bluuebunny/crossref_metadata_2025 huggingface dataset:
Plant preferential allocation and fungal reward decline with soil phosphorus: implications for mycorrhizal mutualism
Authors: Ji Baoming , Bever James D.
Published: June 2016

Explaining the persistence of mutualism remains a challenge in ecology and evolutionary biology. The evolutionary stability of arbuscular mycorrhiza, a most widespread and ancient mutualistic association, is particularly intriguing because plants lack apparent mechanisms to prevent cheaters from gaining competitive advantages over cooperators. We developed a triple isotopic labeling method (14C, 32P, and 33P) within a split‐root design to measure the exchange of carbon (C) and phosphorus (P) between the host plant and two mycorrhizal partners across a soil P gradient. Host plant preferentially allocated more C to the roots associated with the fungus delivering higher P per unit plant C, and the strength of preferential allocation decreased with increasing soil P availability. The host plant received more P per unit of allocated C from the better fungus and this advantageous exchange rate did not depend upon P availability. As a result, the level of preferential allocation was correlated with the differential delivery of P from the two fungi. Our findings suggest that plant preferential allocation to better mutualists can stabilize mutualisms in environments limiting in the traded resource, but as the availability of this resource increases, plant preferential allocation declines. This environmental dependence of preferential allocation generates predictions of declining levels in relative abundance of mutualistic fungi in high‐resource environments.
Larval long‐toed salamanders incur nonconsumptive effects in the presence of nonnative trout
Authors: Kenison Erin K. , Litt Andrea R. , Pilliod David S. , McMahon Thomas E.
Published: June 2016

Predators can influence prey directly through consumption or indirectly through nonconsumptive effects (NCEs) by altering prey behavior, morphology, and life history. We investigated whether predator‐avoidance behaviors by larval long‐toed salamanders (Ambystoma macrodactylum) in lakes with nonnative trout result in NCEs on morphology and development. Field studies in lakes with and without trout were corroborated by experimental enclosures, where prey were exposed only to visual and chemical cues of predators. We found that salamanders in lakes with trout were consistently smaller than in lakes without trout: 38% lower weight, 24% shorter body length, and 29% shorter tail length. Similarly, salamanders in protective enclosures grew 2.9 times slower when exposed to visual and olfactory trout cues than when no trout cues were present. Salamanders in trout‐free lakes and enclosures were 22.7 times and 1.48 times, respectively, more likely to metamorphose during the summer season than those exposed to trout in lakes and/or their cues. Observed changes in larval growth rate and development likely resulted from a facultative response to predator‐avoidance behavior and demonstrate NCEs occurred even when predation risk was only perceived. Reduced body size and growth, as well as delayed metamorphosis, could have ecological consequences for salamander populations existing with fish if those effects carry‐over into lower recruitment, survival, and fecundity.
Nonsystemic fungal endophytes increase survival but reduce tolerance to simulated herbivory in subarcticFestuca rubra
Authors: Santangelo James S. , Kotanen Peter M.
Published: June 2016

Plant–microbial symbioses are widespread in nature and can shape the ecology and evolution of hosts and interacting symbionts. Fungal endophytes—fungi that live asymptomatically within plant tissues—are a pervasive group of symbionts well known for their role in mediating host‐responses to biotic and abiotic stresses. However, they also may become pathogenic and often impose metabolic costs on hosts. Here, we examine the role of fungal endophytes in mediating responses of the host grass red fescue (Festuca rubra) to salt and herbivore stress. We collected 38 red fescue genotypes from within its native range on Akimiski Island, Nunavut, Canada, where it occurs in the supratidal region on the northern part of the island and is heavily grazed by nesting and brood‐rearing snow geese (Chen caerulescens caerulescens) and Canada geese (Branta canadensis). We screened all plants for the presence of the systemic endophyteEpichloë festucaeand sequenced the nonsystemic endophytic community on a subset of these plants. While we did not detectE. festucae, our plants instead were host to a diverse array of nonsystemic fungal endophytes. We then conducted a fully factorial greenhouse experiment where we crossed plant genotype (4 levels) with simulated grazing (clipped or unclipped), endophyte status (present or absent) and salinity (0, 32 or 64 ppt) to examine the ecological role of this endophytic community. Overall, the presence of nonsystemic endophytes increased plant survival, but only in the absence of salt or clipping. On the other hand, these endophytes reduced plant tolerance to simulated herbivory by 69% but had no effect on aboveground plant growth. Thus, our results identify a potential nonsystemic endophyte‐mediated trade‐off in host plant survival and tolerance to herbivory and suggest this trade‐off may be altered by stressful abiotic conditions.
Tick‐, mosquito‐, and rodent‐borne parasite sampling designs for the National Ecological Observatory Network
Authors: Springer Yuri P. , Hoekman David , Johnson Pieter T. J. , Duffy Paul A. , Hufft Rebecca A. , Barnett David T. , Allan Brian F. , Amman Brian R. , Barker Christopher M. , Barrera Roberto , Beard Charles B. , Beati Lorenza , Begon Mike , Blackmore Mark S. , Bradshaw William E. , Brisson Dustin , Calisher Charles H. , Childs James E. , Diuk‐Wasser Maria A. , Douglass Richard J. , Eisen Rebecca J. , Foley Desmond H. , Foley Janet E. , Gaff Holly D. , Gardner Scott L. , Ginsberg Howard S. , Glass Gregory E. , Hamer Sarah A. , Hayden Mary H. , Hjelle Brian , Holzapfel Christina M. , Juliano Steven A. , Kramer Laura D. , Kuenzi Amy J. , LaDeau Shannon L. , Livdahl Todd P. , Mills James N. , Moore Chester G. , Morand Serge , Nasci Roger S. , Ogden Nicholas H. , Ostfeld Richard S. , Parmenter Robert R. , Piesman Joseph , Reisen William K. , Savage Harry M. , Sonenshine Daniel E. , Swei Andrea , Yabsley Michael J.
Published: June 2016

Parasites and pathogens are increasingly recognized as significant drivers of ecological and evolutionary change in natural ecosystems. Concurrently, transmission of infectious agents among human, livestock, and wildlife populations represents a growing threat to veterinary and human health. In light of these trends and the scarcity of long‐term time series data on infection rates among vectors and reservoirs, the National Ecological Observatory Network (NEON) will collect measurements and samples of a suite of tick‐, mosquito‐, and rodent‐borne parasites through a continental‐scale surveillance program. Here, we describe the sampling designs for these efforts, highlighting sampling priorities, field and analytical methods, and the data as well as archived samples to be made available to the research community. Insights generated by this sampling will advance current understanding of and ability to predict changes in infection and disease dynamics in novel, interdisciplinary, and collaborative ways.
Biocontrol insect impacts population growth of its target plant species but not an incidentally used nontarget
Authors: Catton Haley A. , Lalonde Robert G. , Buckley Yvonne M. , De Clerck‐Floate Rosemarie A.
Published: June 2016

Understanding the impact of herbivory on plant populations is a fundamental goal of ecology. Damage to individual plants can be visually striking and affect the fates of individuals, but these impacts do not necessarily translate into population‐level differences in vital rates (survival, growth, or fecundity) or population growth rates. In biological control of weeds, quantitative assessments of population‐level impacts of released agents on both target invasive plants and native, nontarget plants are needed to inform evaluations of the benefits and risks of releasing agents into new regions. Here we present a 3‐yr experimental demographic field study using the European root‐feeding biocontrol weevil, Mogulones crucifer, first released in Canada in 1997 to control the invasive weed Cynoglossum officinale (Boraginaceae). Mogulones crucifer is an effective “search and destroy” agent in Canada, but sporadically feeds, oviposits, and develops on native nontarget Boraginaceae. We investigated the population‐level impacts of this biocontrol insect on its target weed and a native nontarget plant, Hackelia micrantha (Boraginaceae), by releasing large numbers of weevils into naturally occurring patches of H. micrantha growing isolated from or interspersed with C. officinale. We followed the fates of individual plants on release and nonrelease (control) sites for two transition years, developed matrix models to project population growth rates (λ) for each plant species, and examined the contributions from differences in vital rates to changes in λ using life table response experiments (LTRE). In contrast to studies of the insect–plant interaction in its native range, as a biocontrol agent, M. crucifer increased mortality of C. officinale rosettes in the year immediately following release, depressing the weed's λ to below the population replacement level. However, λ for H. micrantha was never depressed below the replacement level, and any differences between release and nonrelease sites in the nontarget could not be explained by significant contributions from vital rates in the LTRE. This study is the first to simultaneously and experimentally examine target and nontarget population‐level impacts of a weed biocontrol insect in the field, and supports the theoretical prediction that plant life history characteristics and uneven herbivore host preferences can interact to produce differences in population‐level impacts between target and nontarget plant species.
Visualizing land‐use and management complexity within biogeochemical cycles of an agricultural landscape
Authors: Nitzsche Kai Nils , Verch Gernot , Premke Katrin , Gessler Arthur , Kayler Zachary E.
Published: June 2016

Crop fields are cultivated across continuities of soil, topography, and local climate that drive biological processes and nutrient cycling at the landscape scale; yet land management and agricultural research are often performed at the field scale, potentially neglecting the context of the surrounding landscape. Adding to this complexity is the overlap of ecosystems and their biogeochemical legacies, as a patchwork of crops fields, natural grasslands, and forests develops across the landscape. Furthermore, as new technologies and policies are introduced, management practices change, including fertilization strategies, which further alter biological productivity and nutrient cycling. All of these environmental, biological, and historical legacies are potentially recorded in the isotopic signal of plant, soil, and sediment organic matter across the landscape. We mapped over 1500 plant, soil, and sediment isotopic values and generated an isotopic landscape (isoscape) over a 40‐km2 agricultural site in NE Germany. We observed distinct patterns in the isotopic composition of organic matter sampled from the landscape that clearly reflect the landscape complexity. C3 crop intrinsic water‐use efficiency reflected a precipitation gradient, while native forest and grassland plant species did not, suggesting that native plants are more adapted to predominant climatic conditions. δ13Csoil patterns reflected both the long‐term input of plant organic matter, which was affected by the local climate conditions, and the repeated cultivation of corn. Soil organic matter 15N isotopic values also revealed spatial differences in fertilization regimes. Forest fragments, in which the nitrogen cycle was relatively open, were more water‐use efficient. Sediments from small water bodies received substantial inputs from surrounding field vegetation but were also affected by seasonal drying. These isotopic maps can be used to visualize large spatial heterogeneity and complexity, and they are a powerful means to interpret past and current trends in agricultural landscapes.
Thermal environment and maternal effects shape egg size in a freshwater fish
Authors: Feiner Zachary S. , Wang Hui‐Yu , Einhouse Donald W. , Jackson James. R. , Rutherford Edward S. , Schelb Chris , Vandergoot Christopher S. , Zorn Troy G. , Höök Tomas O.
Published: June 2016

Offspring size determines offspring survival rates; thus, understanding factors influencing offspring size variability could elucidate variation in population dynamics. Offspring size variation is influenced through multigenerational adaptation to local environments and within‐lifetime plastic responses to environmental variability and maternal effects among individuals. Moreover, offspring size variation may represent trade‐offs in energy allocation within individuals that influence lifetime reproductive success. However, the mechanisms whereby environmental conditions influence offspring size, e.g., via inducing adaptive and plastic variation in population‐scale maternal effects, remain poorly understood. We evaluated intra‐specific variation in maternal effects, egg size, and intra‐individual egg size variation in six populations of walleye (Sander vitreus) and related among‐ and within‐population patterns to thermal conditions. Egg size was conserved within populations and negatively related to long‐term thermal conditions among populations, while maternal effect strengths were positively related to thermal conditions, suggesting that populations inhabiting warmer environments adapted to produce smaller eggs but stronger maternal effects. Within a population, egg size was positively related to colder winters, suggesting cold winters may alter egg size through effects on maternal condition or as an adaptive maternal effect to improve offspring survival. Intra‐individual egg size variation varied little among populations or with female size, but declined with increasing summer and decreasing winter temperatures. Our result suggests that environmental conditions could impact not only short‐term offspring production but also spur adaptive changes in offspring phenotypes. Thus, it is necessary to account for adaptive responses to predict population dynamics under environmental changes.
Conceptual guidelines for the implementation of the ecosystem approach in biodiversity monitoring
Authors: Mueller Melanie , Geist Juergen
Published: June 2016

The theoretical concept of the ecosystem approach (EA) aims at assessing ecosystem function based on integrative assessments of multiple levels of biological organization. Since the United Nations Convention on Biological Diversity in 1992, the EA has been increasingly integrated into environmental policy and legislation, but to date, its practical implementation remains vague with a lack of universal guidelines and concrete recommendations for its use across ecosystem boundaries. On the basis of a review of scientific literature, worldwide environmental legislation and existing monitoring approaches, we identified the most important factors which hamper the feasibility of the EA. We propose a generally applicable methodology for implementing the EA in ecological and environmental monitoring across different ecosystems and habitat types. Successful application of the EA largely depends on adequately standardized and synchronized sampling designs for all abiotic and biotic components, appropriate depth of taxonomic identification, and sufficient spatial and temporal replication. The proposed step‐by‐step guidelines for using the EA are valid across ecosystem types, geographic regions, and for a variety of data types, making them promising tools for ecological monitoring.
Release date influences first‐year site fidelity and survival in captive‐bred Vancouver Island marmots
Authors: Jackson Cheyney L. , Schuster Richard , Arcese Peter
Published: June 2016

Maximizing survival in reintroduced, captive‐bred animals requires evaluation to identify best practices. This is particularly true for critically endangered species like the Vancouver Island marmot, endemic to British Columbia, Canada. From 2003 to 2010, 301 captive‐bred marmots were implanted with transmitters and released at extinct colony locations and other potentially preferred sites to bolster wild populations and establish new colonies. We evaluated release success based on three criteria: (1) site fidelity in the first summer, (2) survival to hibernation in fall, and (3) survival through winter. We used generalized linear mixed models and information theory to estimate the influence on release success of sex, age, and release practices, as well as local and landscape‐level habitat attributes. Our results suggest that overwinter survival most limited release success in the first‐year postrelease. In all years, overwinter survival was lower for newly released captive‐bred marmots than for wild or previously released marmots. Release date best predicted overall success, and was positively related to site fidelity and survival to hibernation but negatively related to overwinter survival. Our findings suggest that focused attempts to optimize release dates are likely to maximize long‐term reintroduction success.
Habitat requirements and ecological niche of two cryptic amphipod species at landscape and local scales
Authors: Eisenring Michael , Altermatt Florian , Westram Anja Marie , Jokela Jukka
Published: June 2016

Cryptic species are phylogenetically diverged taxa that are morphologically indistinguishable and may differ in their ecological and behavioral requirements. This may have important implications for ecosystem services and conservation of biodiversity. We investigated whether two ecologically important cryptic species of the freshwater amphipod Gammarus fossarum (types A and B) are associated with different habitats. We collected data on their occurrence at both the landscape scale (large watersheds) and at the local scale (river reach) to compare macro‐ and microscale environmental parameters associated with their presence. Analysis of the landscape scale data showed that occurrence of types A and B differ with respect to watershed and river size and, interestingly, human impact on river ecomorphology. Whereas type B was mainly found in less forested areas with higher human impact, type A showed the opposite occurrence pattern. Analyses of the local scale data suggested that habitats occupied by type A were characterized by larger gravel, larger stones and less macrophytes than habitats occupied by type B. The landscape and local data set showed contradicting patterns with regard to stream size. Overall, the observed differences between the two types of G. fossarum most likely reflect ecological differences between them, but alternative explanations (e.g., historical colonization processes) cannot be completely ruled out. Our study underlines that common cryptic species can differ in their ecology and response to anthropogenic influence. Such differences in habitat requirements among difficult‐to‐identify taxa present a challenge for biodiversity and ecosystem management. Our results emphasize the importance of conservative and precautionary approaches in maintenance of habitat diversity and environmental heterogeneity.
Latrine marking patterns of badgers (Meles meles) with respect to population density and range size
Authors: Buesching Christina D. , Newman Chris , Service Katrina , Macdonald David W. , Riordan Philip
Published: June 2016

European badgers (Meles meles) use shared defecation sites, termed latrines, to demarcate group ranges. While some latrines are small, comprising few pits with few fresh scats spread over a small area, others are large, comprising many pits with many fresh droppings and extending over a large area. Although many studies have investigated badger latrine usage patterns, and speculated on latrine function, this variation in relative latrine size remains unexplained. Using nearest neighbor analyses, we analyzed the latrine positioning, use, and inter‐latrine distances from four study areas with different population densities. We found that latrines were spaced regularly throughout the range, and border marking was prioritized, increasing the chances of traversing badgers intercepting a latrine. While the numbers of latrines increased with group range size, the number of fresh feces per latrine decreased, suggesting that fresh feces may be a limiting resource in the maintenance of latrines, and that maintaining latrine spacing pattern is more important than the actual number of fresh feces in each latrine. We thus posited that, where territories are small and groups large, the capacity to produce feces exceeds the minimum need for perimeter marking, resulting in fecal redundancy and large latrines. In contrast, in larger territories, especially when occupied by smaller groups, badgers may experience fecal constraint, thus maintaining smaller latrines. We concluded that latrine maintenance and fecal scent‐marking activity in badgers involves a trade‐off between group size and group range area, leading to different degrees of fecal constraint, while energetic costs of signaling are minimized.
Plant genotype influences aquatic‐terrestrial ecosystem linkages through timing and composition of insect emergence
Authors: Compson Zacchaeus G. , Hungate Bruce A. , Whitham Thomas G. , Meneses Nashelly , Busby Posy E. , Wojtowicz Todd , Ford Audrey C. , Adams Kenneth J. , Marks Jane C.
Published: June 2016

Terrestrial leaf litter provides aquatic insects with an energy source and habitat structure, and species differences in litter can influence aquatic insect emergence. Emerging insects also provide energy to riparian predators. We hypothesized that plant genetics would influence the composition and timing of emerging insect communities among individual genotypes ofPopulus angustifoliavarying in litter traits. We also compared the composition and timing of emerging insect communities on litter from mixed genotypes of three cross types of a hybridizing cottonwood complex:P. angustifolia,P. fremontii, and their F1hybrids. Using litter harvested from an experimental common garden, we measured emerging insect community composition, abundance, and production for 12 weeks in large litter packs affixed with emergence traps. Five major findings emerged. (1) In support of the genetic similarity hypothesis, we found that, amongP. angustifoliatree genotypes, litter from more closely related genotypes had more similar litter thickness, nitrogen concentrations, decomposition rates, and emerging insect communities. (2) Genetic similarity was not correlated with other litter traits, although the litter fungal community was a strong predictor of emerging insect communities. (3) Litter decomposition rate, which was the strongest predictor of emerging aquatic insect communities, was influenced by litter thickness, litter N, and the litter fungal community. (4) In contrast to strong community composition differences amongP. angustifoliagenotypes, differences in community composition betweenP. fremontiiandP. angustifoliawere only marginally significant, and communities on F1hybrids were indistinguishable fromP. angustifoliadespite genetic and litter trait differences. (5) Mixed litter packs muted the genetic effects observed in litter packs consisting of single genotypes. These results demonstrate that the genetic structure of riparian forests can affect the composition and timing of aquatic insect emergence. Because many riparian trees are clonal, includingP. angustifolia, large clone size is likely to result in patches of genetically structured leaf litter that may influence the timing and composition of insect emergence within watersheds. Riparian restoration efforts incorporating different tree genotypes could also influence the biodiversity of emerging aquatic insects. Our work illustrates the importance of plant genes for community and ecosystem processes in riparian corridors.
Population dynamics of desert mammals: similarities and contrasts within a multispecies assemblage
Authors: Greenville Aaron C. , Wardle Glenda M. , Nguyen Vuong , Dickman Chris R.
Published: June 2016

Understanding the temporal and spatial dynamics of species populations remains a key focus of population biology, providing vital insight into the drivers that influence demography and into sub‐populations that are vulnerable to extinction. Across regional landscapes, spatially separated sub‐populations may fluctuate in synchrony, or exhibit sub‐structuring due to subtle differences in local intrinsic and extrinsic factors. Using a long‐term data set (17–22 yr) obtained from a large (8000 km2) study region in arid central Australia, we tested firstly for regional synchrony in annual rainfall and the dynamics of five small mammal species across nine widely separated sites. Using Moran's theorem, we predicted that the spatial correlation between the regional sub‐populations of these species would equal that between local density‐independent conditions (annual rainfall). For species that showed synchronous spatial dynamics, we then used multivariate state‐space (MARSS) models to predict that regional rainfall would be positively associated with their populations, whereas species with asynchronous sub‐populations would be influenced largely by other factors. For these latter species, we used MARSS models to test four hypotheses. These were that sub‐population structures: (1) were asynchronous and governed by local site‐specific factors, (2) differed between oasis and non‐oasis sites, (3) differed between burnt and unburnt sites, and (4) differed between three sub‐regions with different rainfall gradients. We found that the spatial population dynamics of our study small mammals differed between and within families. Two species of insectivorous dasyurid marsupials showed asynchronous dynamics, which most likely tracked local conditions, whereas a larger carnivorous marsupial and two species of rodents had strongly synchronous dynamics. These latter species exhibited similar spatial correlations to local and regional rainfall events, providing evidence that the Moran effect operates for some, but not all, species in this arid system. Our results suggest that small mammal populations do not respond in similar ways to shared environmental drivers in arid regions, and hence will vary in their responses to climate change. As arid lands globally are predicted to face climatic shifts that will exacerbate rainfall‐drought cycles, we suggest that future work focuses on exploring these responses at different spatial scales across multiple dryland taxa.
Species and habitats in danger: estimating the relative risk posed by oil spills in the northern Baltic Sea
Authors: Helle Inari , Jolma Ari , Venesjärvi Riikka
Published: June 2016

Large‐scale oil spills can have adverse effects on biodiversity in coastal areas where maritime oil transportation is intense. In this article we conducted a spatial risk assessment to study the risk that potential tanker accidents pose to threatened habitat types and species living in the northern Baltic Sea, which has witnessed a rapid increase in maritime oil transportation within the past two decades. We applied a probabilistic method, which combines three components: a Bayesian network describing tanker accidents and uncertainties related to them, probabilistic maps showing the movement of oil, and a database of threatened species and habitats in the area. The results suggest that spatial risk posed by oil spills varies across the area, and does not correspond, for example, to the frequency of accidents in a given area. The relative risk is highest for seashore meadows, which is important to take into account when managing these habitats. Our analysis underlines the importance of a thorough risk assessment, which is not only based solely on one or two specific factors such as accident probabilities or the trajectories of spilled oil but also contains as broad a view of the consequences as possible. We believe that the probabilistic methodology applied in the study will be of high interest to people who have to cope with uncertainties typical for environmental risk assessment and management.
Convergent diversity and trait composition in temporary streams and ponds
Authors: Schriever Tiffany A. , Lytle David A.
Published: June 2016

Hydrology is the main environmental filter in aquatic ecosystems and may result in shared tolerances and functional traits among species in disparate ecosystems. We analyzed the associations between taxonomic and functional facets of diversity within aquatic ecosystems (ponds vs. streams) across a hydroperiod gradient (1–365 d) to untangle the hydrologic drivers of aquatic invertebrate diversity. We used invertebrate assemblage data from seven arid‐land streams in southeastern Arizona, United States collected over 2 yr and nine temperate woodland ponds in Ontario, Canada collected over 2 yr. Our results showed that although invertebrate assemblages from streams and ponds differ taxonomically, hydroperiod had similar influence on invertebrate trait structure regardless of biogeographic and habitat differences. Streams and ponds independently showed strong positive relationships between functional richness and taxonomic richness; however, the relationship showed a shallower slope in ponds, indicating higher functional redundancy. Intermittent ponds and streams tended to have lower functional and taxonomic richness than their perennial counterparts, but harbored greater beta diversity. Our results suggest that even though ponds and streams are fundamentally different habitats with distinct faunas and unique ecological processes, hydrology produces convergent patterns in both trait composition and diversity patterns.
Population trends for North American winter birds based on hierarchical models
Authors: Soykan Candan U. , Sauer John , Schuetz Justin G. , LeBaron Geoffrey S. , Dale Kathy , Langham Gary M.
Published: June 2016

Managing widespread and persistent threats to birds requires knowledge of population dynamics at large spatial and temporal scales. For over 100 yrs, the Audubon Christmas Bird Count (CBC) has enlisted volunteers in bird monitoring efforts that span the Americas, especially southern Canada and the United States. We employed a Bayesian hierarchical model to control for variation in survey effort among CBC circles and, using CBC data from 1966 to 2013, generated early‐winter population trend estimates for 551 species of birds. Selecting a subset of species that do not frequent bird feeders and have ≥25% range overlap with the distribution of CBC circles (228 species) we further estimated aggregate (i.e., across species) trends for the entire study region and at the level of states/provinces, Bird Conservation Regions, and Landscape Conservation Cooperatives. Moreover, we examined the relationship between ten biological traits—range size, population size, migratory strategy, habitat affiliation, body size, diet, number of eggs per clutch, age at sexual maturity, lifespan, and tolerance of urban/suburban settings—and CBC trend estimates. Our results indicate that 68% of the 551 species had increasing trends within the study area over the interval 1966–2013. When trends were examined across the subset of 228 species, the median population trend for the group was 0.9% per year at the continental level. At the regional level, aggregate trends were positive in all but a few areas. Negative population trends were evident in lower latitudes, whereas the largest increases were at higher latitudes, a pattern consistent with range shifts due to climate change. Nine of 10 biological traits were significantly associated with median population trend; however, none of the traits explained >34% of the deviance in the data, reflecting the indirect relationships between population trend estimates and species traits. Trend estimates based on the CBC are broadly congruent with estimates based on the North American Breeding Bird Survey, another large‐scale monitoring program. Both of these efforts, conducted by citizen scientists, will be required going forward to ensure robust inference about population dynamics in the face of climate and land cover changes.
Testing the trait‐based community framework: Do functional traits predict competitive outcomes?
Authors: Funk Jennifer L. , Wolf Amelia A.
Published: June 2016

Plant traits can be used to understand a range of ecological processes, including competition with invasive species. The extent to which native and invasive species are competing via limiting similarity or trait hierarchies has important implications for the management of invaded communities. We screened 47 native species that co‐occur with Festuca perennis, a dominant invader in California serpentine grassland, for traits pertaining to resource use and acquisition. We then grew F. perennis with 10 species spanning a range of functional similarity in pairwise competition trials. Functionally similar species did not have a strong adverse effect on F. perennis performance as would be expected by limiting similarity theory. Phylogenetic relatedness, which may integrate a number of functional traits, was also a poor predictor of competitive outcome. Instead, species with high specific root length, low root‐to‐shoot biomass ratio, and low leaf nitrogen concentration were more effective at suppressing the growth of F. perennis. Our results suggest that fitness differences (i.e., trait hierarchies) may be more important than niche differences (i.e., limiting similarity) in structuring competitive outcomes in this system and may be a promising approach for the restoration of invaded systems.
Regional diversity reverses the negative impacts of an alien predator on local species‐poor communities
Authors: Loewen Charlie J. G. , Vinebrooke Rolf D.
Published: June 2016

Species diversity is often an implicit source of biological insurance for communities against the impacts of novel perturbations, such as the introduction of an invasive species. High environmental heterogeneity (e.g., a mountainous gradient) is expected to beget greater regional species diversity and variation in functional traits related to environmental tolerances. Thus, heterogeneous metacommunities are expected to provide more tolerant colonists that buffer stressed local communities in the absence of dispersal limitation. We tested the hypothesis that importation of a regional zooplankton pool assembled from a diverse array of lakes and ponds lessens the impacts of a novel predator on local species‐poor alpine communities by increasing response diversity (i.e., diversity of tolerances to environmental change) as mediated by variation in functional traits related to predator evasion. We also tested whether impacts varied with temperature, as warming may modify (e.g., dampen or amplify) invasion effects. An eight‐week factorial experiment ([fishless vs. introducedOncorhynchus mykiss(rainbow trout)] × [ambient temperature vs. heated] × [local vs. local + regional species pool]) was conducted using 32 1,000‐L mesocosms. Associations between experimental treatments and species functional traits were tested by R‐mode linked to Q‐mode (RLQ) and fourth‐corner analyses. Although the introduced predator suppressed local species richness and community biomass, colonization by several montane zooplankters reversed these negative effects, resulting in increased species diversity and production. Invasion resistance was unaffected by higher temperatures, which failed to elicit any significance impacts on the community. We discovered that the smaller body sizes of imported species drove functional overcompensation (i.e., increased production) in invaded communities. The observed ecological surprise showed how regionally sourced biodiversity from a highly heterogeneous landscape can offset, and even reverse, the local negative impacts of an invasive species. Further, prey body size was found to be a key species trait mediating the ecological impacts of the aquatic invasive predator. Our study highlights the novel application of a functional approach to understanding the impacts of biological invasions, using species traits that pertain directly to potential responses to exotic species.
Cold‐evoked potentials – Ready for clinical use?
Authors: Hüllemann P. , Nerdal A. , Binder A. , Helfert S. , Reimer M. , Baron R.
Published: June 2016

Background

Cold‐evoked potentials (CEPs) are known to assess the integrity of A‐delta fibres and the spinothalamic tract. Nevertheless, the clinical value was not investigated previously. The aim of this study was to measure CEPs in 16 healthy subjects from the face, hand and foot sole and to investigate whether CEPs reliably detect A‐delta fibre abnormalities.

Methods

Swift cold stimuli were applied to the skin with a commercially available thermode, which cooled down from 30 to 25 °C in approximately 0.5 s. CEP latencies (N1, N2 and P2) and amplitudes (N1, N2/P2) were recorded with EEG. Reversible A‐fibre function loss was induced by applying a selective A‐fibre block at the superficial radial nerve.

Results

In all 16 subjects CEPs could be recorded from all locations; N2, P2 mean latencies were 276.4 ± 38.9 and 389.8 ± 52.5 (face), 318.6 ± 31.6 ms and 477.7 ± 43.6 (hand), and 627.6 ± 84.4 and 774.2 ± 94.0 (foot sole). N2/P2 amplitudes were 10.7 ± 4.1, 11.3 ± 4.1 and 7.5 ± 4.1 μV. During A‐fibre block no CEPs were detectable in the grand average, which restored 10 min after block removal.

Conclusions

CEPs were reliably recorded in healthy subjects at the hand, face and foot. Experimentally induced reversible A‐delta fibre function loss was detected by CEPs. Functional recovery was assessed as well. This study is basis for further CEP evaluation studies and might be the first step for implementing CEPs in clinical routine for the early diagnosis of small‐fibre disease.

What does this study add?

Cold‐evoked potentials are capable of reliably measuring A‐delta fibre integrity, loss of function and functional recovery in healthy subjects, which is an essential prerequisite for diagnostic use in patients with small‐fibre disease.
Torrefaction and Process Energy Budget Analysis of Powdered, De‐oiled, and In Situ Transesterified Flaxseed Cakes for Energy Generation
Authors: Ali Mehmood , Watson Ian A.
Published: June 2016

Edible vegetable oil seeds are used to produce oil for human consumption and inedible vegetable oil seeds are used to produce biofuels; the residue cakes from the extraction process contain significant energy that can be utilised. This study is a continuation of previous work on oil extraction from flaxseed to produce biodiesel; herein, the residue cake from flaxseed was studied. Three different types of samples (powdered seeds, de‐oiled cake, and in situ transesterified cake of flaxseed) were torrefied (through slow pyrolysis), and the sample properties were characterized. The higher heating value (HHV=36.01±0.36 MJ kg−1) and bulk density (0.33±0.01 g cm−3) of the powdered seeds are higher compared to the other two samples (i.e. de‐oiled cake and in situ transesterified cake). The torrefied biomass was light weight losing its mechanical strength on treatment, making it easier to grind. It was observed that the biomass torrefied at 300 °C had a higher fraction of particles between sieve sizes (between 2.0 and 0.063 mm) compared to the biomass torrefied at 200 °C. The sieve sizes between 0.5 and 0.063 mm showed that more particles of the torrefied biomass treated at 300 °C were collected compared to that torrefied at 200 °C. Due to the loss of hydrogen and oxygen content and the removal of water, the carbon content in the torrefied biomass increased by 25.52, 24.51, and 22.69 % for the powdered seeds, de‐oiled cake, and in situ cake samples, respectively. The powdered seeds had a higher carbon and hydrogen content compared to the de‐oiled and in situ transesterified flaxseed cakes because the powdered seeds contained fatty acids. The powdered seeds had a higher concentration of CO2 gas liberated during treatment compared to the de‐oiled and in situ transesterified cakes. This was attributed to the powdered seeds having a higher concentration of volatile hydrocarbons and a lower ash content. It was observed that the energy ratios were reduced with respect to increasing temperature whereas the highest energy ratios were found for the powdered seeds.
The environmental effect of underground coal gasification semi‐coke on confined groundwater
Authors: Xu Bing , Chen Lunjian , Xing Baolin , Li Long , Zhang Le , Wang Xiaojiao , Chen Huanli , Yi Guiyun , Huang Guangxu
Published: June 2016

From the health and environmental point of view, the control of soluble metal elements and organic compounds in underground coal gasification (UCG) by‐product is of great importance for groundwater protection. Unlike the leaching of gasification ash as well as leaching in normal pressure, the leaching of trace elements and organics from UCG semi‐coke into confined groundwater has received little concern. In this research, UCG model test of Inner Mongolia lignite was performed, the obtained UCG semi‐coke was then soaked by applying stainless steel leaching column at 0.5, 1.0, 1.5 and 2.0 MPa with nitrogen as pressurizing agent, the concentrations of trace element and total organic carbons (TOC values) in lixiviums were finally determined by applying ICP‐MS and TOC analyzer to investigate the slight leaching in confined groundwater. The results indicate that Cd, Co, Cr, Ni, Pb and V are undetected in all lixivium samples, and compared with soaking under normal pressure, the concentrations of As, Ba, Mn and Sr are lower in confined water. TOC values in lixivium samples approximately approach to the background value of groundwater, indicating that no extra organic compounds could be leached and TOC values also show the similar changing trend as As, Ba, Mn and Sr behave under normal and high pressures. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1584–1589, 2016
Are My Professional Evaluation Dispositions to Be Found in My Early Life Experiences?
Authors: Stake Robert E.
Published: June 2016

Having searched for prescient stories from his early life, Robert Stake passes on these observations from recollections, interviews with David Williams, and symposium sessions of the American Evaluation Association in 2012 and 2013. He speaks of opposing views of evaluation held by his parents, perhaps eventually appearing in his writings. He reflects on ordinary evaluation decisions he made about getting married, going to graduate school, and raising children. He does not see such early experiences much paralleling or informing his professional evaluation theories and practices. Readers may see values he found extraprofessionally marking his professional work.
Thoughts About an Early Evaluation Life
Authors: Scriven Michael
Published: June 2016

Scriven describes how he believes the early death of his father, constant intercontinental moving he experienced as a child, and associated fractures in relationships he began with peers influenced his “attitude towards the value of reason,” which is his “main professional area of publication and evaluation.” He recounts stories of developing his own evaluation life by running away from home at age 14 (following his father's example); writing an award‐winning essay on quantitatively evaluating acts of valor (as he wanted to be a RAF pilot like his father); pursuing math, science, and philosophy in college; critiquing parapsychology; evaluating sports cars; exploring and teaching critical thinking; deciding where to go to university and where to work; and eventually being pulled into professional evaluation by being asked to work on a White House task force that included evaluating university courses and curricula on critical thinking; and collaborating with other early evaluation theorists.
Childhood Influences on My Work
Authors: House Ernie
Published: June 2016

House tells stories about his childhood experiences with adults who were making what he felt were poor evaluations. He had similar evaluation experiences as a teacher and slowly developed his own views about how evaluation could be most fairly and appropriately accomplished in everyday life. He began applying these ideas and many others when he was put in charge of a national evaluation in the 1960s, drawing upon perspectives of many colleagues he assembled to give him advice. He retained a healthy skepticism that typifies all his work, based on the childhood convictions he developed through observing and defending himself from poor adult evaluations.
Autobiography as Case Study
Authors: Kushner Saville
Published: June 2016

Kushner comments on the rest of this issue and offers suggestions for future work and the future of evaluation.
Connections, Themes, and Implications for the Future of Evaluation
Authors: Williams David Dwayne
Published: June 2016

This final article explores some of the unique and common connections the seven early and influential evaluators have made between their extraprofessional and professional evaluation lives, as reflected in their comments and stories in their individual articles and one prominent theme noted across all cases: These evaluators described how their values developed and eventually shaped their evaluation approaches. In addition, some subthemes are identified and questions for further study are posed. Following, in one page each, the seven authors review their colleagues’ articles and offer their own responses regarding what they learned from each other and what possible implications they foresee for future evaluation. Based on these reviews, readers are invited to think about possible implications for their own and their clients’ evaluation lives. The entire document invites readers to relate to evaluation less as a technology and more as a values‐based activity involving their own values and those of other participants in their evaluations.
Tests on the Monotonicity Properties of KOSPI 200 Options Prices
Authors: Sim Myounghwa , Ryu Doojin , Yang Heejin
Published: June 2016

This study demonstrates that the basic properties predicted by one‐dimensional diffusion option pricing models are often violated, even in a highly liquid and leading options market. We analyze a high‐quality intraday dataset of KOSPI 200 index options, one of the most actively traded options markets in the world, and find that option prices often do not monotonically correlate with underlying prices. We also empirically show that option prices often do not change, despite changes in underlying prices, when options are heavily traded by individual investors, who are normally noisy and uninformed. Our evidence is partially consistent with the implications of demand‐based option pricing models, which predict that investor demand can significantly influence option prices in the presence of limits to arbitrage. © 2015 Wiley Periodicals, Inc. Jrl Fut Mark 36:625–646, 2016