bluuebunny/crossref_metadata_2025_split huggingface dataset:
Limits on carbon sequestration in arid blue carbon ecosystems
Authors: Schile Lisa M. , Kauffman J. Boone , Crooks Stephen , Fourqurean James W. , Glavan Jane , Megonigal J. Patrick 
Published: December 2016

AbstractCoastal ecosystems produce and sequester significant amounts of carbon (“blue carbon”), which has been well documented in humid and semi‐humid regions of temperate and tropical climates but less so in arid regions where mangroves, marshes, and seagrasses exist near the limit of their tolerance for extreme temperature and salinity. To better understand these unique systems, we measured whole‐ecosystem carbon stocks in 58 sites across the United Arab Emirates (UAE) in natural and planted mangroves, salt marshes, seagrass beds, microbial mats, and coastal sabkha (inter‐ and supratidal unvegetated salt flats). Natural mangroves held significantly more carbon in above‐ and belowground biomass than other vegetated ecosystems. Planted mangrove carbon stocks increased with age, but there were large differences for sites of similar age. Soil carbon varied widely across sites (2–367 Mg C/ha), with ecosystem averages that ranged from 49 to 156 Mg C/ha. For the first time, microbial mats were documented to contain soil carbon pools comparable to vascular plant‐dominated ecosystems, and could arguably be recognized as a unique blue carbon ecosystem. Total ecosystem carbon stocks ranged widely from 2 to 515 Mg C/ha (seagrass bed and mangrove, respectively). Seagrass beds had the lowest carbon stock per unit area, but the largest stock per total area due to their large spatial coverage. Compared to similar ecosystems globally, mangroves and marshes in the UAE have lower plant and soil carbon stocks; however, the difference in soil stocks is far larger than with plant stocks. This incongruent difference between stocks is likely due to poor carbon preservation under conditions of weakly reduced soils (200–350 mV), coarse‐grained sediments, and active shoreline migration. This work represents the first attempt to produce a country‐wide coastal ecosystem carbon accounting using a uniform sampling protocol, and was motivated by specific policy goals identified by the Abu Dhabi Global Environmental Data Initiative. These carbon stock data supported two objectives: to quantify carbon stocks and infer sequestration capacity in arid blue carbon ecosystems, and to explore the potential to incorporate blue carbon science into national reporting and planning documents.
Functional community structure of African monodominant Gilbertiodendron dewevrei forest influenced by local environmental filtering
Authors: Kearsley Elizabeth , Verbeeck Hans , Hufkens Koen , Van de Perre Frederik , Doetterl Sebastian , Baert Geert , Beeckman Hans , Boeckx Pascal , Huygens Dries 
Published: December 2016

AbstractMonodominant patches of forest dominated by Gilbertiodendron dewevrei are commonly found in central African tropical forests, alongside forests with high species diversity. Although these forests are generally found sparsely distributed along rivers, their occurrence is not thought to be (clearly) driven by edaphic conditions but rather by trait combinations of G. dewevrei that aid in achieving monodominance. Functional community structure between these monodominant and mixed forests has, however, not yet been compared. Additionally, little is known about nondominant species in the monodominant forest community. These two topics are addressed in this study. We investigate the functional community structure of 10 one‐hectare plots of monodominant and mixed forests in a central region of the Congo basin, in DR Congo. Thirteen leaf and wood traits are measured, covering 95% (basal area weighted) of all species present in the plots, including leaf nutrient contents, leaf isotopic compositions, specific leaf area, wood density, and vessel anatomy. The trait‐based assessment of G. dewevrei shows an ensemble of traits related to water use and transport that could be favorable for its location near forest rivers. Moreover, indications have been found for N and P limitations in the monodominant forest, possibly related to ectomycorrhizal associations formed with G. dewevrei. Reduced leaf N and P contents are found at the community level for the monodominant forest and for different nondominant groups, as compared to those in the mixed forest. In summary, this work shows that environmental filtering does prevail in the monodominant G. dewevrei forest, leading to lower functional diversity in this forest type, with the dominant species showing beneficial traits related to its common riverine locations and with reduced soil N and P availability found in this environment, both coregulating the tree community assembly.
Habitat–performance relationships of a large mammal on a predator‐free island dominated by humans
Authors: Allen Andrew M. , Dorey Augusta , Malmsten Jonas , Edenius Lars , Ericsson Göran , Singh Navinder J. 
Published: December 2016

AbstractThe demographic consequences of changes in habitat use driven by human modification of landscape, and/or changes in climate, are important for any species. We investigated habitat–performance relationships in a declining island population of a large mammal, the moose (Alces alces), in an environment that is predator‐free but dominated by humans. We used a combination of demographic data, knowledge of habitat selection, and multiannual movement data of female moose (n = 17) to understand how space use patterns affect fecundity and calf survival. The calving rate was 0.64 and was similar to calving rates reported in other populations. Calf survival was 0.22 (annually) and 0.32 (postsummer), which are particularly low compared to other populations where postsummer survival is typically above 0.7. Home ranges were mainly composed of arable land (>40%), and selection for arable land was higher in winter than in summer, which contrasts with previous studies. Females that spent more time in broadleaf forest in the summer prior to the rut had higher fecundity rates, while more time spent in arable land resulted in lower fecundity rates. Females that spent more time in thicket/scrubland habitats during winter had lower calf survival, while females that had higher use of mixed forests tended to have higher calf survival. The dominance, and subsequent use, of suboptimal foraging habitats may lead to poor body condition of females at parturition, which may lower calf body weights and affect the mother's ability to lactate. In addition, our results indicated that the growing season has advanced significantly in recent decades, which may be causing a mismatch between parturition and optimal resource availability. These effects may exacerbate the female's ability to meet the energetic demands of lactation. Therefore, the observed low calf survival appears to be caused by a combination of factors related to current land use and may also be due to changing vegetation phenology. These results have important implications for the management of species in human‐dominated landscapes in the face of climate change, and for an increased understanding of how species may adapt to future land use and climate change.
Host plant density and patch isolation drive occupancy and abundance at a butterfly's northern range margin
Authors: Fourcade Yoan , Öckinger Erik 
Published: December 2016

AbstractMarginal populations are usually small, fragmented, and vulnerable to extinction, which makes them particularly interesting from a conservation point of view. They are also the starting point of range shifts that result from climate change, through a process involving colonization of newly suitable sites at the cool margin of species distributions. Hence, understanding the processes that drive demography and distribution at high‐latitude populations is essential to forecast the response of species to global changes. We investigated the relative importance of solar irradiance (as a proxy for microclimate), habitat quality, and connectivity on occupancy, abundance, and population stability at the northern range margin of the Oberthür's grizzled skipper butterflyPyrgus armoricanus. For this purpose, butterfly abundance was surveyed in a habitat network consisting of 50 habitat patches over 12 years. We found that occupancy and abundance (average and variability) were mostly influenced by the density of host plants and the spatial isolation of patches, while solar irradiance and grazing frequency had only an effect on patch occupancy. Knowing that the distribution of host plants extends further north, we hypothesize that the actual variable limiting the northern distribution ofP. armoricanusmight be its dispersal capacity that prevents it from reaching more northern habitat patches. The persistence of this metapopulation in the face of global changes will thus be fundamentally linked to the maintenance of an efficient network of habitats.
Phylogeographic patterns of a lower intertidal isopod in the Gulf of California and the Caribbean and comparison with other intertidal isopods
Authors: Hurtado Luis A. , Mateos Mariana , Liu Shuang 
Published: December 2016

AbstractA growing body of knowledge on the diversity and evolution of intertidal isopods across different regions worldwide has enhanced our understanding on biological diversification at the poorly studied, yet vast, sea–land interface. High genetic divergences among numerous allopatric lineages have been identified within presumed single broadly distributed species.Excirolana mayanais an intertidal isopod that is commonly found in sandy beaches throughout the Gulf of California. Its distribution in the Pacific extends from this basin to Colombia and in the Atlantic from Florida to Venezuela. Despite its broad distribution and ecological importance, its evolutionary history has been largely neglected. Herein, we examined phylogeographic patterns ofE. mayanain the Gulf of California and the Caribbean, based on maximum‐likelihood and Bayesian phylogenetic analyses ofDNAsequences from four mitochondrial genes (16SrDNA, 12SrDNA, cytochrome oxidase I gene, and cytochrome b gene). We compared the phylogeographic patterns ofE. mayanawith those of the coastal isopodsLigiaandExcirolana braziliensis(Gulf of California and Caribbean) andTylos(Gulf of California). We found highly divergent lineages in both, the Gulf of California and Caribbean, suggesting the presence of multiple species. We identified two instances of Atlantic–Pacific divergences. Some geographical structuring among the major clades found in the Caribbean is observed. Haplotypes from the Gulf of California form a monophyletic group sister to a lineage found in Venezuela. Phylogeographic patterns ofE. mayanain the Gulf of California differ from those observed inLigiaandTylosin this region. Nonetheless, several clades ofE. mayanahave similar distributions to clades of these two other isopod taxa. The high levels of cryptic diversity detected inE. mayanaalso pose challenges for the conservation of this isopod and its fragile environment, the sandy shores.
Using species distribution models to define nesting habitat of the eastern metapopulation of double‐crested cormorants
Authors: Sheehan Kate L. , Esswein Samuel T. , Dorr Brian S. , Yarrow Greg K. , Johnson Ron J. 
Published: December 2016

AbstractWhen organisms with similar phenotypes have conflicting management and conservation initiatives, approaches are needed to differentiate among subpopulations or discrete groups. For example, the eastern metapopulation of the double‐crested cormorant (Phalacrocorax auritus) has a migratory phenotype that is culled because they are viewed as a threat to commercial and natural resources, whereas resident birds are targeted for conservation. Understanding the distinct breeding habitats of resident versus migratory cormorants would aid in identification and management decisions. Here, we use species distribution models (SDM: Maxent) of cormorant nesting habitat to examine the eastern P. auritus metapopulation and the predicted breeding sites of its phenotypes. We then estimate the phenotypic identity of breeding colonies of cormorants where management plans are being developed. We transferred SDMs trained on data from resident bird colonies in Florida and migratory bird colonies in Minnesota to South Carolina in an effort to identify the phenotype of breeding cormorants there based on the local landscape characteristics. Nesting habitat characteristics of cormorant colonies in South Carolina more closely resembled those of the Florida phenotype than those of birds of the Minnesota phenotype. The presence of the resident phenotype in summer suggests that migratory and resident cormorants will co‐occur in South Carolina in winter. Thus, there is an opportunity for separate management strategies for the two phenotypes in that state. We found differences in nesting habitat characteristics that could be used to refine management strategies and reduce human conflicts with abundant winter migrants and, at the same time, conserve less common colonies of resident cormorants. The models we use here show potential for advancing the study of geographically overlapping phenotypes with differing conservation and management priorities.
Comparative mitochondrial and chloroplast genomics of a genetically distinct form of Sargassum contributing to recent “Golden Tides” in the Western Atlantic
Authors: Amaral‐Zettler Linda A. , Dragone Nicholas B. , Schell Jeffrey , Slikas Beth , Murphy Leslie G. , Morrall Clare E. , Zettler Erik R. 
Published: December 2016

AbstractOver the past 5 years, massive accumulations of holopelagic species of the brown macroalga Sargassum in coastal areas of the Caribbean have created “golden tides” that threaten local biodiversity and trigger economic losses associated with beach deterioration and impact on fisheries and tourism. In 2015, the first report identifying the cause of these extreme events implicated a rare form of the holopelagic species Sargassum natans (form VIII). However, since the first mention of S. natans VIII in the 1930s, based solely on morphological characters, no molecular data have confirmed this identification. We generated full‐length mitogenomes and partial chloroplast genomes of all representative holopelagic Sargassum species, S. fluitans III and S. natans I alongside the putatively rare S. natans VIII, to demonstrate small but consistent differences between S. natans I and VIII (7 bp differences out of the 34,727). Our comparative analyses also revealed that both S. natans I and S. natans VIII share a very close phylogenetic relationship with S. fluitans III (94‐ and 96‐bp differences of 34,727). We designed novel primers that amplified regions of the cox2 and cox3 marker genes with consistent polymorphic sites that enabled differentiation between the two S. natans forms (I and VIII) from each other and both from S. fluitans III in over 150 Sargassum samples including those from the 2014 golden tide event. Despite remarkable gene synteny and sequence conservation, the three Sargassum forms differ in morphology, ecology, and distribution patterns, warranting more extensive interrogation of holopelagic Sargassum genomes as a whole.
Intensified wind pollination mediated by pollen dimorphism after range expansion in an ambophilous biennialAconitum gymnandrum
Authors: Wang Lin‐Lin , Zhang Chan , Yang Ming‐Liu , Zhang Guo‐Peng , Zhang Zhi‐Qiang , Yang Yong‐Ping , Duan Yuan‐Wen 
Published: December 2016

AbstractPollination systems and associated floral traits generally differ between core and marginal populations of a species. However, such differences are rarely examined in plants with a mixed wind‐ and bumblebee‐pollination system, and the role of wind pollination during range expansion in ambophilous plants remains unclear. We compared floral traits and the contributions of bumblebee and wind pollination in refugium and marginal populations of the ambophilous plantAconitum gymnandrum. We found that most floral traits differed between the two populations, and those traits associated with the shift to wind pollination were pronounced in the marginal population. Bumblebee visitation rates varied significantly, but were generally low in the marginal population. Wind pollination occurred in both populations, and the efficiency was lower than that of bumblebee pollination. Two types of pollen grains, namely round and fusiform pollen, were transported to a stigma by bumblebees and wind, but fusiform pollen contributed to wind pollination to a larger degree, especially in the marginal population. Our results suggest that wind pollination was enhanced by pollen dimorphism in the marginal population ofA. gymnandrum, and wind pollination may provide reproductive assurance when bumblebee activity is unpredictable during range expansion, indicating that ambophily is stable in this species and shift in pollination system could be common when plants colonize new habitats.
Vertebrate defense against parasites: Interactions between avoidance, resistance, and tolerance
Authors: Klemme Ines , Karvonen Anssi 
Published: December 2016

AbstractHosts can utilize different types of defense against the effects of parasitism, including avoidance, resistance, and tolerance. Typically, there is tremendous heterogeneity among hosts in these defense mechanisms that may be rooted in the costs associated with defense and lead to trade‐offs with other life‐history traits. Trade‐offs may also exist between the defense mechanisms, but the relationships between avoidance, resistance, and tolerance have rarely been studied. Here, we assessed these three defense traits under common garden conditions in a natural host–parasite system, the trematode eye‐flukeDiplostomum pseudospathaceumand its second intermediate fish host. We looked at host individuals originating from four genetically distinct populations of two closely related salmonid species (Atlantic salmon,Salmo salarand sea trout,Salmo trutta trutta) to estimate the magnitude of variation in these defense traits and the relationships among them. We show species‐specific variation in resistance and tolerance and population‐specific variation in resistance. Further, we demonstrate evidence for a trade‐off between resistance and tolerance. Our results suggest that the variation in host defense can at least partly result from a compromise between different interacting defense traits, the relative importance of which is likely to be shaped by environmental components. Overall, this study emphasizes the importance of considering different components of the host defense system when making predictions on the outcome of host–parasite interactions.
Difference in response of water use to evaporative demand for codominant diffuse‐porous versus ring‐porous tree species under N addition in a temperate forest
Authors: Ouyang Lei , Zhao Ping , Zhu Liwei , Zhang Zhenzhen , Zhao Xiuhua , Ni Guangyan 
Published: December 2016

AbstractIn this study, we explored the impacts of nitrogen (N) addition on water transpiration of codominant trees with different wood anatomy and their response of water use to varying vapor pressure deficit (VPD). Three tree species, diffuse‐porous Liquidambar formosana Hance (maple), ring‐porous Quercus variabilis Blume (cork oak), and Quercus acutissima Carruth (sawtooth oak), were selected for this research. These temperate forest trees grow in a climatic transitional zone located in Henan Province of Central China, and have been under N addition treatments of different levels since April 2013. The N treatments include control, low N (25 kg N ha−1 year−1), and high N levels (50 kg N ha−1 year−1). The measured data of stem sap flow from April to October 2015 showed that maple trees used more water than oak trees and N addition generally decreased the water transport of maple and sawtooth oak but induced no significant change of water transpiration for cork oak. Water use in maple increased with VPD, whereas relatively flat response for both oaks was observed, suggesting a much stricter stomatal control. Under N addition, water transport in all tree species showed a significant decline in the wet period (August), during which there were more precipitation and cloudy days than in dry May when VPD is >1.80 kPa. However, changes of vessel size, hydraulic conductivity, and root biomass that are associated with N addition for both ring‐ and diffuse‐porous species remain unknown and require further investigation.
Structured decision making as a framework for large‐scale wildlife harvest management decisions
Authors: Robinson Kelly F. , Fuller Angela K. , Hurst Jeremy E. , Swift Bryan L. , Kirsch Arthur , Farquhar James , Decker Daniel J. , Siemer William F. 
Published: December 2016

AbstractFish and wildlife harvest management at large spatial scales often involves making complex decisions with multiple objectives and difficult tradeoffs, population demographics that vary spatially, competing stakeholder values, and uncertainties that might affect management decisions. Structured decision making (SDM) provides a formal decision analytic framework for evaluating difficult decisions by breaking decisions into component parts and separating the values of stakeholders from the scientific evaluation of management actions and uncertainty. The result is a rigorous, transparent, and values‐driven process. This decision‐aiding process provides the decision maker with a more complete understanding of the problem and the effects of potential management actions on stakeholder values, as well as how key uncertainties can affect the decision. We use a case study to illustrate how SDM can be used as a decision‐aiding tool for management decision making at large scales. We evaluated alternative white‐tailed deer (Odocoileus virginianus) buck‐harvest regulations in New York designed to reduce harvest of yearling bucks, taking into consideration the values of the state wildlife agency responsible for managing deer, as well as deer hunters. We incorporated tradeoffs about social, ecological, and economic management concerns throughout the state. Based on the outcomes of predictive models, expert elicitation, and hunter surveys, the SDM process identified management alternatives that optimized competing objectives. The SDM process provided biologists and managers insight about aspects of the buck‐harvest decision that helped them adopt a management strategy most compatible with diverse hunter values and management concerns.
Early warning signals, nonlinearity, and signs of hysteresis in real ecosystems
Authors: Litzow Michael A. , Hunsicker Mary E. 
Published: December 2016

AbstractEarly warning signals (EWS) might dramatically improve our ability to manage nonlinear ecological change. However, the degree to which theoretical EWS predictions are supported in empirical systems remains unclear. The goal of this study is to make recommendations for identifying the types of ecological transitions that are expected to show EWS. We conducted a review and meta‐analysis of published studies and comparative analysis of eight northeast Pacific Ocean time series to illustrate the importance of testing for nonlinearity in empirical EWS studies. We found that published studies demonstrating nonlinearity in ecosystem dynamics are more likely to support EWS predictions than studies with linear or undetermined dynamics. The northeast Pacific time series in our analysis were often too short for formal tests of nonlinearity, a common problem in empirical studies. To assess the evidence for nonlinear dynamics in these data, we tested for state‐dependent driver–response relationships consistent with hysteresis, a central feature of nonlinear ecological models. This analysis supported the results of the literature meta‐analysis. Four time series with driver–response relationships consistent with hysteresis generally supported theoretical EWS predictions, while four without evidence of hysteresis failed to support EWS predictions. Theoretical support for EWS is largely generated from nonlinear models, and we conclude that tests for either nonlinear dynamics or hysteresis are needed before employing EWS.