Search

A “green roof” is a roof on a structure created by humans, which has a plant community (and various hangers-on) established on it. There are many potential benefits of green roofs, ranging from moderation of local microclimates to modulations of storm runoffs, and green roofs may serve the enhancement of biodiversity conservation, as well. Green roofs would seem to be quintessential examples of a “novel ecosystem”. Here, I first outline some dimensions of the novelty that warrant more research. Green roofs can provide many opportunities for creative ecological research in the assembly, dynamics and functioning of novel ecosystems. Then, I briefly discuss some potential biodiversity hazards that are created along with green roofs. Recognizing these potential “shadows” of a green roof by no means belies the strong and compelling rationale for promoting green roofs, in terms of sustainability and livability of human structures; instead the points I raise are simply issues which should be evaluated and quantified when promoting green roofs broadly as a design strategy in new buildings or retrofitted existing structures. [ABSTRACT FROM AUTHOR]

Science is an organized enterprise of inquiry which tries to tie together multiple strands of evidence to craft coherent explanations for disparate patterns in the natural world. Philosophers call this enterprise “inference towards the best explanation”. Such inferences at times depend upon detailed quantitative models, but at times one can rely upon the confluence of multiple strands of qualitative evidence. Humans are having unquestionable influences upon many aspects of the earth system at present, on land, in freshwater systems, and indeed the ocean, including devastating impacts on biodiversity. There are many patterns in the world at present – shrinking glaciers, shifting seasonal patterns in species’ life histories, and altered spatial distributions – which point to the signal of climate change, independent of the details of quantitative climate models. Yet, there are many other factors at play, often confounding clear assessment of the specific role of climate change in observed changes in the world. A deeper synoptic understanding of the drivers and impacts of climate change would be incredibly valuable and is urgently needed, even if in the end (though this seems increasingly unlikely) anthropogenic drivers were not the main factor underlying observed climate change. [ABSTRACT FROM PUBLISHER]

Resource theory and metabolic scaling theory suggest that the dynamics of a pathogen within a host should strongly depend upon the rate of host cell metabolism. Once an infection occurs, key ecological interactions occur on or within the host organism that determine whether the pathogen dies out, persists as a chronic infection, or grows to densities that lead to host death. We hypothesize that, in general, conditions favoring rapid host growth rates should amplify the replication and proliferation of both fungal and viral pathogens. If a host population experiences an increase in mortality, to persist it must have a higher growth rate, per host, often reflecting greater resource availability per capita. We hypothesize that this could indirectly foster the pathogen, which also benefits from increased within-host resource turnover. We first bring together in a short review a number of key prior studies which illustrate resource effects on viral and fungal pathogen dynamics. We then report new results from a semi-continuous cell culture experiment with SHIV, demonstrating that higher mortality rates indeed can promote viral proliferation. We develop a simple model that illustrates dynamical consequences of these resource effects, including interesting effects such as alternative stable states and oscillatory dynamics. Our paper contributes to a growing body of literature at the interface of ecology and infectious disease epidemiology, emphasizing that host abundances alone do not drive community dynamics: the physiological state and resource content of infected hosts also strongly influence host–pathogen interactions. [ABSTRACT FROM PUBLISHER]

Saturating functional responses are a unifying principle in ecology, influencing processes at organizational levels from dietary specialization in individuals, to population instability, to community-level indirect interactions among alternative prey. These effects are interrelated. We explore a predator–prey model and demonstrate that unstable dynamics promote coexistence of specialist and generalist predators, when the specialist attacks only high-quality prey, and the generalist attacks high- and low-quality prey (that alone cannot maintain the predator). Coexisting specialist and generalist predators are vulnerable to invasion and replacement by predators with fixed partial preferences. The evolutionarily stable partial preference increases with increasing dynamic instability, but typically declines with increasing abundance of the low-quality prey. Coexisting specialist and generalist consumers, or partial preferences, typically reduce the potential for poor-quality prey to indirectly benefit high-quality prey. We suggest that dynamic instability may also contribute to the evolutionary maintenance of seemingly maladaptive oviposition choices by insect parasitoids. [ABSTRACT FROM PUBLISHER]

An introduction is presented in which the editor discusses several articles within the issue on topics including ethical issues in science, experimental methodology and social organization of science.

Infectious disease influences the dynamics of host populations and the structure of species communities via impacts on host demography. Species that share infectious diseases are well-known to interact indirectly through the process of apparent competition, but there has been little attention given to the role of vectors in these indirect interactions. Here we explore how vector-borne disease and host-vector interactions can drive apparent competitive interactions. We show that different facets of the ecology associated with vector-host-host interactions affect the structure of the three-species assemblage. Crucially, the patterns associated with invasion of alternative hosts, the spread of the infectious disease by the vector, and the dynamics of the community interactions are influenced by the mode of transmission. We highlight the role of alternative hosts on disease amplification, dilution and magnification and discuss the results with reference to recent developments in apparent competition and community structure. [ABSTRACT FROM AUTHOR]

The article focuses on the possibility of a parasite- and vector-free world, based on the concept of counterfactual history. The author notes that this vision should be realized as many species in natural communities are threatened by parasites and infectious diseases. The argument citing the use of these parasites and vectors in vaccination program is discussed by the author. Other benefits of parasites and vectors to humanity are mentioned.

The integration of community ecology into the understanding and management of vectors and vector-borne diseases has largely occurred only recently. This compendium examines a variety of community interactions that can affect vector or vector-borne disease dynamics. They include: the importance of risk of predation, risk of ectoparasatism, competition, interactions of competition with transgenic control, apparent competition mediated through vectors, indirect effects of pesticides, vector diversity, and parasite diversity within a vector. In this paper, we summarize these studies and introduce several additional important questions in need of further exploration. [ABSTRACT FROM AUTHOR]

The author reflects on the transformation of community ecology in the context of the coexistence of species in communities. It provides an overview of the observations made by Russian nobleman Prince Petr Kropotkin in the 19th century regarding the role of cooperation in evolution. It discusses the role of competition and food web interactions in community ecology. Information is presented on resource competition between species, according to Robert MacArthur.