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Filters: Tags: {"type":"Wildlife and Plants","name":"other wildlife"} (X) > Categories: Publication (X) > partyWithName: Robert R. Dunn (X)

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Species loss can result in the subsequent loss of affiliate species. Though largely ignored to date, these coextinctions can pose threats to human health by altering the composition, quantity and distribution of zoonotic parasites. We simulated host extinctions from more than 1300 host–parasite associations for 29 North American carnivores to investigate changes in parasite composition and species richness. We also explored the geography of zoonotic parasite richness under three carnivore composition scenarios and examined corresponding levels of human exposure. We found that changes in parasite assemblages differed among parasite groups. Because viruses tend to be generalists, the proportion of parasites that are...
Abstract (from http://link.springer.com/article/10.1007%2Fs11252-014-0406-8): Urbanization is thought to lead to the loss of biodiversity both because of habitat disturbance and the increased abundance of invasive species. However, most studies of biodiversity in cities are conducted on a short time scale, usually less than 3 years, and so miss the long-term dynamics of communities inhabiting these ecosystems. Here we use a study performed in the early 70’s on North Carolina State University (Raleigh, USA) as a baseline to evaluate the long term effects of disturbance and introduced species on native ant communities. Ant species were sampled almost 40 years later using a variety of sampling techniques in order to...
Urbanization represents an unintentional global experiment that can provide insights into how species will respond and interact under future global change scenarios. Cities produce many conditions that are predicted to occur widely in the future, such as warmer temperatures, higher carbon dioxide (CO2) concentrations and exacerbated droughts. In using cities as surrogates for global change, it is challenging to disentangle climate variables—such as temperature—from co-occurring or confounding urban variables—such as impervious surface—and then to understand the interactive effects of multiple climate variables on both individual species and species interactions. However, such interactions are also difficult to replicate...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1111/gcb.12791/abstract): Urban green spaces provide ecosystem services to city residents, but their management is hindered by a poor understanding of their ecology. We examined a novel ecosystem service relevant to urban public health and esthetics: the consumption of littered food waste by arthropods. Theory and data from natural systems suggest that the magnitude and resilience of this service should increase with biological diversity. We measured food removal by presenting known quantities of cookies, potato chips, and hot dogs in street medians (24 sites) and parks (21 sites) in New York City, USA. At the same sites, we assessed ground-arthropod diversity...
Because microorganisms are sensitive to temperature, ongoing global warming is predicted to influence microbial community structure and function. We used large-scale warming experiments established at two sites near the northern and southern boundaries of US eastern deciduous forests to explore how microbial communities and their function respond to warming at sites with differing climatic regimes. Soil microbial community structure and function responded to warming at the southern but not the northern site. However, changes in microbial community structure and function at the southern site did not result in changes in cellulose decomposition rates. While most global change models rest on the assumption that taxa...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1111/pce.12790/full): Future climate change is expected to increase temperature (T) and atmospheric vapour pressure deficit (VPD) in many regions, but the effect of persistent warming on plant stomatal behaviour is highly uncertain. We investigated the effect of experimental warming of 1.9–5.1 °C and increased VPD of 0.5–1.3 kPa on transpiration and stomatal conductance (gs) of tree seedlings in the temperate forest understory (Duke Forest, North Carolina, USA). We observed peaked responses of transpiration to VPD in all seedlings, and the optimum VPD for transpiration (Dopt) shifted proportionally with increasing chamber VPD. Warming increased mean water use...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1111/gcb.12919/abstract;jsessionid=64EF530762E939D509B9B308CD377394.f03t04): Anthropogenic climate change has altered temperate forest phenology, but how these trends will play out in the future is controversial. We measured the effect of experimental warming of 0.6–5.0 °C on the phenology of a diverse suite of 11 plant species in the deciduous forest understory (Duke Forest, North Carolina, USA) in a relatively warm year (2011) and a colder year (2013). Our primary goal was to dissect how temperature affects timing of spring budburst, flowering, and autumn leaf coloring for functional groups with different growth habits, phenological niches, and xylem anatomy....
Abstract (from http://onlinelibrary.wiley.com/doi/10.1111/gcb.13550/abstract): Biological effects of climate change are expected to vary geographically, with a strong signature of latitude. For ectothermic animals, there is systematic latitudinal variation in the relationship between climate and thermal performance curves, which describe the relationship between temperature and an organism's fitness. Here, we ask whether these documented latitudinal patterns can be generalized to predict arthropod responses to warming across mid- and high temperate latitudes, for taxa whose thermal physiology has not been measured. To address this question, we used a novel natural experiment consisting of a series of urban warming...
Abstract (from http://rsbl.royalsocietypublishing.org/content/10/11/20140586?rss=1): Climate warming is predicted to cause many changes in ectotherm communities, one of which is phenological mismatch, wherein one species' development advances relative to an associated species or community. Phenological mismatches already lead to loss of pollination services, and we predict that they also cause loss of biological control. Here, we provide evidence that a pest develops earlier due to urban warming but that phenology of its parasitoid community does not similarly advance. This mismatch is associated with greater egg production that likely leads to more pests on trees. This publication was developed as part of the...
Abstract (from http://rspb.royalsocietypublishing.org/content/283/1840/20161574): A substantial amount of global carbon is stored in mature trees. However, no experiments to date test how warming affects mature tree carbon storage. Using a unique, citywide, factorial experiment, we investigated how warming and insect herbivory affected physiological function and carbon sequestration (carbon stored per year) of mature trees. Urban warming increased herbivorous arthropod abundance on trees, but these herbivores had negligible effects on tree carbon sequestration. Instead, urban warming was associated with an estimated 12% loss of carbon sequestration, in part because photosynthesis was reduced at hotter sites. Ecosystem...
Abstract (from http://trace.tennessee.edu/utk_gradthes/2396/): Many effects of a changing climate for organisms, communities, and ecosystems are already apparent. Less studied are the effects of increases in temperature on species interactions. While warming may potentially disrupt interactions among species, species interactions may also mediate individual species responses to ongoing climatic change. In this experiment we manipulated temperature in field-based, open-top chambers for three years to examine the relationship between biotic interactions and climatic warming on the population dynamics of seedlings of Quercus alba. We investigated the effect of warming on rates of insect herbivory on Q. alba seedlings....
Effects of climate warming on wild populations of organisms are expected to be greatest at higher latitudes, paralleling greater anticipated increases in temperature in these regions. Yet, these expectations assume that populations in different regions are equally susceptible to the effects of warming. This is unlikely to be the case. Here, we develop a series of predictive models for physiological thermal tolerances in ants based on current and future climates. We found that tropical ants have lower warming tolerances, a metric of susceptibility to climate warming, than temperate ants despite greater increases in temperature at higher latitudes. Using climatic, ecological and phylogenetic data, we refine our predictions...
Abstract (from http://rspb.royalsocietypublishing.org/content/282/1806/20142608): The amount of energy consumed within an average city block is an order of magnitude higher than that consumed in any other ecosystem over a similar area. This is driven by human food inputs, but the consequence of these resources for urban animal populations is poorly understood. We investigated the role of human foods in ant diets across an urbanization gradient in Manhattan using carbon and nitrogen stable isotopes. We found that some—but not all—ant species living in Manhattan's most urbanized habitats had δ13C signatures associated with processed human foods. In particular, pavement ants ( Tetramorium sp. E) had increased levels...