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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 explores professions in the fields of ecology and evolution. He explains why the pursuit of ecology and evolution can be profitable professions. He describes the concept of education. He emphasizes the importance of an education in ecology and evolution. He believes an understanding of ecology and evolution is important to being an effective citizen.

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.

The article discusses the role of seasonality in habitat selection. According to biologist Steve Fretwell, most populations live in a seasonal environment. He theorizes that the exact temporal pattern of variation in demographic parameters affects the extent at which seasonal cycles affect a population size. Experimental and theoretical studies on the role of seasonality in population dynamics are cited. Also explained are the implications of seasonality to evolutionary process and population mobility.

Niche conservatism is the phenomenon in which species or other phylogenetic lineages seem to exhibit much the same ecological niche over their geographical ranges or over evolutionary time scales. Previous studies have suggested that optimal habitat selection call constrain niche evolution (and thus may help explain niche conservatism), in effect by preventing populations from experiencing unfavorable sink environments with conditions outside the niche. This paper relaxes a key assumption in prior literature, by allowing habitat selection decisions to be conditional upon an individual's phenotype. We use individual-based simulations of evolution in source-sink landscapes to examine the consequences of phenotype-matching habitat selection. If each individual obeys a "perfect'" habitat selection rule moving to another habitat only if that movement increases the match between its phenotype and the habitat's optimum--then habitat selection can speed up the rate of adaptation to sink environments, and thus facilitate niche evolution. We also note that habitat selection can also indirectly influence the pool of variation available for selection, and thereby potentially alter to some degree this conclusion. [ABSTRACT FROM AUTHOR]

The author talks about the uses and abuses of comparative demography. The author argues about the context of how spatial variation in predation pressure maps onto spatial variation in realized mortality rates. The author suggests that whether or not the expected relationship between predation pressure and mortality rate holds will depend on the nature of density dependence in the prey population. The author states that examining temporal trends in demography is a valuable and essential tool when monitoring populations trending towards extinction.

The article discusses various reports published within the issue, including one by Cheryl B. Schultz and Elizabeth E. Crone on a survey of academics and practitioners concerned with butterfly ecology and another by Guy Pe'er and Josef Settele about the challenge of integrating ecological processes across spatial scales.

The article reflects on how scientists can use behavioral indicators to monitor the behaviors of individuals of other species to make inferences about the habitat quality they experience. The author shares his personal experience of how he became aware of the behavioral dimension of ecology when he was a graduate student at Harvard University in the 1970s. It discusses the factors that influence predator-prey interactions like heterospecific cuing and the food web. Also noted the direct impacts caused by humans on the information environment which, according to the author, are bound to disrupt preexisting webs of information that organisms historically depended upon in a variety of ways.

The article emphasizes the need to maintain a sense of historical continuity and context in the ecological sciences despite the explosion of knowledge. It describes the difficulties of keeping up with the latest ideas and findings for certain disciplines. It explains why the metacommunity perspective is essential in various theoretical approaches in ecology. It discusses the metapopulation concept developed by Richard Levins.

I am honored that the editors of the Israel Journal of Ecology and Evolution have invited me to write a series of essays with a style that differs from the standard cut-and-dried journal article. my broad aim in these essays will be to reflect on puzzles that strike me as providing likely directions for profitable inquiry in the areas of ecology and evolution, and often their interface, as well as on more general issues concerning the rhythm and direction of our science. Israeli scientists have long been at the forefront of fundamental advances in these disciplines, and it is a privilege to have this opportunity. Some of these essays will spring from my own work, and others will be reflections on issues and themes far from my own specialized interests. [ABSTRACT FROM AUTHOR]