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Current unprecedented declines in biodiversity reduce the ability of ecological communities to provide many fundamental ecosystem services. Here we evaluate evidence that reduced biodiversity affects the transmission of infectious diseases of humans, other animals and plants. In principle, loss of biodiversity could either increase or decrease disease transmission. However, mounting evidence indicates that biodiversity loss frequently increases disease transmission. In contrast, areas of naturally high biodiversity may serve as a source pool for new pathogens. Overall, despite many remaining questions, current evidence indicates that preserving intact ecosystems and their endemic biodiversity should generally reduce the prevalence of infectious diseases., In June 2010, a new organization, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)--patterned after the Intergovernmental Panel on Climate Change (IPCC)--was established to assess changes to the [...]

Biodiversity is good for you Changes in biodiversity have the potential to either increase or reduce the incidence of infectious disease in plants and animals -- including humans -- because they involve interactions among species. At a minimum, this requires a host and a pathogen; often many more species are involved, including additional hosts, vectors and other organisms with which these species interact. Felicia Keesing and colleagues review the evidence that reduced biodiversity affects the transmission of infectious diseases of humans, other animals and plants. Despite important questions still to be answered, they conclude that the evidence that biodiversity exerts a protective effect on infectious diseases is sufficiently strong to include biodiversity protection as a strategy to improve health. Current unprecedented declines in biodiversity reduce the ability of ecological communities to provide many fundamental ecosystem services. Here we evaluate evidence that reduced biodiversity affects the transmission of infectious diseases of humans, other animals and plants. In principle, loss of biodiversity could either increase or decrease disease transmission. However, mounting evidence indicates that biodiversity loss frequently increases disease transmission. In contrast, areas of naturally high biodiversity may serve as a source pool for new pathogens. Overall, despite many remaining questions, current evidence indicates that preserving intact ecosystems and their endemic biodiversity should generally reduce the prevalence of infectious diseases., Author(s): Felicia Keesing [sup.1] , Lisa K. Belden [sup.2] , Peter Daszak [sup.3] , Andrew Dobson [sup.4] , C. Drew Harvell [sup.5] , Robert D. Holt [sup.6] , Peter Hudson [...]

Parasites can have strong impacts but are thought to contribute little biomass to ecosystems'. We quantified the biomass of free-living and parasitic species in three estuaries on the Pacific coast [...]

Parasites count too Parasites -- and other infectious agents -- can have a major impact on an ecosystem, by targeting a prominent prey or predator species. But a study of the biomass of free-living and parasitic species in three estuaries on the Pacific coast of California and Baja California suggests that parasite ecology should be given more weighty consideration in food-web analysis and ecosystem modelling in future. The surprise finding was that parasites have substantial biomass in these ecosystems, even exceeding that of top predators. For instance the biomass of trematodes -- parasitic flukes -- was particularly high, comparable to that of birds, fish, burrowing shrimps and polychaetes. Parasites can have strong impacts but are thought to contribute little biomass to ecosystems.sup.1,2,3. We quantified the biomass of free-living and parasitic species in three estuaries on the Pacific coast of California and Baja California. Here we show that parasites have substantial biomass in these ecosystems. We found that parasite biomass exceeded that of top predators. The biomass of trematodes was particularly high, being comparable to that of the abundant birds, fishes, burrowing shrimps and polychaetes. Trophically transmitted parasites and parasitic castrators subsumed more biomass than did other parasitic functional groups. The extended phenotype biomass controlled by parasitic castrators sometimes exceeded that of their uninfected hosts. The annual production of free-swimming trematode transmission stages was greater than the combined biomass of all quantified parasites and was also greater than bird biomass. This biomass and productivity of parasites implies a profound role for infectious processes in these estuaries., Author(s): Armand M. Kuris [sup.1] , Ryan F. Hechinger [sup.1] , Jenny C. Shaw [sup.1] , Kathleen L. Whitney [sup.1] , Leopoldina Aguirre-Macedo [sup.2] , Charlie A. Boch [sup.1] , [...]

The provisioning of sustaining goods and services that we obtain from natural ecosystems is a strong economic justification for the conservation of biological diversity. Understanding the relationship between these goods and services and changes in the size, arrangement, and quality of natural habitats is a fundamental challenge of natural resource management. In this paper, we describe a new approach to assessing the implications of habitat loss for loss of ecosystem services by examining how the provision of different ecosystem services is dominated by species from different trophic levels. We then develop a mathematical model that illustrates how declines in habitat quality and quantity lead to sequential losses of trophic diversity. The model suggests that declines in the provisioning of services will initially be slow but will then accelerate as species from higher trophic levels are lost at faster rates. Comparison of these patterns with empirical examples of ecosystem collapse (and assembly) suggest similar patterns occur in natural systems impacted by anthropogenic change. In general, ecosystem goods and services provided by species in the upper trophic levels will be lost before those provided by species lower in the food chain. The decrease in terrestrial food chain length predicted by the model parallels that observed in the oceans following overexploitation. The large area requirements of higher trophic levels make them as susceptible to extinction as they are in marine systems where they are systematically exploited. Whereas the traditional species-area curve suggests that 50% of species are driven extinct by an order-of-magnitude decline in habitat abundance, this magnitude of loss may represent the loss of an entire trophic level and all the ecosystem services performed by the species on this trophic level. Key words: biodiversity; conservation; ecosystem function; ecosystem services; food web; Little Rock Lake; species--area; species loss; trophic collapse.

An explanation of the terms polity and membership and their relationship to politics with reference to ecological citizenship is presented. Citizenship is of importance in the environmental debate as an intellectual challenge and as an answer to the question of how a society can be maintained.

An analytical and typological approach to environmental sustainability overcomes the limitations of the definitional and discursive methodologies in sustainability policies. The strategy focuses on the interlink between environmental sustainability, sustainable development and social justice and proposes diverse conceptions and packages of sustainability based on human welfare. Although social justice is central to discourses on sustainability policies, the potential appropriate regime of social justice varies in conceptions of environmental sustainability and sustainable development.

The role that pathogens play in structuring ecological communities needs to be examined from both a theoretical and empirical perspective. This paper provides a brief introduction to the ecology and epidemiology of brucellosis in Yellowstone National Park. Observed patterns of infection for brucellosis in bison in national parks in the United States suggest that Brucella has a relatively sharply defined threshold for establishment and that the proportion of the host population infected increases as a relatively simple function of population density. Unfortunately, the threshold population for Brucella establishment in bison is low, a herd of at least 200 individuals; this makes it very hard to eradicate Brucella from wild populations. Simple calculations based on observed prevalence and recruitment data for the Yellowstone bison herd suggest that unacceptably high levels of culling would be required to eradicate brucellosis in the park. A simple mathematical model is used to describe aspects of the population dynamics of Brucella. The analyses suggest that an understanding of infectious disease dynamics is crucial to the management and conservation of wild and domestic ungulate species in and around national parks and other nature reserves. The consequences of disease control for the maintenance of biodiversity in other natural and captive communities need to be better understood. Key words: bison; Brucella; cattle; disease ecology; elk; epidemiology; pathogen; population dynamics; Yellowstone., INTRODUCTION Ecologists are beginning to show interest in models for pathogens that infect more than one host species. This work develops from the earlier studies of Holt and Pickering (Holt [...]

Author(s): Mark E. Torchin (corresponding author) [1]; Kevin D. Lafferty [2]; Andrew P. Dobson [3]; Valerie J. McKenzie [1]; Armand M. Kuris [1] Damage caused by introduced species results from [...]

Plans for building a two-lane road through 50 kilometres of the Serengeti National Park in Tanzania must be halted. The road will cause an environmental disaster by curtailing the migration [...]

Author(s): Jon Paul Rodríguez [1, 2]; Gillian Ashenfelter [1]; Franklin Rojas-Suárez [3]; Juan Javier García Fernández [4]; Luis Suárez [5]; Andrew P. Dobson [1] Sir Red Data Books and Red [...]