bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential declines in Alaskan boreal forest vitality related to climate and competition
Authors: Trugman Anna T. , Medvigy David , Anderegg William R. L. , Pacala Stephen W. 
Published: October 2017

AbstractRapid warming and changes in water availability at high latitudes alter resource abundance, tree competition, and disturbance regimes. While these changes are expected to disrupt the functioning of boreal forests, their ultimate implications for forest composition are uncertain. In particular, recent site‐level studies of the Alaskan boreal forest have reported both increases and decreases in productivity over the past few decades. Here, we test the idea that variations in Alaskan forest growth and mortality rates are contingent on species composition. Using forest inventory measurements and climate data from plots located throughout interior and south‐central Alaska, we show significant growth and mortality responses associated with competition, midsummer vapor pressure deficit, and increased growing season length. The governing climate and competition processes differed substantially across species. Surprisingly, the most dramatic climate response occurred in the drought tolerant angiosperm species, trembling aspen, and linked high midsummer vapor pressure deficits to decreased growth and increased insect‐related mortality. Given that species composition in the Alaskan and western Canadian boreal forests is projected to shift toward early‐successional angiosperm species due to fire regime, these results underscore the potential for a reduction in boreal productivity stemming from increases in midsummer evaporative demand.
Simulating the onset of spring vegetation growth across the Northern Hemisphere
Authors: Liu Qiang , Fu Yongshuo H. , Liu Yongwen , Janssens Ivan A. , Piao Shilong 
Published: October 2017

AbstractChanges in the spring onset of vegetation growth in response to climate change can profoundly impact climate–biosphere interactions. Thus, robust simulation of spring onset is essential to accurately predict ecosystem responses and feedback to ongoing climate change. To date, the ability of vegetation phenology models to reproduce spatiotemporal patterns of spring onset at larger scales has not been thoroughly investigated. In this study, we took advantage of phenology observations via remote sensing to calibrate and evaluated six models, including both one‐phase (considering only forcing temperatures) and two‐phase (involving forcing, chilling, and photoperiod) models across the Northern Hemisphere between 1982 and 2012. Overall, we found that the model that integrated the photoperiod effect performed best at capturing spatiotemporal patterns of spring phenology in boreal and temperate forests. By contrast, all of the models performed poorly in simulating the onset of growth in grasslands. These results suggest that the photoperiod plays a role in controlling the onset of growth in most Northern Hemisphere forests, whereas other environmental factors (e.g., precipitation) should be considered when simulating the onset of growth in grasslands. We also found that the one‐phase model performed as well as the two‐phase models in boreal forests, which implies that the chilling requirement is probably fulfilled across most of the boreal zone. Conversely, two‐phase models performed better in temperate forests than the one‐phase model, suggesting that photoperiod and chilling play important roles in these temperate forests. Our results highlight the significance of including chilling and photoperiod effects in models of the spring onset of forest growth at large scales, and indicate that the consideration of additional drivers may be required for grasslands.
Temperature and soil fertility as regulators of tree line Scots pine growth and survival—implications for the acclimation capacity of northern populations
Authors: Rousi Matti , Possen Boy J. M. H. , Ruotsalainen Seppo , Silfver Tarja , Mikola Juha 
Published: October 2017

AbstractThe acclimation capacity of leading edge tree populations is crucially important in a warming climate. Theoretical considerations suggest that adaptation through genetic change is needed, but this may be a slow process. Both positive and catastrophic outcomes have been predicted, while empirical studies have lagged behind theory development. Here we present results of a 30‐year study of 55,000 Scots pine (Pinus sylvestris) trees, planted in 15 common gardens in three consecutive years near and beyond the present Scots pine tree line. Our results show that, contrary to earlier predictions, even long‐distance transfers to the North can be successful when soil fertility is high. This suggests that present northern populations have a very high acclimation capacity. We also found that while temperature largely controls Scots pine growth, soil nutrient availability plays an important role—in concert with interpopulation genetic variation—in Scots pine survival and fitness in tree line conditions. These results suggest that rapid range expansions and substantial growth enhancements of Scots pine are possible in fertile sites as seed production and soil nutrient mineralization are both known to increase under a warming climate. Finally, as the ontogenetic pattern of tree mortality was highly site specific and unpredictable, our results emphasize the need for long‐term field trials when searching for the factors that control fitness of trees in the variable edaphic and climatic conditions of the far North.
Diversification in tropics and subtropics following the mid‐Miocene climate change: A case study of the spider genusNesticella
Authors: Ballarin Francesco , Li Shuqiang 
Published: October 2017

AbstractCaves may offer suitable refugia for troglophilic invertebrates during periods of unfavourable climatic conditions because of their stable microclimates. As a consequence, allopatric divergence from their epigean counterparts may occur, leading to formation of truly hypogean communities (the Climatic Relict Hypothesis). Unlike the well‐studied effects of Pleistocene glaciations, we know little about how ancient climate changes drove the development of cave‐dwelling organisms living at both middle and lower latitudes. We investigate the evolutionary history of the troglophilic spider genusNesticella(Araneae, Nesticidae) in relation to Asian Neogene (23–2.6 Ma) climatic changes. Our analyses discern clear differences in the evolution of the two main clades ofNesticella, which occur in temperate/subtropical and tropical latitudes. Eastern AsianNesticellagradually evolved greater sedentariness and a strict subterranean lifestyle starting from the middle Miocene Epoch (~15–14 Ma) in conjunction with the progressive deterioration of the climate and vegetational shifts. Caves appear to have acted as refugia because of their internally uniform temperature and humidity, which allowed these spiders to survive increasing external seasonality and habitat loss. In contrast, a uniform accumulation of lineages, long‐lasting times for dispersals and the lack of a comparable habitat shifting characterized the tropical lineage. This difference in pattern likely owes to the mild effects of climate change at low latitudes and the consequent lack of strong climatic drivers in tropical environments. Thus, the mid‐Miocene climatic shift appears to be the major evolutionary force shaping the ecological differences between Asian troglophilic invertebrates and the driver of the permanent hypogean communities in middle latitudes.
Global climate change increases risk of crop yield losses and food insecurity in the tropical Andes
Authors: Tito Richard , Vasconcelos Heraldo L. , Feeley Kenneth J. 
Published: October 2017

AbstractOne of the greatest current challenges to human society is ensuring adequate food production and security for a rapidly growing population under changing climatic conditions. Climate change, and specifically rising temperatures, will alter the suitability of areas for specific crops and cultivation systems. In order to maintain yields, farmers may be forced to change cultivation practices, the timing of cultivation, or even the type of crops grown. Alternatively, farmers can change the location where crops are cultivated (e.g., to higher elevations) to track suitable climates (in which case the plants will have to grow in different soils), as cultivated plants will otherwise have to tolerate warmer temperatures and possibly face novel enemies. We simulated these two last possible scenarios (for temperature increases of 1.3°C and 2.6°C) in the Peruvian Andes through a field experiment in which several traditionally grown varieties of potato and maize were planted at different elevations (and thus temperatures) using either the local soil or soil translocated from higher elevations. Maize production declined by 21%–29% in response to new soil conditions. The production of maize and potatoes declined by >87% when plants were grown under warmer temperatures, mainly as a result of the greater incidence of novel pests. Crop quality and value also declined under simulated migration and warming scenarios. We estimated that local farmers may experience severe economic losses of up to 2,300 US$ ha−1 yr−1. These findings reveal that climate change is a real and imminent threat to agriculture and that there is a pressing need to develop effective management strategies to reduce yield losses and prevent food insecurity. Importantly, such strategies should take into account the influences of non‐climatic and/or biotic factors (e.g., novel pests) on plant development.
Carbon sequestration and turnover in soil under the energy crop Miscanthus: repeated 13C natural abundance approach and literature synthesis
Authors: Zang Huadong , Blagodatskaya Evgenia , Wen Yuan , Xu Xingliang , Dyckmans Jens , Kuzyakov Yakov 
Published: October 2017

AbstractThe stability and turnover of soil organic matter (SOM) are a very important but poorly understood part of carbon (C) cycling. Conversion of C3 grassland to the C4 energy crop Miscanthus provides an ideal opportunity to quantify medium‐term SOM dynamics without disturbance (e.g., plowing), due to the natural shift in the δ13C signature of soil C. For the first time, we used a repeated 13C natural abundance approach to measure C turnover in a loamy Gleyic Cambisol after 9 and 21 years of Miscanthus cultivation. This is the longest C3–C4 vegetation change study on C turnover in soil under energy crops. SOM stocks under Miscanthus and reference grassland were similar down to 1 m depth. However, both increased between 9 and 21 years from 105 to 140 mg C ha−1 (P < 0.05), indicating nonsteady state of SOM. This calls for caution when estimating SOM turnover based on a single sampling. The mean residence time (MRT) of old C (>9 years) increased with depth from 19 years (0–10 cm) to 30–152 years (10–50 cm), and remained stable below 50 cm. From 41 literature observations, the average SOM increase after conversion from cropland or grassland to Miscanthus was 6.4 and 0.4 mg C ha−1, respectively. The MRT of total C in topsoil under Miscanthus remained stable at ~60 years, independent of plantation age, corroborating the idea that C dynamics are dominated by recycling processes rather than by C stabilization. In conclusion, growing Miscanthus on C‐poor arable soils caused immediate C sequestration because of higher C input and decreased SOM decomposition. However, after replacing grasslands with Miscanthus, SOM stocks remained stable and the MRT of old C3‐C increased strongly with depth.
Idaho forest growth response to post‐thinning energy biomass removal and complementary soil amendments
Authors: Sherman Lauren A. , Page‐Dumroese Deborah S. , Coleman Mark D. 
Published: October 2017

AbstractUtilization of woody biomass for biofuel can help meet the need for renewable energy production. However, there is a concern biomass removal will deplete soil nutrients, having short‐ and long‐term effects on tree growth. This study aimed to develop short‐term indicators to assess the impacts of the first three years after small‐diameter woody biomass removal on forest productivity to establish optimal biomass retention levels for mixed‐conifer forests in the Inland Northwest region, and to evaluate the ability of soil amendments to compensate for potential adverse effects from biomass removal. We examined impacts of four biomass retention‐level treatments at two study locations: full biomass removal (0x), full biomass retention (1x), double biomass retention (2x), and unthinned control. We combined biomass retention with four soil amendment treatments: biochar (B), fertilizer (F), fertilizer and biochar combined (FB), and an untreated control (C). We considered treatment effects on basal area and total stem volume growth for all trees per plot (plot trees) and for the six largest trees per plot (crop trees). Biomass removal had no effect on plot (P > 0.40) or crop tree growth (P > 0.65) compared to normal biomass retention. High biomass retention (2x) decreased plot tree growth as compared to normal biomass retention (1x) levels (P < 0.05) after three years. This growth difference was not explained by soil moisture, temperature, or nutrient uptake. While there were strong tree growth differences between study locations, patterns of biomass and amendment treatment responses did not differ. Fertilizer increased basal area growth and total volume growth (P < 0.10) as expected, because nitrogen is limiting in the region. Biochar had no effect on tree growth (P > 0.47). Initial findings after three years suggest removing small‐diameter biomass for biofuel feedstocks is feasible in the Inland Northwest without negative impacts on tree growth.
Consensus, uncertainties and challenges for perennial bioenergy crops and land use
Authors: Whitaker Jeanette , Field John L. , Bernacchi Carl J. , Cerri Carlos E. P. , Ceulemans Reinhart , Davies Christian A. , DeLucia Evan H. , Donnison Iain S. , McCalmont Jon P. , Paustian Keith , Rowe Rebecca L. , Smith Pete , Thornley Patricia , McNamara Niall P. 
Published: October 2017

AbstractPerennial bioenergy crops have significant potential to reduce greenhouse gas (GHG) emissions and contribute to climate change mitigation by substituting for fossil fuels; yet delivering significantGHGsavings will require substantial land‐use change, globally. Over the last decade, research has delivered improved understanding of the environmental benefits and risks of this transition to perennial bioenergy crops, addressing concerns that the impacts of land conversion to perennial bioenergy crops could result in increased rather than decreasedGHGemissions. For policymakers to assess the most cost‐effective and sustainable options for deployment and climate change mitigation, synthesis of these studies is needed to support evidence‐based decision making. In 2015, a workshop was convened with researchers, policymakers and industry/business representatives from theUK,EUand internationally. Outcomes from global research on bioenergy land‐use change were compared to identify areas of consensus, key uncertainties, and research priorities. Here, we discuss the strength of evidence for and against six consensus statements summarising the effects of land‐use change to perennial bioenergy crops on the cycling of carbon, nitrogen and water, in the context of the whole life‐cycle of bioenergy production. Our analysis suggests that the direct impacts of dedicated perennial bioenergy crops on soil carbon and nitrous oxide are increasingly well understood and are often consistent with significant life cycleGHGmitigation from bioenergy relative to conventional energy sources. We conclude that theGHGbalance of perennial bioenergy crop cultivation will often be favourable, with maximumGHGsavings achieved where crops are grown on soils with low carbon stocks and conservative nutrient application, accruing additional environmental benefits such as improved water quality. The analysis reported here demonstrates there is a mature and increasingly comprehensive evidence base on the environmental benefits and risks of bioenergy cultivation which can support the development of a sustainable bioenergy industry.
Health sciences libraries in the United States: new directions
Authors: Epstein Barbara A. 
Published: October 2017

AbstractThis article is the third in a series in this regular feature. The intention of the series is to look at important global developments in health science libraries. These articles will serve as a road map, describing the key changes in the field and exploring factors driving these changes. The present article by the current president of the Medical Library Association outlines two important developments in the United States. The topics chosen for consideration are national initiatives in the United States impacting health sciences libraries and librarians and enhanced roles for U.S. health sciences librarians in providing support for research.J.M.
Inhaled Cryptococcus neoformans elicits allergic airway inflammation independent of Nuclear Factor Kappa B signalling in lung epithelial cells
Authors: McDermott Andrew J. , Tumey Tyler A. , Huang Mingwei , Hull Christina M. , Klein Bruce S. 
Published: October 2017

SummaryPulmonary challenge with the ubiquitous fungus Cryptococcus neoformans results in allergic airway inflammation (AAI) characterized by robust recruitment of eosinophils and T cells producing type 2 cytokines to the lungs. Previous studies have demonstrated a critical role for Nuclear Factor Kappa B (NF‐κB) activation within lung epithelial cells (LECs) in driving AAI in response to protein allergens, yet the role of LEC‐intrinsic NF‐κB in promoting AAI following exposure to C. neoformans is poorly understood. To investigate the role of LEC‐intrinsic NF‐κB in promoting AAI following C. neoformans challenge, we used IKK∆LEC mice, which lack canonical NF‐κB activation specifically within LECs. IKK∆LEC and littermate control mice were intranasally challenged with 106 CFU of C. neoformans strain 52D, and lung tissues were collected at 7, 14 and 21 days post infection to assess the development of AAI. Notably, the absence of epithelial NF‐κB signalling did not affect the magnitude or kinetics of lung eosinophilia when compared with the response in wild‐type control mice. The total numbers of lung T cells producing the type 2 cytokines interleukin‐5 and interleukin‐13 were also unchanged in IKK∆LEC mice. Furthermore, IKK∆LEC mice showed no defect in the recruitment of protective interferon‐γ‐producing CD4 T cells to the lungs, fungal clearance, or host survival compared with control mice. Immunofluorescence imaging surprisingly revealed no evidence of nuclear localization of NF‐κB in LECs in response to C. neoformans challenge, indicating that NF‐κB is not activated within these cells. Taken together, these data strongly suggest that NF‐κB signalling within LECs does not promote AAI observed in response to C. neoformans.
Crack propagation in silica from reactive classical molecular dynamics simulations
Authors: Rimsza Jessica M. , Jones Reese E. , Criscenti Louise J. 
Published: October 2017

AbstractMechanistic insight into the process of crack growth can be obtained through molecular dynamics (MD) simulations. In this investigation of fracture propagation, a slit crack was introduced into an atomistic amorphous silica model and mode I stress was applied through far‐field loading until the crack propagates. Atomic displacements and forces and an Irving–Kirkwood method with a Lagrangian kernel estimator were used to calculate the J‐integral of classical fracture mechanics around the crack tip. The resulting fracture toughness (KIC), 0.76 ± 0.16 MPa√m, agrees with experimental values. In addition, the stress fields and dissipation energies around the slit crack indicate the development of an inelastic region ~30Å in diameter. This is one of the first reports of KIC values obtained from up‐scaled atomic‐level energies and stresses through the J‐integral. The application of the ReaxFF classical MD force field in this study provides the basis for future research into crack growth in multicomponent oxides in a variety of environmental conditions.
Coupled experimental phase diagram study and thermodynamic optimization of the Li2O–MgO–SiO2 system
Authors: Konar Bikram , Kim Dong‐Geun , Jung In‐Ho 
Published: October 2017

AbstractA coupled key phase diagram study and critical evaluation and optimization of all available experimental data of the Li2O–MgO–SiO2 system was performed to obtain a set of Gibbs energy functions to reproduce all the reliable phase equilibria and thermodynamic data. Differential scanning calorimetry measurements and equilibration/quenching experiments were performed in the Li2SiO3–MgO and Li4SiO4–Mg2SiO4 sections, respectively, using sealed Pt capsules to prevent the volatile loss of Li. According to the present experimental results, Li2MgSiO4 is the only compound present in the Li4SiO4–Mg2SiO4 isopleth, which shows a peritectic melting at 1465 ± 6°C (1738 ± 6 K). The Modified Quasichemical Model, which considers short‐range ordering in the melt, was employed to describe the thermodynamic properties of the liquid phase. The Li4SiO4–Li2MgSiO4 and Mg2SiO4‐rich solid solutions were modeled using the Compound Energy Formalism.
High temperature electrode‐electrolyte interface formation between LiMn1.5Ni0.5O4 and Li1.4Al0.4Ge1.6(PO4)3
Authors: Robinson J. Pierce , Kichambare Padmakar D. , Deiner Jay L. , Miller Ryan , Rottmayer Michael A. , Koenig Gary M. 
Published: October 2017

AbstractAll‐solid‐state lithium‐ion electrolytes offer substantial safety benefits compared to flammable liquid organic electrolytes. However, a great challenge in solid electrolyte batteries is forming a stable and ion conducting interface between the electrolyte and active material. This study investigates and characterizes a possible solid‐state electrode‐electrolyte pair for the high voltage active cathode material LiMn1.5Ni0.5O4 (LMNO) and electrolyte Li1+xAlxGe2‐x(PO4)3 (LAGP). In situ X‐ray diffraction measurements were taken on pressed pellets comprised of a blend of LMNO and LAGP during exposure to elevated temperatures to determine the product materials that form at the interface of LMNO and LAGP and the temperatures at which they form. In particular, above 600°C a material consistent with LiMnPO4 was formed. Scanning electron microscopy and energy‐dispersive X‐ray spectroscopy were used to image the morphology and elemental compositions of product materials at the interface, and electrochemical characterization was performed on LMNO‐coated LAGP electrolyte pellet half cells. Although the voltage of Li/LAGP/LMNO assembled batteries was promising, thick interfacial phases resulted in high electrochemical resistance, demonstrating the need for further understanding and control over material processing in the LAGP/LMNO system to reduce interfacial resistance and improve electrochemical performance.
Hydrothermal synthesis of silicon oxide clad uranium oxide nanowires
Authors: He Lingfeng , Harp Jason M. , Wagner Adrian R. , Hoggan Rita E. , Tolman Kevin R. 
Published: October 2017

AbstractA facile method to synthesize silicon oxide clad uranium oxide nanowires is presented. U3Si2, used as a precursor, was oxidized to produce uranium oxide nanocrystallites and amorphous silicon oxide under hydrothermal conditions at 300°C and a pressure of 7.8 × 106 Pa. The growth of uranium oxide nanowires was assisted by silicon oxide via assembling the uranium oxide nanocrystallites in an amorphous silicon oxide matrix. The microstructure and composition of silicon oxide clad uranium oxide nanowires were characterized by XRD, SEM, TEM, and EDS. The uranium oxide in the nanowires was determined as UO2.34 with a fluoride cubic structure.