forests of central Ohio, but that the number and quality of habitat patches within the urban matrix influences longer-term trends in urban populations.
In the Swiss canto of Aargau, Altermatt concluded that urban sites likely serve as sinks for butterflies within the overall habitat matrix, drawing immigrants from adjacent, higher-quality habitats. Our search identified three papers that touch on demographic changes in urban populations relative to wildland populations. All three studies found that urban populations of species have higher survival rates, particularly during the winter or inactive season, than do conspecific populations outside of urban areas.
Two of the papers Lehrer, Schooley and Whittington ; Chiappero et al. Chiappero et al. Specifically, the non-urban populations have greater annual demographic fluctuation in the form of higher turnover than that of their urban counterparts. Most wild individuals die each year and are replaced the subsequent season by mixing of a small pool of overwintering adults, whereas in urban settings, perhaps owing to the heat island effect of cities, rodent populations have greater winter survival.
Although there may be sufficient demographic plasticity in this species to preclude urban to wildland spillover, under our framework, reduced winter cull selection in urban settings could produce genotypes that are maladaptive to wild habitats. Lehrer, Schooley and Whittington found that there were no differences in survivorship between urban and non-urban populations of woodchucks Marmota monax during the active season, but survival rates were higher for woodchucks in urban environments during the inactive season.
Since a significant amount of mortality in rural woodchucks comes in the inactive season where hibernating woodchucks have insufficient fat stores to survive the winter cold, the subsidy effect of urban areas either via heat island effect during winter or additional foraging opportunities during the active season could also result in maladaptive traits to spill over into wild populations.
Cause-specific mortality during the active season differed as well. Natural predators dominated cause of death in rural settings, whereas in urban settings vehicles constituted the largest cause of death for woodchucks. This points to different selection pressures at work on the two populations, and could result also result in spillover of maladaptive traits. Both of the previous examples only suggest a potential for ecological spillover. However, Kauffman, Frick and Linthicum conclude that observed overall increases in the peregrine falcon population of rural habitats is not supported by the intrinsic growth rate of birds in this habitat, and is instead a result of immigration from urban dispersers.
We found three papers that address urban to wildland spillover effects within the context of ecological traps Leston and Rodewald ; Mannan, Steidl and Boal ; Dybala et al. Ecological traps describe habitats within a heterogeneous habitat matrix that have lower fitness for focal species despite having similar per capita resources when compared with similar habitats Robertson and Hutto They are habitats where reproduction and survival are insufficient to support a population despite provision of sufficient resources to attract immigration from regional population sources, and which are chosen over other high-quality habitats that would support sustainable populations Battin Each of the papers we found examined the potential for urban areas to function as traps for the larger surrounding wildland matrix.
Two of the studies directly tested ecological trap dynamics Leston and Rodewald ; Mannan et al. We also found three papers focused on novel predator—prey dynamics Rodewald et al. Urbanized environments significantly alter trophic interactions in many ways, including winnowing species pools to generalist organisms capable of surviving in highly modified habitats subject to high disturbance, resource subsidies, modified foraging dynamics, dispersal and other changes Chace and Walsh ; McKinney The three papers, all focused on birds whose dispersal capabilities allow for potential movement between urban and wildland environments, explored whether changes in trophic interactions spill over into adjacent wildland areas.
Our search revealed three papers that indirectly address phenological changes related to animals butterflies and birds and the potential for these changes to spill over into nominally unaltered wildland settings. Altermatt describes the potential for spillover when urban-induced phenological shifts are maladaptive to wildland settings, or when phenologically isolated populations develop.
Chamberlain et al. Species diversity in urban settings, i.
This is due to the influx of non-native global generalists via accidental or intentional introductions which replace native specialists unable to tolerate modified human ecology in the developed setting. Spillover effects may occur where urban taxa are functionally or phylogenetically related to taxa in surrounding wildlands, impacting native ecology. The two papers we found only inferred that potential spillover effects exist; none made direct tests of these effects.
Climate Smart Cities: Grenada
There are shortcomings in the literature when considering the effects of urban species populations on wildland species populations. Many articles we found seemed to be good candidates to discuss spillover dynamics in urban systems. We also discovered that for this topic, coverage of both taxonomic groups and geographic locations is limited. The taxonomic bias seen within the general conservation literature Clark and May ; Shwartz et al.
Similarly, we found that the geographic bias present in the general conservation literature Lawler et al. Each node can represent a discrete opportunity to engage with the relevant research on the subject as well as to consider site-specific details pertinent to spillover potential in a particular case study. Considered separately, individual nodes of the spillover framework may not necessarily indicate realized spillover, since it is mainly the connection and interaction between nodes that leads to realized spillover effects.
Proposed framework outlining ecological spillover pathway. Nodes in brown are in urban areas whereas nodes in green are in wildland areas. Node 3 is the interface between urban and wildland population interactions. The framework nodes are arranged to allow an analysis to move from an urban landscape toward an adjacent or surrounding wildland landscape. This unidirectionality is an assumed premise, developed with the understanding that all nodes are interconnected and that the spillover process may move in both directions simultaneously.
Net spillover may be positive, negative or neutral in terms of effect size, but this assessment is not meant to connote a subjective value of the spillover effect that transcends the context of the particular intervention under consideration. For example, if increased fecundity of native species X within a restored habitat patch in an urban setting results in increased emigration to surrounding wildlands, this may represent a positive effect on the wildland population of species X; an increase, in absolute terms.
This spillover framework aims to provide a tool for understanding what quantitative analysis of spillover is possible, where resources can be allocated to illuminate areas of uncertainty, and subsequent assessments of risk relevant to restoration and conservation planning. Recently, Plowright et al. This framework incorporates the rich research history in epidemiology and disease ecology into an interacting hierarchy of spillover pathways and bottlenecks to understand gaps in knowledge, determine the parameters of risk analysis, examine potential points of intervention and control, and develop mathematical models for zoonotic spillover, among other goals.
We share these goals in our framework for ecological spillover from urban to wildland ecosystems in terms of restoration or conservation activities across those habitat types. There are several parallels in this zoonotic spillover framework and the framework we propose for ecological spillover. This is especially true for the cases we present of pathogens moving between the urban matrix and wildlands. The detailed synthesis presented by Plowright et al. Thus, the framework as proposed by Plowright et al. Under our ecological spillover framework, then, a generic pathogen would pass through all nodes as identified in Figure 5 conforming to our conceptual framework , while also conforming to the more detailed framework proposed by Plowright et al.
To our knowledge, there is no analogous framework proposed for analyzing spillover in other ecological categories beyond pathogens, and our proposed ecological spillover framework aims to fill this gap. Conservationists and restoration practitioners may be concerned with spillover effects between populations of a particular threatened or endangered species intra-specific interactions , or between communities of multiple interacting species inter-specific interactions. Managers may also be interested in spillover effects on an ecosystem process or service, such as pollination.
Clear identification of the focal construct allows for assessment of what is known about that subject, and serves to concentrate efforts on understanding potential spatial and temporal interactions that may be relevant in terms of spillover. For example, analyzing potential intra-specific spillover would differ from inter-specific spillover effects i.
- Free News Delivery by Email;
- Cómo hablar de sexo con los adolescentes para que te escuchen (Spanish Edition);
- Lycra: How A Fiber Shaped America (Routledge Series for Creative Teaching and Learning in Anthropology).
- Dynamics of urban St. George |.
- St George News.
- A Gênese (Portuguese Edition);
We have identified several potential spillover factors, defined as potentially quantifiable modifications to both urban and wildland environments that are likely to alter existing ecological relationships. Additional project-specific factors may be more relevant to individual interventions. Spillover factors may include incidence of specific diseases, modifications to trophic dynamics, intra-specific competition, phenological changes, genetic changes at the population level, or other factors.
As in defining the focal construct, determining the scope of knowledge of the spillover factor and identification of gaps is key for this node in the spillover framework. For example, differences in phenology between urban and wildland populations may reduce interaction between these two populations, preventing the conveyance of a potential spillover factor. It is therefore important to determine the dispersal ability of a given spillover effect, the vectors available roads, air-travel with birds or insects, parasitism etc.
Once a spillover is conveyed to a recipient wildland environment, the subject wildland population must be susceptible to acquiring the spillover effect or may exhibit resistance or resilience to acquiring the change. Establishment allows for a gestation within the new wildland environment, wherein the spillover factor persists, and either immediately or following a lag, spreads in the new wildland population, beyond the initial area of acquisition. In the case of a regional restoration program goal of increasing the fitness of a wildland population of a given species, a quantifiable reduction in fitness of the wildland population as a result of spillover, would indicate a negative spillover effect.
If there is a quantifiable increase in the fitness of the wildland population as a result of spillover, then it can be said that the spillover effect is considered positive. Finally, if there is no quantifiable change in the fitness of the wildland population as a result of spillover, then it can be said that the spillover effect is neutral. This is different from saying that there was no spillover effect, because the spillover effect has been acquired, has established, and has spread. For example, if the spillover factor is a disease that only targets individuals that are past reproductive age, there may be no net effect on overall population fitness.
Our review of the literature found that eight different types of ecological relationships can be affected by urban to wildland spillover, including disease transmission, genetics, source-sink dynamics, demographic changes, ecological traps, novel predator—prey dynamics, phenology and diversity.
However, we found no examples of papers that give these relationships a full analysis under this spillover framework. In one instance, Blitzer et al. Oro et al. As carnivores can have large foraging and reproductive home ranges even in the case of a reliable subsidy , there is potential for genetic exchange between urban and wildland populations with unknown effects. We submit that the analysis of both urban and agricultural spillover can be approached with the spillover framework described earlier. As an example of how the spillover framework can be applied, Plowright et al.
The authors tested both urban and rural populations of flying foxes and showed that urban populations of flying fox had much higher rates of infection than their rural counterparts. Therefore, based on this simulation, while urban flying fox populations pose great risk of infection to horse and human populations in urban areas, reduced migration dampens the risk of this infection spilling over into wildland flying fox populations Node 6 and leading to outbreaks of the disease in other wildland species Nodes 7 and 8.
Although there may be a sizable literature on any one of these individual steps, as one moves through the spillover framework from urban to wildland populations, no studies explicitly link all framework nodes, though two studies allow for inference of spillover dynamics at work across all nodes Catterall et al. As a result, we found no articles that discuss urban to wildland spillover directly. This result is mirrored by that found by Blitzer et al. In that study, the authors reviewed evidence for spillover within five functional groups herbivores, pathogens, pollinators, predators and seed dispersers and found less than five studies per group that examined managed to natural spillover directionality.
In this study, Blitzer et al. With urbanization increasing globally, urban environments are becoming more important with regards to conservation strategies. Recently, there have been more studies focused on urban biodiversity conservation, but there are large gaps in our knowledge base on urban conservation research generally Shwartz et al. Therefore, importance should be placed on understanding how urban species populations can affect the broader regional population of a species through inter- and intra-specific interactions.
Recent urban research has focused on disease transmission, genetics, and source-sink dynamics; the categories of research that elicited the greatest number of results in our review. Going forward, research on demographic changes, ecological traps, predator—prey dynamics, phenology and ecosystem services with regard to spillover dynamics in urban systems should be conducted to augment understanding of spillover as proposed by our framework.
Our work found limited taxonomic and geographic coverage, and we recommend researchers diversify studies by including other taxonomic groups and geographic locations not well represented in the literature that may have particular ecological relevance for study sites in terms of spillover. Future research should also include examinations of regional and landscape scale factors. Spillover dynamics from urban to regional wildland populations are happening on a landscape or regional scale Shwartz et al. As such, new efforts should focus on impacts occurring at a larger scale.
Moving forward, our recommendations for policy-makers, planners, and land managers are multifaceted. First, one must consider inter- and intra-specific interactions between the urban population and the regional population. In many cases, the two populations do not exist in isolation and there is a permeable barrier in both directions for species to interact Fig. Our analysis clearly shows that interactions are occurring between these two urban and wildland populations. Whether the net spillover effect between these populations is positive, negative or neutral, the species interactions should be accounted for in management and policy decisions.
Second, there is little research on spillover dynamics, and those tasked with responsibilities in conservation or restoration management should build their own specific framework tailored to the species, urban system s of concern, surrounding wildland and project goals. The framework nodes can then serve as topical benchmarks to examine the existing literature for previously documented effects relevant to the conservation action.
Further, this initial literature review can illuminate gaps in existing research about the spillover system, and point to areas of study that will fill in unknown components and determine linkages within the framework. The proposed framework builds upon established research of urban systems and is helpful in identifying knowledge gaps and understanding the relevant processes and interactions within the urban and wildland setting.
Studies that compare urban systems to rural systems are a first step in the process of acquiring information that helps complete our proposed spillover framework while quantifying how urban and wildland populations of species are different reveals new knowledge useful for structuring a study to look at spillover dynamics between the two systems.