Models of invasion and establishment of African Mustard (Brassica tournefortii)

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Berry, Kristin H.; Gowan, Timothy A.; Miller, David M.; Brooks, Matthew L.

2015-01-01

Introduced exotic plants can drive ecosystem change. We studied invasion and establishment ofBrassica tournefortii (African mustard), a noxious weed, in the Chemehuevi Valley, western Sonoran Desert, California. We used long-term data sets of photographs, transects for biomass of annual plants, and densities of African mustard collected at irregular intervals between 1979 and 2009. We suggest that African mustard may have been present in low numbers along the main route of travel, a highway, in the late 1970s; invaded the valley along a major axial valley ephemeral stream channel and the highway; and by 2009, colonized 22 km into the eastern part of the valley. We developed predictive models for invasibility and establishment of African mustard. Both during the initial invasion and after establishment, significant predictor variables of African mustard densities were surficial geology, proximity to the highway and axial valley ephemeral stream channel, and number of small ephemeral stream channels. The axial valley ephemeral stream channel was the most vulnerable of the variables to invasions. Overall, African mustard rapidly colonized and quickly became established in naturally disturbed areas, such as stream channels, where geological surfaces were young and soils were weakly developed. Older geological surfaces (e.g., desert pavements with soils 140,000 to 300,000 years old) were less vulnerable. Microhabitats also influenced densities of African mustard, with densities higher under shrubs than in the interspaces. As African mustard became established, the proportional biomass of native winter annual plants declined. Early control is important because African mustard can colonize and become well established across a valley in 20 yr.

Seasonal cues induce phenotypic plasticity of Drosophila suzukii to enhance winter survival.

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Shearer, Peter W; West, Jessica D; Walton, Vaughn M; Brown, Preston H; Svetec, Nicolas; Chiu, Joanna C

2016-03-22

As global climate change and exponential human population growth intensifies pressure on agricultural systems, the need to effectively manage invasive insect pests is becoming increasingly important to global food security. Drosophila suzukii is an invasive pest that drastically expanded its global range in a very short time since 2008, spreading to most areas in North America and many countries in Europe and South America. Preliminary ecological modeling predicted a more restricted distribution and, for this reason, the invasion of D. suzukii to northern temperate regions is especially unexpected. Investigating D. suzukii phenology and seasonal adaptations can lead to a better understanding of the mechanisms through which insects express phenotypic plasticity, which likely enables invasive species to successfully colonize a wide range of environments. We describe seasonal phenotypic plasticity in field populations of D. suzukii. Specifically, we observed a trend of higher proportions of flies with the winter morph phenotype, characterized by darker pigmentation and longer wing length, as summer progresses to winter. A laboratory-simulated winter photoperiod and temperature (12:12 L:D and 10 °C) were sufficient to induce the winter morph phenotype in D. suzukii. This winter morph is associated with increased survival at 1 °C when compared to the summer morph, thus explaining the ability of D. suzukii to survive cold winters. We then used RNA sequencing to identify gene expression differences underlying seasonal differences in D. suzukii physiology. Winter morph gene expression is consistent with known mechanisms of cold-hardening such as adjustments to ion transport and up-regulation of carbohydrate metabolism. In addition, transcripts involved in oogenesis and DNA replication were down-regulated in the winter morph, providing the first molecular evidence of a reproductive diapause in D. suzukii. To date, D. suzukii cold resistance studies suggest that this

Payment mechanisms for winter road maintenance services

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Adel Abdi

2013-12-01

Full Text Available In countries with severe winters a major part of the annual budget for road maintenance is allocated on performance of winter road maintenance tasks. Finding appropriate remuneration forms to compensate entrepreneurs for performed road measures during winter is not an easy task in order to minimise or eliminate disputes and satisfy both client organisations and contractors. On the other hand improper reimbursement models lead either to the client’s annual budget imbalance due to unnecessary cost overruns or affect contractor’s cash-flow. Such cases in turn affect just-in-time winter road maintenance and then traffic safety. To solve such problems, a number of countries in cold regions like Sweden have developed different remuneration models based more on weather data called Weather Index. Therefore the objective of this paper is to investigate and evaluate the payment models applied in Sweden. The study uses a number of approaches namely; domestic questionnaire survey, analysis of a number of contract documents, a series of meetings with the project managers and an international benchmarking. The study recognised four remuneration models for winter maintenance service of which one based on weather data statistics. The study reveals the payment model based on weather data statistics is only applied for the roads with higher traffic flow and the model generates most uncertainty.

Energy and tannin extract supplementation for dairy cows on annual winter pastures

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Tiago Pansard Alves

2017-05-01

Full Text Available Energy supplementation can increase the consumption of metabolizable energy and substrate for microbial growth, while condensed tannins aid in increasing the duodenal flow of foodborne metabolizable proteins. The objective of this study was to evaluate the effects of energy supplementation and the inclusion of tannin extract (TE from Acacia mearnsii (Weibull Black, Tanac S. A., Montenegro, Brazil on the production performance of dairy cows grazing on winter pastures. Nine multiparous Holstein cows in mid lactation were distributed in a 3 × 3 Latin square experimental design over three periods of 28 days (21 adaptation and 7 sampling. The treatments were: without supplementation (WS, supplementation with 4 kg of corn grain (CG, and corn grain + 80 g of tannin extract (TE. The dry matter (DM intake from pastures was similar among treatments, but the consumption of DM of the supplement was higher in the CG treatment than that in the TE treatment. The total DM intake was higher for the supplemented animals (17.3 kg?day-1 than that for the unsupplemented animals (14.9 kg?day-1 and in the TE treatment (17.7 kg?day-1 than in the CG treatment (16.7 kg day-1. Milk production increased from the unsupplemented to the supplemented animals (20.9 to 23.5 kg, respectively, while the content of urea N in the milk decreased (12.6 to 10.5 mg?100 mL-1, respectively. There were no differences in milk production or content of milk urea N between the CG and TE treatments. Energy supplementation is a tool for improving the nutritional profile and the performance of dairy cows in mid lactation grazing on annual winter pastures, while tannin extract aids in improving the energy balance.

Using resistance and resilience concepts to reduce impacts of invasive annual grasses and altered fire regimes on the sagebrush ecosystem and greater sage-grouse: A strategic multi-scale approach

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Jeanne C. Chambers; David A. Pyke; Jeremy D. Maestas; Mike Pellant; Chad S. Boyd; Steven B. Campbell; Shawn Espinosa; Douglas W. Havlina; Kenneth E. Mayer; Amarina Wuenschel

2014-01-01

This Report provides a strategic approach for conservation of sagebrush ecosystems and Greater Sage- Grouse (sage-grouse) that focuses specifically on habitat threats caused by invasive annual grasses and altered fire regimes. It uses information on factors that influence (1) sagebrush ecosystem resilience to disturbance and resistance to invasive annual grasses and (2...

Large-scale climate variation modifies the winter grouping behavior of endangered Indiana bats

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Thogmartin, Wayne E.; McKann, Patrick C.

2014-01-01

Power laws describe the functional relationship between 2 quantities, such as the frequency of a group as the multiplicative power of group size. We examined whether the annual size of well-surveyed wintering populations of endangered Indiana bats (Myotis sodalis) followed a power law, and then leveraged this relationship to predict whether the aggregation of Indiana bats in winter was influenced by global climate processes. We determined that Indiana bat wintering populations were distributed according to a power law (mean scaling coefficient α = −0.44 [95% confidence interval {95% CI} = −0.61, −0.28). The antilog of these annual scaling coefficients ranged between 0.67 and 0.81, coincident with the three-fourths power found in many other biological phenomena. We associated temporal patterns in the annual (1983–2011) scaling coefficient with the North Atlantic Oscillation (NAO) index in August (βNAOAugust = −0.017 [90% CI = −0.032, −0.002]), when Indiana bats are deciding when and where to hibernate. After accounting for the strong effect of philopatry to habitual wintering locations, Indiana bats aggregated in larger wintering populations during periods of severe winter and in smaller populations in milder winters. The association with August values of the NAO indicates that bats anticipate future winter weather conditions when deciding where to roost, a heretofore unrecognized role for prehibernation swarming behavior. Future research is needed to understand whether the three-fourths–scaling patterns we observed are related to scaling in metabolism.

Winter precipitation and fire in the Sonoran Desert

Energy Technology Data Exchange (ETDEWEB)

Rogers, G.F.; Vint, M.K.

1987-01-01

Historical fire and climate records from the Arizona Upland portion of the Tonto National forest were used to test the hypothesis that fires burn larger areas in the Sonoran Desert after two wet winters than after one. We found that many more hectares burn in years following two winters that are wetter than normal, than during any other years. We agree with other ecologists, that desert fire occurrence is probably related to increased production of winter annual plants, and we suggest ways that the relationship may be clarified.

Contrasting effects of temperature and winter mixing on the seasonal and inter-annual variability of the carbonate system in the Northeast Atlantic Ocean

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C. Dumousseaud

2010-05-01

Full Text Available Future climate change as a result of increasing atmospheric CO₂ concentrations is expected to strongly affect the oceans, with shallower winter mixing and consequent reduction in primary production and oceanic carbon drawdown in low and mid-latitudinal oceanic regions. Here we test this hypothesis by examining the effects of cold and warm winters on the carbonate system in the surface waters of the Northeast Atlantic Ocean for the period between 2005 and 2007. Monthly observations were made between the English Channel and the Bay of Biscay using a ship of opportunity program. During the colder winter of 2005/2006, the maximum depth of the mixed layer reached up to 650 m in the Bay of Biscay, whilst during the warmer (by 2.6 ± 0.5 °C winter of 2006/2007 the mixed layer depth reached only 300 m. The inter-annual differences in late winter concentrations of nitrate (2.8 ± 1.1 μmol l⁻¹ and dissolved inorganic carbon (22 ± 6 μmol kg⁻¹, with higher concentrations at the end of the colder winter (2005/2006, led to differences in the dissolved oxygen anomaly and the chlorophyll α-fluorescence data for the subsequent growing season. In contrast to model predictions, the calculated air-sea CO₂ fluxes (ranging from +3.7 to −4.8 mmol m⁻² d⁻¹ showed an increased oceanic CO₂ uptake in the Bay of Biscay following the warmer winter of 2006/2007 associated with wind speed and sea surface temperature differences.

Reproductive arrest and stress resistance in winter-acclimated Drosophila suzukii.

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Toxopeus, Jantina; Jakobs, Ruth; Ferguson, Laura V; Gariepy, Tara D; Sinclair, Brent J

2016-06-01

Overwintering insects must survive the multiple-stress environment of winter, which includes low temperatures, reduced food and water availability, and cold-active pathogens. Many insects overwinter in diapause, a developmental arrest associated with high stress tolerance. Drosophila suzukii (Diptera: Drosophilidae), spotted wing drosophila, is an invasive agricultural pest worldwide. Its ability to overwinter and therefore establish in temperate regions could have severe implications for fruit crop industries. We demonstrate here that laboratory populations of Canadian D. suzukii larvae reared under short-day, low temperature, conditions develop into dark 'winter morph' adults similar to those reported globally from field captures, and observed by us in southern Ontario, Canada. These winter-acclimated adults have delayed reproductive maturity, enhanced cold tolerance, and can remain active at low temperatures, although they do not have the increased desiccation tolerance or survival of fungal pathogen challenges that might be expected from a more heavily melanised cuticle. Winter-acclimated female D. suzukii have underdeveloped ovaries and altered transcript levels of several genes associated with reproduction and stress. While superficially indicative of reproductive diapause, the delayed reproductive maturity of winter-acclimated D. suzukii appears to be temperature-dependent, not regulated by photoperiod, and is thus unlikely to be 'true' diapause. The traits of this 'winter morph', however, likely facilitate overwintering in southern Canada, and have probably contributed to the global success of this fly as an invasive species. Copyright © 2016 Elsevier Ltd. All rights reserved.

Controls on winter ecosystem respiration in temperate and boreal ecosystems

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T. Wang; P. Ciais; S.L. Piao; C. Ottle; P. Brender; F. Maignan; A. Arain; A. Cescatti; D. Gianelle; C. Gough; L Gu; P. Lafleur; T. Laurila; B. Marcolla; H. Margolis; L. Montagnani; E. Moors; N. Saigusa; T. Vesala; G. Wohlfahrt; C. Koven; A. Black; E. Dellwik; A. Don; D. Hollinger; A. Knohl; R. Monson; J. Munger; A. Suyker; A. Varlagin; S. Verma

2011-01-01

Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the factors influencing the spatial and temporal...

Development of restriction enzyme analyses to distinguish winter moth from bruce spanworm and hybrids between them

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Marinko Sremac; Joseph Elkinton; Adam. Porter

2011-01-01

Elkinton et. al. recently completed a survey of northeastern North America for the newly invasive winter moth, Operophtera brumata L. The survey used traps baited with the winter moth pheromone, which consists of a single compound also used by Bruce spanworm, O. bruceata (Hulst), the North American congener of winter moth. Our...

Bottom-up control of consumers leads to top-down indirect facilitation of invasive annual herbs in semiarid Chile.

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Madrigal, Jaime; Kelt, Douglas A; Meserve, Peter L; Gutierrez, Julio R; Squeo, Francisco A

2011-02-01

The abundance of exotic plants is thought to be limited by competition with resident species (including plants and generalist herbivores). In contrast, observations in semiarid Chile suggest that a native generalist rodent, the degu (Octodon degus), may be facilitating the expansion of exotic annual plants. We tested this hypothesis with a 20-year data set from a World Biosphere Reserve in mediterranean Chile. In this semiarid environment, rainfall varies annually and dramatically influences cover by both native and exotic annual plants; degu population density affects the composition and cover of exotic and native annual plants. In low-rainfall years, cover of both native and exotic herbs is extremely low. Higher levels of precipitation result in proportional increases in cover of all annual plants (exotic and native species), leading in turn to increases in degu population densities, at which point they impact native herbs in proportion to their greater cover, indirectly favoring the expansion of exotic plants. We propose that bottom-up control of consumers at our site results in top-down indirect facilitation of invasive annual herbs, and that this pattern may be general to other semiarid ecosystems.

Nitrogen and carbohydrate fractions in exclusive Tifton 85 and in pasture oversown with annual winter forage species - 10.4025/actascianimsci.v34i1.11428

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Ana Claudia Ruggieri

2011-11-01

Full Text Available The experiment was undertaken at the Faculty of Agrarian and Veterinary Sciences (FCAV Jaboticabal, São Paulo State, Brazil, during winter-spring-summer of 2001-2002, to determine the fractionation of nitrogen and carbohydrates in Tifton 85 (Cynodon dactylon Vanderyst x Cynodon nlemfuensis (L. Pers, exclusively or oversown with winter annual forage species. Treatments comprised bristle oat (Avena strigosa Schreb, yellow oat (Avena byzantina C. Koch, triticale (X Triticosecale Wittmack, bristle oat + yellow oat, bristle oat + triticale, yellow oat + triticale, bristle oat + yellow oat + triticale seeded in Tifton 85 and sole crop (control. Experimental design was composed of completely randomized blocks with three replications. Fodder was cut 20 cm high (presence of winter forage and 10 cm high (Tifton 85 pasture. Crude protein, total carbohydrate and the fractions of nitrogen compounds and carbohydrates were determined. Decrease was reported in the levels of chemical compounds in winter forage species and in Tifton 85 during the evaluation periods. The content of nitrogen compounds and carbohydrates varied widely during the evaluation period according to the morphological characteristics of grass species and botanical composition of pastures.

Non-Invasive Assessment of the Interrelationships of Diet, Pregnancy Rate, Group Composition, and Physiological and Nutritional Stress of Barren-Ground Caribou in Late Winter.

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Kyle Joly

Full Text Available The winter diet of barren-ground caribou may affect adult survival, timing of parturition, neonatal survival, and postpartum mass. We used microhistological analyses and hormone levels in feces to determine sex-specific late-winter diets, pregnancy rates, group composition, and endocrine-based measures of physiological and nutritional stress. Lichens, which are highly digestible but contain little protein, dominated the diet (> 68% but were less prevalent in the diets of pregnant females as compared to non-pregnant females and males. The amount of lichens in the diets of pregnant females decreased at higher latitudes and as winter progressed. Pregnancy rates (82.1%, 95% CI = 76.0 - 88.1% of adult cows were within the expected range for a declining herd, while pregnancy status was not associated with lichen abundance in the diet. Most groups (80% were of mixed sex. Male: female ratios (62:100 were not skewed enough to affect the decline. Levels of hormones indicating nutritional stress were detected in areas of low habitat quality and at higher latitudes. Levels of hormones indicated that physiological stress was greatest for pregnant cows, which faced the increasing demands of gestation in late winter. These fecal-based measures of diet and stress provided contextual information for the potential mechanisms of the ongoing decline. Non-invasive techniques, such as monitoring diets, pregnancy rates, sex ratios and stress levels from fecal samples, will become increasingly important as monitoring tools as the industrial footprint continues to expand in the Arctic.

Hourly and seasonable variation in catch of winter moths and bruce spanworm in pheromone-baited traps

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Joseph Elkinton; Natalie Leva; George Boettner; Roy Hunkins; Marinko. Sremac

2011-01-01

Elkinton et al. recently completed a survey of northeastern North America for the newly invasive winter moth, Operophtera brumata L. The survey used traps baited with the winter moth pheromone, which, as far as it is known, consists of a single compound that is also used by Bruce spanworm, the North American congener of winter moth, O....

Titan's Emergence from Winter

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Flasar, F. Michael; Achterberg, Richard; Jennings, Donald; Schinder, Paul

2011-01-01

We summarize the changes in Titans thermal structure derived from Cassini CIRS and radio-occultation data during the transition from winter to early spring. Titan's surface, and middle atmosphere show noticeable seasonal change, whereas that in most of the troposphere is mated. This can be understood in terms of the relatively small radiative relaxation time in the middle atmosphere and much larger time scale in the troposphere. The surface exhibits seasonal change because the heat capacity in an annual skin depth is much smaller than that in the lowest scale height of the troposphere. Surface temperatures rise 1 K at raid and high latitudes in the winter northern hemisphere and cool in the southern hemisphere. Changes in in the middle atmosphere are more complicated. Temperatures in the middle stratosphere (approximately 1 mbar) increase by a few kelvin at mid northern latitudes, but those at high latitudes first increase as that region moves out of winter shadow, and then decrease. This probably results from the combined effect of increased solar heating as the suit moves higher in the sky and the decreased adiabatic warming as the sinking motions associated with the cross-equatorial meridional cell weaken. Consistent with this interpretation, the warm temperatures observed higher up at the winter polar stratopause cool significantly.

Invasion of Winter Moth in New England: Effects of Defoliation and Site Quality on Tree Mortality

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Michael J. Simmons

2014-10-01

Full Text Available Widespread and prolonged defoliation by the European winter moth, Operophtera brumata L., has occurred in forests of eastern Massachusetts for more than a decade and populations of winter moth continue to invade new areas of New England. This study characterized the forests of eastern Massachusetts invaded by winter moth and related the duration of winter moth defoliation estimated using dendrochronology to observed levels of tree mortality and understory woody plant density. Quercus basal area mortality in mixed Quercus and mixed Quercus—Pinus strobus forests in eastern Massachusetts ranged from 0–30%; mortality of Quercus in these forests was related to site quality and the number of winter moth defoliation events. In addition, winter moth defoliation events lead to a subsequent increase in understory woody plant density. Our results indicate that winter moth defoliation has been an important disturbance in New England forests that may have lasting impacts.

Cool-season annual pastures with clovers to supplement wintering beef cows nursing calves

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Gunter Stacey A

2012-07-01

Full Text Available Abstract In December of 3 years, 87 beef cows with nursing calves (594 ± 9.8 kg; calving season, September to November at side were stratified by body condition score, body weight, cow age, and calf gender and divided randomly into 6 groups assigned to 1 of 6 cool-season annual pastures (0.45 ha/cow that had been interseeded into a dormant common bermudagrass (Cynodon dactylon [L.] Pers./bahiagrass (Paspalum notatum Flugge sod. Pastures contained 1 of the following 3 seeding mixtures (2 pastures/mixture: 1 wheat (Triticum aestivum L. and ryegrass (Lolium multiflorum Lam., WRG, 2 wheat and ryegrass plus red clover (Trifolium pretense L., WRR, or 3 wheat and ryegrass plus white (Trifolium repens L. and crimson clovers (Trifolium incarnatum L., WRW. All groups had ad libitum access to grass hay (12% crude protein; 58% total digestible nutrients. The second week in December, cow estrous cycles were synchronized and artificially inseminated. In late December, a bull was placed with each group for 60-d. Data were analyzed with an analysis of variance using a mixed model containing treatment as the fixed effect and year as the random effect. Body weight and condition scores did not differ (P ≥ 0.27 among cows between February and June. Calf birth weights or average daily gain did not differ (P ≥ 0.17 among treatments; however, calves grazing pastures with clovers did tend (P = 0.06 to weigh more than calves grazing grass only. Weaning weight per cow exposed to a bull was greater (P = 0.02 for WRR and WRW than WRG. Cows grazing winter-annual pastures containing clovers tended to wean more calf body weight per cow exposed to a bull than cows grazing the grass only pastures.

Winter Video Series Coming in January | Poster

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The Scientific Library’s annual Summer Video Series was so successful that it will be offering a new Winter Video Series beginning in January. For this inaugural event, the staff is showing the eight-part series from National Geographic titled “American Genius.” 

Nitrogen and Winter Cover Crop Effects on Spring and Summer Nutrient Uptake

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Fertilization of bermudagrass [Cynodon dactylon (L.) Pers.] with swine-lagoon effluent in summer, April to September, does not match the period of productivity of the winter annual cover crops, annual ryegrass (Lolium multiflorum L.), cereal rye (Secale cereale), and berseem clover (Trifolium alexan...

Demographic consequences of invasion by a native, controphic competitor to an insular bird population.

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Johnson, K M; Germain, R R; Tarwater, C E; Reid, J M; Arcese, P

2018-05-01

Species invasions and range shifts can lead to novel competitive interactions between historically resident and colonizing species, but the demographic consequences of such interactions remain controversial. We present results from field experiments and 45 years of demographic monitoring to test the hypothesis that the colonization of Mandarte Is., BC, Canada, by fox sparrows (Passerella iliaca) caused the long-term decline of the resident population of song sparrows (Melospiza melodia). Several lines of evidence indicate that competition with fox sparrows for winter food reduced over-winter survival in juvenile song sparrows by 48% from 1960 to 2015, enforcing population decline despite an increase in annual reproductive rate in song sparrows over the same period. Preference for locally abundant seeds presented at experimental arenas suggested complete overlap in diet in song and fox sparrows, and observations at arenas baited with commercial seed showed that fox sparrows displaced song sparrows in 91-100% of interactions in two periods during winter. In contrast, we found no evidence of interspecific competition for resources during the breeding season. Our results indicate that in the absence of marked shifts in niche dimension, range expansions by dominant competitors have the potential to cause the extirpation of historically resident species when competitive interactions between them are strong and resources not equitably partitioned.

Excess winter mortality and cold temperatures in a subtropical city, Guangzhou, China.

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Chun-Quan Ou

Full Text Available BACKGROUND: A significant increase in mortality was observed during cold winters in many temperate regions. However, there is a lack of evidence from tropical and subtropical regions, and the influence of ambient temperatures on seasonal variation of mortality was not well documented. METHODS: This study included 213,737 registered deaths from January 2003 to December 2011 in Guangzhou, a subtropical city in Southern China. Excess winter mortality was calculated by the excess percentage of monthly mortality in winters over that of non-winter months. A generalized linear model with a quasi-Poisson distribution was applied to analyze the association between monthly mean temperature and mortality, after controlling for other meteorological measures and air pollution. RESULTS: The mortality rate in the winter was 26% higher than the average rate in other seasons. On average, there were 1,848 excess winter deaths annually, with around half (52% from cardiovascular diseases and a quarter (24% from respiratory diseases. Excess winter mortality was higher in the elderly, females and those with low education level than the young, males and those with high education level, respectively. A much larger winter increase was observed in out-of-hospital mortality compared to in-hospital mortality (45% vs. 17%. We found a significant negative correlation of annual excess winter mortality with average winter temperature (rs=-0.738, P=0.037, but not with air pollution levels. A 1 °C decrease in monthly mean temperature was associated with an increase of 1.38% (95% CI:0.34%-2.40% and 0.88% (95% CI:0.11%-1.64% in monthly mortality at lags of 0-1 month, respectively. CONCLUSION: Similar to temperate regions, a subtropical city Guangzhou showed a clear seasonal pattern in mortality, with a sharper spike in winter. Our results highlight the role of cold temperature on the winter mortality even in warm climate. Precautionary measures should be strengthened to mitigate

Species distribution modeling for the invasive raccoon dog (Nyctereutes procyonoides in Austria and first range predictions for alpine environments

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Duscher Tanja

2017-01-01

Full Text Available Species distribution models are important tools for wildlife management planning, particularly in the case of invasive species. We employed a recent framework for niche-based invasive species distribution modeling to predict the probability of presence for the invasive raccoon dog (Nyctereutes procyonoides in Austria. The raccoon dog is an adaptive, mobile and highly reproductive Asiatic canid that has successfully invaded many parts of Europe. It is known to occur in Austria since 1963 and is now widespread in the northern and eastern parts of the country, but its population density remains low. With the help of a species distribution model we identified focal areas for future monitoring and management actions, and we address some management implications for the raccoon dog in Austria. We also determined the environmental predictors of raccoon dog distribution in this alpine country. Its distribution seems to be mainly limited by climatic factors (snow depth, duration of snow cover, winter precipitation and mean annual temperature and is thus linked to elevation. Consequently, we assumed the Alps to be a barrier for the spread of the invasive raccoon dog in Europe; however, its ecological permeability is expected to increase with ongoing climate change.

Snowpack, fire, and forest disturbance: interactions affect montane invasions by non-native shrubs.

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Stevens, Jens T; Latimer, Andrew M

2015-06-01

Montane regions worldwide have experienced relatively low plant invasion rates, a trend attributed to increased climatic severity, low rates of disturbance, and reduced propagule pressure relative to lowlands. Manipulative experiments at elevations above the invasive range of non-native species can clarify the relative contributions of these mechanisms to montane invasion resistance, yet such experiments are rare. Furthermore, global climate change and land use changes are expected to cause decreases in snowpack and increases in disturbance by fire and forest thinning in montane forests. We examined the importance of these factors in limiting montane invasions using a field transplant experiment above the invasive range of two non-native lowland shrubs, Scotch broom (Cytisus scoparius) and Spanish broom (Spartium junceum), in the rain-snow transition zone of the Sierra Nevada of California. We tested the effects of canopy closure, prescribed fire, and winter snow depth on demographic transitions of each species. Establishment of both species was most likely at intermediate levels of canopy disturbance, but at this intermediate canopy level, snow depth had negative effects on winter survival of seedlings. We used matrix population models to show that an 86% reduction in winter snowfall would cause a 2.8-fold increase in population growth rates in Scotch broom and a 3.5-fold increase in Spanish broom. Fall prescribed fire increased germination rates, but decreased overall population growth rates by reducing plant survival. However, at longer fire return intervals, population recovery between fires is likely to keep growth rates high, especially under low snowpack conditions. Many treatment combinations had positive growth rates despite being above the current invasive range, indicating that propagule pressure, disturbance, and climate can all strongly affect plant invasions in montane regions. We conclude that projected reductions in winter snowpack and increases in

From Fireproof Desert to Flammable Grassland: Buffelgrass Invasion in the Sonoran Desert

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Betancourt, J. L.

2007-12-01

Only a few decades ago, the Sonoran Desert of northwestern Mexico and southern Arizona was considered mostly fireproof, a case of not enough fine fuel to connect the dominant shrubs and cacti. This has changed with invasions by non-native, winter annual and summer-flower perennial grasses that are rapidly transforming fireproof desert into flammable grassland. Of particular concern is buffelgrass, Pennisetum ciliare, a fire-prone and invasive African perennial grass that has already converted millions of hectares across Sonora since the mid-1960s and has made quick headway in southern and central Arizona beginning in the 1980s. Near Tucson and Phoenix, AZ, buffelgrass invasion is proceeding exponentially, with population expansion (and the costs of mitigation) more than doubling every year. As this conversion progresses, there will be increased fire risks, lost tourist revenue, diminished property values, insurmountable setbacks to conservation efforts, and the threat of large ignition fronts in desert valleys routinely spreading into the mountains. Although somewhat belated, an integrated, multi-jurisdictional effort is being organized to reduce ecological and economic impacts. My presentation will summarize the history and context of buffelgrass introduction and invasion, the disconnect in attitudes and policies across state and international boundaries, ongoing management efforts, the role of science and responsibilities of scientists, accelerated spread with changing climate, and impacts to regional ecosystems and economies. This narrative may serve as a template for other semi-arid lands where buffelgrass and similar grasses have become invasive, including Australia, South America, and many islands in the Pacific Ocean (including Hawaii), Indian Ocean, and Caribbean Sea.

Performance of Chlorella sorokiniana under simulated extreme winter conditions

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Cuaresma, M.; Buffing, M.F.; Janssen, M.G.J.; Lobato, C.V.; Wijffels, R.H.

2012-01-01

High annual microalgae productivities can only be achieved if solar light is efficiently used through the different seasons. During winter the productivity is low because of the light and temperature conditions. The productivity and photosynthetic efficiency of Chlorella sorokiniana were assessed

Winter climate limits subantarctic low forest growth and establishment.

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Harsch, Melanie A; McGlone, Matt S; Wilmshurst, Janet M

2014-01-01

Campbell Island, an isolated island 600 km south of New Zealand mainland (52 °S, 169 °E) is oceanic (Conrad Index of Continentality  =  -5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6 °C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally.

Summer fallow soil management - impact on rainfed winter wheat

DEFF Research Database (Denmark)

Li, Fucui; Wang, Zhaohui; Dai, Jian

2014-01-01

Summer fallow soil management is an important approach to improve soil and crop management in dryland areas. In the Loess Plateau regions, the annual precipitation is low and varies annually and seasonally, with more than 60% concentrated in the summer months from July to September, which...... is the summer fallow period in the winter wheat-summer fallow cropping system. With bare fallow in summer as a control, a 3-year location-fixed field experiment was conducted in the Loess Plateau to investigate the effects of wheat straw retention (SR), green manure (GM) planting, and their combination on soil...... water retention (WR) during summer fallow, winter wheat yield, and crop water use and nitrogen (N) uptake. The results showed that SR increased soil WR during summer fallow by 20 mm on average compared with the control over 3 experimental years but reduced the grain yield by 8% in the third year...

Winter-to-winter variations in indoor radon

International Nuclear Information System (INIS)

Mose, D.G.; Mushrush, G.W.; Kline, S.W.

1989-01-01

Indoor radon concentrations in northern Virginia and central Maryland show a strong dependence on weather. Winter tends to be associated with higher than average indoor radon, and summer with lower than average. However, compared to the winter of 1986-1987, the winter of 1987-1988 was warmer and drier. Consequently, winter-to-winter indoor radon decreased by about 25%. This winter-to-winter decrease is unexpectedly large, and simulates winter-to-summer variations that have been reported

Relationship of deer and moose populations to previous winters' snow

Science.gov (United States)

Mech, L.D.; McRoberts, R.E.; Peterson, R.O.; Page, R.E.

1987-01-01

(1) Linear regression was used to relate snow accumulation during single and consecutive winters with white-tailed deer (Odocoileus virginianus) fawn:doe ratios, mosse (Alces alces) twinning rates and calf:cow ratios, and annual changes in deer and moose populations. Significant relationships were found between snow accumulation during individual winters and these dependent variables during the following year. However, the strongest relationships were between the dependent variables and the sums of the snow accumulations over the previous three winters. The percentage of the variability explained was 36 to 51. (2) Significant relationships were also found between winter vulnerability of moose calves and the sum of the snow accumulations in the current, and up to seven previous, winters, with about 49% of the variability explained. (3) No relationship was found between wolf numbers and the above dependent variables. (4) These relationships imply that winter influences on maternal nutrition can accumulate for several years and that this cumulative effect strongly determines fecundity and/or calf and fawn survivability. Although wolf (Canis lupus L.) predation is the main direct mortality agent on fawns and calves, wolf density itself appears to be secondary to winter weather in influencing the deer and moose populations.

Observations of Whooping Cranes During Winter Aerial Surveys: 1950–2011

Data.gov (United States)

Department of the Interior — The Aransas-Wood Buffalo population of whooping cranes (Grus americana) declined to near extinction by the 1940s. Starting in winter 1950–1951, annual aerial surveys...

Gross primary production controls the subsequent winter CO2 exchange in a boreal peatland.

Science.gov (United States)

Zhao, Junbin; Peichl, Matthias; Öquist, Mats; Nilsson, Mats B

2016-12-01

In high-latitude regions, carbon dioxide (CO 2 ) emissions during the winter represent an important component of the annual ecosystem carbon budget; however, the mechanisms that control the winter CO 2 emissions are currently not well understood. It has been suggested that substrate availability from soil labile carbon pools is a main driver of winter CO 2 emissions. In ecosystems that are dominated by annual herbaceous plants, much of the biomass produced during the summer is likely to contribute to the soil labile carbon pool through litter fall and root senescence in the autumn. Thus, the summer carbon uptake in the ecosystem may have a significant influence on the subsequent winter CO 2 emissions. To test this hypothesis, we conducted a plot-scale shading experiment in a boreal peatland to reduce the gross primary production (GPP) during the growing season. At the growing season peak, vascular plant biomass in the shaded plots was half that in the control plots. During the subsequent winter, the mean CO 2 emission rates were 21% lower in the shaded plots than in the control plots. In addition, long-term (2001-2012) eddy covariance data from the same site showed a strong correlation between the GPP (particularly the late summer and autumn GPP) and the subsequent winter net ecosystem CO 2 exchange (NEE). In contrast, abiotic factors during the winter could not explain the interannual variation in the cumulative winter NEE. Our study demonstrates the presence of a cross-seasonal link between the growing season biotic processes and winter CO 2 emissions, which has important implications for predicting winter CO 2 emission dynamics in response to future climate change. © 2016 John Wiley & Sons Ltd.

Interannual control of plankton communities by deep winter mixing and prey/predator interactions in the NW Mediterranean: Results from a 30-year 3D modeling study

Science.gov (United States)

Auger, P. A.; Ulses, C.; Estournel, C.; Stemmann, L.; Somot, S.; Diaz, F.

2014-05-01

A realistic modeling approach is designed to address the role of winter mixing on the interannual variability of plankton dynamics in the north-western (NW) Mediterranean basin. For the first time, a high-resolution coupled hydrodynamic-biogeochemical model (Eco3m-S) covering a 30-year period (1976-2005) is validated on available in situ and satellite data for the NW Mediterranean. In this region, cold, dry winds in winter often lead to deep convection and strong upwelling of nutrients into the euphotic layer. High nutrient contents at the end of winter then support the development of a strong spring bloom of phytoplankton. Model results indicate that annual primary production is not affected by winter mixing due to seasonal balance (minimum in winter and maximum in spring). However, the total annual water column-integrated phytoplankton biomass appears to be favored by winter mixing because zooplankton grazing activity is low in winter and early spring. This reduced grazing is explained here by the rarefaction of prey due to both light limitation and the effect of mixing-induced dilution on prey/predator interactions. A negative impact of winter mixing on winter zooplankton biomass is generally simulated except for mesozooplankton. This difference is assumed to stem from the lower parameterized mortality, top trophic position and detritivorous diet of mesozooplankton in the model. Moreover, model suggests that the variability of annual mesozooplankton biomass is principally modulated by the effects of winter mixing on winter biomass. Thus, interannual variability of winter nutrient contents in the euphotic layer, resulting from winter mixing, would control spring primary production and thus annual mesozooplankton biomass. Our results show a bottom-up control of mesozooplankton communities, as observed at a coastal location of the Ligurian Sea.

Winter climate limits subantarctic low forest growth and establishment.

Directory of Open Access Journals (Sweden)

Melanie A Harsch

Full Text Available Campbell Island, an isolated island 600 km south of New Zealand mainland (52 °S, 169 °E is oceanic (Conrad Index of Continentality  =  -5 with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6 °C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C, dry winters (total winter precipitation <400 mm. Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally.

Winter Climate Limits Subantarctic Low Forest Growth and Establishment

Science.gov (United States)

Harsch, Melanie A.; McGlone, Matt S.; Wilmshurst, Janet M.

2014-01-01

Campbell Island, an isolated island 600 km south of New Zealand mainland (52°S, 169°E) is oceanic (Conrad Index of Continentality  = −5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6°C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally. PMID:24691026

Nutritional composition and in vitro digestibility of grass and legume winter (cover) crops.

Science.gov (United States)

Brown, A N; Ferreira, G; Teets, C L; Thomason, W E; Teutsch, C D

2018-03-01

In dairy farming systems, growing winter crops for forage is frequently limited to annual grasses grown in monoculture. The objectives of this study were to determine how cropping grasses alone or in mixtures with legumes affects the yield, nutritional composition, and in vitro digestibility of fresh and ensiled winter crops and the yield, nutritional composition, and in vitro digestibility of the subsequent summer crops. Experimental plots were planted with 15 different winter crops at 3 locations in Virginia. At each site, 4 plots of each treatment were planted in a randomized complete block design. The 15 treatments included 5 winter annual grasses [barley (BA), ryegrass (RG), rye (RY), triticale (TR), and wheat (WT)] in monoculture [i.e., no legumes (NO)] or with 1 of 2 winter annual legumes [crimson clover (CC) and hairy vetch (HV)]. After harvesting the winter crops, corn and forage sorghum were planted within the same plots perpendicular to the winter crop plantings. The nutritional composition and the in vitro digestibility of winter and summer crops were determined for fresh and ensiled samples. Growing grasses in mixtures with CC increased forage dry matter (DM) yield (2.84 Mg/ha), but the yield of mixtures with HV (2.47 Mg/ha) was similar to that of grasses grown in monoculture (2.40 Mg/ha). Growing grasses in mixtures with legumes increased the crude protein concentration of the fresh forage from 13.0% to 15.5% for CC and to 17.3% for HV. For neutral detergent fiber (NDF) concentrations, the interaction between grasses and legumes was significant for both fresh and ensiled forages. Growing BA, RY, and TR in mixtures with legumes decreased NDF concentrations, whereas growing RG and WT with legumes did not affect the NDF concentrations of either the fresh or the ensiled forages. Growing grasses in mixtures with legumes decreased the concentration of sugars of fresh forages relative to grasses grown in monoculture. Primarily, this decrease can be

Ecological impacts of winter water level drawdowns on lake littoral zones: A review

Science.gov (United States)

Roy, Allison

2017-01-01

Freshwater littoral zones harbor diverse ecological communities and serve numerous ecosystem functions that are controlled, in part, by natural water level fluctuations. However, human alteration of lake hydrologic regimes beyond natural fluctuations threaten littoral zone ecological integrity. One type of hydrologic alteration in lakes is winter water level drawdowns, which are frequently employed for hydropower, flood control, and macrophyte control, among other purposes. Here, we synthesize the abiotic and biotic responses to annual and novel winter water level drawdowns in littoral zones of lakes and reservoirs. The dewatering, freezing, and increased erosion of exposed lakebeds drive changes in the littoral zone. Shoreline-specific physicochemical conditions such as littoral slope and shoreline exposure further induce modifications. Loss of fine sediment decreases nutrient availability over time, but desiccation may promote a temporary nutrient pulse upon re-inundation. Annual winter drawdowns can decrease taxonomic richness of macrophytes and benthic invertebrates and shift assemblage composition to favor taxa with r-selected life history strategies and with functional traits resistant to direct and indirect drawdown effects. Fish assemblages, though less directly affected by winter drawdowns (except where there is critically low dissolved oxygen), experience negative effects via indirect pathways like decreased food resources and spawning habitat. We identify eight general research gaps to guide future research that could improve our understanding about the complex effects of winter drawdowns on littoral zone ecology.

Seeking explanations for recent changes in abundance of wintering Eurasian Wigeon (Anas penelope) in northwest Europe

DEFF Research Database (Denmark)

Fox, Anthony David; Dalby, Lars; Christensen, Thomas Kjær

2016-01-01

the range. However, because over 75% of the population of over 1 million individuals winters in Belgium, the Netherlands, UK and France, there was no evidence for a major movement in the centre of gravity of the wintering distribution. Between-winter changes in overall flyway abundance were highly......We analysed annual changes in abundance of Eurasian Wigeon (Anas penelope) derived from mid-winter International Waterbird Census data throughout its northwest European flyway since 1988 using log-linear Poisson regression modelling. Increases in abundance in the north and east of the wintering...... range (Norway, Sweden, Denmark, Germany, Switzerland), stable numbers in the central range (Belgium,Netherlands,UKand France) and declining abundance in the west and south of the wintering range (Spain and Ireland) suggest a shift in wintering distribution consistent with milder winters throughout...

Annual, semi-annual and ter-annual variations of gravity wave momentum flux in 13 years of SABER data

Science.gov (United States)

Chen, Dan; Preusse, Peter; Ern, Manfred; Strube, Cornelia

2017-04-01

In this study, the variations at different time scales such as the annual cycle, the semiannual oscillation (SAO), the ter-annual cycle (about four monthly) and the quasi-biennial oscillation (QBO) in zonal mean GW amplitudes and GW momentum flux (GWMF) have been investigated using satellite observations from 2002-2014 and combining ECMWF high resolution data with the GORGRAT model. The global distribution (patterns) of spectral amplitudes of GW momentum flux in stratosphere and mesosphere (from 30 km to 90 km) show that the annual cycle is the most predominant variation, and then are SAO, ter-annual cycle and QBO. For annual components, two relatively isolated amplitude maxima appear in each hemisphere: a subtropical maximum is associated with convective sources in summer, a mid and high latitude maximum is associated with the polar vortex in winter. In the subtropics, GWs propagate upward obliquely to the higher latitudes. The winter maximum in the southern hemisphere has larger momentum flux than that one in the northern hemisphere. While on the SH the phase (i.e. time corresponding to the maximum GWMF) continuously descends with the maximum in July in the upper mesosphere and in September in the lower stratosphere, on the northern hemisphere, the phase has no visible altitude dependence with a maximum in December. For semiannual variations, in the MLT (70-80 km) region, there is an obvious enhancement of spectral amplitude at equatorial latitudes which relate to the dissipation of convectively forced GWs. The SAO in absolute momentum flux and the annual cycle in zonal momentum flux indicated that the variations at mid-latitudes (about from 30°-40°) are not a SAO signals but rather an annual cycle when the direction of GWMF is considered. The ter-annual cycle may be related to the duration of active convection in subtropical latitudes (from June to Sep. in north hemisphere) Indications for QBO are found latitude extension to mid-latitudes in stratosphere of

Winter therapy for the accelerators

CERN Multimedia

Corinne Pralavorio

2016-01-01

Hundreds of people are hard at work during the year-end technical stop as all the accelerators are undergoing maintenance, renovation and upgrade operations in parallel.   The new beam absorber on its way to Point 2 before being lowered into the LHC tunnel for installation. The accelerator teams didn’t waste any time before starting their annual winter rejuvenation programme over the winter. At the end of November, as the LHC ion run was beginning, work got under way on the PS Booster, where operation had already stopped. On 14 December, once the whole complex had been shut down, the technical teams turned their attention to the other injectors and the LHC. The year-end technical stop (YETS) provides an opportunity to carry out maintenance work on equipment and repair any damage as well as to upgrade the machines for the upcoming runs. Numerous work projects are carried out simultaneously, so good coordination is crucial. Marzia Bernardini's team in the Enginee...

Shrubland carbon sink depends upon winter water availability in the warm deserts of North America

Science.gov (United States)

Biederman, Joel A.; Scott, Russell L.; John A. Arnone,; Jasoni, Richard L.; Litvak, Marcy E.; Moreo, Michael T.; Papuga, Shirley A.; Ponce-Campos, Guillermo E.; Schreiner-McGraw, Adam P.; Vivoni, Enrique R.

2018-01-01

Global-scale studies suggest that dryland ecosystems dominate an increasing trend in the magnitude and interannual variability of the land CO2 sink. However, such model-based analyses are poorly constrained by measured CO2 exchange in open shrublands, which is the most common global land cover type, covering ∼14% of Earth’s surface. Here we evaluate how the amount and seasonal timing of water availability regulate CO2 exchange between shrublands and the atmosphere. We use eddy covariance data from six US sites across the three warm deserts of North America with observed ranges in annual precipitation of ∼100–400mm, annual temperatures of 13–18°C, and records of 2–8 years (33 site-years in total). The Chihuahuan, Sonoran and Mojave Deserts present gradients in both mean annual precipitation and its seasonal distribution between the wet-winter Mojave Desert and the wet-summer Chihuahuan Desert. We found that due to hydrologic losses during the wettest summers in the Sonoran and Chihuahuan Deserts, evapotranspiration (ET) was a better metric than precipitation of water available to drive dryland CO2 exchange. In contrast with recent synthesis studies across diverse dryland biomes, we found that NEP could not be directly predicted from ET due to wintertime decoupling of the relationship between ecosystem respiration (Reco) and gross ecosystem productivity (GEP). Ecosystem water use efficiency (WUE=GEP/ET) did not differ between winter and summer. Carbon use efficiency (CUE=NEP/GEP), however, was greater in winter because Reco returned a smaller fraction of carbon to the atmosphere (23% of GEP) than in summer (77%). Combining the water-carbon relations found here with historical precipitation since 1980, we estimate that lower average winter precipitation during the 21st century reduced the net carbon sink of the three deserts by an average of 6.8TgC yr1. Our results highlight that winter precipitation is critical to the annual carbon balance of these

The responses of microbial temperature relationships to seasonal change and winter warming in a temperate grassland.

Science.gov (United States)

Birgander, Johanna; Olsson, Pål Axel; Rousk, Johannes

2018-01-18

Microorganisms dominate the decomposition of organic matter and their activities are strongly influenced by temperature. As the carbon (C) flux from soil to the atmosphere due to microbial activity is substantial, understanding temperature relationships of microbial processes is critical. It has been shown that microbial temperature relationships in soil correlate with the climate, and microorganisms in field experiments become more warm-tolerant in response to chronic warming. It is also known that microbial temperature relationships reflect the seasons in aquatic ecosystems, but to date this has not been investigated in soil. Although climate change predictions suggest that temperatures will be mostly affected during winter in temperate ecosystems, no assessments exist of the responses of microbial temperature relationships to winter warming. We investigated the responses of the temperature relationships of bacterial growth, fungal growth, and respiration in a temperate grassland to seasonal change, and to 2 years' winter warming. The warming treatments increased winter soil temperatures by 5-6°C, corresponding to 3°C warming of the mean annual temperature. Microbial temperature relationships and temperature sensitivities (Q 10 ) could be accurately established, but did not respond to winter warming or to seasonal temperature change, despite significant shifts in the microbial community structure. The lack of response to winter warming that we demonstrate, and the strong response to chronic warming treatments previously shown, together suggest that it is the peak annual soil temperature that influences the microbial temperature relationships, and that temperatures during colder seasons will have little impact. Thus, mean annual temperatures are poor predictors for microbial temperature relationships. Instead, the intensity of summer heat-spells in temperate systems is likely to shape the microbial temperature relationships that govern the soil-atmosphere C

Climatic potential for tourism in the Black Forest, Germany — winter season

Science.gov (United States)

Endler, Christina; Matzarakis, Andreas

2011-05-01

Climate change, whether natural or human-caused, will have an impact on human life, including recreation and tourism among other things. In this study, methods from biometeorology and tourism climatology are used to assess the effect of a changed climate on tourism and recreation in particular. The study area is the Black Forest mountainous region of south-west Germany, which is well known for its tourist and recreational assets. Climate model projections for the 2021-2050 period based on REMO-UBA simulations with a high spatial resolution of 10 km are compared to a 30-year reference period (1971-2000) using the IPCC emission scenarios A1B and B1. The results show that the mean winter air temperature will increase by up to 1.8°C, which is the most pronounced warming compared to the other seasons. The annual precipitation amount will increase marginally by 5% in the A1B scenario and 10% in the B1 scenario. Winter precipitation contributes about 10% (A1B) and 30% (B1) to variations in annual precipitation. Although the results show that winter precipitation will increase slightly, snow days affecting skiing will be reduced on average by approximately 40% due to regional warming. Cold stress will be reduced on average by up to 25%. The result is that the thermal environment will be advanced, and warmer winters are likely to lead to an upward altitudinal shift of ski resorts and winter sport activities, thus displacing land-use currently dedicated to nature conservation.

Migration and winter distribution of the Chestnutcollared Longspur

Directory of Open Access Journals (Sweden)

Ellison Kevin

2017-12-01

Full Text Available The Chestnut-collared Longspur (Calcarius ornatus is one of five grassland songbirds, endemic within North America, with populations that have declined >65% since the 1960s. These species breed and winter in the northern and southern Great Plains, respectively. Identifying migration routes, wintering sites, and the timing of their habitat use is key for understanding the relative magnitude of threats across the annual cycle and effectively targeting habitats for conservation. We tracked migratory movements of seven Chestnut-collared Longspurs with light-level geolocators deployed in Canada. Individuals wintered up to 112-1,200km apart. All followed the Central Flyway, circumvented high-elevation terrain, and traveled east of the breeding location. Unlike most songbirds, the durations of spring and fall migrations were similar; on average 42 ± 7d and 41 ± 5d during fall and spring migrations, respectively, for an approximately 2,000km migration; this highlights the need to better understand habitat requirements during migration for grassland songbirds. Using geospatial habitat data, we assessed winter distribution overlap with four other endemic grassland songbirds; wintering range overlapped 63-99%. Future studies should use more precise devices (e.g., archival GPS units, programmed for data collection dates from this study, to identify specific migratory sites for better conserving this and associated grassland species.

Regional meteorological drivers and long term trends of winter-spring nitrate dynamics across watersheds in northeastern North America

Science.gov (United States)

Crossman, Jill; Eimers, M Catherine; Casson, Nora J.; Burns, Douglas A.; Campbell, John L.; Likens, Gene E; Mitchell, Myron J; Nelson, Sarah J.; Shanley, James B.; Watmough, Shaun A.; Webster, Kara L

2016-01-01

This study evaluated the contribution of winter rain-on-snow (ROS) events to annual and seasonal nitrate (N-NO3) export and identified the regional meteorological drivers of inter-annual variability in ROS N-NO3 export (ROS-N) at 9 headwater streams located across Ontario, Canada and the northeastern United States. Although on average only 3.3 % of annual precipitation fell as ROS during winter over the study period, these events contributed a significant proportion of annual and winter N-NO3 export at the majority of sites (average of 12 and 42 %, respectively); with the exception of the most northern catchment, where total winter precipitation was exceptionally low (average 77 mm). In years with a greater magnitude of ROS events, the timing of the peak N-NO3 export period (during spring melt) was redistributed to earlier in the year. Variability in ROS frequency and magnitude amongst sites was high and a generalised linear model demonstrated that this spatial variability could be explained by interactive effects between regional and site-specific drivers. Snowpack coverage was particularly important for explaining the site-specific ROS response. Specifically, ROS events were less common when higher temperatures eliminated snow cover despite increasing the proportion of winter rainfall, whereas ROS event frequency was greater at sites where sufficient snow cover remained. This research suggests that catchment response to changes in N deposition is sensitive to climate change; a vulnerability which appears to vary in intensity throughout the seasonally snow-covered temperate region. Furthermore, the sensitivity of stream N-NO3 export to ROS events and potential shifts (earlier) in the timing of N-NO3 export relative to other nutrients affect downstream nutrient stoichiometry and the community composition of phytoplankton and other algae.

Characteristics of Winter Surface Air Temperature Anomalies in Moscow in 1970-2016 under Conditions of Reduced Sea Ice Area in the Barents Sea

Science.gov (United States)

Shukurov, K. A.; Semenov, V. A.

2018-01-01

On the basis of observational data on daily mean surface air temperature (SAT) and sea ice concentration (SIC) in the Barents Sea (BS), the characteristics of strong positive and negative winter SAT anomalies in Moscow have been studied in comparison with BS SIC data obtained in 1949-2016. An analysis of surface backward trajectories of air-particle motions has revealed the most probable paths of both cold and warm air invasions into Moscow and located regions that mostly affect strong winter SAT anomalies in Moscow. Atmospheric circulation anomalies that cause strong winter SAT anomalies in Moscow have been revealed. Changes in the ways of both cold and warm air invasions have been found, as well as an increase in the frequency of blocking anticyclones in 2005-2016 when compared to 1970-1999. The results suggest that a winter SIC decrease in the BS in 2005-2016 affects strong winter SAT anomalies in Moscow due to an increase in the frequency of occurrence of blocking anticyclones to the south of and over the BS.

Phenology of abundance of bivalve spat and of their epibenthic predators: limited evidence for mismatches after cold winters

NARCIS (Netherlands)

Dekker, R.; Beukema, J.J.

2014-01-01

Annual recruitment of bivalves in the Wadden Sea is usually more successful in summers after cold than after mild winters. The new generation (0-group) of the main predators (shrimps and shore crabs) of early benthic stages of bivalves appear later in spring on tidal flats after colder winters. If

Epidemiology of Hospitalizations Associated with Invasive Candidiasis, United States, 2002-20121.

Science.gov (United States)

Strollo, Sara; Lionakis, Michail S; Adjemian, Jennifer; Steiner, Claudia A; Prevots, D Rebecca

2016-01-01

Invasive candidiasis is a major nosocomial fungal disease in the United States associated with high rates of illness and death. We analyzed inpatient hospitalization records from the Healthcare Cost and Utilization Project to estimate incidence of invasive candidiasis-associated hospitalizations in the United States. We extracted data for 33 states for 2002-2012 by using codes from the International Classification of Diseases, 9th Revision, Clinical Modification, for invasive candidiasis; we excluded neonatal cases. The overall age-adjusted average annual rate was 5.3 hospitalizations/100,000 population. Highest risk was for adults >65 years of age, particularly men. Median length of hospitalization was 21 days; 22% of patients died during hospitalization. Median unadjusted associated cost for inpatient care was $46,684. Age-adjusted annual rates decreased during 2005-2012 for men (annual change -3.9%) and women (annual change -4.5%) and across nearly all age groups. We report a high mortality rate and decreasing incidence of hospitalizations for this disease.

Minimally invasive distal pancreatectomy

NARCIS (Netherlands)

Røsok, Bård I.; de Rooij, Thijs; van Hilst, Jony; Diener, Markus K.; Allen, Peter J.; Vollmer, Charles M.; Kooby, David A.; Shrikhande, Shailesh V.; Asbun, Horacio J.; Barkun, Jeffrey; Besselink, Marc G.; Boggi, Ugo; Conlon, Kevin; Han, Ho Seong; Hansen, Paul; Kendrick, Michael L.; Kooby, David; Montagnini, Andre L.; Palanivelu, Chinnasamy; Wakabayashi, Go; Zeh, Herbert J.

2017-01-01

The first International conference on Minimally Invasive Pancreas Resection was arranged in conjunction with the annual meeting of the International Hepato-Pancreato-Biliary Association (IHPBA), in Sao Paulo, Brazil on April 19th 2016. The presented evidence and outcomes resulting from the session

Marine assemblages respond rapidly to winter climate variability.

Science.gov (United States)

Morley, James W; Batt, Ryan D; Pinsky, Malin L

2017-07-01

Even species within the same assemblage have varied responses to climate change, and there is a poor understanding for why some taxa are more sensitive to climate than others. In addition, multiple mechanisms can drive species' responses, and responses may be specific to certain life stages or times of year. To test how marine species respond to climate variability, we analyzed 73 diverse taxa off the southeast US coast in 26 years of scientific trawl survey data and determined how changes in distribution and biomass relate to temperature. We found that winter temperatures were particularly useful for explaining interannual variation in species' distribution and biomass, although the direction and magnitude of the response varied among species from strongly negative, to little response, to strongly positive. Across species, the response to winter temperature varied greatly, with much of this variation being explained by thermal preference. A separate analysis of annual commercial fishery landings revealed that winter temperatures may also impact several important fisheries in the southeast United States. Based on the life stages of the species surveyed, winter temperature appears to act through overwinter mortality of juveniles or as a cue for migration timing. We predict that this assemblage will be responsive to projected increases in temperature and that winter temperature may be broadly important for species relationships with climate on a global scale. © The Authors Global Change Biology Published by John Wiley & Sons Ltd.

Plant functional traits of dominant native and invasive species in mediterranean-climate ecosystems.

Science.gov (United States)

Funk, Jennifer L; Standish, Rachel J; Stock, William D; Valladares, Fernando

2016-01-01

The idea that dominant invasive plant species outperform neighboring native species through higher rates of carbon assimilation and growth is supported by several analyses of global data sets. However, theory suggests that native and invasive species occurring in low-resource environments will be functionally similar, as environmental factors restrict the range of observed physiological and morphological trait values. We measured resource-use traits in native and invasive plant species across eight diverse vegetation communities distributed throughout the five mediterranean-climate regions, which are drought prone and increasingly threatened by human activities, including the introduction of exotic species. Traits differed strongly across the five regions. In regions with functional differences between native and invasive species groups, invasive species displayed traits consistent with high resource acquisition; however, these patterns were largely attributable to differences in life form. We found that species invading mediterranean-climate regions were more likely to be annual than perennial: three of the five regions were dominated by native woody species and invasive annuals. These results suggest that trait differences between native and invasive species are context dependent and will vary across vegetation communities. Native and invasive species within annual and perennial groups had similar patterns of carbon assimilation and resource use, which contradicts the widespread idea that invasive species optimize resource acquisition rather than resource conservation. .

Annual forage cropping-systems for midwestern ruminant livestock production

OpenAIRE

McMillan, John Ernest

2016-01-01

Annual forage cropping systems are a vital aspect of livestock forage production. One area where this production system can be enhanced is the integration of novel annual forages into conventional cropping systems. Two separate projects were conducted to investigate alternative forage options in annual forage production. In the first discussed research trial, two sets of crops were sown following soft red winter wheat (Triticum aestivum L.) grain harvest, at two nitrogen application rates 56 ...

Winter carbon dioxide effluxes from Arctic ecosystems: An overview and comparison of methodologies

DEFF Research Database (Denmark)

Björkman, M.P.; Morgner, E.; Cooper, E.J.

2010-01-01

removal, (3) diffusion measurements, F2-point, within the snowpack, and (4) a trace gas technique, FSF6, with multiple gas sampling within the snowpack. According to measurements collected from shallow and deep snow cover in High Arctic Svalbard and subarctic Sweden during the winter of 2007......The winter CO2 efflux from subnivean environments is an important component of annual C budgets in Arctic ecosystems and consequently makes prediction and estimations of winter processes as well as incorporations of these processes into existing models important. Several methods have been used......, Fsoil is assumed to measure soil production, whereas FSF6, Fsnow, and F2-point are considered better approaches for quantifying exchange processes between the soil, snow, and the atmosphere. This study indicates that estimates of winter CO2 emissions may vary more as a result of the method used than...

Mid-winter European dabbling duck distributions are not linked to species body mass

DEFF Research Database (Denmark)

Dalby, Lars; Delany, Simon; Fox, Anthony David

are likely to play a major role in determining the wintering distribution of short- to medium-distance migratory bird species and its inter-annual variability. As avian thermoregulatory costs scale allometrically with body size, we predicted that the mean mid-winter temperature experienced by six species...... of dabbling ducks wintering in Western Europe would be negatively correlated with body mass. We found no evidence for such a relationship in a large-scale analysis testing for a link between temperature and dabbling duck distributions, suggesting that other factors such as those related to feeding ecology......In order to understand the current changes and to predict future changes in wintering dabbling duck (Anas sp.) distributions in response to climate change, it is important to understand how species distribute themselves on a continental scale in response to temperature. Thermoregulatory costs...

Secondary invasions of noxious weeds associated with control of invasive Tamarix are frequent, idiosyncratic and persistent

Science.gov (United States)

González, Eduardo; Sher, Anna A.; Anderson, Robert M.; Bay, Robin F.; Bean, Daniel W.; Bissonnete, Gabriel J.; Cooper, David J.; Dohrenwend, Kara; Eichhorst, Kim D.; El Waer, Hisham; Kennard, Deborah K.; Harms-Weissinger, Rebecca; Henry, Annie L.; Makarick, Lori J.; Ostoja, Steven M.; Reynolds, Lindsay V.; Robinson, W. Wright; Shafroth, Patrick B.; Tabacchi, Erich

2017-01-01

Control of invasive species within ecosystems may induce secondary invasions of non-target invaders replacing the first alien. We used four plant species listed as noxious by local authorities in riparian systems to discern whether 1) the severity of these secondary invasions was related to the control method applied to the first alien; and 2) which species that were secondary invaders persisted over time. In a collaborative study by 16 research institutions, we monitored plant species composition following control of non-native Tamarix trees along southwestern U.S. rivers using defoliation by an introduced biocontrol beetle, and three physical removal methods: mechanical using saws, heavy machinery, and burning in 244 treated and 79 untreated sites across six U.S. states. Physical removal favored secondary invasions immediately after Tamarix removal (0–3 yrs.), while in the biocontrol treatment, secondary invasions manifested later (> 5 yrs.). Within this general trend, the response of weeds to control was idiosyncratic; dependent on treatment type and invader. Two annual tumbleweeds that only reproduce by seed (Bassia scoparia and Salsola tragus) peaked immediately after physical Tamarix removal and persisted over time, even after herbicide application. Acroptilon repens, a perennial forb that vigorously reproduces by rhizomes, and Bromus tectorum, a very frequent annual grass before removal that only reproduces by seed, were most successful at biocontrol sites, and progressively spread as the canopy layer opened. These results demonstrate that strategies to control Tamarix affect secondary invasions differently among species and that time since disturbance is an important, generally overlooked, factor affecting response.

Can transgenerational plasticity contribute to the invasion success of annual plant species?

Science.gov (United States)

Fenesi, Annamária; Dyer, Andrew R; Geréd, Júliánna; Sándor, Dorottya; Ruprecht, Eszter

2014-09-01

Adaptive transgenerational plasticity (TGP), i.e., significantly higher fitness when maternal and offspring conditions match, might contribute to the population growth of non-native species in highly variable environments. However, comparative studies that directly test this hypothesis are lacking. Therefore, we performed a reciprocal split-brood experiment to compare TGP in response to N and water availability in single populations of two invasive (Amaranthus retroflexus, Galinsoga parviflora) and two congeneric non-invasive introduced species (Amaranthus albus, Galinsoga ciliata). We hypothesized that the transgenerational effect is adaptive: (1) in invasive species compared with non-invasive adventives, and (2) in stressful conditions compared with resource-rich environments. The phenotypic variation among offspring was generated, in large part, by our experimental treatments in the maternal generation; therefore, we demonstrated a direct TGP effect on the offspring's adult fitness. We found evidence, for the first time, that invasive and non-invasive adventive species differ regarding the expression of TGP in the adult stage, as adaptive responses were found exclusively in the invasive species. The manifestation of TGP was more explicit under resource-rich conditions; therefore, it might contribute to the population dynamics of non-native species in resource-rich sites rather than to their ecological tolerance spectra.

Wintering the common viper (Vipera berus with embryos

Directory of Open Access Journals (Sweden)

Korosov Andrey Victorovich

2012-03-01

Full Text Available For the Vipers from Karelia phenomenon wintering females with embryos and the annual breeding were found. They were very large and heavy females (L.t. > 62 cm, W > 160 g, for which the mass loss due to pregnancy are not significant. Analysis of the size of 1450 individuals in a Kizhi population of viper showed that the proportion of females that can hibernate from embryos amounts to less than 3%.

Annual and inter-annual variations of 6.5-day-planetary-waves in MLT observed by TIMED/SABER

Science.gov (United States)

Huang, Yingying; Li, Huijun; Li, Chongyin; Zhang, Shaodong

2017-04-01

Annual and inter-annual variations of 6.5DWs in 20-110 km, 52°S-52°N, 2002-2016 are studied by using v2.0 TIMED/SABER kinetic temperature data. Firstly, global annual variations of 6.5DW's spectral power and amplitudes are obtained. Strong wave amplitudes emerge in 30°S/N-50°S/N, and peaks in altitude separate in stratosphere (40-50 km), mesosphere (80-90 km) and the lower thermosphere (100-110 km), respectively. Their annual variations are similar in both hemispheres, but different in altitude. In 40-50 km, the annual maximums emerge mostly in winters: Dec.-Jan. in the NH and Jul.-Aug. in the SH. In MLT, annual peaks arise twice in each half of year. In 80-90 km, they're mainly in equinoctial seasons and winters: May, Aug.-Sep. and Jan. in the NH and Feb., Nov. and May in the SH. In 100-110 km, they emerge mainly in equinoctial seasons: Apr.-May and Aug.-Sep. in the NH and Feb.-Mar. and Oct.-Nov. in the SH. Then, inter-annual variations of 6.5DW amplitudes during the 14-year period are studied. Frequency spectra of monthly-mean amplitudes show that, main dynamics in long-term variations of 6.5DWs are AO and SAO in both hemispheres. Besides, QBO are visible in both hemispheres and 4-month period signals are noticed in the NH in MLT. Amplitudes of SAO, AO and QBO are obtained by bandpass filter. Their amplitudes are comparable in stratosphere and mesosphere, and QBO signals are weaker than the others in the LT. Vertical variations both of SAO and AO amplitudes are very stable. AO structures have little inter-annual changes, while inter-annual variations of SAO are significant and are related with 6.5DW. It means that annual and inter-annual variations of 6.5DW are mainly controlled by AO and SAO, respectively. Although QBO signals are weaker and their variations are less regular than AO and SAO, their phases seems to relate with inter-annual variations of 6.5DW as well.

A fifty year record of winter glacier melt events in southern Chile, 38°–42°S

International Nuclear Information System (INIS)

Brock, Ben W; Burger, Flavia; Montecinos, Aldo; Rivera, Andrés

2012-01-01

Little is known about the frequency and potential mass balance impact of winter glacier melt events. In this study, daily atmospheric temperature soundings from the Puerto Montt radiosonde (41.43°S) are used to reconstruct winter melting events at the glacier equilibrium line altitude in the 38°–42°S region of southern Chile, between 1960 and 2010. The representativeness of the radiosonde temperatures to near-surface glacier temperatures is demonstrated using meteorological records from close to the equilibrium line on two glaciers in the region over five winters. Using a degree-day model we estimate an average of 0.28 m of melt and 21 melt days in the 15 June–15 September period each year, with high inter-annual variability. The majority of melt events are associated with midlatitude migratory high pressure systems crossing Chile and northwesterly flows, that force adiabatic compression and warm advection, respectively. There are no trends in the frequency or magnitude of melt events over the period of record, but the annual frequency of winter melt days shows a significant, although rather weak and probably non-linear, relationship to late winter and early spring values of a multivariate El Niño Southern Oscillation Index (MEI). (letter)

Fossil palm beetles refine upland winter temperatures in the Early Eocene Climatic Optimum.

Science.gov (United States)

Archibald, S Bruce; Morse, Geoffrey E; Greenwood, David R; Mathewes, Rolf W

2014-06-03

Eocene climate and associated biotic patterns provide an analog system to understand their modern interactions. The relationship between mean annual temperatures and winter temperatures-temperature seasonality-may be an important factor in this dynamic. Fossils of frost-intolerant palms imply low Eocene temperature seasonality into high latitudes, constraining average winter temperatures there to >8 °C. However, their presence in a paleocommunity may be obscured by taphonomic and identification factors for macrofossils and pollen. We circumvented these problems by establishing the presence of obligate palm-feeding beetles (Chrysomelidae: Pachymerina) at three localities (a fourth, tentatively) in microthermal to lower mesothermal Early Eocene upland communities in Washington and British Columbia. This provides support for warmer winter Eocene climates extending northward into cooler Canadian uplands.

Contrasting Seasonal Survivorship of Two Migratory Songbirds Wintering in Threatened Mangrove Forests

Directory of Open Access Journals (Sweden)

Anna M. Calvert

2010-06-01

Full Text Available Long-distance migrants wintering in tropical regions face a number of critical conservation threats throughout their lives, but seasonal estimates of key demographic parameters such as winter survival are rare. Using mist-netting-based mark-recapture data collected in coastal Costa Rica over a six-year period, we examined variation in within- and between-winter survivorship of the Prothonotary Warbler (Protonotaria citrea; 753 young and 376 adults banded, a declining neotropical habitat specialist that depends on threatened mangrove forests during the nonbreeding season. We derived parallel seasonal survivorship estimates for the Northern Waterthrush (Seiurus noveboracensis; 564 young and 93 adults banded, a cohabitant mangrove specialist that has not shown the same population decline in North America, to assess whether contrasting survivorship might contribute to the observed differences in the species’ population trajectories. Although average annual survival probability was relatively similar between the two species for both young and adult birds, monthly estimates indicated that relative to Northern Waterthrush, Prothonotary Warblers exhibited: greater interannual variation in survivorship, especially within winters; greater variation in survivorship among the three study sites; lower average between-winter survivorship, particularly among females, and; a sharp decline in between-winter survivorship from 2003 to 2009 for both age groups and both sexes. Rather than identifying one seasonal vital rate as a causal factor of Prothonotary Warbler population declines, our species comparison suggests that the combination of variable within-winter survival with decreasing between-winter survival demands a multi-seasonal approach to the conservation of this and other tropical-wintering migrants.

Seasonal and annual precipitation time series trend analysis in North Carolina, United States

Science.gov (United States)

Sayemuzzaman, Mohammad; Jha, Manoj K.

2014-02-01

The present study performs the spatial and temporal trend analysis of the annual and seasonal time-series of a set of uniformly distributed 249 stations precipitation data across the state of North Carolina, United States over the period of 1950-2009. The Mann-Kendall (MK) test, the Theil-Sen approach (TSA) and the Sequential Mann-Kendall (SQMK) test were applied to quantify the significance of trend, magnitude of trend, and the trend shift, respectively. Regional (mountain, piedmont and coastal) precipitation trends were also analyzed using the above-mentioned tests. Prior to the application of statistical tests, the pre-whitening technique was used to eliminate the effect of autocorrelation of precipitation data series. The application of the above-mentioned procedures has shown very notable statewide increasing trend for winter and decreasing trend for fall precipitation. Statewide mixed (increasing/decreasing) trend has been detected in annual, spring, and summer precipitation time series. Significant trends (confidence level ≥ 95%) were detected only in 8, 7, 4 and 10 nos. of stations (out of 249 stations) in winter, spring, summer, and fall, respectively. Magnitude of the highest increasing (decreasing) precipitation trend was found about 4 mm/season (- 4.50 mm/season) in fall (summer) season. Annual precipitation trend magnitude varied between - 5.50 mm/year and 9 mm/year. Regional trend analysis found increasing precipitation in mountain and coastal regions in general except during the winter. Piedmont region was found to have increasing trends in summer and fall, but decreasing trend in winter, spring and on an annual basis. The SQMK test on "trend shift analysis" identified a significant shift during 1960 - 70 in most parts of the state. Finally, the comparison between winter (summer) precipitations with the North Atlantic Oscillation (Southern Oscillation) indices concluded that the variability and trend of precipitation can be explained by the

Analysis of winter climate simulations performed with ARPEGE-Climat (T63) in the framework of PROVOST

Energy Technology Data Exchange (ETDEWEB)

Parey, S.; Dichampt-Martineu, Ch.; Caneill, J.Y. [Electricite de France, 78 - Chatou (France). Research Branch, Environment

1997-12-01

The interest of EDF for seasonal forecasting is a consequence of the high sensitivity of electricity consumption to temperature, especially during the winter season. That is why the Research branch of EDF is involved in the PROVOST project (PRediction Of climate Variations On Seasonal and inter-annual Timescales). Two sets of simulations are studied. The first one was calculated apart from the PROVOST experiments with the LMD model covering the 1970 to 1992 winters with eleven simulations per winter. The second one was calculated at EDF in the framework of PROVOST with ARPEGE-Climat model, covering the 1979 to 1994 winters (nine simulations per winter). The probabilistic formulation of climatic scenarios in function of the seasonal simulations with ARPEGE-Climat gives good results if the monthly mean temperature is taken into account. (R.P.) 3 refs.

Winter Pea: Promising New Crop for Washington's Dryland Wheat-Fallow Region

Directory of Open Access Journals (Sweden)

William F. Schillinger

2017-05-01

Full Text Available A 2-year tillage-based winter wheat (Triticum aestivum L.-summer fallow (WW-SF rotation has been practiced by the vast majority of farmers in the low-precipitation (<300 mm annual rainfed cropping region of east-central Washington and north-central Oregon for 140 years. Until recently, alternative crops (i.e., those other than WW so far tested have not been as economically viable or stable as WW-SF. A 6-year field study was conducted near Ritzville, WA (292 mm avg. annual precipitation to determine the yield and rotation benefits of winter pea (Pisum sativum L. (WP. Two 3-year rotations were evaluated: WP-spring wheat (SW-SF vs. WW-SW-SF. Winter pea yields averaged 2,443 vs. 4,878 kg/ha for WW. No fertilizer was applied to WP whereas 56 kg N and 11 kg S/ha were applied to WW. Winter pea used significantly less soil water than WW. Over the winter months, a lesser percentage of precipitation was stored in the soil following WP compared to WW because: (i very little WP residue remained on the soil surface after harvest compared to WW, and (ii the drier the soil, the more precipitation is stored in the soil over winter. However, soil water content in the spring was still greater following WP vs. WW. Soil residual N in the spring (7 months after the harvest of WP and WW was greater in WP plots despite not applying fertilizer to produce WP. Spring wheat grown after both WP and WW received the identical quantity of N, P, and S fertilizer each year. Average yield of SW was 2,298 and 2,011 kg/ha following WP and WW, respectively (P < 0.01. Adjusted gross economic returns for these two rotation systems were similar. Based partially on the results of this study, numerous farmers in the dry WW-SF region have shown keen interest in WP and acreage planted WP in east-central Washington has grown exponentially since 2013. This paper provides the first report of the potential for WP in the typical WW-SF region of the inland Pacific Northwest (PNW.

Seasonal and Annual Survival of East-Atlantic Pale-Bellied Brent Geese Branta hrota Assessed by Capture-Recapture Analysis

DEFF Research Database (Denmark)

Clausen, P.; Frederiksen, M.; Percival, S. M.

2001-01-01

areas by intensive field studies. In this paper we use standard capture-recapture analysis to investigate seasonal and annual survival rates of the population. We divided the year into three periods with different spatial distribution of the geese, autumn (September-December), winter (Jan...... spring to autumn (0.982 MSR), -resulting in an overall annual survival rate of 0.870. We discuss the variation in seasonal and annual mortality rates in relation to constraints faced by the birds such as seasonal changes in availability of food resources, severe winters, long-distance migration...

Invasive meningococcal disease in children in Jerusalem

Science.gov (United States)

STEIN-ZAMIR, C.; ABRAMSON, N.; ZENTNER, G.; SHOOB, H.; VALINSKY, L.; BLOCK, C.

2008-01-01

SUMMARY Neisseria meningitidis is an important cause of childhood meningitis and septicaemia. Between 1999 and 2005, 133 invasive meningococcal disease (IMD) cases occurred in Jerusalem, 112 (84·2%) of them in children aged 0–14 years. The annual incidence rate in Jerusalem was higher than the national average (2·45±0·6 vs. 1·13±0·16/100 000 population, P=0·002). Most of the children (82·1%) were from low socio-economic Arab and Jewish ultra-orthodox communities; mortality was higher among Arab than Jewish children (1·3 vs. 0·22/100 000 person-years, P=0·004). A cluster of 10 children with severe meningococcal sepsis (three fatalities) emerged in the winter of 2003–2004. Compared to the other 102 cases in 1999–2005 both meningococcaemia (100% vs. 51%, P=0·003) and mortality (30% vs. 6·9%, P=0·014) rates were higher. Serogroup B comprised 77·6% of the bacterial isolates. Pulsed-field gel electrophoresis showed considerable variability among cluster isolates, but significant resemblance in Arab cases throughout 1999–2005. The increased susceptibility of specific sub-populations to IMD necessitates further evaluation. PMID:17662169

Defining Winter and Identifying Synoptic Air Mass Change in the Northeast and Northern Plains U.S. since 1950

Science.gov (United States)

Chapman, C. J.; Pennington, D.; Beitscher, M. R.; Godek, M. L.

2017-12-01

Understanding and forecasting the characteristics of winter weather change in the northern U.S. is vital to regional economy, agriculture, tourism and resident life. This is especially true in the Northeast and Northern Plains where substantial changes to the winter season have already been documented in the atmospheric science and biological literature. As there is no single established definition of `winter', this research attempts to identify the winter season in both regions utilizing a synoptic climatological approach with air mass frequencies. The Spatial Synoptic Classification is used to determine the daily air mass/ weather type conditions since 1950 at 40 locations across the two regions. Annual frequencies are first computed as a baseline reference. Then winter air mass frequencies and departures from normal are calculated to define the season along with the statistical significance. Once the synoptic winter is established, long-term regional changes to the season and significance are explored. As evident global changes have occurred after 1975, an Early period of years prior to 1975 and a Late set for all years following this date are compared. Early and Late record synoptic changes are then examined to assess any thermal and moisture condition changes of the regional winter air masses over time. Cold to moderately dry air masses dominate annually in both regions. Northeast winters are also characterized by cold to moderate dry air masses, with coastal locations experiencing more Moist Polar types. The Northern Plains winters are dominated by cold, dry air masses in the east and cold to moderate dry air masses in the west. Prior to 1975, Northeast winters are defined by an increase in cooler and wetter air masses. Dry Tropical air masses only occur in this region after 1975. Northern Plains winters are also characterized by more cold, dry air masses prior to 1975. More Dry Moderate and Moist Moderate air masses have occurred since 1975. These results

Winter time burst of CO2 from the High Arctic soils of Svalbard

DEFF Research Database (Denmark)

Friborg, Thomas; Hansen, Birger; Elberling, Bo

of relatively few measurements which appear to give small and constant emission rates. Further, most studies of the processes behind winter time emission of CO2 conclude that the flux during this time of year can be linked to the respiratory release of CO2 from soil micro organisms, which is temperature...... the winter at a high arctic location in Svalbard (78°N). Measurements were conducted in the field during the winter season of 2004-2005 and show reliable and continuous measurements of CO2 fluxes down to a level of 0.01 ìmol m-2 s-1 and good correspondence with other types of soil chambers. Our results...... indicate that a substantial part of the annual CO2 emission from the ecosystem occur during the freeze in period, where more CO2 is emitted from the soil over a few weeks than the accumulated flux for the rest of the winter. During the coldest part of the...

Epidemiology of Hospitalizations Associated with Invasive Candidiasis, United States, 2002–20121

Science.gov (United States)

Strollo, Sara; Lionakis, Michail S.; Adjemian, Jennifer; Steiner, Claudia A.

2017-01-01

Invasive candidiasis is a major nosocomial fungal disease in the United States associated with high rates of illness and death. We analyzed inpatient hospitalization records from the Healthcare Cost and Utilization Project to estimate incidence of invasive candidiasis–associated hospitalizations in the United States. We extracted data for 33 states for 2002–2012 by using codes from the International Classification of Diseases, 9th Revision, Clinical Modification, for invasive candidiasis; we excluded neonatal cases. The overall age-adjusted average annual rate was 5.3 hospitalizations/100,000 population. Highest risk was for adults >65 years of age, particularly men. Median length of hospitalization was 21 days; 22% of patients died during hospitalization. Median unadjusted associated cost for inpatient care was $46,684. Age-adjusted annual rates decreased during 2005–2012 for men (annual change –3.9%) and women (annual change –4.5%) and across nearly all age groups. We report a high mortality rate and decreasing incidence of hospitalizations for this disease. PMID:27983497

SEASONALITY OF ANNUAL PLANT ESTABLISHMENT INFLUENCES THE INTERACTIONBETWEEN THE NON-NATIVE ANNUAL GRASS BROMUS MADRITENSIS SSP. RUBENS AND MOJAVE DESERT PERENNIALS

Energy Technology Data Exchange (ETDEWEB)

L A. DEFALCO; G. C. FERNANDEZ; R. S. NOWAK

2004-01-01

Competition between native and non-native species can change the composition and structure of plant communities, but in deserts the timing of non-native plant establishment can modulate their impacts to native species. In a field experiment, we varied densities of the non-native annual grass Bromus madritensis ssp. rubens around individuals of three native perennials--Larrea iridentata, Achnatherum hymenoides, and Pleuraphis rigida--in either winter or spring. Additional plots were prepared for the Same perennial species and seasons, but with a mixture of native annual species. Relative growth rates of perennial shoots (RGRs) declined with increasing Bromus biomass when Bromus that was established in winter had 2-3 mo of growth and high water use before perennial growth began. However, this high water use did not significantly reduce water potentials for the perennials, suggesting Bromus that established earlier depleted other soil resources, such as N, otherwise used by perennial plants. Spring-established Bromus had low biomass even at higher densities and did not effectively reduce RGRs, resulting in an overall lower impact to perennials than when Bromus was established in winter. Similarly, growth and reproduction of perennials with mixed annuals as neighbors did not differ from those with Bromus neighbors of equivalent biomass, but densities of these annuals did not support the high biomass necessary to reduce perennial growth. Thus, impacts of native Mojave Desert annuals to perennials are expected to be lower than those of Bromus because seed dormancy and narrow requirements for seedling survivorship produce densities and biomass lower than those achieved by Bromus. In comparing the effects of Bromus among perennial species, the impact of increased Bromus biomass on RGR was lower for Larrea than for the two perennial grasses, probably because Lurrea maintains low growth rates throughout the year, even after Bromus has completed its life cycle. This contrasts

Invasive American bullfrogs and African clawed frogs in South America

DEFF Research Database (Denmark)

Barbosa, Fabiana G.; Both, Camila; Bastos, Miguel

2017-01-01

.5% of the protected areas within the Atlantic Forest may be most at risk of invasion by L. catesbeianus and X. laevis under current climate conditions, followed by areas in the Cerrado (51.7), Tropical Andes (37.6%), Tumbes-Choco-Magdalena (22.5%), and Chilean Winter Rainfall and Valdivian Forests (20...

Winter Cover Crop Effects on Nitrate Leaching in Subsurface Drainage as Simulated by RZWQM-DSSAT

Science.gov (United States)

Malone, R. W.; Chu, X.; Ma, L.; Li, L.; Kaspar, T.; Jaynes, D.; Saseendran, S. A.; Thorp, K.; Yu, Q.

2007-12-01

Planting winter cover crops such as winter rye (Secale cereale L.) after corn and soybean harvest is one of the more promising practices to reduce nitrate loss to streams from tile drainage systems without negatively affecting production. Because availability of replicated tile-drained field data is limited and because use of cover crops to reduce nitrate loss has only been tested over a few years with limited environmental and management conditions, estimating the impacts of cover crops under the range of expected conditions is difficult. If properly tested against observed data, models can objectively estimate the relative effects of different weather conditions and agronomic practices (e.g., various N fertilizer application rates in conjunction with winter cover crops). In this study, an optimized winter wheat cover crop growth component was integrated into the calibrated RZWQM-DSSAT hybrid model and then we compare the observed and simulated effects of a winter cover crop on nitrate leaching losses in subsurface drainage water for a corn-soybean rotation with N fertilizer application rates over 225 kg N ha-1 in corn years. Annual observed and simulated flow-weighted average nitrate concentration (FWANC) in drainage from 2002 to 2005 for the cover crop treatments (CC) were 8.7 and 9.3 mg L-1 compared to 21.3 and 18.2 mg L-1 for no cover crop (CON). The resulting observed and simulated FWANC reductions due to CC were 59% and 49%. Simulations with the optimized model at various N fertilizer rates resulted in average annual drainage N loss differences between CC and CON to increase exponentially from 12 to 34 kg N ha-1 for rates of 11 to 261 kg N ha-1. The results suggest that RZWQM-DSSAT is a promising tool to estimate the relative effects of a winter crop under different conditions on nitrate loss in tile drains and that a winter cover crop can effectively reduce nitrate losses over a range of N fertilizer levels.

Seasonality intensification and long-term winter cooling as a part of the Late Pliocene climate development

Science.gov (United States)

Klotz, Stefan; Fauquette, Séverine; Combourieu-Nebout, Nathalie; Uhl, Dieter; Suc, Jean-Pierre; Mosbrugger, Volker

2006-01-01

A mutual climatic range method is applied to the Mediterranean marine pollen record of Semaforo (Vrica section, Calabria, Italy) covering the period from ∼2.46 Ma to ∼2.11 Ma. The method yields detailed information on summer, annual and winter temperatures and on precipitation during the nine obliquity and precession-controlled 'glacial' periods (marine isotope stages 96 to 80) and eight 'interglacial' periods (marine isotope stages 95 to 81) characterising this time interval. The reconstruction reveals higher temperatures of at least 2.8 °C in mean annual and 2.2 °C in winter temperatures, and 500 mm in precipitation during the 'interglacials' as compared to the present-day climate in the study area. During the 'glacials', temperatures are generally lower as compared to the present-day climate in the region, but precipitation is equivalent. Along the consecutive 'interglacials', a trend toward a reduction in annual and winter temperatures by more than 2.3 °C, and toward a higher seasonality is observed. Along the consecutive 'glacials', a trend toward a strong reduction in all temperature parameters of at least 1.6 °C is reconstructed. Climatic amplitudes of 'interglacial-glacial' transitions increase from the older to the younger cycles for summer and annual temperatures. The cross-spectral analyses suggest obliquity related warm/humid-cold/dry 'interglacial-glacial' cycles which are superimposed by precession related warm/dry- cold/humid cycles. A time displacement in the development of temperatures and precipitation is indicated for the obliquity band by temperatures generally leading precipitation change at ∼4 kyr, and on the precession band of ∼9.6 kyr in maximum.

NNDSS - Table II. Invasive Pneumococcal to Legionellosis

Data.gov (United States)

U.S. Department of Health & Human Services — NNDSS - Table II. Invasive Pneumococcal to Legionellosis - 2014.In this Table, all conditions with a 5-year average annual national total of more than or equals...

Impact of an icy winter on the Pacific oyster (Crassostrea gigas Thunberg, 1793) populations in Scandinavia

DEFF Research Database (Denmark)

Strand, Åsa; Blanda, Elisa; Bodvin, Torjan

2012-01-01

The Pacific oyster (Crassostrea gigas) is an invasive species that has dispersed into Scandinavia during the last few decades. The objective of this study was to evaluate the effects of extreme winter conditions on the mortality of the Pacific oyster in Scandinavia. The study was done by compilin...

Simulating the influences of various fire regimes on caribou winter habitat

Science.gov (United States)

Rupp, T. Scott; Olson, Mark; Adams, Layne G.; Dale, Bruce W.; Joly, Kyle; Henkelman, Jonathan; Collins, William B.; Starfield, Anthony M.

2006-01-01

Caribou are an integral component of high‐latitude ecosystems and represent a major subsistence food source for many northern people. The availability and quality of winter habitat is critical to sustain these caribou populations. Caribou commonly use older spruce woodlands with adequate terrestrial lichen, a preferred winter forage, in the understory. Changes in climate and fire regime pose a significant threat to the long‐term sustainability of this important winter habitat. Computer simulations performed with a spatially explicit vegetation succession model (ALFRESCO) indicate that changes in the frequency and extent of fire in interior Alaska may substantially impact the abundance and quality of winter habitat for caribou. We modeled four different fire scenarios and tracked the frequency, extent, and spatial distribution of the simulated fires and associated changes to vegetation composition and distribution. Our results suggest that shorter fire frequencies (i.e., less time between recurring fires) on the winter range of the Nelchina caribou herd in eastern interior Alaska will result in large decreases of available winter habitat, relative to that currently available, in both the short and long term. A 30% shortening of the fire frequency resulted in a 3.5‐fold increase in the area burned annually and an associated 41% decrease in the amount of spruce–lichen forest found on the landscape. More importantly, simulations with more frequent fires produced a relatively immature forest age structure, compared to that which currently exists, with few stands older than 100 years. This age structure is at the lower limits of stand age classes preferred by caribou from the Nelchina herd. Projected changes in fire regime due to climate warming and/or additional prescribed burning could substantially alter the winter habitat of caribou in interior Alaska and lead to changes in winter range use and/or population dynamics.

Computed tomography versus invasive coronary angiography

DEFF Research Database (Denmark)

Napp, Adriane E.; Haase, Robert; Laule, Michael

2017-01-01

Objectives: More than 3.5 million invasive coronary angiographies (ICA) are performed in Europe annually. Approximately 2 million of these invasive procedures might be reduced by noninvasive tests because no coronary intervention is performed. Computed tomography (CT) is the most accurate...... angiography (ICA) is the reference standard for detection of CAD.• Noninvasive computed tomography angiography excludes CAD with high sensitivity.• CT may effectively reduce the approximately 2 million negative ICAs in Europe.• DISCHARGE addresses this hypothesis in patients with low-to-intermediate pretest...

Legal immigrants: invasion of alien microbial communities during winter occurring desert dust storms.

Science.gov (United States)

Weil, Tobias; De Filippo, Carlotta; Albanese, Davide; Donati, Claudio; Pindo, Massimo; Pavarini, Lorenzo; Carotenuto, Federico; Pasqui, Massimiliano; Poto, Luisa; Gabrieli, Jacopo; Barbante, Carlo; Sattler, Birgit; Cavalieri, Duccio; Miglietta, Franco

2017-03-10

A critical aspect regarding the global dispersion of pathogenic microorganisms is associated with atmospheric movement of soil particles. Especially, desert dust storms can transport alien microorganisms over continental scales and can deposit them in sensitive sink habitats. In winter 2014, the largest ever recorded Saharan dust event in Italy was efficiently deposited on the Dolomite Alps and was sealed between dust-free snow. This provided us the unique opportunity to overcome difficulties in separating dust associated from "domestic" microbes and thus, to determine with high precision microorganisms transported exclusively by desert dust. Our metagenomic analysis revealed that sandstorms can move not only fractions but rather large parts of entire microbial communities far away from their area of origin and that this microbiota contains several of the most stress-resistant organisms on Earth, including highly destructive fungal and bacterial pathogens. In particular, we provide first evidence that winter-occurring dust depositions can favor a rapid microbial contamination of sensitive sink habitats after snowmelt. Airborne microbial depositions accompanying extreme meteorological events represent a realistic threat for ecosystem and public health. Therefore, monitoring the spread and persistence of storm-travelling alien microbes is a priority while considering future trajectories of climatic anomalies as well as anthropogenically driven changes in land use in the source regions.

Competition for soil nitrate and invasive weed resistance of three shrub-steppe growth forms

Science.gov (United States)

Eamonn D. Leonard

2007-01-01

Determining mechanisms responsible for weed resistance and invasion success are two issues that have potential in aiding successful land management decisions. The first experiment evaluates the competitive effects of an invasive annual grass downy brome (Bromus tectorum L.), an invasive biennial forb dyer's woad (Isatis tinctoria...

Climate and changing winter distribution of alcids in the Northwest Atlantic

Directory of Open Access Journals (Sweden)

Richard R. Veit

2015-04-01

Full Text Available Population level impacts upon seabirds from changing climate are increasingly evident, and include effects on phenology, migration, dispersal, annual survivorship and reproduction. Most population data on seabirds derive from nesting colonies; documented climate impacts on winter ecology are scarce. We studied interannual variability in winter abundance of six species of alcids (Charadriiformes, Alcidae from a 58-year time series of data collected in Massachusetts 1954-2011. We used counts of birds taken during fall and winter from coastal vantage points. Counts were made by amateur birders, but coverage was consistent in timing and location. We found significant association between winter abundance of all six species of alcids and climate, indexed by North Atlantic Oscillation (NAO, at two temporal scales: 1. Significant linear trends at the 58-year scale of the time series; and 2. Shorter term fluctuations corresponding to the 5-8 year periodicity of NAO. Thus, variation in winter abundance of all six species of alcids was significantly related to the combined short-term and longer-term components of variation in NAO. Two low-Arctic species (Atlantic Puffin and Black Guillemot peaked during NAO positive years, while two high Arctic species (Dovekie and Thick-billed Murre peaked during NAO negative years. For Common Murres and Razorbills, southward shifts in winter distribution have been accompanied by southward expansion of breeding range, and increase within the core of the range. The proximate mechanism governing these changes is unclear, but, as for most other species of seabirds whose distributions have changed with climate, seems likely to be through their prey.

Diurnal Freeze-Thaw Cycles Modify Winter Soil Respiration in a Desert Shrub-Land Ecosystem

Directory of Open Access Journals (Sweden)

Peng Liu

2016-07-01

Full Text Available Winter soil respiration (Rs is becoming a significant component of annual carbon budgets with more warming in winter than summer. However, little is known about the controlling mechanisms of winter Rs in dryland. We made continuous measurements of Rs in four microsites (non-crust (BS, lichen (LC, moss (MC, and a mixture of moss and lichen (ML in a desert shrub-land ecosystem northern China, to investigate the causes of Rs dynamics in winter. The mean winter Rs ranged from 0.10 to 0.17 µmol CO2 m−2·s−1 across microsites, with the highest value in BS. Winter Q10 (known as the increase in respiration rate per 10 °C increase in temperature values (2.8–19 were much higher than those from the growing season (1.5. Rs and Q10 were greatly enhanced in freeze-thaw cycles compared to frozen days. Diurnal patterns of Rs between freeze-thaw and frozen days differed. Although the freeze-thaw period was relatively short, its cumulative Rs contributed significantly to winter Rs. The presence of biocrust might induce lower temperature, thus having fewer freeze-thaw cycles relative to bare soil, leading to the lower Rs for microsites with biocrusts. In conclusion, winter Rs in drylands was sensitive to soil temperature (Ts and Ts-induced freeze-thaw cycles. The temperature impact on Rs varied among soil cover types. Winter Rs in drylands may become more important as the climate is continuously getting warmer.

Satellite-based annual evaporation estimates of invasive alien plant ...

African Journals Online (AJOL)

... of densely-invaded riparian areas is likely more pronounced. We concluded that the clearing of IAPs by the WFW programme has a positive effect on the availability of water resources through a reduction in ET. Keywords: invasive alien plants; indigenous vegetation; remote sensing; water use; evapotranspiration; SEBAL; ...

Applying stochastic small-scale damage functions to German winter storms

Science.gov (United States)

Prahl, B. F.; Rybski, D.; Kropp, J. P.; Burghoff, O.; Held, H.

2012-03-01

Analyzing insurance-loss data we derive stochastic storm-damage functions for residential buildings. On district level we fit power-law relations between daily loss and maximum wind speed, typically spanning more than 4 orders of magnitude. The estimated exponents for 439 German districts roughly range from 8 to 12. In addition, we find correlations among the parameters and socio-demographic data, which we employ in a simplified parametrization of the damage function with just 3 independent parameters for each district. A Monte Carlo method is used to generate loss estimates and confidence bounds of daily and annual storm damages in Germany. Our approach reproduces the annual progression of winter storm losses and enables to estimate daily losses over a wide range of magnitudes.

Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

Science.gov (United States)

Yeo, In-Young; Lee, Sangchui; Sadeghi, Ali M.; Beeson, Peter C.; Hively, W. Dean; McCarty, Greg W.; Lang, Megan W.

2013-01-01

Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay Watershed (CBW), which is located in the Mid-Atlantic US, winter cover crop use has been emphasized and federal and state cost-share programs are available to farmers to subsidize the cost of winter cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops at the watershed scale and to identify critical source areas of high nitrate export. A physically-based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data and satellite-based estimates of winter cover crop species performance to simulate hydrological processes and nutrient cycling over the period of 1991–2000. Multiple scenarios were developed to obtain baseline information on nitrate loading without winter cover crops planted and to investigate how nitrate loading could change with different winter cover crop planting scenarios, including different species, planting times, and implementation areas. The results indicate that winter cover crops had a negligible impact on water budget, but significantly reduced nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading was approximately 14 kg ha−1, but it decreased to 4.6–10.1 kg ha−1 with winter cover crops resulting in a reduction rate of 27–67% at the watershed scale. Rye was most effective, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of winter cover crops (~30 days of additional growing days) was crucial, as it lowered nitrate export by an additional ~2 kg ha−1 when compared to late planting scenarios. The effectiveness of cover cropping increased with increasing extent of winter cover crop implementation. Agricultural fields with well-drained soils

Crop growth and nitrogen turnover under increased temperatures and low autumn and winter light intensity

DEFF Research Database (Denmark)

Thomsen, Ingrid Kaag; Lægdsmand, Mette; Olesen, Jørgen E

2010-01-01

The rise in mean annual temperatures under the projected climate change will affect both soil organic matter turnover and cropping patterns in agriculture. Nitrogen (N) mineralization may be higher during autumn and winter and may increase the risk of nitrate leaching. Our study tested whether...... before the late sowing of wheat caused generally higher levels of inorganic N to accumulate in soil. Despite the higher mineralization under the raised temperatures, at T+8 the late-sown winter wheat was able to reduce soil inorganic N to a lower level than late-sown wheat at the two lower temperatures...

Winters fuels report

International Nuclear Information System (INIS)

1995-01-01

The outlook for distillate fuel oil this winter is for increased demand and a return to normal inventory patterns, assuming a resumption of normal, cooler weather than last winter. With industrial production expected to grow slightly from last winter's pace, overall consumption is projected to increase 3 percent from last winter, to 3.4 million barrels per day during the heating season (October 1, 1995-March 31, 1996). Much of the supply win come from stock drawdowns and refinery production. Estimates for the winter are from the Energy Information Administration's (EIA) 4th Quarter 1995 Short-Tenn Energy Outlook (STEO) Mid-World Oil Price Case forecast. Inventories in place on September 30, 1995, of 132 million barrels were 9 percent below the unusually high year-earlier level. Inventories of high-sulfur distillate fuel oil, the principal type used for heating, were 13 percent lower than a year earlier. Supply problems are not anticipated because refinery production and the ready availability of imports should be adequate to meet demand. Residential heating off prices are expected to be somewhat higher than last winter's, as the effects of lower crude oil prices are offset by lower distillate inventories. Heating oil is forecast to average $0.92 per gallon, the highest price since the winter of 1992-93. Diesel fuel (including tax) is predicted to be slightly higher than last year at $1.13 per gallon. This article focuses on the winter assessment for distillate fuel oil, how well last year's STEO winter outlook compared to actual events, and expectations for the coming winter. Additional analyses include regional low-sulfur and high-sulfur distillate supply, demand, and prices, and recent trends in distillate fuel oil inventories

Post-fire Downy Brome (Bromus tectorum) invasion at high elevation in Wyoming

Science.gov (United States)

The invasive annual grass downy brome is the most ubiquitous weed in sagebrush systems of western North America. The center of invasion has largely been the Great Basin region, but there is an increasing abundance and distribution in the Rocky Mountain States. We evaluated post-fire vegetation chang...

Winter rye as a bioenergy feedstock: impact of crop maturity on composition, biological solubilization and potential revenue.

Science.gov (United States)

Shao, Xiongjun; DiMarco, Kay; Richard, Tom L; Lynd, Lee R

2015-01-01

Winter annual crops such as winter rye (Secale cereale L) can produce biomass feedstock on seasonally fallow land that continues to provide high-value food and feed from summer annuals such as corn and soybeans. As energy double crops, winter grasses are likely to be harvested while still immature and thus structurally different from the fully senesced plant material typically used for biofuels. This study investigates the dynamic trends in biomass yield, composition, and biological solubilization over the course of a spring harvest season. The water soluble fraction decreased with increasing maturity while total carbohydrate content stayed roughly constant at about 65%. The protein mass fraction decreased with increasing maturity, but was counterbalanced by increasing harvest yield resulting in similar total protein across harvest dates. Winter rye was ground and autoclaved then fermented at 15 g/L total solids by either (1) Clostridium thermocellum or (2) simultaneous saccharification and cofermentation (SSCF) using commercial cellulases (CTec2 and HTec2) and a xylose-fermenting Saccharomyces cerevisiae strain. Solubilization of total carbohydrate dropped significantly as winter rye matured for both C. thermocellum (from approximately 80% to approximately 50%) and SSCF (from approximately 60% to approximately 30%). C. thermocellum achieved total solubilization 33% higher than that of SSCF for the earliest harvest date and 50% higher for the latest harvest date. Potential revenue from protein and bioethanol was stable over a range of different harvest dates, with most of the revenue due to ethanol. In a crop rotation with soybean, recovery of the soluble protein from winter rye could increase per hectare protein production by 20 to 35%. Double-cropping winter rye can produce significant biomass for biofuel production and feed protein as coproduct without competing with the main summer crop. During a 24-day harvest window, the total carbohydrate content remained

Winter to winter recurrence of atmospheric circulation anomalies over East Asia and its impact on winter surface air temperature anomalies.

Science.gov (United States)

Zhao, Xia; Yang, Guang

2017-01-01

The persistence of atmospheric circulation anomalies over East Asia shows a winter to winter recurrence (WTWR) phenomenon. Seasonal variations in sea level pressure anomalies and surface wind anomalies display significantly different characteristics between WTWR and non-WTWR years. The WTWR years are characterized by the recurrence of both a strong (weak) anomalous Siberian High and an East Asian winter monsoon over two successive winters without persistence through the intervening summer. However, anomalies during the non-WTWR years have the opposite sign between the current and ensuing winters. The WTWR of circulation anomalies contributes to that of surface air temperature anomalies (SATAs), which is useful information for improving seasonal and interannual climate predictions over East Asia and China. In the positive (negative) WTWR years, SATAs are cooler (warmer) over East Asia in two successive winters, but the signs of the SATAs are opposite in the preceding and subsequent winters during the non-WTWR years.

Controls on winter ecosystem respiration in temperate and boreal ecosystems

Directory of Open Access Journals (Sweden)

T. Wang

2011-07-01

Full Text Available Winter CO₂ fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the factors influencing the spatial and temporal patterns of winter ecosystem respiration (R_eco of northern ecosystems are poorly understood. For this reason, we analyzed eddy covariance flux data from 57 ecosystem sites ranging from ~35° N to ~70° N. Deciduous forests were characterized by the highest winter R_eco rates (0.90 ± 0.39 g C m⁻² d⁻¹, when winter is defined as the period during which daily air temperature remains below 0 °C. By contrast, arctic wetlands had the lowest winter R_eco rates (0.02 ± 0.02 g C m⁻² d⁻¹. Mixed forests, evergreen needle-leaved forests, grasslands, croplands and boreal wetlands were characterized by intermediate winter R_eco rates (g C m⁻² d⁻¹ of 0.70(±0.33, 0.60(±0.38, 0.62(±0.43, 0.49(±0.22 and 0.27(±0.08, respectively. Our cross site analysis showed that winter air (T_air and soil (T_soil temperature played a dominating role in determining the spatial patterns of winter R_eco in both forest and managed ecosystems (grasslands and croplands. Besides temperature, the seasonal amplitude of the leaf area index (LAI, inferred from satellite observation, or growing season gross primary productivity, which we use here as a proxy for the amount of recent carbon available for R_eco in the subsequent winter, played a marginal role in winter CO₂ emissions from forest ecosystems. We found that winter R_eco sensitivity to temperature variation across space (

Exploitable Lipids and Fatty Acids in the Invasive Oyster Crassostrea gigas on the French Atlantic Coast

Directory of Open Access Journals (Sweden)

Flore Dagorn

2016-05-01

Full Text Available Economic exploitation is one means to offset the cost of controlling invasive species, such as the introduced Pacific oyster (Crassostrea gigas Thunberg on the French Atlantic coast. Total lipid and phospholipid (PL fatty acids (FAs and sterols were examined in an invasive population of C. gigas in Bourgneuf Bay, France, over four successive seasons, with a view to identify possible sources of exploitable substances. The total lipid level (% dry weight varied from 7.1% (winter to 8.6% (spring. Of this, PLs accounted for 28.1% (spring to 50.4% (winter. Phosphatidylcholine was the dominant PL throughout the year (up to 74% of total PLs in winter. Plasmalogens were identified throughout the year as a series of eleven dimethylacetals (DMAs with chain lengths between C16 and C20 (up to 14.5% of PL FAs + DMAs in winter. Thirty-seven FAs were identified in the PL FAs. Eicosapentaenoic acid (20:5n-3 EPA/7.53% to 14.5% and docosahexaenoic acid (22:6n-3 DHA/5.51% to 9.5% were the dominant polyunsaturated FAs in all seasons. Two non-methylene-interrupted dienoic (NMID FAs were identified in all seasons: 7,13-docosadienoic and 7,15-docosadienoic acids, the latter being present at relatively high levels (up to 9.6% in winter. Twenty free sterols were identified, including cholesterol at 29.9% of the sterol mixture and about 33% of phytosterols. C. gigas tissues thus contained exploitable lipids for health benefits or as a potential source of high-quality commercial lecithin.

Exploitable Lipids and Fatty Acids in the Invasive Oyster Crassostrea gigas on the French Atlantic Coast

Science.gov (United States)

Dagorn, Flore; Couzinet-Mossion, Aurélie; Kendel, Melha; Beninger, Peter G.; Rabesaotra, Vony; Barnathan, Gilles; Wielgosz-Collin, Gaëtane

2016-01-01

Economic exploitation is one means to offset the cost of controlling invasive species, such as the introduced Pacific oyster (Crassostrea gigas Thunberg) on the French Atlantic coast. Total lipid and phospholipid (PL) fatty acids (FAs) and sterols were examined in an invasive population of C. gigas in Bourgneuf Bay, France, over four successive seasons, with a view to identify possible sources of exploitable substances. The total lipid level (% dry weight) varied from 7.1% (winter) to 8.6% (spring). Of this, PLs accounted for 28.1% (spring) to 50.4% (winter). Phosphatidylcholine was the dominant PL throughout the year (up to 74% of total PLs in winter). Plasmalogens were identified throughout the year as a series of eleven dimethylacetals (DMAs) with chain lengths between C16 and C20 (up to 14.5% of PL FAs + DMAs in winter). Thirty-seven FAs were identified in the PL FAs. Eicosapentaenoic acid (20:5n-3 EPA/7.53% to 14.5%) and docosahexaenoic acid (22:6n-3 DHA/5.51% to 9.5%) were the dominant polyunsaturated FAs in all seasons. Two non-methylene-interrupted dienoic (NMID) FAs were identified in all seasons: 7,13-docosadienoic and 7,15-docosadienoic acids, the latter being present at relatively high levels (up to 9.6% in winter). Twenty free sterols were identified, including cholesterol at 29.9% of the sterol mixture and about 33% of phytosterols. C. gigas tissues thus contained exploitable lipids for health benefits or as a potential source of high-quality commercial lecithin. PMID:27231919

Preventing desert locust plagues: optimizing management interventions

NARCIS (Netherlands)

Huis, van A.; Cressman, K.; Magor, J.I.

2007-01-01

Solitarious desert locusts, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae), inhabit the central, arid, and semi-arid parts of the species¿ invasion area in Africa, the Middle East, and South-West Asia. Their annual migration circuit takes them downwind to breed sequentially where winter,

Winter is losing its cool

Science.gov (United States)

Feng, S.

2017-12-01

Winter seasons have significant societal impacts across all sectors ranging from direct human health to ecosystems, transportation, and recreation. This study quantifies the severity of winter and its spatial-temporal variations using a newly developed winter severity index and daily temperature, snowfall and snow depth. The winter severity and the number of extreme winter days are decreasing across the global terrestrial areas during 1901-2015 except the southeast United States and isolated regions in the Southern Hemisphere. These changes are dominated by winter warming, while the changes in daily snowfall and snow depth played a secondary role. The simulations of multiple CMIP5 climate models can well capture the spatial and temporal variations of the observed changes in winter severity and extremes during 1951-2005. The models are consistent in projecting a future milder winter under various scenarios. The winter severity is projected to decrease 60-80% in the middle-latitude Northern Hemisphere under the business-as-usual scenario. The winter arrives later, ends earlier and the length of winter season will be notably shorter. The changes in harsh winter in the polar regions are weak, mainly because the warming leads to more snowfall in the high latitudes.

Does winter region affect spring arrival time and body mass of king eiders in northern Alaska?

Science.gov (United States)

Powell, Abby N.; Oppel, Steffen

2009-01-01

Events during the non-breeding season may affect the body condition of migratory birds and influence performance during the following breeding season. Migratory birds nesting in the Arctic often rely on endogenous nutrients for reproductive efforts, and are thus potentially subject to such carry-over effects. We tested whether king eider (Somateria spectabilis) arrival time and body mass upon arrival at breeding grounds in northern Alaska were affected by their choice of a winter region in the Bering Sea. We captured birds shortly after arrival on breeding grounds in early June 2002–2006 at two sites in northern Alaska and determined the region in which individuals wintered using satellite telemetry or stable isotope ratios of head feathers. We used generalized linear models to assess whether winter region explained variation in arrival body mass among individuals by accounting for sex, site, annual variation, and the date a bird was captured. We found no support for our hypothesis that either arrival time or arrival body mass of king eiders differed among winter regions. We conclude that wintering in different regions in the Bering Sea is unlikely to have reproductive consequences for king eiders in our study areas.

Analysis of monthly, winter, and annual temperatures in Zagreb, Croatia, from 1864 to 2010: the 7.7-year cycle and the North Atlantic Oscillation

Science.gov (United States)

Sen, Asok K.; Ogrin, Darko

2016-02-01

Long instrumental records of meteorological variables such as temperature and precipitation are very useful for studying regional climate in the past, present, and future. They can also be useful for understanding the influence of large-scale atmospheric circulation processes on the regional climate. This paper investigates the monthly, winter, and annual temperature time series obtained from the instrumental records in Zagreb, Croatia, for the period 1864-2010. Using wavelet analysis, the dominant modes of variability in these temperature series are identified, and the time intervals over which these modes may persist are delineated. The results reveal that all three temperature records exhibit low-frequency variability with a dominant periodicity at around 7.7 years. The 7.7-year cycle has also been observed in the temperature data recorded at several other stations in Europe, especially in Northern and Western Europe, and may be linked to the North Atlantic Oscillation (NAO) and/or solar/geomagnetic activity.

Tolerance of subzero winter cold in kudzu (Pueraria montana var. lobata) and its implications for northward migration in a warming climate

Science.gov (United States)

Kudzu (Pueraria montana var. lobata) is an important invasive species that was planted throughout southeastern North America until the mid-20th century. Winter survival is commonly assumed to control its distribution; however, its cold tolerance thresholds have not been determined. Here, we used bio...

Resistance to invasion and resilience to fire in desert shrublands of North America

Science.gov (United States)

Matthew L. Brooks; Jeanne C. Chambers

2011-01-01

Settlement by Anglo-Americans in the desert shrublands of North America resulted in the introduction and subsequent invasion of multiple nonnative grass species. These invasions have altered presettlement fire regimes, resulted in conversion of native perennial shrublands to nonnative annual grasslands, and placed many native desert species at risk. Effective...

A comparison of annual and seasonal carbon dioxide effluxes between subarctic Sweden and high-arctic Svalbard

DEFF Research Database (Denmark)

Björkman, Mats P.; Morgner, Elke; Björk, Robert G.

2010-01-01

in the literature. Winter emissions varied in their contribution to total annual production between 1 and 18%. Artificial snow drifts shortened the snow-free period by 2 weeks and decreased the annual CO2 emission by up to 20%. This study suggests that future shifts in vegetation zones may increase soil respiration...

A global analysis of the comparability of winter chill models for fruit and nut trees.

Science.gov (United States)

Luedeling, Eike; Brown, Patrick H

2011-05-01

Many fruit and nut trees must fulfill a chilling requirement to break their winter dormancy and resume normal growth in spring. Several models exist for quantifying winter chill, and growers and researchers often tacitly assume that the choice of model is not important and estimates of species chilling requirements are valid across growing regions. To test this assumption, Safe Winter Chill (the amount of winter chill that is exceeded in 90% of years) was calculated for 5,078 weather stations around the world, using the Dynamic Model [in Chill Portions (CP)], the Chilling Hours (CH) Model and the Utah Model [Utah Chill Units (UCU)]. Distributions of the ratios between different winter chill metrics were mapped on a global scale. These ratios should be constant if the models were strictly proportional. Ratios between winter chill metrics varied substantially, with the CH/CP ratio ranging between 0 and 34, the UCU/CP ratio between -155 and +20 and the UCU/CH ratio between -10 and +5. The models are thus not proportional, and chilling requirements determined in a given location may not be valid elsewhere. The Utah Model produced negative winter chill totals in many Subtropical regions, where it does not seem to be useful. Mean annual temperature and daily temperature range influenced all winter chill ratios, but explained only between 12 and 27% of the variation. Data on chilling requirements should always be amended with information on the location and experimental conditions of the study in which they were determined, ideally including site-specific conversion factors between winter chill models. This would greatly facilitate the transfer of such information across growing regions, and help prepare growers for the impact of climate change.

Fire-driven alien invasion in a fire-adapted ecosystem

Science.gov (United States)

Keeley, Jon E.; Brennan, Teresa J.

2012-01-01

Disturbance plays a key role in many alien plant invasions. However, often the main driver of invasion is not disturbance per se but alterations in the disturbance regime. In some fire-adapted shrublands, the community is highly resilient to infrequent, high-intensity fires, but changes in the fire regime that result in shorter fire intervals may make these communities more susceptible to alien plant invasions. This study examines several wildfire events that resulted in short fire intervals in California chaparral shrublands. In one study, we compared postfire recovery patterns in sites with different prefire stand ages (3 and 24 years), and in another study we compared sites that had burned once in four years with sites that had burned twice in this period. The population size of the dominant native shrub Adenostoma fasciculatum was drastically reduced following fire in the 3-year sites relative to the 24-year sites. The 3-year sites had much greater alien plant cover and significantly lower plant diversity than the 24-year sites. In a separate study, repeat fires four years apart on the same sites showed that annual species increased significantly after the second fire, and alien annuals far outnumbered native annuals. Aliens included both annual grasses and annual forbs and were negatively correlated with woody plant cover. Native woody species regenerated well after the first fire but declined after the second fire, and one obligate seeding shrub was extirpated from two sites by the repeat fires. It is concluded that some fire-adapted shrublands are vulnerable to changes in fire regime, and this can lead to a loss of native diversity and put the community on a trajectory towards type conversion from a woody to an herbaceous system. Such changes result in alterations in the proportion of natives to non-natives, changes in functional types from deeply rooted shrubs to shallow rooted grasses and forbs, increased fire frequency due to the increase in fine fuels

Fire-driven alien invasion in a fire-adapted ecosystem.

Science.gov (United States)

Keeley, Jon E; Brennan, Teresa J

2012-08-01

Disturbance plays a key role in many alien plant invasions. However, often the main driver of invasion is not disturbance per se but alterations in the disturbance regime. In some fire-adapted shrublands, the community is highly resilient to infrequent, high-intensity fires, but changes in the fire regime that result in shorter fire intervals may make these communities more susceptible to alien plant invasions. This study examines several wildfire events that resulted in short fire intervals in California chaparral shrublands. In one study, we compared postfire recovery patterns in sites with different prefire stand ages (3 and 24 years), and in another study we compared sites that had burned once in four years with sites that had burned twice in this period. The population size of the dominant native shrub Adenostoma fasciculatum was drastically reduced following fire in the 3-year sites relative to the 24-year sites. The 3-year sites had much greater alien plant cover and significantly lower plant diversity than the 24-year sites. In a separate study, repeat fires four years apart on the same sites showed that annual species increased significantly after the second fire, and alien annuals far outnumbered native annuals. Aliens included both annual grasses and annual forbs and were negatively correlated with woody plant cover. Native woody species regenerated well after the first fire but declined after the second fire, and one obligate seeding shrub was extirpated from two sites by the repeat fires. It is concluded that some fire-adapted shrublands are vulnerable to changes in fire regime, and this can lead to a loss of native diversity and put the community on a trajectory towards type conversion from a woody to an herbaceous system. Such changes result in alterations in the proportion of natives to non-natives, changes in functional types from deeply rooted shrubs to shallow rooted grasses and forbs, increased fire frequency due to the increase in fine fuels

New winter hardy winter bread wheat cultivar (Triticum aestivum L. Voloshkova

Directory of Open Access Journals (Sweden)

Л. М. Голик

2007-12-01

Full Text Available Creation of Initial raw for breeding of winter wheat by change of the development type under low temperatures influence was described. Seeds of spring wheat were vernalized in aluminum weighting bottle. By using low temperatures at sawing of M2-6 at the begin ind of optimal terms of sawing of winter wheat, new winter-hardy variety of Voloshkova was bred.

Impacts of the EA and SCA patterns on the 20th century NAO-winter precipitation relationship in Europe

Science.gov (United States)

Comas-Bru, Laia; McDermott, Frank

2013-04-01

Much of the 20th century multi-decadal variability in the NAO-winter precipitation relationship over the N. Atlantic / European sector can be ascribed to the combined effects of the North Atlantic Oscillation (NAO) and either the East Atlantic pattern (EA) or the Scandinavian pattern (SCA). The NAO, EA and SCA indices employed here are defined as the three leading vectors of the cross-correlation matrix calculated from monthly sea-level pressure anomalies for 138 complete winters from the 20CRv2 dataset (Compo et al., 2011). Winter precipitation data over Europe for the entire 20th century is derived from the high resolution CRU-TS3.1 climate dataset (Mitchell and Jones, 2005). Here we document for the first time, that different NAO/EA and NAO/SCA combinations systematically influence winter precipitation conditions in Europe as a consequence of NAO dipole migrations. We find that the zero-correlated line of the NAO-winter precipitation relationship migrates southwards when the EA is in the opposite phase to the NAO. This can be related to a south-westwards migration of the NAO dipole under these conditions, as shown by teleconnectivity maps. Similarly, a clockwise movement of the NAO-winter climate correlated areas occurs when the phase of the SCA is opposite to that of the NAO, reflecting a clockwise movement of the NAO dipole under these conditions. An important implication of these migrations is that they influence the spatial and temporal stationarity of climate-NAO relationships. As a result, the link between winter precipitation patterns and the NAO is not straightforward in some regions such as the southern UK, Ireland and France. For instance, much of the inter-annual variability in the N-S winter precipitation gradient in the UK, originally attributed to inter-annual and inter-decadal variability of the NAO, reflects the migration of the NAO dipole, linked to linear combinations of the NAO and the EA. Our results indicate that when the N-S winter

Blood lead concentrations in Alaskan tundra swans: linking breeding and wintering areas with satellite telemetry.

Science.gov (United States)

Ely, Craig R; Franson, J Christian

2014-04-01

Tundra swans (Cygnus columbianus) like many waterfowl species are susceptible to lead (Pb) poisoning, and Pb-induced mortality has been reported from many areas of their wintering range. Little is known however about Pb levels throughout the annual cycle of tundra swans, especially during summer when birds are on remote northern breeding areas where they are less likely to be exposed to anthropogenic sources of Pb. Our objective was to document summer Pb levels in tundra swans throughout their breeding range in Alaska to determine if there were population-specific differences in blood Pb concentrations that might pose a threat to swans and to humans that may consume them. We measured blood Pb concentrations in tundra swans at five locations in Alaska, representing birds that winter in both the Pacific Flyway and Atlantic Flyway. We also marked swans at each location with satellite transmitters and coded neck bands, to identify staging and wintering sites and determine if winter site use correlated with summer Pb concentrations. Blood Pb levels were generally low (<0.2 μg/ml) in swans across all breeding areas. Pb levels were lower in cygnets than adults, suggesting that swans were likely exposed to Pb on wintering areas or on return migration to Alaska, rather than on the summer breeding grounds. Blood Pb levels varied significantly across the five breeding areas, with highest concentrations in birds on the North Slope of Alaska (wintering in the Atlantic Flyway), and lowest in birds from the lower Alaska Peninsula that rarely migrate south for winter.

33 CFR 100.109 - Winter Harbor Lobster Boat Race, Winter Harbor, ME.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Winter Harbor Lobster Boat Race, Winter Harbor, ME. 100.109 Section 100.109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.109 Winter Harbor...

Dna c-values of 20 invasive alien species and 3 native species in south china

OpenAIRE

Gong Ni; Wang Yu-Tao; Björn Lars Olof; Li Shao-Shan

2014-01-01

Cultivated fields and forests in South China are experiencing serious damage due to invasive alien plants. We investigated the relation between DNA C-values and invasiveness. The DNA C-values of 23 species ranged from 0.39 pg to 3.37 pg. Herbs, perennials and native species had higher mean DNA C-values than shrubs, annuals and invasive alien species. DNA C-values decreased with increasing invasiveness. Paederia scandens, a harmful native species, has the lo...

Variations of annual and seasonal runoff in Guangdong Province, south China: spatiotemporal patterns and possible causes

Science.gov (United States)

Zhang, Qiang; Xiao, Mingzhong; Singh, Vijay P.; Xu, Chong-Yu; Li, Jianfeng

2015-06-01

In this study, we thoroughly analyzed spatial and temporal distributions of runoff and their relation with precipitation changes based on monthly runoff dataset at 25 hydrological stations and monthly precipitation at 127 stations in Guangdong Province, south China. Trends of the runoff and precipitation are detected using Mann-Kendall trend test technique. Correlations between runoff and precipitation are tested using Spearman's and Pearson's correlation coefficients. The results indicate that: (1) annual maximum monthly runoff is mainly in decreasing tendency and significant increasing annual minimum monthly runoff is observed in the northern and eastern Guangdong Province. In addition, annual mean runoff is observed to be increasing at the stations located in the West and North Rivers and the coastal region; (2) analysis of seasonal runoff variations indicates increasing runoff in spring, autumn and winter. Wherein, significant increase of runoff is found at 8 stations and only 3 stations are dominated by decreasing runoff in winter; (3) runoff changes of the Guangdong Province are mainly the results of precipitation changes. The Guangdong Province is wetter in winter, spring and autumn. Summer is coming to be drier as reflected by decreasing runoff in the season; (4) both precipitation change and water reservoirs also play important roles in the increasing of annual minimum monthly streamflow. Seasonal shifts of runoff variations may pose new challenges for the water resources management under the influences of climate changes and intensifying human activities.

Annual ring validation of the south african sardine Sardinops sagax ...

African Journals Online (AJOL)

A total of 21 sardine Sardinops sagax otoliths, collected in winter and spring 1994, were examined with a scanning electron microscope to validate growth zones using daily growth increments. Increment numbers and widths for the first, second and third annual growth zones served to back-calculate hatching dates and to ...

Invasion of Old World Phragmites australis in the New World: precipitation and temperature patterns combined with human influences redesign the invasive niche

DEFF Research Database (Denmark)

Guo, Wen-Yong; Lambertini, Carla; Li, Xiu-Zhen

2013-01-01

niches. We suggest that an increase in precipitation in the 20(th) century, global warming and human-made habitats have shaped the invasive niches of the two lineages in the New World. However, as the invasions are on-going and human and natural disturbances occur concomitantly, the future distribution....... australis (Haplotype M and Med) in both their native and introduced ranges using environmental niche models (ENMs) to assess (i) whether a niche shift accompanied the invasions in the New World; (ii) the role of biologically relevant climatic variables and human influence in the process of invasion...... for temperature fluctuations and increased precipitation. The introduced Med lineage has enlarged its original subtropical niche to the tropics-subtropics, invading regions with a high annual mean temperature (> c. 10 °C) and high precipitation in the driest period. Human influence is an important factor for both...

The DISAM Journal of International Security Assistance Management. Volume 23, Number 2, Winter 2001

Science.gov (United States)

2001-01-01

The DISAM Journal, Winter 2001 90 Protection Project to continue its study of international trafficking, prostitution, slavery , debt bondage and other...amounting to debt bondage , involuntary servitude, or slavery . This includes about 50,000 women and children trafficked annually into the U.S. [Section 102...Vietnamese to receive modern demining equipment and other mine- related assistance through the U.S. humanitarian demining program. The Vietnamese will

Arctic vegetation damage by winter-generated coal mining pollution released upon thawing

DEFF Research Database (Denmark)

Elberling, B.; Søndergaard, J.; Jensen, L.A.

2007-01-01

summer period. Here we show that heat generation within an oxidizing, sulfidic, coal-mining waste-rock pile in Svalbard (78° N) is high enough to keep the pile warm (roughly 5 °C throughout the year) despite mean annual air temperatures below -5 °C. Consequently, weathering processes continue year...... the adverse environmental impacts of cold region coal-mining need to pay more attention to winter processes including AMD generation and accumulation of weathering products....

Characteristics of foraging sites and protein status in wintering muskoxen: insights from isotopes of nitrogen

Science.gov (United States)

Gustine, David D.; Barboza, Perry S.; Lawler, James P.; Arthur, Stephen M.; Shults, Brad S.; Persons, Kate; Adams, Layne G.

2011-01-01

Identifying links between nutritional condition of individuals and population trajectories greatly enhances our understanding of the ecology, conservation, and management of wildlife. For northern ungulates, the potential impacts of a changing climate to populations are predicted to be nutritionally mediated through an increase in the severity and variance in winter conditions. Foraging conditions and the availability of body protein as a store for reproduction in late winter may constrain productivity in northern ungulates, yet the link between characteristics of wintering habitats and protein status has not been established for a wild ungulate. We used a non‐invasive proxy of protein status derived from isotopes of N in excreta to evaluate the influence of winter habitats on the protein status of muskoxen in three populations in Alaska (2005–2008). Multiple regression and an information‐theoretic approach were used to compare models that evaluated the influence of population, year, and characteristics of foraging sites (components of diet and physiography) on protein status for groups of muskoxen. The observed variance in protein status among groups of muskoxen across populations and years was partially explained (45%) by local foraging conditions that affected forage availability. Protein status improved for groups of muskoxen as the amount of graminoids in the diet increased (−0.430 ± 0.31, β± 95% CI) and elevation of foraging sites decreased (0.824 ± 0.67). Resources available for reproduction in muskoxen are highly dependent upon demographic, environmental, and physiographic constraints that affect forage availability in winter. Due to their very sedentary nature in winter, muskoxen are highly susceptible to localized foraging conditions; therefore, the spatial variance in resource availability may exert a strong effect on productivity. Consequently, there is a clear need to account for climate–topography effects in winter at multiple scales

Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic

Science.gov (United States)

Gustine, David D.; Brinkman, Todd J.; Lindgren, Michael A.; Schmidt, Jennifer I.; Rupp, T. Scott; Adams, Layne G.

2014-01-01

Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus) are an important subsistence resource for communities throughout the north and a species that depends on terrestrial lichen in late-successional forests and tundra systems. Projected increases in area burned and reductions in stand ages may reduce lichen availability within caribou winter ranges. Sufficient reductions in lichen abundance could alter the capacity of these areas to support caribou populations. To assess the potential role of a changing fire regime on winter habitat for caribou, we used a simulation modeling platform, two global circulation models (GCMs), and a moderate emissions scenario to project annual fire characteristics and the resulting abundance of lichen-producing vegetation types (i.e., spruce forests and tundra >60 years old) across a modeling domain that encompassed the winter ranges of the Central Arctic and Porcupine caribou herds in the Alaskan-Yukon Arctic. Fires were less numerous and smaller in tundra compared to spruce habitats throughout the 90-year projection for both GCMs. Given the more likely climate trajectory, we projected that the Porcupine caribou herd, which winters primarily in the boreal forest, could be expected to experience a greater reduction in lichen-producing winter habitats (−21%) than the Central Arctic herd that wintered primarily in the arctic tundra (−11%). Our results suggest that caribou herds wintering in boreal forest will undergo fire-driven reductions in lichen-producing habitats that will, at a minimum, alter their distribution. Range shifts of caribou resulting from fire-driven changes to winter habitat may diminish access to caribou for rural communities that reside in fire-prone areas.

Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic.

Directory of Open Access Journals (Sweden)

David D Gustine

Full Text Available Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus are an important subsistence resource for communities throughout the north and a species that depends on terrestrial lichen in late-successional forests and tundra systems. Projected increases in area burned and reductions in stand ages may reduce lichen availability within caribou winter ranges. Sufficient reductions in lichen abundance could alter the capacity of these areas to support caribou populations. To assess the potential role of a changing fire regime on winter habitat for caribou, we used a simulation modeling platform, two global circulation models (GCMs, and a moderate emissions scenario to project annual fire characteristics and the resulting abundance of lichen-producing vegetation types (i.e., spruce forests and tundra >60 years old across a modeling domain that encompassed the winter ranges of the Central Arctic and Porcupine caribou herds in the Alaskan-Yukon Arctic. Fires were less numerous and smaller in tundra compared to spruce habitats throughout the 90-year projection for both GCMs. Given the more likely climate trajectory, we projected that the Porcupine caribou herd, which winters primarily in the boreal forest, could be expected to experience a greater reduction in lichen-producing winter habitats (-21% than the Central Arctic herd that wintered primarily in the arctic tundra (-11%. Our results suggest that caribou herds wintering in boreal forest will undergo fire-driven reductions in lichen-producing habitats that will, at a minimum, alter their distribution. Range shifts of caribou resulting from fire-driven changes to winter habitat may diminish access to caribou for rural communities that reside in fire-prone areas.

Climate-driven effects of fire on winter habitat for caribou in the Alaskan-Yukon Arctic.

Science.gov (United States)

Gustine, David D; Brinkman, Todd J; Lindgren, Michael A; Schmidt, Jennifer I; Rupp, T Scott; Adams, Layne G

2014-01-01

Climatic warming has direct implications for fire-dominated disturbance patterns in northern ecosystems. A transforming wildfire regime is altering plant composition and successional patterns, thus affecting the distribution and potentially the abundance of large herbivores. Caribou (Rangifer tarandus) are an important subsistence resource for communities throughout the north and a species that depends on terrestrial lichen in late-successional forests and tundra systems. Projected increases in area burned and reductions in stand ages may reduce lichen availability within caribou winter ranges. Sufficient reductions in lichen abundance could alter the capacity of these areas to support caribou populations. To assess the potential role of a changing fire regime on winter habitat for caribou, we used a simulation modeling platform, two global circulation models (GCMs), and a moderate emissions scenario to project annual fire characteristics and the resulting abundance of lichen-producing vegetation types (i.e., spruce forests and tundra >60 years old) across a modeling domain that encompassed the winter ranges of the Central Arctic and Porcupine caribou herds in the Alaskan-Yukon Arctic. Fires were less numerous and smaller in tundra compared to spruce habitats throughout the 90-year projection for both GCMs. Given the more likely climate trajectory, we projected that the Porcupine caribou herd, which winters primarily in the boreal forest, could be expected to experience a greater reduction in lichen-producing winter habitats (-21%) than the Central Arctic herd that wintered primarily in the arctic tundra (-11%). Our results suggest that caribou herds wintering in boreal forest will undergo fire-driven reductions in lichen-producing habitats that will, at a minimum, alter their distribution. Range shifts of caribou resulting from fire-driven changes to winter habitat may diminish access to caribou for rural communities that reside in fire-prone areas.

Correlation analyses of Baltic Sea winter water mass formation and its impact on secondary and tertiary production

Directory of Open Access Journals (Sweden)

Jörn Schmidt

2007-09-01

Full Text Available The thermal stratification of the upper water layers in the BalticSea varies seasonally in response to the annual cycle of solarheating and wind-induced mixing. In winter, the stratificationdown to the halocline is almost completely eroded by convectionand strong wind mixing. Monthly averaged temperature profilesobtained from the ICES hydrographic database were used to studythe long-term variability (1950 to 2005 of winter water massformation in different deep basins of the Baltic Sea east ofthe island of Bornholm. Besides strong interannual variabilityof deep winter water temperatures, the last two decades showa positive trend (increase of 1-1.5°C. Correlationsof winter surface temperatures to temperatures of the winterwater body located directly above or within the top of the haloclinewere strongly positive until the autumn months. Such a closecoupling allows sea surface temperatures in winter to be usedto forecast the seasonal development of the thermal signaturein deeper layers with a high degree of confidence. The most significantimpact of winter sea surface temperatures on the thermal signaturein this depth range can be assigned to February/March. Strongersolar heating during spring and summer results in thermal stratificationof the water column leading to a complete decoupling of surfaceand deep winter water temperatures. Based on laboratory experiments,temperature-dependent relationships were utilised to analyseinterannual variations of biological processes with special emphasison the upper trophic levels (e.g., stage-specific developmentalrates of zooplankton and survival rates of fish eggs.

Arctic lake physical processes and regimes with implications for winter water availability and management in the National Petroleum Reserve Alaska.

Science.gov (United States)

Jones, Benjamin M; Arp, Christopher D; Hinkel, Kenneth M; Beck, Richard A; Schmutz, Joel A; Winston, Barry

2009-06-01

Lakes are dominant landforms in the National Petroleum Reserve Alaska (NPRA) as well as important social and ecological resources. Of recent importance is the management of these freshwater ecosystems because lakes deeper than maximum ice thickness provide an important and often sole source of liquid water for aquatic biota, villages, and industry during winter. To better understand seasonal and annual hydrodynamics in the context of lake morphometry, we analyzed lakes in two adjacent areas where winter water use is expected to increase in the near future because of industrial expansion. Landsat Thematic Mapper and Enhanced Thematic Mapper Plus imagery acquired between 1985 and 2007 were analyzed and compared with climate data to understand interannual variability. Measured changes in lake area extent varied by 0.6% and were significantly correlated to total precipitation in the preceding 12 months (p water-level monitoring, and lake-ice thickness measurements and growth models were used to better understand seasonal hydrodynamics, surface area-to-volume relations, winter water availability, and more permanent changes related to geomorphic change. Together, these results describe how lakes vary seasonally and annually in two critical areas of the NPRA and provide simple models to help better predict variation in lake-water supply. Our findings suggest that both overestimation and underestimation of actual available winter water volume may occur regularly, and this understanding may help better inform management strategies as future resource use expands in the NPRA.

Intrusion of the Bay of Bengal water into the Arabian Sea during winter monsoon and associated chemical and biological response

Digital Repository Service at National Institute of Oceanography (India)

PrasannaKumar, S.; Narvekar, J.; Kumar, A.; Shaji, C.; Anand, P.; Sabu, P.; Rijomon, G.; Josia, J.; Jayaraj, K.A.; Radhika, A.; Nair, K.K.C.

off. The hydrological imbalance thus created on an annual scale will have to be balanced by the inter-basin exchange. In winter this happens through the intrusion of Bay of Bengal waters into the Arabian Sea, when the southward flowing East India...

Phenology of exotic invasive weeds associated with downy brome

Science.gov (United States)

The exotic and highly invasive annual grass downy brome (Bromus tectorum) has invaded millions of hectares of rangelands throughout the Intermountain West. Downy brome increases the chance, rate, season and spread of wildfires, resulting in the destruction of native plant communities and the wildli...

The Right Organ for the Right Recipient: the Ninth Annual American Society of Transplant Surgeons' State-of-the-Art Winter Symposium.

Science.gov (United States)

Sung, Randall S; Abt, Peter L; Desai, Dev M; Garvey, Catherine A; Segev, Dorry L; Kaufman, Dixon B

2011-01-01

With an increasing number of individuals with end-stage organ disease and the increasing success of organ transplantation, the demand for transplants has steadily increased. This growth has led to a greater need to utilize organs from as many donors as possible. As selection criteria have become less stringent to accommodate increasing demand, transplant outcomes are more strongly influenced by recipient and donor factors; thus, finding the right organ for the right recipient is more important than ever. The Ninth Annual American Society of Transplant Surgeons (ASTS) State-of-the-Art Winter Symposium, entitled "The Right Organ for the Right Recipient," addressed the matching of donor organs to appropriate recipients. Representative dilemmas in the matching of donor organs with recipients were discussed. These included the following: matching by donor and recipient risk characteristics; use of organs with risk for disease transmission; biologic incompatibility; use of organs from donors after cardiac death; the justification for combined organ transplants like liver-kidney and kidney-pancreas; and the role of allocation in facilitating the matching of donors and recipients. Regardless of the particular issue, decisions about donor-recipient matching should be evidence-based, practical, and made with the goal of maximizing organ utilization while still protecting individual patient interests. © 2011 John Wiley & Sons A/S.

Winter Weather Emergencies

Science.gov (United States)

Severe winter weather can lead to health and safety challenges. You may have to cope with Cold related health problems, including ... there are no guarantees of safety during winter weather emergencies, you can take actions to protect yourself. ...

Dna c-values of 20 invasive alien species and 3 native species in south china

Directory of Open Access Journals (Sweden)

Gong Ni

2014-01-01

Full Text Available Cultivated fields and forests in South China are experiencing serious damage due to invasive alien plants. We investigated the relation between DNA C-values and invasiveness. The DNA C-values of 23 species ranged from 0.39 pg to 3.37 pg. Herbs, perennials and native species had higher mean DNA C-values than shrubs, annuals and invasive alien species. DNA C-values decreased with increasing invasiveness. Paederia scandens, a harmful native species, has the lowest DNA C-value among the perennials, indicating that native species with low nuclear content may also possess an invasive potential.

Influence of nutrients on feed intake and condition of captive canvasbacks in winter

Science.gov (United States)

Perry, M.C.; Kuenzel, W.J.; Williams, B.K.; Serafin, J.A.

1986-01-01

Dramatic changes in the food habits and distribution of canvasbacks (Aythya valisineria) in Chesapeake Bay during the 1970's generated a need to evaluate the nutritional value of food items and the requirements of this species on its wintering grounds. Groups of captive canvasbacks were maintained ad libitum on 5 diets during the winters of 1978-79 and 1979-80 to evaluate the effects of varying protein and energy levels on feed intake and condition. Feed intake during the 1979-80 winter was 42% greater for those ducks fed the low energy (1,543 kcal/kg) diet than for those fed the high energy (3,638 kcal/kg) diet. Canvasbacks fed the high energy diet, however, consumed 317 kcal/bird day, whereas those fed the low energy diet consumed only 191 kcal/bird day. Body weight of males and females did not differ among groups fed different diets, but there were seasonal differences (P < 0.05) for both sexes aggregated across diets. Data from this study indicate that canvasbacks may be unable to adjust intake rates to compensate for low energy foods and subsequently may store less fat or modify behavior. However, decreased weight, feed intake, and activity of ducks fed ad libitum rations occurred in mid-winter irrespective of diet quality and appeared to be an endogenous component of their annual cycle that persists in captivity. These changes apparently have a selective advantage of increasing the probability of survival in ducks by decreasing energy expenditure during periods of winter stress.

Control of invasive weeds with prescribed burning

Science.gov (United States)

DiTomaso, Joseph M.; Brooks, Matthew L.; Allen, Edith B.; Minnich, Ralph; Rice, Peter M.; Kyser, Guy B.

2006-01-01

Prescribed burning has primarily been used as a tool for the control of invasive late-season annual broadleaf and grass species, particularly yellow starthistle, medusahead, barb goatgrass, and several bromes. However, timely burning of a few invasive biennial broadleaves (e.g., sweetclover and garlic mustard), perennial grasses (e.g., bluegrasses and smooth brome), and woody species (e.g., brooms and Chinese tallow tree) also has been successful. In many cases, the effectiveness of prescribed burning can be enhanced when incorporated into an integrated vegetation management program. Although there are some excellent examples of successful use of prescribed burning for the control of invasive species, a limited number of species have been evaluated. In addition, few studies have measured the impact of prescribed burning on the long-term changes in plant communities, impacts to endangered plant species, effects on wildlife and insect populations, and alterations in soil biology, including nutrition, mycorrhizae, and hydrology. In this review, we evaluate the current state of knowledge on prescribed burning as a tool for invasive weed management.

Projecting pest population dynamics under global warming: the combined effect of inter- and intra-annual variations.

Science.gov (United States)

Zidon, Royi; Tsueda, Hirotsugu; Morin, Efrat; Morin, Shai

2016-06-01

The typical short generation length of insects makes their population dynamics highly sensitive not only to mean annual temperatures but also to their intra-annual variations. To consider the combined effect of both thermal factors under global warming, we propose a modeling framework that links general circulation models (GCMs) with a stochastic weather generator and population dynamics models to predict species population responses to inter- and intra-annual temperature changes. This framework was utilized to explore future changes in populations of Bemisia tabaci, an invasive insect pest-species that affects multiple agricultural systems in the Mediterranean region. We considered three locations representing different pest status and climatic conditions: Montpellier (France), Seville (Spain), and Beit-Jamal (Israel). We produced ensembles of local daily temperature realizations representing current and future (mid-21st century) climatic conditions under two emission scenarios for the three locations. Our simulations predicted a significant increase in the average number of annual generations and in population size, and a significant lengthening of the growing season in all three locations. A negative effect was found only in Seville for the summer season, where future temperatures lead to a reduction in population size. High variability in population size was observed between years with similar annual mean temperatures, suggesting a strong effect of intra-annual temperature variation. Critical periods were from late spring to late summer in Montpellier and from late winter to early summer in Seville and Beit-Jamal. Although our analysis suggested that earlier seasonal activity does not necessarily lead to increased populations load unless an additional generation is produced, it is highly likely that the insect will become a significant pest of open-fields at Mediterranean latitudes above 40° during the next 50 years. Our simulations also implied that current

Winter swarming behavior by the exotic cladoceran Daphnia lumholtzi Sars, 1885 in a Kentucky (USA) reservoir

Science.gov (United States)

Beaver, John R.; Renicker, Thomas R.; Tausz, Claudia E.; Young, Jade L.; Thomason, Jennifer C.; Wolf, Zachary L.; Russell, Amber L.; Cherry, Mac A.; Scotese, Kyle C.; Koenig, Dawn T.

2018-01-01

We describe swarming behavior in the invasive cladoceran Daphnia lumholtzi Sars, 1885 in a Kentucky, USA, reservoir during winter 2017. The taxon is a highly successful tropical invader and has spread throughout the lower latitude systems in the USA since its discovery in 1991. Other than a few isolated reports, the abundance of D. lumholtzi is often 10,000 organisms L-1) of sexually reproducing females of this exotic cladoceran at water column temperatures <10°C.

Arctic lake physical processes and regimes with implications for winter water availability and management in the national petroleum reserve alaska

Science.gov (United States)

Jones, Benjamin M.; Arp, C.D.; Hinkel, Kenneth M.; Beck, R.A.; Schmutz, J.A.; Winston, B.

2009-01-01

Lakes are dominant landforms in the National Petroleum Reserve Alaska (NPRA) as well as important social and ecological resources. Of recent importance is the management of these freshwater ecosystems because lakes deeper than maximum ice thickness provide an important and often sole source of liquid water for aquatic biota, villages, and industry during winter. To better understand seasonal and annual hydrodynamics in the context of lake morphometry, we analyzed lakes in two adjacent areas where winter water use is expected to increase in the near future because of industrial expansion. Landsat Thematic Mapper and Enhanced Thematic Mapper Plus imagery acquired between 1985 and 2007 were analyzed and compared with climate data to understand interannual variability. Measured changes in lake area extent varied by 0.6% and were significantly correlated to total precipitation in the preceding 12 months (p modeled lake area extent from 1985 to 2007 showed no long-term trends. In addition, high-resolution aerial photography, bathymetric surveys, water-level monitoring, and lake-ice thickness measurements and growth models were used to better understand seasonal hydrodynamics, surface area-to-volume relations, winter water availability, and more permanent changes related to geomorphic change. Together, these results describe how lakes vary seasonally and annually in two critical areas of the NPRA and provide simple models to help better predict variation in lake-water supply. Our findings suggest that both overestimation and underestimation of actual available winter water volume may occur regularly, and this understanding may help better inform management strategies as future resource use expands in the NPRA. ?? 2008 Springer Science+Business Media, LLC.

Study on the weediness of winter wheat in a long-term fertilization field experiment.

Science.gov (United States)

Lehoczky, E; Kismányoky, A; Kismányoky, T

2006-01-01

The study was carried out in Keszthely, in the long-term fertilization field experiment in April of 2005. In the experiment we had opportunity to compare the weediness in NPK and NPK + FYM* treatments, and we could study the effect of increasing N dosis on the weeds and winter wheat. The weed survey was made on the 20th of April at the end of tillering. For the weed survey used the Balázs-Ujvárosi method. After that we collected all the weeds from the plots per 1 m2. We counted, measured the fresh and dry matter weight of aerial parts. Winter wheat sampels were taken also from all plots (1 running meter per plot). In the experiment 10 weed species were found, 9 annual: Ambrosia artemisiifolia, Consolida regalis, Galium aparine, Lamiunt amplexicaule, Matricaria inodora, Papaver rhoeas, Stellaria media, Veronica hederifolia, Veronica triphyllos, and 1 perennial: Cirsium arvense. Veronica hederifolia was the dominant species in both fertilized plots, Stellaria media has the second highest weed coverage. The manuring treatments, and the N-dosis has important and significantly effect to the weedeness and the biomass production of winter wheat. On the control plots was the relation of biomass weight of weeds the highest. This relation reduced to the effect of N treatments, wich had an favorable effect on the winter wheat.

Annual and seasonal tornado activity in the United States and the global wind oscillation

Science.gov (United States)

Moore, Todd W.

2018-06-01

Previous studies have searched for relationships between tornado activity and atmospheric teleconnections to provide insight on the relationship between tornadoes, their environments, and larger scale patterns in the climate system. Knowledge of these relationships is practical because it can improve seasonal and sub-seasonal predictions of tornado probability and, therefore, help mitigate tornado-related losses. This study explores the relationships between the annual and seasonal tornado activity in the United States and the Global Wind Oscillation. Time series herein show that phases of the Global Wind Oscillation, and atmospheric angular momentum anomalies, vary over a period of roughly 20-25 years. Rank correlations indicate that tornado activity is weakly correlated with phases 2, 3, and 4 (positive) and 6, 7, and 8 (negative) of the Global Wind Oscillation in winter, spring, and fall. The correlation is not as clear in summer or at the annual scale. Non-parametric Mann-Whitney U tests indicate that winters and springs with more phase 2, 3, and 4 and fewer phase 6, 7, and 8 days tend to have more tornadoes. Lastly, logistic regression models indicate that winters and springs with more phase 2, 3, and 4 days have greater likelihoods of having more than normal tornado activity. Combined, these analyses suggest that seasons with more low atmospheric angular momentum days, or phase 2, 3, and 4 days, tend to have greater tornado activity than those with fewer days, and that this relationship is most evident in winter and spring.

Annual and seasonal tornado activity in the United States and the global wind oscillation

Science.gov (United States)

Moore, Todd W.

2017-08-01

Previous studies have searched for relationships between tornado activity and atmospheric teleconnections to provide insight on the relationship between tornadoes, their environments, and larger scale patterns in the climate system. Knowledge of these relationships is practical because it can improve seasonal and sub-seasonal predictions of tornado probability and, therefore, help mitigate tornado-related losses. This study explores the relationships between the annual and seasonal tornado activity in the United States and the Global Wind Oscillation. Time series herein show that phases of the Global Wind Oscillation, and atmospheric angular momentum anomalies, vary over a period of roughly 20-25 years. Rank correlations indicate that tornado activity is weakly correlated with phases 2, 3, and 4 (positive) and 6, 7, and 8 (negative) of the Global Wind Oscillation in winter, spring, and fall. The correlation is not as clear in summer or at the annual scale. Non-parametric Mann-Whitney U tests indicate that winters and springs with more phase 2, 3, and 4 and fewer phase 6, 7, and 8 days tend to have more tornadoes. Lastly, logistic regression models indicate that winters and springs with more phase 2, 3, and 4 days have greater likelihoods of having more than normal tornado activity. Combined, these analyses suggest that seasons with more low atmospheric angular momentum days, or phase 2, 3, and 4 days, tend to have greater tornado activity than those with fewer days, and that this relationship is most evident in winter and spring.

Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

Science.gov (United States)

Yeo, I.-Y.; Lee, S.; Sadeghi, A. M.; Beeson, P. C.; Hively, W. D.; McCarty, G. W.; Lang, M. W.

2014-12-01

Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay watershed (CBW), which is located in the mid-Atlantic US, winter cover crop use has been emphasized, and federal and state cost-share programs are available to farmers to subsidize the cost of cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops to improve water quality at the watershed scale (~ 50 km2) and to identify critical source areas of high nitrate export. A physically based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data to simulate hydrological processes and agricultural nutrient cycling over the period of 1990-2000. To accurately simulate winter cover crop biomass in relation to growing conditions, a new approach was developed to further calibrate plant growth parameters that control the leaf area development curve using multitemporal satellite-based measurements of species-specific winter cover crop performance. Multiple SWAT scenarios were developed to obtain baseline information on nitrate loading without winter cover crops and to investigate how nitrate loading could change under different winter cover crop planting scenarios, including different species, planting dates, and implementation areas. The simulation results indicate that winter cover crops have a negligible impact on the water budget but significantly reduce nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading from agricultural lands was approximately 14 kg ha-1, but decreased to 4.6-10.1 kg ha-1 with cover crops resulting in a reduction rate of 27-67% at the watershed scale. Rye was the most effective species, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of cover crops (~ 30

The seesaw effect of winter temperature change on the recruitment of cotton bollworms Helicoverpa armigera through mismatched phenology.

Science.gov (United States)

Reddy, Gadi V P; Shi, Peijian; Hui, Cang; Cheng, Xiaofei; Ouyang, Fang; Ge, Feng

2015-12-01

Knowing how climate change affects the population dynamics of insect pests is critical for the future of integrated pest management. Rising winter temperatures from global warming can drive increases in outbreaks of some agricultural pests. In contrast, here we propose an alternative hypothesis that both extremely cold and warm winters can mismatch the timing between the eclosion of overwintering pests and the flowering of key host plants. As host plants normally need higher effective cumulative temperatures for flowering than insects need for eclosion, changes in flowering time will be less dramatic than changes in eclosion time, leading to a mismatch of phenology on either side of the optimal winter temperature. We term this the "seesaw effect." Using a long-term dataset of the Old World cotton bollworm Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) in northern China, we tested this seesaw hypothesis by running a generalized additive model for the effects of the third generation moth in the preceding year, the winter air temperature, the number of winter days below a critical temperature and cumulative precipitation during winter on the demography of the overwintering moth. Results confirmed the existence of the seesaw effect of winter temperature change on overwintering populations. Pest management should therefore consider the indirect effect of changing crop phenology (whether due to greenhouse cultivation or to climate change) on pest outbreaks. As arthropods from mid- and high latitudes are actually living in a cooler thermal environment than their physiological optimum in contrast to species from lower latitudes, the effects of rising winter temperatures on the population dynamics of arthropods in the different latitudinal zones should be considered separately. The seesaw effect makes it more difficult to predict the average long-term population dynamics of insect pests at high latitudes due to the potential sharp changes in annual growth rates

Fleshy fruit removal and nutritional composition of winter-fruiting plants: a comparison of non-native invasive and native species

Science.gov (United States)

Cathryn H. Greenberg; Scott T. Walter

2010-01-01

Invasive, non-native plants threaten forest ecosystems by reducing native plant species richness and potentially altering ecosystem processes. Seed dispersal is critical for successful invasion and range expansion by non-native plants; dispersal is likely to be enhanced if they can successfully compete with native plants for disperser services. Fruit production by non-...

Annual and seasonal CO2 fluxes from Russian southern taiga soils

International Nuclear Information System (INIS)

Kurganova, I.; Lopes De Gerenyu, V.; Rozanova, L.; Sapronov, D.; Myakshina, T.; Kudeyarov, V.

2003-01-01

Annual and seasonal characteristics of CO 2 emission from five different ecosystems were studied in situ (Russia, Moscow Region) from November 1997 through October 2000. The annual behaviour of the soil respiration rate is influenced by weather conditions during a particular year. Annual CO 2 fluxes from the soils depend on land use of the soils and averaged 684 and 906 g C/m 2 from sandy Albeluvisols (sod-podzolic soils) under forest and grassland, respectively. Annual emission from clay Phaeozems (grey forest soils) was lower and ranged from 422 to 660 g C/m 2 ; the order of precedence was arable 2 fluxes caused by weather conditions ranged from 18% (forest ecosystem on Phaeozems) to 31% (agro-ecosystem). The contribution from the cold period (with snow, November-April) to the annual CO 2 flux was substantial and averaged 21% and 14% for natural and agricultural ecosystems, respectively. The CO 2 fluxes comprised approximately 48-51% in summer, 23-24% in autumn, 18-20% in spring and 7-10% in winter of the total annual carbon dioxide flux

Application of regional climate models to the Indian winter monsoon over the western Himalayas.

Science.gov (United States)

Dimri, A P; Yasunari, T; Wiltshire, A; Kumar, P; Mathison, C; Ridley, J; Jacob, D

2013-12-01

The Himalayan region is characterized by pronounced topographic heterogeneity and land use variability from west to east, with a large variation in regional climate patterns. Over the western part of the region, almost one-third of the annual precipitation is received in winter during cyclonic storms embedded in westerlies, known locally as the western disturbance. In the present paper, the regional winter climate over the western Himalayas is analyzed from simulations produced by two regional climate models (RCMs) forced with large-scale fields from ERA-Interim. The analysis was conducted by the composition of contrasting (wet and dry) winter precipitation years. The findings showed that RCMs could simulate the regional climate of the western Himalayas and represent the atmospheric circulation during extreme precipitation years in accordance with observations. The results suggest the important role of topography in moisture fluxes, transport and vertical flows. Dynamical downscaling with RCMs represented regional climates at the mountain or even event scale. However, uncertainties of precipitation scale and liquid-solid precipitation ratios within RCMs are still large for the purposes of hydrological and glaciological studies. Copyright © 2013 Elsevier B.V. All rights reserved.

PM 2.5 and NO 2 assessment in 21 European study centres of ECRHS II: annual means and seasonal differences

Science.gov (United States)

Hazenkamp-von Arx, Marianne E.; Götschi, Thomas; Ackermann-Liebrich, Ursula; Bono, Roberto; Burney, Peter; Cyrys, Josef; Jarvis, Deborah; Lillienberg, Linnea; Luczynska, Christina; Maldonado, Jose A.; Jaén, Angeles; de Marco, Roberto; Mi, Yahong; Modig, Lars; Bayer-Oglesby, Lucy; Payo, Felix; Soon, Argo; Sunyer, Jordi; Villani, Simona; Weyler, Joost; Künzli, Nino

The follow-up of cohorts of adults from more than 20 European centres of the former ECRHS I (1989-1992) investigates long-term effects of exposure to ambient air pollution on respiratory health, in particular asthma and change of pulmonary function. Since PM 2.5 is not routinely monitored in Europe, we measured PM 2.5 concentrations in 21 participating centres to estimate 'background' exposure in these cities. Winter (November-February), summer (May-August) and annual mean (all months) values of PM 2.5 were determined from measuring periods between June 2000 and November 2001. Sampling was conducted for 7 days per month for a year. Annual and winter mean concentrations of PM 2.5 vary substantially being lowest in Iceland and highest in centres in Northern Italy. Annual mean concentrations ranged from 3.7 to 44.9 μg m -3, winter mean concentrations from 4.8 to 69.2 μg m -3, and summer mean concentrations from 3.3 to 23.1 μg m -3. Seasonal variability occurred but did not follow the same pattern across all centres. Therefore, ranking of centres varied from summer to winter. Simultaneously, NO 2 concentrations were measured using passive sampling tubes. Annual mean NO 2 concentrations range from 4.9 to 72.1 μg m -3 with similar seasonal variations across centres and constant ranking of centres between seasons. The correlation between annual NO 2 and PM 2.5 concentrations is fair (Spearman correlation coefficient rs=0.75), but when considered as monthly means the correlation is far less consistent and varies substantially between centres. The range of PM 2.5 mass concentrations obtained in ECRHS II is larger than in other current cohort studies on long-term effects of air pollution. This substantial variation in PM 2.5 exposure will improve statistical power in future multi-level health analyses and to some degree may compensate for the lack of information on within-city variability. Seasonal means may be used to indicate potential differences in the toxicity

Environmental and physiological influences to isotopic ratios of N and protein status in a montane ungulate in winter

Science.gov (United States)

Gustine, David D.; Barboza, Perry S.; Adams, Layne G.; Wolf, Nathan B.

2014-01-01

Winter severity can influence large herbivore populations through a reduction in maternal proteins available for reproduction. Nitrogen (N) isotopes in blood fractions can be used to track the use of body proteins in northern and montane ungulates. We studied 113 adult female caribou for 13 years throughout a series of severe winters that reduced population size and offspring mass. After these severe winters, offspring mass increased but the size of the population remained low. We devised a conceptual model for routing of isotopic N in blood in the context of the severe environmental conditions experienced by this population. We measured δ15N in three blood fractions and predicted the relative mobilization of dietary and body proteins. The δ15N of the body protein pool varied by 4‰ and 46% of the variance was associated with year. Annual variation in δ15N of body protein likely reflected the fall/early winter diet and winter locations, yet 15% of the isotopic variation in amino acid N was due to body proteins. Consistent isotopic differences among blood N pools indicated that animals tolerated fluxes in diet and body stores. Conservation of body protein in caribou is the result of active exchange among diet and body N pools. Adult females were robust to historically severe winter conditions and prioritized body condition and survival over early investment in offspring. For a vagile ungulate residing at low densities in a predator-rich environment, protein restrictions in winter may not be the primary limiting factor for reproduction.

Mapping and spatial-temporal modeling of Bromus tectorum invasion in central Utah

Science.gov (United States)

Jin, Zhenyu

Cheatgrass, or Downy Brome, is an exotic winter annual weed native to the Mediterranean region. Since its introduction to the U.S., it has become a significant weed and aggressive invader of sagebrush, pinion-juniper, and other shrub communities, where it can completely out-compete native grasses and shrubs. In this research, remotely sensed data combined with field collected data are used to investigate the distribution of the cheatgrass in Central Utah, to characterize the trend of the NDVI time-series of cheatgrass, and to construct a spatially explicit population-based model to simulate the spatial-temporal dynamics of the cheatgrass. This research proposes a method for mapping the canopy closure of invasive species using remotely sensed data acquired at different dates. Different invasive species have their own distinguished phenologies and the satellite images in different dates could be used to capture the phenology. The results of cheatgrass abundance prediction have a good fit with the field data for both linear regression and regression tree models, although the regression tree model has better performance than the linear regression model. To characterize the trend of NDVI time-series of cheatgrass, a novel smoothing algorithm named RMMEH is presented in this research to overcome some drawbacks of many other algorithms. By comparing the performance of RMMEH in smoothing a 16-day composite of the MODIS NDVI time-series with that of two other methods, which are the 4253EH, twice and the MVI, we have found that RMMEH not only keeps the original valid NDVI points, but also effectively removes the spurious spikes. The reconstructed NDVI time-series of different land covers are of higher quality and have smoother temporal trend. To simulate the spatial-temporal dynamics of cheatgrass, a spatially explicit population-based model is built applying remotely sensed data. The comparison between the model output and the ground truth of cheatgrass closure demonstrates

Sub-annual paleoenvironmental information evaluated from intensity variations of fluorescent annual layers in a stalagmite from Ryuo-do Cave, Nagasaki Prefecture, western Japan

Science.gov (United States)

Sasaki, Hana; Onishi, Yuri; Ishihara, Yoshiro; Yoshimura, Kazuhisa

2017-04-01

vary stratigraphically, and multiple types of fluorescence intensity pattern are observed in the stalagmite. When the co-precipitation of FA is governed by the hiatus model, it is suggested that a gradual increase in the annual layers will result from a large accumulation of calcite after the annual peak in the FA concentration, whereas there will be a gradual decrease if the main growth occurs before the annual peak in FA concentration. However, in the case of the PC model, a gradually increasing type of pattern is formed if the main growth occurs before the annual peak in FA concentration, and a gradually decreasing type is formed if the main growth occurs afterwards. If the annual peak of FA concentration occurs several months after high summer, it is suggested that intervals showing a gradually increasing type were formed in winter, and intervals showing a gradually decreasing type were formed in the early summer, in the case of the hiatus model. In the case of PC model, the seasons are reversed. In the climatic environment around the Ryuo-do Cave, the growth rates of stalagmites are affected by cave air circulation in winter and by rainfall (rainy season) in early summer.

Winter maintenance performance measure.

Science.gov (United States)

2016-01-01

The Winter Performance Index is a method of quantifying winter storm events and the DOTs response to them. : It is a valuable tool for evaluating the States maintenance practices, performing post-storm analysis, training : maintenance personnel...

European seasonal and annual temperature variability, trends, and extremes since 1500.

Science.gov (United States)

Luterbacher, Jürg; Dietrich, Daniel; Xoplaki, Elena; Grosjean, Martin; Wanner, Heinz

2004-03-05

Multiproxy reconstructions of monthly and seasonal surface temperature fields for Europe back to 1500 show that the late 20th- and early 21st-century European climate is very likely (>95% confidence level) warmer than that of any time during the past 500 years. This agrees with findings for the entire Northern Hemisphere. European winter average temperatures during the period 1500 to 1900 were reduced by approximately 0.5 degrees C (0.25 degrees C for annual mean temperatures) compared to the 20th century. Summer temperatures did not experience systematic century-scale cooling relative to present conditions. The coldest European winter was 1708/1709; 2003 was by far the hottest summer.

Estimating winter survival of winter wheat by simulations of plant frost tolerance

NARCIS (Netherlands)

Bergjord Olsen, A.K.; Persson, T.; Wit, de A.; Nkurunziza, L.; Sindhøj, E.; Eckersten, H.

2018-01-01

Based on soil temperature, snow depth and the grown cultivar's maximum attainable level of frost tolerance (LT50c), the FROSTOL model simulates development of frost tolerance (LT50) and winter damage, thereby enabling risk calculations for winter wheat survival. To explore the accuracy of this

Using species distribution model to estimate the wintering population size of the endangered scaly-sided merganser in China.

Directory of Open Access Journals (Sweden)

Qing Zeng

Full Text Available Scaly-sided Merganser is a globally endangered species restricted to eastern Asia. Estimating its population is difficult and considerable gap exists between populations at its breeding grounds and wintering sites. In this study, we built a species distribution model (SDM using Maxent with presence-only data to predict the potential wintering habitat for Scaly-sided Merganser in China. Area under the receiver operating characteristic curve (AUC method suggests high predictive power of the model (training and testing AUC were 0.97 and 0.96 respectively. The most significant environmental variables included annual mean temperature, mean temperature of coldest quarter, minimum temperature of coldest month and precipitation of driest quarter. Suitable conditions for Scaly-sided Merganser are predicted in the middle and lower reaches of the Yangtze River, especially in Jiangxi, Hunan and Hubei Provinces. The predicted suitable habitat embraces 6,984 km of river. Based on survey results from three consecutive winters (2010-2012 and previous studies, we estimated that the entire wintering population of Scaly-sided Merganser in China to be 3,561 ± 478 individuals, which is consistent with estimate in its breeding ground.

Incorporating Yearly Derived Winter Wheat Maps Into Winter Wheat Yield Forecasting Model

Science.gov (United States)

Skakun, S.; Franch, B.; Roger, J.-C.; Vermote, E.; Becker-Reshef, I.; Justice, C.; Santamaría-Artigas, A.

2016-01-01

Wheat is one of the most important cereal crops in the world. Timely and accurate forecast of wheat yield and production at global scale is vital in implementing food security policy. Becker-Reshef et al. (2010) developed a generalized empirical model for forecasting winter wheat production using remote sensing data and official statistics. This model was implemented using static wheat maps. In this paper, we analyze the impact of incorporating yearly wheat masks into the forecasting model. We propose a new approach of producing in season winter wheat maps exploiting satellite data and official statistics on crop area only. Validation on independent data showed that the proposed approach reached 6% to 23% of omission error and 10% to 16% of commission error when mapping winter wheat 2-3 months before harvest. In general, we found a limited impact of using yearly winter wheat masks over a static mask for the study regions.

Winter weather demand considerations.

Science.gov (United States)

2015-04-01

Winter weather has varied effects on travel behavior. Using 418 survey responses from the Northern Virginia : commuting area of Washington, D.C. and binary logit models, this study examines travel related changes under : different types of winter wea...

The influence of sowing period and seeding norm on autumn vegetation, winter hardiness and yield of winter cereal crops

Directory of Open Access Journals (Sweden)

Potapova G. N.

2017-10-01

Full Text Available the winter wheat and triticale in the middle part of the Ural Mountains haven’t been seeded before. The technology of winter crop cultivation should be improved due to the production of new varieties of winter rye. Winter hardiness and yield of winter rye are higher in comparison with winter triticale and especially with winter wheat. The sowing period and the seeding rate influence the amount of yield and winter hardiness. The winter hardiness of winter cereals and the yield of the rye variety Iset sowed on August 25 and the yield of the triticale variety Bashkir short-stalked and wheat Kazanskaya 560 sowed on August 15 were higher. It is important to sow winter grain in local conditions in the second half of August. The sowing this period allows to provide plants with the necessary amount of positive temperatures (450–500 °C. This helps the plants to form 3–4 shoots of tillering and a mass of 10 dry plants reaching 3–5 grams. The winter grain crops in the middle part of the Ural Mountains should be sown with seeding rates of 6 and 7 million of sprouting grains per 1 ha, and the seeds must be cultivated with fungicidal preparation before seeding.

Winter cyclone frequency and following freshet streamflow formation on the rivers in Belarus

Science.gov (United States)

Partasenok, Irina S.; Groisman, Pavel Ya; Chekan, Grigoriy S.; Melnik, Viktor I.

2014-09-01

We studied long-term fluctuations of streamflow and occurrence of extreme phenomena on the rivers of Belarus during the post-World War II period. It was found that formation of annual runoff within the nation has no constant tendencies and varies from year to year. At the same time, analysis of intra-annual distribution of streamflow reveals significant changes since the 1970s, first of all, increase of winter and decrease of spring streamflow. As a result, the frequency of extreme floods has decreased. These changes in water regime are associated with climatic anomalies (increase of the surface air temperatures) caused by large-scale alterations in atmospheric circulation, specifically in trajectories of cyclones. During the last two decades, the frequency of Atlantic and southern cyclones has changed and caused decreasing of cold season storms and extreme phenomena on the rivers.

Invasion of non-native grasses causes a drop in soil carbon storage in California grasslands

Energy Technology Data Exchange (ETDEWEB)

Koteen, Laura E; Harte, John [Energy and Resources Group, 310 Barrows Hall, University of California, Berkeley, CA 94720 (United States); Baldocchi, Dennis D, E-mail: lkoteen@berkeley.edu [Department of Environmental Science, Policy and Management, 137 Mulford Hall, University of California, Berkeley, CA 94720 (United States)

2011-10-15

Vegetation change can affect the magnitude and direction of global climate change via its effect on carbon cycling among plants, the soil and the atmosphere. The invasion of non-native plants is a major cause of land cover change, of biodiversity loss, and of other changes in ecosystem structure and function. In California, annual grasses from Mediterranean Europe have nearly displaced native perennial grasses across the coastal hillsides and terraces of the state. Our study examines the impact of this invasion on carbon cycling and storage at two sites in northern coastal California. The results suggest that annual grass invasion has caused an average drop in soil carbon storage of 40 Mg/ha in the top half meter of soil, although additional mechanisms may also contribute to soil carbon losses. We attribute the reduction in soil carbon storage to low rates of net primary production in non-native annuals relative to perennial grasses, a shift in rooting depth and water use to primarily shallow sources, and soil respiratory losses in non-native grass soils that exceed production rates. These results indicate that even seemingly subtle land cover changes can significantly impact ecosystem functions in general, and carbon storage in particular.

Invasion of non-native grasses causes a drop in soil carbon storage in California grasslands

International Nuclear Information System (INIS)

Koteen, Laura E; Harte, John; Baldocchi, Dennis D

2011-01-01

Vegetation change can affect the magnitude and direction of global climate change via its effect on carbon cycling among plants, the soil and the atmosphere. The invasion of non-native plants is a major cause of land cover change, of biodiversity loss, and of other changes in ecosystem structure and function. In California, annual grasses from Mediterranean Europe have nearly displaced native perennial grasses across the coastal hillsides and terraces of the state. Our study examines the impact of this invasion on carbon cycling and storage at two sites in northern coastal California. The results suggest that annual grass invasion has caused an average drop in soil carbon storage of 40 Mg/ha in the top half meter of soil, although additional mechanisms may also contribute to soil carbon losses. We attribute the reduction in soil carbon storage to low rates of net primary production in non-native annuals relative to perennial grasses, a shift in rooting depth and water use to primarily shallow sources, and soil respiratory losses in non-native grass soils that exceed production rates. These results indicate that even seemingly subtle land cover changes can significantly impact ecosystem functions in general, and carbon storage in particular.

Invasion of non-native grasses causes a drop in soil carbon storage in California grasslands

Science.gov (United States)

Koteen, Laura E.; Baldocchi, Dennis D.; Harte, John

2011-10-01

Vegetation change can affect the magnitude and direction of global climate change via its effect on carbon cycling among plants, the soil and the atmosphere. The invasion of non-native plants is a major cause of land cover change, of biodiversity loss, and of other changes in ecosystem structure and function. In California, annual grasses from Mediterranean Europe have nearly displaced native perennial grasses across the coastal hillsides and terraces of the state. Our study examines the impact of this invasion on carbon cycling and storage at two sites in northern coastal California. The results suggest that annual grass invasion has caused an average drop in soil carbon storage of 40 Mg/ha in the top half meter of soil, although additional mechanisms may also contribute to soil carbon losses. We attribute the reduction in soil carbon storage to low rates of net primary production in non-native annuals relative to perennial grasses, a shift in rooting depth and water use to primarily shallow sources, and soil respiratory losses in non-native grass soils that exceed production rates. These results indicate that even seemingly subtle land cover changes can significantly impact ecosystem functions in general, and carbon storage in particular.

A trajectory analysis of atmospheric transport of black carbon aerosols to Canadian high Arctic in winter and spring (1990–2005

Directory of Open Access Journals (Sweden)

L. Huang

2010-06-01

Full Text Available Black carbon (BC particles accumulated in the Arctic troposphere and deposited on snow have been calculated to have significant effects on radiative forcing of the Arctic regional climate. Applying cluster analysis technique on 10-day backward trajectories, seven distinct transport pathways (or clusters affecting Alert (82.5° N, 62.5° W, Nunavut in Canada are identified in this work. Transport frequency associated with each pathway is obtained as the fraction of trajectories in that cluster. Based on atmospheric transport frequency and BC surface flux from surrounding regions (i.e. North America, Europe, and former USSR, a linear regression model is constructed to investigate the inter-annual variations of BC observed at Alert in January and April, representative of winter and spring respectively, between 1990 and 2005. Strong correlations are found between BC concentrations predicted with the regression model and measurements at Alert for both seasons (R² equals 0.77 and 0.81 for winter and spring, respectively. Results imply that atmospheric transport and BC emission are the major contributors to the inter-annual variations in BC concentrations observed at Alert in the cold seasons for the 16-year period. Other factors, such as deposition, could also contribute to the variability in BC concentrations but were not considered in this analysis. Based on the regression model the relative contributions of regional BC emissions affecting Alert are attributed to the Eurasian sector, composed of the European Union and the former USSR, and the North American sector. Considering both seasons, the model suggests that former USSR is the major contributor to the near-surface BC levels at the Canadian high Arctic site with an average contribution of about 67% during the 16-year period, followed by European Union (18% and North America (15%. In winter, the atmospheric transport of BC aerosols from Eurasia is found to be even more

The nuclear winter

International Nuclear Information System (INIS)

Velikhow, Y.P.

1986-01-01

Nuclear winter is an example of possible secondary effects, and if we speak of secondary we are thinking of small-scale second-order effects, but a nuclear winter is not a second-order effect. If you calculate the amount of heat produced by a nuclear explosion, it is a very small amount which does not have any chance of changing the Earth's climate, but a nuclear explosion drives or stars some new mechanism - the mechanism of nuclear winter - after 100 megatons of dust are transferred to the upper atmosphere. Another example of such amplification is radioactive fall-out, especially long-life radioactive fall-out after the possible elimination of the nuclear power industry, nuclear storage and distribution of storage waste around the globe. This is a very powerful amplification mechanism

The dynamics of avian influenza in western Arctic snow geese: implications for annual and migratory infection patterns

Science.gov (United States)

Samuel, Michael D.; Hall, Jeffrey S.; Brown, Justin D.; Goldberg, Diana R.; Ip, Hon S.; Baranyuk, Vasily V.

2015-01-01

Wild water birds are the natural reservoir for low-pathogenic avian influenza viruses (AIV). However, our ability to investigate the epizootiology of AIV in these migratory populations is challenging, and despite intensive worldwide surveillance, remains poorly understood. We conducted a cross-sectional, retrospective analysis in Pacific Flyway lesser snow geese Chen caerulescens to investigate AIV serology and infection patterns. We collected nearly 3,000 sera samples from snow geese at 2 breeding colonies in Russia and Canada during 1993-1996 and swab samples from > 4,000 birds at wintering and migration areas in the United States during 2006-2011. We found seroprevalence and annual seroconversion varied considerably among years. Seroconversion and infection rates also differed between snow goose breeding colonies and wintering areas, suggesting that AIV exposure in this gregarious waterfowl species is likely occurring during several phases (migration, wintering and potentially breeding areas) of the annual cycle. We estimated AIV antibody persistence was longer (14 months) in female geese compared to males (6 months). This relatively long period of AIV antibody persistence suggests that subtype-specific serology may be an effective tool for detection of exposure to subtypes associated with highly-pathogenic AIV. Our study provides further evidence of high seroprevalence in Arctic goose populations, and estimates of annual AIV seroconversion and antibody persistence for North American waterfowl. We suggest future AIV studies include serology to help elucidate the epizootiological dynamics of AIV in wild bird populations.

Annual elk calf survival in a multiple carnivore system

Science.gov (United States)

Eacker, Daniel R.; Hebblewhite, Mark; Proffitt, Kelly M.; Jimenez, Benjamin S.; Mitchell, Michael S.; Robinson, Hugh S.

2016-01-01

The realized effect of multiple carnivores on juvenile ungulate recruitment may depend on the carnivore assemblage as well as compensation from forage and winter weather severity, which may mediate juvenile vulnerability to predation in ungulates. We used a time-to-event approach to test for the effects of risk factors on annual elk (Cervus canadensis) calf survival and to estimate cause-specific mortality rates for 2 elk populations in adjacent study areas in the southern Bitterroot Valley, Montana, USA, during 2011–2014. We captured and radio-tagged 286 elk calves: 226 neonates, and 60 6-month-old calves. Summer survival probability was less variable than winter (P = 0.12) and averaged 0.55 (95% CI = 0.47–0.63), whereas winter survival varied more than summer and significantly across study years (P = 0.003) and averaged 0.73 (95% CI = 0.64–0.81). During summer, elk calf survival increased with biomass of preferred forage biomass, and was slightly lower following winters with high precipitation; exposure to mountain lion (Puma concolor) predation risk was unimportant. In contrast, during winter, we found that exposure to mountain lion predation risk influenced survival, with a weak negative effect of winter precipitation. We found no evidence that forage availability or winter weather severity mediated vulnerability to mountain lion predation risk in summer or winter (e.g., an interaction), indicating that the effect of mountain lion predation was constant regardless of spatial variation in forage or weather. Mountain lions dominated known causes of elk calf mortality in summer and winter, with estimated cause-specific mortality rates of 0.14 (95% CI = 0.09–0.20) and 0.12 (95% CI = 0.07–0.18), respectively. The effect of carnivores on juvenile ungulate recruitment varies across ecological systems depending on relative carnivore densities. Mountain lions may be the most important carnivore for ungulates, especially where grizzly

Winter fine particulate air quality in Cranbrook, British Columbia, 1973 to 1999

International Nuclear Information System (INIS)

McDonald, L.E.

2001-06-01

Fine particulate levels in Cranbrook, BC, are analyzed and reported based on monitoring records which began in 1973. Prior to 1988 the sampler collected all particle sizes, but was subsequently replaced with a selective size inlet to capture only PM 1 0 particles or smaller. A mathematical relationship was produced and used to convert historical total suspended particulates measurements to PM 1 0. It was determined that only monitoring records obtained during the winter months could be reliably converted in this fashion; however, that was not a problem since the winter months happen to correspond to the highest levels of fine particulates. Results of the analysis showed increased levels of PM 1 0 from the early 1970s to the early 1980s; during this time average and maximum annual PM 1 0 levels in Cranbrook were higher than those in Los Angeles in 1999. Winter PM 1 0 levels began to fall through the late 1980s and early 1990s. The lowest average and maximum (18 microgram/cubic metre and 47 microgram/cubic metre, respectively) was recorded in the winter of 1996/1997. Worst conditions were recorded in 1980/1981 when 15 of 21 samples exceeded the current provincial PM 1 0 air quality objective of 50 microgram/cubic metre. In the five winters between 1994/1995 and 1998/1999 only three of 109 samples exceeded the provincial objective. There appears to be no correlation between known changes in industrial and mobile sources of pollutants and historical patterns of fine particulate air pollution in Cranbrook, BC. Observation and experience over three decades suggest that the major source of PM 1 0 in Cranbrook was combustion of wood for home heating. The most probable major cause of the improvements in winter air quality was identified as the gradual conversion from wood to natural gas fired appliances through the 1980s and the 1990s. The 115 per cent increase in the cost of natural gas in the last two years unfortunately, will again make wood an attractive alternative

The stock of invasive insect species and its economic determinants.

Science.gov (United States)

Hlasny, Vladimir

2011-06-01

Invasions of nonindigenous organisms have long been linked to trade, but the contribution of individual trade pathways remains poorly understood, because species are not observed immediately upon arrival and the number of species arriving annually is unknown. Species interception records may count both new arrivals and species long introduced. Furthermore, the stock of invasive insect species already present is unknown. In this study, a state-space model is used to infer the stock of detected as well as undetected invasive insect species established in the United States. A system of equations is estimated jointly to distinguish the patterns of introduction, identification, and eradication. Introductions of invasive species are modeled as dependent on the volume of trade and arrival of people. Identifications depend on the public efforts at invasive species research, as well as on the established stock of invasive species that remain undetected. Eradications of both detected and undetected invasive species depend on containment and quarantine efforts, as well as on the stock of all established invasive species. These patterns are estimated by fitting the predicted number of invasive species detections to the observed record in the North American Non-Indigenous Arthropod Database. The results indicate that agricultural imports are the most important pathway of introduction, followed by immigration of people. Expenditures by the U.S. Department of Agriculture and the Agricultural Research Service are found to explain the species identification record well. Between three and 38 invasive insect species are estimated to be established in the United States undetected.

Global Invader Impact Network (GIIN): toward standardized evaluation of the ecological impacts of invasive plants.

Science.gov (United States)

Barney, Jacob N; Tekiela, Daniel R; Barrios-Garcia, Maria Noelia; Dimarco, Romina D; Hufbauer, Ruth A; Leipzig-Scott, Peter; Nuñez, Martin A; Pauchard, Aníbal; Pyšek, Petr; Vítková, Michaela; Maxwell, Bruce D

2015-07-01

Terrestrial invasive plants are a global problem and are becoming ubiquitous components of most ecosystems. They are implicated in altering disturbance regimes, reducing biodiversity, and changing ecosystem function, sometimes in profound and irreversible ways. However, the ecological impacts of most invasive plants have not been studied experimentally, and most research to date focuses on few types of impacts, which can vary greatly among studies. Thus, our knowledge of existing ecological impacts ascribed to invasive plants is surprisingly limited in both breadth and depth. Our aim was to propose a standard methodology for quantifying baseline ecological impact that, in theory, is scalable to any terrestrial plant invader (e.g., annual grasses to trees) and any invaded system (e.g., grassland to forest). The Global Invader Impact Network (GIIN) is a coordinated distributed experiment composed of an observational and manipulative methodology. The protocol consists of a series of plots located in (1) an invaded area; (2) an adjacent removal treatment within the invaded area; and (3) a spatially separate uninvaded area thought to be similar to pre-invasion conditions of the invaded area. A standardized and inexpensive suite of community, soil, and ecosystem metrics are collected allowing broad comparisons among measurements, populations, and species. The method allows for one-time comparisons and for long-term monitoring enabling one to derive information about change due to invasion over time. Invader removal plots will also allow for quantification of legacy effects and their return rates, which will be monitored for several years. GIIN uses a nested hierarchical scale approach encompassing multiple sites, regions, and continents. Currently, GIIN has network members in six countries, with new members encouraged. To date, study species include representatives of annual and perennial grasses; annual and perennial forbs; shrubs; and trees. The goal of the GIIN

Prevalence of operator fatigue in winter maintenance operations.

Science.gov (United States)

Camden, Matthew C; Medina-Flintsch, Alejandra; Hickman, Jeffrey S; Bryce, James; Flintsch, Gerardo; Hanowski, Richard J

2018-02-02

Similar to commercial motor vehicle drivers, winter maintenance operators are likely to be at an increased risk of becoming fatigued while driving due to long, inconsistent shifts, environmental stressors, and limited opportunities for sleep. Despite this risk, there is little research concerning the prevalence of winter maintenance operator fatigue during winter emergencies. The purpose of this research was to investigate the prevalence, sources, and countermeasures of fatigue in winter maintenance operations. Questionnaires from 1043 winter maintenance operators and 453 managers were received from 29 Clear Road member states. Results confirmed that fatigue was prevalent in winter maintenance operations. Over 70% of the operators and managers believed that fatigue has a moderate to significant impact on winter maintenance operations. Approximately 75% of winter maintenance operators reported to at least sometimes drive while fatigued, and 96% of managers believed their winter maintenance operators drove while fatigued at least some of the time. Furthermore, winter maintenance operators and managers identified fatigue countermeasures and sources of fatigue related to winter maintenance equipment. However, the countermeasures believed to be the most effective at reducing fatigue during winter emergencies (i.e., naps) were underutilized. For example, winter maintenance operators reported to never use naps to eliminate fatigue. These results indicated winter maintenance operations are impacted by operator fatigue. These results support the increased need for research and effective countermeasures targeting winter maintenance operator fatigue. Copyright © 2018 Elsevier Ltd. All rights reserved.

Annual nitrate drawdown observed by SOCCOM profiling floats and the relationship to annual net community production

Science.gov (United States)

Johnson, Kenneth S.; Plant, Joshua N.; Dunne, John P.; Talley, Lynne D.; Sarmiento, Jorge L.

2017-08-01

Annual nitrate cycles have been measured throughout the pelagic waters of the Southern Ocean, including regions with seasonal ice cover and southern hemisphere subtropical zones. Vertically resolved nitrate measurements were made using in situ ultraviolet spectrophotometer (ISUS) and submersible ultraviolet nitrate analyzer (SUNA) optical nitrate sensors deployed on profiling floats. Thirty-one floats returned 40 complete annual cycles. The mean nitrate profile from the month with the highest winter nitrate minus the mean profile from the month with the lowest nitrate yields the annual nitrate drawdown. This quantity was integrated to 200 m depth and converted to carbon using the Redfield ratio to estimate annual net community production (ANCP) throughout the Southern Ocean south of 30°S. A well-defined, zonal mean distribution is found with highest values (3-4 mol C m-2 yr-1) from 40 to 50°S. Lowest values are found in the subtropics and in the seasonal ice zone. The area weighted mean was 2.9 mol C m-2 yr-1 for all regions south of 40°S. Cumulative ANCP south of 50°S is 1.3 Pg C yr-1. This represents about 13% of global ANCP in about 14% of the global ocean area.Plain Language SummaryThis manuscript reports on 40 annual cycles of nitrate observed by chemical sensors on SOCCOM profiling floats. The annual drawdown in nitrate concentration by phytoplankton is used to assess the spatial variability of annual net community production in the Southern Ocean. This ANCP is a key component of the global carbon cycle and it exerts an important control on atmospheric carbon dioxide. We show that the results are consistent with our prior understanding of Southern Ocean ANCP, which has required decades of observations to accumulate. The profiling floats now enable annual resolution of this key process. The results also highlight spatial variability in ANCP in the Southern Ocean.

Using flowering and heat-loss models for improving greenhouse energy-use efficiency in annual bedding plant production

Science.gov (United States)

In temperate climates, annual bedding plants are typically produced in heated greenhouses from late winter through early summer. Temperature, photoperiod, light intensity, and transplant date are commonly manipulated during commercial production so that plants are in flower for predetermined market ...

Introduction: Exotic Annual Bromus in the Western USA

Science.gov (United States)

Germino, Matthew; Chambers, Jeanne C.; Brown, Cynthia S.

2016-01-01

The spread and impacts of exotic species are unambiguous, global threats to many ecosystems. A prominent example is the suite of annual grasses in the Bromus genus (Bromus hereafter) that originate from Europe and Eurasia but have invaded or are invading large areas of the Western USA. This book brings a diverse, multidisciplinary group of authors together to synthesize current knowledge, research needs, and management implications for Bromus. Exotic plant invasions are multifaceted problems, and understanding and managing them requires the biological, ecological, sociological, and economic perspectives that are integrated in this book. Knowing how well information from one geographic or environmental setting can transfer to another is a key need for broadly distributed Bromus species especially given ongoing climate change. Thus, the chapters in the book compare and contrast invasibility of different ecoregions and invasiveness of different Bromus species. A universal theme is managing for ecosystems that are resilient to disturbance and resistant to invasion which will be essential for adaptation to the human-caused problem of Bromus in the Western USA.

Non-invasive plant growth measurements for detection of blue-light dose response of stem elongation in Chrysanthemum morifolium

DEFF Research Database (Denmark)

Kjær, Katrine Heinsvig

2012-01-01

. In the present study a non-invasive plant growth sensor (PlantEye, Phenospex B.V, Heerlen, NL) was tested in analysing changes in diurnal stem elongation patterns and plant height in response to the spectral quality of the light environment. Plants were grown in four different LED supplemental lighting...... treatments with 0%, 12.5%, 18.5% and 22.5% blue light under greenhouse conditions in winter (18 h day/4 h night). The non-invasive measurements were carried out automatically every four hour with three repetitions, and supported by manual measurements of plant height every third day. A strong linear relation...... between the non-invasive measurements and manual measurements of plant height was achieved, and a blue-light dose-response showing a decrease in plant height in relation to an increase in blue light was demonstrated. However, the non-invasive plant growth sensor was not able to distinguish between diurnal...

Invasive alien birds in Denmark

DEFF Research Database (Denmark)

Fox, Anthony David; Heldbjerg, Henning; Nyegaard, Timme

2015-01-01

Avian Introduced Alien Species (IAS) constitute a threat to the integrity of native biodiversity, the economy and human health, so here we briefly review some of the problems posed by such species around the world in relation to such bird species in Denmark. A new European Union Regulation...... on Invasive Alien Species implemented in January 2015 establishes a framework for actions to combat alien species, which requires Member States to prevent the spread of alien species, provide early warning and rapid responses to their presence and management of established alien species where they occur. We...... show the importance of mechanisms such as DOF’s (Dansk Ornitologisk Forening, BirdLife Denmark) Atlas project, Common Bird Census (breeding and wintering species) and DOFbasen to contribute data on the current geographical and numerical distribution of the few serious alien avian species already...

Invasive alien birds in Denmark

DEFF Research Database (Denmark)

Nyegaard, Timme; Heldbjerg, Henning; Fox, Anthony David

Avian Introduced Alien Species (IAS) constitute a threat to the integrity of native biodiversity, the economy and human health, so here we briefly review some of the problems posed by such species around the world in relation to bird species in Denmark. A new European Union Regulation on Invasive...... Alien Species implemented in January 2015 requires a framework for actions to combat alien species, which requires Member States to prevent the spread of alien species, provide early warning and rapid responses to their presence and management of established alien species where they occur. We show...... the importance of mechanisms such as DOFs (Danish Ornithological Society, BirdLife Denmark) Atlas project, Common Bird Monitoring (breeding and wintering species) and DOFbasen to contribute data on the current geographical and numerical distribution of the few serious alien avian species already present...

From Cyclone Tracks to the Costs of European Winter Storms: A Probabilistic Loss Assessment Model

Science.gov (United States)

Orwig, K.; Renggli, D.; Corti, T.; Reese, S.; Wueest, M.; Viktor, E.; Zimmerli, P.

2014-12-01

European winter storms cause billions of dollars of insured losses every year. Therefore, it is essential to understand potential impacts of future events, and the role reinsurance can play to mitigate the losses. The authors will present an overview on natural catastrophe risk assessment modeling in the reinsurance industry, and the development of a new innovative approach for modeling the risk associated with European winter storms.The new innovative approach includes the development of physically meaningful probabilistic (i.e. simulated) events for European winter storm loss assessment. The meteorological hazard component of the new model is based on cyclone and windstorm tracks identified in the 20thCentury Reanalysis data. The knowledge of the evolution of winter storms both in time and space allows the physically meaningful perturbation of historical event properties (e.g. track, intensity, etc.). The perturbation includes a random element but also takes the local climatology and the evolution of the historical event into account.The low-resolution wind footprints taken from the 20thCentury Reanalysis are processed by a statistical-dynamical downscaling to generate high-resolution footprints for both the simulated and historical events. Downscaling transfer functions are generated using ENSEMBLES regional climate model data. The result is a set of reliable probabilistic events representing thousands of years. The event set is then combined with country and site-specific vulnerability functions and detailed market- or client-specific information to compute annual expected losses.

Mitochondrial phenotypic flexibility enhances energy savings during winter fast in king penguin chicks.

Science.gov (United States)

Monternier, Pierre-Axel; Marmillot, Vincent; Rouanet, Jean-Louis; Roussel, Damien

2014-08-01

Energy conservation is a key priority for organisms that live in environments with seasonal shortages in resource supplies or that spontaneously fast during their annual cycle. The aim of this study was to determine whether the high fasting endurance of winter-acclimatized king penguin chicks (Aptenodytes patagonicus) is associated with an adjustment of mitochondrial bioenergetics in pectoralis muscle, the largest skeletal muscle in penguins. The rates of mitochondrial oxygen consumption, and ATP synthesis and mitochondrial efficiency (ATP/O ratio) were measured in winter-acclimatized chicks. We used pyruvate/malate and palmitoyl-l-carnitine/malate as respiratory substrates and results from naturally fasted chicks were compared to experimentally re-fed chicks. Bioenergetics analysis of pectoralis muscle revealed that mitochondria are on average 15% more energy efficient in naturally fasted than in experimentally fed chicks, indicating that fasted birds consume less nutrients to sustain their energy-demanding processes. We also found that moderate reductions in temperature from 38°C to 30°C further increase by 23% the energy coupling efficiency at the level of mitochondria, suggesting that king penguin chicks realize additional energy savings while becoming hypothermic during winter. It has been calculated that this adjustment of mitochondrial efficiency in skeletal muscle may contribute to nearly 25% of fasting-induced reduction in mass-specific metabolic rate measured in vivo. The present study shows that the regulation of mitochondrial efficiency triggers the development of an economical management of resources, which would maximize the conservation of endogenous fuel stores by decreasing the cost of living in fasted winter-acclimatized king penguin chicks. © 2014. Published by The Company of Biologists Ltd.

Impacts of Climate Variability on Non-native Plant Invasion in the Western U.S.

Science.gov (United States)

Bradley, B. A.

2006-12-01

Plant invasions are changing ecosystem structure and function throughout the United States. In many areas of the west, invasive species such as tamarisk (Tamarix spp.), cheatgrass (Bromus tectorum), and yellow starthistle (Centaurea solstitialis) dominate landscapes. Expansion of these species is occurring at a staggering rate, and invasion rates may change in the future as native ecosystems become more or less susceptible to invasion because of changes in climate. For example, evidence suggests that some plant invaders are favored under increased ambient CO2 levels, potentially leading to increased invasion with continued greenhouse gas emissions. In this work, I predict how western invasive plant species may also be affected by changes in climate variability. According to IPCC reports, rising ocean temperatures may change the frequency and intensity of El Niño events, potentially resulting in wetter El Niño years and/or more extreme and lengthier drought. In semi-arid systems, changing frequency or magnitude of extreme weather events may further shift the competitive balance between native and invasive species. For example, cheatgrass and yellow starthistle, both annual invaders, display high inter-annual variability in response to water availability. As a result, plants are larger and produce more seeds than native competitors during extreme wet years. This phenological response is so strong in cheatgrass communities that it can be observed in regional satellite records. Further, dense cheatgrass growth leads to a secondary feedback in the form of wildfire; higher density cheatgrass increases fire frequency in shrublands and enables further cheatgrass colonization. In this work, I synthesize knowledge of invasive plant phenological response under different climate conditions, drawing on information gathered through geographical mapping efforts at state or regional levels by university and agency researchers. Using the ranges of climate tolerance from current

Invasive flora within urban railway areas: a case study from Lublin (Poland and Lviv (Ukraine

Directory of Open Access Journals (Sweden)

Bożena Denisow

2017-12-01

Full Text Available Heterogeneous and disturbed habitats within railway areas create an ideal environment for establishment of invasive plant species. In this study, we compared the invasive species composition and abundance within railway areas of two cities, Lublin, SE Poland and Lviv, W Ukraine. In total, 70 invasive species were recorded. The invasive species list was similar for the two cities, with the most invasive species occurring at both (81.4%, 8.5% occurring only in Lublin and 10% only in Lviv. The proportion of invasive species in the total flora was almost 1.5-fold higher at Lviv compared to Lublin. Invasive species have originated mainly from continental America (45.7%, followed by Asia and Eurasia. The participation of invasive plants derived from Asia and Eurasia at Lviv is higher than at Lublin. The invasive flora includes a wide range of taxonomic groups, with a predominance of Asteraceae and Poaceae. The ecological attributes of invasive species on railway areas are: mainly annual therophytes, mostly wind- and insect pollination modes, a predominance of generative reproduction, anthropochorous and anemochorous dispersal and short-term persistent, long-term persistent or transient seed banks.

46 CFR 45.73 - Winter freeboard.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Winter freeboard. 45.73 Section 45.73 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Freeboards § 45.73 Winter freeboard. The minimum winter freeboard (fw) in inches is obtained by the formula: fw=f(s)+T s...

The gut microbiome of hooded cranes (Grus monacha) wintering at Shengjin Lake, China.

Science.gov (United States)

Zhao, Guanghong; Zhou, Lizhi; Dong, Yuanqiu; Cheng, Yuanyuan; Song, Yunwei

2017-06-01

Gut microbes of animals play critical roles in processes such as digestion and immunity. Therefore, identifying gut microbes will shed light on understanding the annual life of animal species, particularly those that are threatened or endangered. In the present study, we conducted nucleotide sequence analyses of the 16S rRNA genes of gut microbiome of the hooded cranes (Grus monacha) wintering at Shengjin Lake, China, by Illumina high-throughput sequencing technology. We acquired 503,398 high-quality sequences and 785 operational taxonomic units (OTUs) from 15 fecal samples from different cranes, representing 22 phyla that were dominated by Firmicutes, Proteobacteria, and Actinobacteria. A total of 305 genera were identified that were dominated by Clostridium, Lysinibacillus, and Enterobacter. The core gut microbiome comprised 26 genera, including many probiotic species such as Clostridium, Bacillus, Cellulosilyticum, and Cellulomonas that could catabolize cellulose. The findings reported here contribute to our knowledge of the microbiology of hooded cranes and will likely advance efforts to protect waterbirds that inhabit Shengjin Lake Reserve during winter. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Transcription through the eye of a needle: daily and annual cyclic gene expression variation in Douglas-fir needles.

Science.gov (United States)

Cronn, Richard; Dolan, Peter C; Jogdeo, Sanjuro; Wegrzyn, Jill L; Neale, David B; St Clair, J Bradley; Denver, Dee R

2017-07-24

Perennial growth in plants is the product of interdependent cycles of daily and annual stimuli that induce cycles of growth and dormancy. In conifers, needles are the key perennial organ that integrates daily and seasonal signals from light, temperature, and water availability. To understand the relationship between seasonal cycles and seasonal gene expression responses in conifers, we examined diurnal and circannual needle mRNA accumulation in Douglas-fir (Pseudotsuga menziesii) needles at diurnal and circannual scales. Using mRNA sequencing, we sampled 6.1 × 10 9 reads from 19 trees and constructed a de novo pan-transcriptome reference that includes 173,882 tree-derived transcripts. Using this reference, we mapped RNA-Seq reads from 179 samples that capture daily and annual variation. We identified 12,042 diurnally-cyclic transcripts, 9299 of which showed homology to annotated genes from other plant genomes, including angiosperm core clock genes. Annual analysis revealed 21,225 circannual transcripts, 17,335 of which showed homology to annotated genes from other plant genomes. The timing of maximum gene expression is associated with light intensity at diurnal scales and photoperiod at annual scales, with approximately half of transcripts reaching maximum expression +/- 2 h from sunrise and sunset, and +/- 20 days from winter and summer solstices. Comparisons with published studies from other conifers shows congruent behavior in clock genes with Japanese cedar (Cryptomeria), and a significant preservation of gene expression patterns for 2278 putative orthologs from Douglas-fir during the summer growing season, and 760 putative orthologs from spruce (Picea) during the transition from fall to winter. Our study highlight the extensive diurnal and circannual transcriptome variability demonstrated in conifer needles. At these temporal scales, 29% of expressed transcripts show a significant diurnal cycle, and 58.7% show a significant circannual cycle. Remarkably

Seasonal and inter-annual sea surface height variations of the northern Indian Ocean from the TOPEX/POSEIDON altimeter

Digital Repository Service at National Institute of Oceanography (India)

PrasannaKumar, S.; Snaith, H.; Challenor, P.; Guymer, H.T.

along the east and west coast of India, and offshore movement of the high (low) SSH patch during winter (summer) away from the tip of India indicates the role of remote forcings along the boundary and into the interior oceans. Inter-annual variability...

The need for spatially explicit quantification of benefits in invasive-species management.

Science.gov (United States)

Januchowski-Hartley, Stephanie R; Adams, Vanessa M; Hermoso, Virgilio

2018-04-01

Worldwide, invasive species are a leading driver of environmental change across terrestrial, marine, and freshwater environments and cost billions of dollars annually in ecological damages and economic losses. Resources limit invasive-species control, and planning processes are needed to identify cost-effective solutions. Thus, studies are increasingly considering spatially variable natural and socioeconomic assets (e.g., species persistence, recreational fishing) when planning the allocation of actions for invasive-species management. There is a need to improve understanding of how such assets are considered in invasive-species management. We reviewed over 1600 studies focused on management of invasive species, including flora and fauna. Eighty-four of these studies were included in our final analysis because they focused on the prioritization of actions for invasive species management. Forty-five percent (n = 38) of these studies were based on spatial optimization methods, and 35% (n = 13) accounted for spatially variable assets. Across all 84 optimization studies considered, 27% (n = 23) explicitly accounted for spatially variable assets. Based on our findings, we further explored the potential costs and benefits to invasive species management when spatially variable assets are explicitly considered or not. To include spatially variable assets in decision-making processes that guide invasive-species management there is a need to quantify environmental responses to invasive species and to enhance understanding of potential impacts of invasive species on different natural or socioeconomic assets. We suggest these gaps could be filled by systematic reviews, quantifying invasive species impacts on native species at different periods, and broadening sources and enhancing sharing of knowledge. © 2017 Society for Conservation Biology.

Winter warming from large volcanic eruptions

Science.gov (United States)

Robock, Alan; Mao, Jianping

1992-01-01

An examination of the Northern Hemisphere winter surface temperature patterns after the 12 largest volcanic eruptions from 1883-1992 shows warming over Eurasia and North America and cooling over the Middle East which are significant at the 95-percent level. This pattern is found in the first winter after tropical eruptions, in the first or second winter after midlatitude eruptions, and in the second winter after high latitude eruptions. The effects are independent of the hemisphere of the volcanoes. An enhanced zonal wind driven by heating of the tropical stratosphere by the volcanic aerosols is responsible for the regions of warming, while the cooling is caused by blocking of incoming sunlight.

Crop and livestock enterprise integration: Effects of annual crops used for fall forage production on livestock productivity

Science.gov (United States)

Diversification of farm enterprises is important to maintain sustainable production systems. Systems that integrate crops and livestock may prove beneficial to each enterprise. Our objectives were to determine the effects of annual crops grazed in the fall and early-winter period on cow and calf gro...

Biogeochemical Impact of Snow Cover and Cyclonic Intrusions on the Winter Weddell Sea Ice Pack

Science.gov (United States)

Tison, J.-L.; Schwegmann, S.; Dieckmann, G.; Rintala, J.-M.; Meyer, H.; Moreau, S.; Vancoppenolle, M.; Nomura, D.; Engberg, S.; Blomster, L. J.; Hendrickx, S.; Uhlig, C.; Luhtanen, A.-M.; de Jong, J.; Janssens, J.; Carnat, G.; Zhou, J.; Delille, B.

2017-12-01

Sea ice is a dynamic biogeochemical reactor and a double interface actively interacting with both the atmosphere and the ocean. However, proper understanding of its annual impact on exchanges, and therefore potentially on the climate, notably suffer from the paucity of autumnal and winter data sets. Here we present the results of physical and biogeochemical investigations on winter Antarctic pack ice in the Weddell Sea (R. V. Polarstern AWECS cruise, June-August 2013) which are compared with those from two similar studies conducted in the area in 1986 and 1992. The winter 2013 was characterized by a warm sea ice cover due to the combined effects of deep snow and frequent warm cyclones events penetrating southward from the open Southern Ocean. These conditions were favorable to high ice permeability and cyclic events of brine movements within the sea ice cover (brine tubes), favoring relatively high chlorophyll-a (Chl-a) concentrations. We discuss the timing of this algal activity showing that arguments can be presented in favor of continued activity during the winter due to the specific physical conditions. Large-scale sea ice model simulations also suggest a context of increasingly deep snow, warm ice, and large brine fractions across the three observational years, despite the fact that the model is forced with a snowfall climatology. This lends support to the claim that more severe Antarctic sea ice conditions, characterized by a longer ice season, thicker, and more concentrated ice are sufficient to increase the snow depth and, somehow counterintuitively, to warm the ice.

Ecosystem impacts of exotic annual invaders in the genus Bromus

Science.gov (United States)

Matthew J. Germino; Jayne Belnap; John M. Stark; Edith B Allen; Benjamin Rau

2016-01-01

An understanding of the impacts of exotic plant species on ecosystems is necessary to justify and guide efforts to limit their spread, restore natives, and plan for conservation. Invasive annual grasses such as Bromus tectorum, B. rubens, B. hordeaceus, and B. diandrus (hereafter collectively referred to as Bromus) transform the structure and function of ecosystems...

US annual report to the ICES working group on introductions and transfers of marine organisms

Science.gov (United States)

Provides annual update on new introductions to the US, new regulations, and major research/management efforts in the US related to marine invasive species, with focus on activities in the North Atlantic

Annual energy analysis of concrete containing phase change materials for building envelopes

International Nuclear Information System (INIS)

Thiele, Alexander M.; Jamet, Astrid; Sant, Gaurav; Pilon, Laurent

2015-01-01

Highlights: • Adding PCM to concrete walls can significantly reduce the cooling needs of buildings. • Climate, season, and wall orientation strongly affect energy and cost savings. • The PCM melting temperature should be near the desired indoor temperature. • Benefits are maximum for outdoor temperature oscillating around set indoor temperature. • Adding PCM had little effect on heating energy needs and associated cost savings. - Abstract: This paper examines the annual energy and cost savings potential of adding microencapsulated phase change material to the exterior concrete walls of an average-sized single family home in California climate zones 3 (San Francisco, CA) and 9 (Los Angeles, CA). The annual energy and cost savings were larger for South- and West-facing walls than for other walls. They were also the largest when the phase change temperature was near the desired indoor temperature. The addition of microencapsulated phase change material to the building walls reduced the cooling load in summer substantially more than the heating load in winter. This was attributed to the cold winter temperatures resulting in nearly unidirectional heat flux on many days. The annual cooling load reduction in an average-sized single family home in San Francisco and in Los Angeles ranged from 85% to 100% and from 53% to 82%, respectively, for phase change material volume fraction ranging from 0.1 to 0.3. The corresponding annual electricity cost savings ranged from $36 to $42 in San Francisco and from $94 to $143 in Los Angeles. From an energy standpoint, the best climate for using building materials containing uniformly distributed microencapsulated phase change material would have outdoor temperature oscillations centered around the desired indoor temperature for the entire year

Remote sensing of California estuaries: Monitoring climate change and invasive species

Science.gov (United States)

Mulitsch, Melinda Jennifer

The spread of invasive species and climate change are among the most serious global environmental threats. The goal of this dissertation was to link inter-annual climate change and biological invasions at a landscape scale using novel remote sensing techniques applied to the San Francisco Bay/Sacramento- San Joaquin Delta Estuary. I evaluated the use of hyperspectral imagery for detecting invasive aquatic species in the Delta using 3 m HyMap hyperspectral imagery. The target invasive aquatics weeds were the emergent water hyacinth (Eichhornia crassipes) and the submerged Brazilian waterweed (Egeria densa). Data were analyzed using linear spectral mixture analysis (SMA). The results show the weeds were mapped with a classification accuracy of 90.6% compared to 2003 sample sites and 82.6% accuracy compared to 2004 sample sites. Brazilian waterweed locations were successfully mapped but the abundances were overestimated because we did not separate it from other submerged aquatic vegatation (SAV). I evaluated 3 m HyMap imagery, from 2004, for SAV species in the Delta, including: Brazilian waterweed ( Egeria densa), Eurasian watermilfoil (Myriophyllum spicatum ), curlyleaf pondweed (Potamogeton crispus), coontail (Ceratophyllum demersum), American pondweed (Potamogeton nodosus), fanwort (Cabomba caroliniana), and common elodea (Elodea canadensis). Data were analyzed using SMA with a classification accuracy of 84.4%. Spectral simulations of Brazilian waterweed and American pondweed show how spectral properties can change at different water depths and varying water quality. Finally I address the effect of inter-annual climate change on the estuary ecology in the San Francisco Bay by analyzing current (2002) and historical (1994-1996) Airborne Visible Infrared Imaging Spectrometer (AVIRIS) datasets to map salt marsh species distribution. The species in the estuary, Salicornia virginica, Spartinia foliosa, Scirpus robustus, and Distichlis spicata undergo dramatic changes in

Annual plan, December 1999

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

This annual plan is being provided as required under Section 'D' of the Alberta Energy and Utilities Board Information Letter IL 90-8. The objective is to provide the Board, NOVA Gas Transmission (NGTL) customers and other interested parties with a comprehensive overview of NOVA Gas Transmission's pipeline system expansion plans for the gas year 2000/ 2001, and the winter season of the 2001/2002 gas year. The plan includes descriptions of NGTL's design assumptions and criteria, as well as long term outlook for field deliverability, productive capability, gas deliveries, proposed facility additions, capital expenditures, revenue requirements and firm service demand rates. Major factors affecting the facility requirements for the period under consideration are a decrease in the maximum day delivery volume at the Empress border point, an increase in intra-Alberta maximum day delivery volumes and associated decline in productive capability. Chapter One of the Plan describes the the Annual Plan process itself; Chapter Two is devoted to a discussion of facilities design methodology; Chapter Three deals with economic assumptions; Chapter Four describes design flow, while Chapters Five and Six outline the mainline , meter stations, laterals, and lateral loops facility requirements. Chapter Seven provides and overview of the capital and financial forecasts. tabs., figs.

Range estimates and habitat use of invasive Silver Carp (Hypophthalmichthys molitrix): Evidence of sedentary and mobile individuals

Science.gov (United States)

Prechtel, Austin R.; Coulter, Alison A.; Etchison, Luke; Jackson, P. Ryan; Goforth, Reuben R.

2018-01-01

Unregulated rivers provide unobstructed corridors for the dispersal of both native and invasive species. We sought to evaluate range size and habitat use of an invasive species (Silver Carp, Hypophthalmichthys molitrix) in an unimpounded river reach (Wabash River, IN), to provide insights into the dispersal of invasive species and their potential overlap with native species. We hypothesized that range size would increase with fish length, be similar among sexes, and vary annually while habitats used would be deeper, warmer, lower velocity, and of finer substrate. Silver Carp habitat use supported our hypotheses but range size did not vary with sex or length. 75% home range varied annually, suggesting that core areas occupied by individuals may change relative to climate-based factors (e.g., water levels), whereas broader estimates of range size remained constant across years. Ranges were often centered on landscape features such as tributaries and backwaters. Results of this study indicate habitat and landscape features as potential areas where Silver Carp impacts on native ecosystems may be the greatest. Observed distribution of range sizes indicates the presence of sedentary and mobile individuals within the population. Mobile individuals may be of particular importance as they drive the spread of the invasive species into new habitats.

36 CFR 1002.19 - Winter activities.

Science.gov (United States)

2010-07-01

... RECREATION § 1002.19 Winter activities. (a) Skiing, snowshoeing, ice skating, sledding, innertubing, tobogganing and similar winter sports are prohibited on Presidio Trust roads and in parking areas open to...

A study on the intra-annual variation and the spatial distribution of precipitation amount and duration over Greece on a 10 day basis

Science.gov (United States)

Bartzokas, A.; Lolis, C. J.; Metaxas, D. A.

2003-02-01

The intra-annual variation of precipitation amount and duration and their spatial distribution during the year are studied on a 10 day basis for the Greek region, using S-mode and T-mode factor analysis. (i) For the intra-annual variation of precipitation amount, two modes were revealed: the first shows one broad maximum during the conventional winter in stations affected by the sea; the second presents two maxima, the first during late autumn-early winter and the second during late spring, corresponding to the northern mainland stations. (ii) For the spatial distribution of precipitation, three main patterns were revealed: the first one is the winter pattern, with the maximum over the west windward area; the second is the summer pattern, with a maximum over the north inland region; and the third is the autumn pattern, with the maximum over northwestern Greece. (iii) For precipitation duration, two types of intra-annual variation were revealed. The first one is similar to the first of the analysis for precipitation amount; the second presents two maxima, the first during the beginning of December and the second during the middle of February, corresponding to the areas of northwestern and northeastern Greece. (iv) For the spatial distribution of precipitation duration, three main patterns were revealed: the first is the summer pattern, which is similar to the second of the analysis for precipitation amount; the second is the winter pattern, with the spatial maximum located over the eastern mainland and western Crete; finally, the third one is the autumn pattern, with the maximum in northwestern Greece. During the third 10 day period of October and the second 10 day period of February, precipitation seems to present singularities, possibly due to fluctuations in atmospheric circulation. The above intra-annual variations and spatial distribution patterns are connected to the seasonal variations of the depression trajectories, the atmospheric instability, the influence

Plant invasions: Merging the concepts of species invasiveness and community invasibility

Czech Academy of Sciences Publication Activity Database

Richardson, D. M.; Pyšek, Petr

2006-01-01

Roč. 30, č. 3 (2006), s. 409-431 ISSN 0309-1333 Institutional research plan: CEZ:AV0Z60050516 Keywords : plant invasions * species invasiveness * community invasibility Subject RIV: EF - Botanics Impact factor: 1.278, year: 2006

Cold-season temperature in the Swiss Alps from AD 1100-1500; trends, intra-annual variability and forcing factors

Science.gov (United States)

de Jong, Rixt; Kamenik, Christian; Grosjean, Martin

2010-05-01

To fully understand past climatic changes and their forcing factors, detailed reconstructions of past summer and winter temperatures are required. Winter temperature reconstructions are scarce, however, because most biological proxies are biased towards the growing season. This study presents a detailed reconstruction of winter temperatures based on Chrysophyte stomatocysts, silicious scales formed by so-called 'golden algae'. Previous studies (Kamenik and Schmidt, 2005; Pla and Catalan, 2005) have demonstrated the sensitivity of these algae to cold-season temperatures. Chrysophyte stomatocyst analysis was carried out on varved sediments from Lake Silvaplana (1791 m a.s.l.) at annual to near-annual resolution for two periods; AD 1100-1500 and AD 1870-2004. For both periods the reference date 'date of spring mixing' (Smix) was reconstructed using a transfer function developed for the Austrian Alps (Kamenik and Schmidt, 2005). In the Austrian Alps, Smix was primarily driven by air temperature in the cold season. The strength of stomatocysts as a proxy for winter temperature was tested by directly comparing reconstructed Smix with measured temperatures from nearby meteostation Sils Maria for the period AD 1870 - 2004. Correlation was highest (R = -0.6; p number of eruptions during the much shorter instrumental period (Fischer et al., 2007). References: T. Crowley. Science 289, 270-277 (2000) E. Fischer et al. Geophys. Res. Lett. 34, L05707 (2007) C. Kamenik and R. Schmidt. Boreas 34, 477-489 (2005) I. Larocque-Tobler et al. Quat. Sci. Rev., accepted. S. Pla and J. Catalan. Clim. Dyn. 24, 263-278 (2005) M. Trachsel et al. Manuscript in review

Examining winter visitor use in Yellowstone National Park

Science.gov (United States)

Mae A. Davenport; Wayne A. Freimund; William T. Borrie; Robert E. Manning; William A. Valliere; Benjamin Wang

2000-01-01

This research was designed to assist the managers of Yellowstone National Park (YNP) in their decision making about winter visitation. The focus of this report is on winter use patterns and winter visitor preferences. It is the author’s hope that this information will benefit both the quality of winter experiences and the stewardship of the park resources. This report...

Winter Dew Harvest in Mexico City

Directory of Open Access Journals (Sweden)

Arias-Torres Jorge Ernesto

2015-12-01

Full Text Available This study presents experimental and theoretical results of winter dew harvest in México City in terms of condensation rate. A simplified theoretical model based on a steady-state energy balance on a radiator-condenser was fitted, as a function of the ambient temperature, the relative humidity and the wind velocity. A glass sheet and aluminum sheet white-painted were used as samples over the outdoor experiments. A good correlation was obtained between the theoretical and experimental data. The experimental results show that there was condensation in 68% of the winter nights on both condensers. The total winter condensed mass was 2977 g/m2 and 2888 g/m2 on the glass sheet and aluminum sheet white-painted, respectively. Thus, the condensed mass on the glass was only 3% higher than that on the painted surface. The maximum nightly dew harvests occurred during December, which linearly reduced from 50 g/m2 night to 22 g/m2 night as the winter months went by. The condensation occurred from 1:00 a.m. to 9:00 a.m., with maximum condensation rates between 6:00 a.m. and 7:00 a.m. The dew harvest can provide a partial alternative to the winter water shortage in certain locations with similar climates to the winter in Mexico City, as long as pollution is not significant.

23rd annual meeting of German Society for Neuroradiology

International Nuclear Information System (INIS)

Kuehne, D.

1987-01-01

Book of abstracts of this annual meeting summarizing the 58 lectures that dealt with the following subjects: Pathologic changes of the cervical vertebral canal and of the cervico-occipital region, as detected by modern imaging techniques (18 papers); diagnostic examination of the urbita and the middle cranial fossa (12 papers); invasive methods of neuroradiology (13 papers); 15 papers on freely chosen subjects. (MG) [de

Coping with the cold: an ecological context for the abundance and distribution of rock sandpipers during winter in upper Cook Inlet, Alaska

Science.gov (United States)

Ruthrauff, Daniel R.; Gill, Robert E.; Tibbitts, T. Lee

2013-01-01

Shorebirds are conspicuous and abundant at high northern latitudes during spring and summer, but as seasonal conditions deteriorate, few remain during winter. To the best of our knowledge, Cook Inlet, Alaska (60.6˚ N, 151.6˚ W), is the world’s coldest site that regularly supports wintering populations of shorebirds, and it is also the most northerly nonbreeding location for shorebirds in the Pacific Basin. During the winters of 1997–2012, we conducted aerial surveys of upper Cook Inlet to document the spatial and temporal distribution and number of Rock Sandpipers (Calidris ptilocnemis) using the inlet. The average survey total was 8191 ± 6143 SD birds, and the average of each winter season’s highest single-day count was 13 603 ± 4948 SD birds. We detected only Rock Sandpipers during our surveys, essentially all of which were individuals of the nominate subspecies (C. p. ptilocnemis). Survey totals in some winters closely matched the population estimate for this subspecies, demonstrating the region’s importance as a nonbreeding resource to the subspecies. Birds were most often found at only a handful of sites in upper Cook Inlet, but shifted their distribution to more southerly locations in the inlet during periods of extreme cold. Two environmental factors allow Rock Sandpipers to inhabit Cook Inlet during winter: 1) an abundant bivalve (Macoma balthica) food source and 2) current and tidal dynamics that keep foraging substrates accessible during all but extreme periods of cold and ice accretion. C. p. ptilocnemis is a subspecies of high conservation concern for which annual winter surveys may serve as a relatively inexpensive population-monitoring tool that will also provide insight into adaptations that allow these birds to exploit high-latitude environments in winter.

Leadership in American Indian Communities: Winter Lessons

Science.gov (United States)

Metoyer, Cheryl A.

2010-01-01

Winter lessons, or stories told in the winter, were one of the ways in which tribal elders instructed and directed young men and women in the proper ways to assume leadership responsibilities. Winter lessons stressed the appropriate relationship between the leader and the community. The intent was to remember the power and purpose of that…

Ecosystem impacts of exotic annual invaders in the Genus Bromus

Science.gov (United States)

Germino, Matthew J.; Belnap, Jayne; Stark, John M.; Allen, Edith B.; Rau, Benjamin M.

2016-01-01

An understanding of the impacts of exotic plant species on ecosystems is necessary to justify and guide efforts to limit their spread, restore natives, and plan for conservation. Invasive annual grasses such as Bromus tectorum, B. rubens, B. hordeaceus, and B. diandrus (hereafter collectively referred to as Bromus) transform the structure and function of ecosystems they dominate. Experiments that prove cause-and-effect impacts of Bromus are rare, yet inferences can be gleaned from the combination of Bromus-ecosystem associations, ecosystem condition before/after invasion, and an understanding of underlying mechanisms. Bromus typically establishes in bare soil patches and can eventually replace perennials such as woody species or bunchgrasses, creating a homogeneous annual cover. Plant productivity and cover are less stable across seasons and years when Bromus dominates, due to a greater response to annual climate variability. Bromus’ “flash” of growth followed by senescence early in the growing season, combined with shallow rooting and annual habit, may lead to incomplete use of deep soil water, reduced C sequestration, and accelerated nutrient cycling. Litter produced by Bromus alters nearly all aspects of ecosystems and notably increases wildfire occurrence. Where Bromus has become dominant, it can decrease soil stability by rendering soils bare for months following fire or episodic, pathogen-induced stand failure. Bromus-invaded communities have lower species diversity, and associated species tend to be generalists adapted to unstable and variable habitats. Changes in litter, fire, and soil properties appear to feedback to reinforce Bromus’ dominance in a pattern that portends desertification.

Evaluation of the energy and comfort performance of a plus-energy house under Scandinavian winter conditions

DEFF Research Database (Denmark)

Pean, Thibault Quentin; Gennari, Luca; Kazanci, Ongun Berk

evaluation, these results show an encouraging trend towards achieving an annual positive energy balance as designed for this plus-energy house. The thermal environmental conditions in the semi-outdoor space resulted more comfortable than the outdoors, with reduced wind velocity, protection from rain......A plus-energy house was studied in terms of indoor environmental conditions and energy balance, during Scandinavian winter conditions. The studied building, EMBRACE, is a single-family detached dwelling of 59 m2 with two floors. The house also integrates a semi-outdoor space, covered by a glazed...

[Distribution pattern of riparian invasive plants in Luanhe Basin, North China and its relationship with environment].

Science.gov (United States)

Ren, Ying; He, Ping; Xu, Jie; Jia, Jiao

2017-06-18

In this study, the invasive plant species from the riparian vegetation in 56 sampling sites of Luanhe Basin were identified, and the correlations between their composition, spatial distribution and environmental factors were explored. In the basin, a total of 26 invasive species were registered, which belonged to 19 genera and 12 families, and 73.1% of them were annual plants. Asteraceae and Amaranthaceae were the two dominant families with the most invasive species, attributing to 50% of the total invasive species. Amaranthus retroflexus, Bidens frondosa and Chenopodium serotinum appeared with the highest frequencies. The number of invasive species and the invasive intensity at each site were significantly negatively correlated with the altitude. The distribution of invasive plants was significantly influenced by the intensity of human activities. The invasive plants were mainly distributed in the plain area, shallow mountainous area with many reservoirs, and the mountainous area with developed tourism around Chengde City, meanwhile, only few species with broad ecological amplitude existed in the plateau area. In general, species with higher invasive grades were mainly distributed in low and medium altitude areas below 400 m. Except for A. retroflexus, no high-grade invasive plants were discovered in high altitude area so far.

Trends in the epidemiology of invasive Haemophilus influenzae disease in Queensland, Australia from 2000 to 2013: what is the impact of an increase in invasive non-typable H. influenzae (NTHi)?

Science.gov (United States)

Wan Sai Cheong, J; Smith, H; Heney, C; Robson, J; Schlebusch, S; Fu, J; Nourse, C

2015-10-01

Following the introduction of vaccination against Haemophilus influenzae type b (Hib), cases of invasive encapsulated Hib disease have decreased markedly. This study aimed to examine subsequent epidemiological trends in invasive H. influenzae disease in Queensland, Australia and in particular, assess the clinical impact and public health implications of invasive non-typable H. influenzae (NTHi) strains. A multicentre retrospective study was conducted from July 2000 to June 2013. Databases of major laboratories in Queensland including Queensland Forensic and Scientific Services (jurisdictional referral laboratory for isolate typing) were examined to identify cases. Demographic, infection site, Indigenous status, serotype, and mortality data were collected. In total, 737 invasive isolates were identified, of which 586 (79·5%) were serotyped. Hib, NTHi and encapsulated non-b strains, respectively, constituted 12·1%, 69·1% and 18·8% of isolates. The predominant encapsulated non-b strains were f (45·5%) and a (27·3%) serotypes. Of isolates causing meningitis, 48·9% were NTHi, 14·9% Hib, 14·9% Hie, 10·6% Hif, 6·4% Hia and 4·3% were untyped. During the study period, there was an increase in the incidence of invasive NTHi disease (P = 0·007) with seasonal peaks in winter and spring (P 0·001) and Hib (P = 0·039) than non-Indigenous patients. In Queensland, invasive H. influenzae disease is now predominantly encountered in adults and most commonly caused by NTHi strains with demonstrated pathogenicity extending to otherwise young or immunocompetent individuals. Routine public health notification of these strains is recommended and recent available immunization options should be considered.

Time Series Remote Sensing in Monitoring the Spatio-Temporal Dynamics of Plant Invasions: A Study of Invasive Saltcedar (Tamarix Spp.)

Science.gov (United States)

Diao, Chunyuan

In today's big data era, the increasing availability of satellite and airborne platforms at various spatial and temporal scales creates unprecedented opportunities to understand the complex and dynamic systems (e.g., plant invasion). Time series remote sensing is becoming more and more important to monitor the earth system dynamics and interactions. To date, most of the time series remote sensing studies have been conducted with the images acquired at coarse spatial scale, due to their relatively high temporal resolution. The construction of time series at fine spatial scale, however, is limited to few or discrete images acquired within or across years. The objective of this research is to advance the time series remote sensing at fine spatial scale, particularly to shift from discrete time series remote sensing to continuous time series remote sensing. The objective will be achieved through the following aims: 1) Advance intra-annual time series remote sensing under the pure-pixel assumption; 2) Advance intra-annual time series remote sensing under the mixed-pixel assumption; 3) Advance inter-annual time series remote sensing in monitoring the land surface dynamics; and 4) Advance the species distribution model with time series remote sensing. Taking invasive saltcedar as an example, four methods (i.e., phenological time series remote sensing model, temporal partial unmixing method, multiyear spectral angle clustering model, and time series remote sensing-based spatially explicit species distribution model) were developed to achieve the objectives. Results indicated that the phenological time series remote sensing model could effectively map saltcedar distributions through characterizing the seasonal phenological dynamics of plant species throughout the year. The proposed temporal partial unmixing method, compared to conventional unmixing methods, could more accurately estimate saltcedar abundance within a pixel by exploiting the adequate temporal signatures of

Trophic ecology and persistence of invasive silver carp Hypophthalmichthys molitrix in an oligotrophic South African impoundment

CSIR Research Space (South Africa)

Lübcker, N

2016-12-01

Full Text Available (median annual suspended chlorophyll a = 0.08 µg l-1), and limited access to rivers considered large enough for successful spawning, has implications for their invasive potential in other systems. Stomach content and stable isotope analysis were used...

Invasion of Old World Phragmites australis in the New World: precipitation and temperature patterns combined with human influences redesign the invasive niche.

Science.gov (United States)

Guo, Wen-Yong; Lambertini, Carla; Li, Xiu-Zhen; Meyerson, Laura A; Brix, Hans

2013-11-01

After its introduction into North America, Euro-Asian Phragmites australis became an aggressive invasive wetland grass along the Atlantic coast of North America. Its distribution range has since expanded to the middle, south and southwest of North America, where invasive P. australis has replaced millions of hectares of native plants in inland and tidal wetlands. Another P. australis invasion from the Mediterranean region is simultaneously occurring in the Gulf region of the United States and some countries in South America. Here, we analysed the occurrence records of the two Old World invasive lineages of P. australis (Haplotype M and Med) in both their native and introduced ranges using environmental niche models (ENMs) to assess (i) whether a niche shift accompanied the invasions in the New World; (ii) the role of biologically relevant climatic variables and human influence in the process of invasion; and (iii) the current potential distribution of these two lineages. We detected local niche shifts along the East Coast of North America and the Gulf Coast of the United States for Haplotype M and around the Mississippi Delta and Florida of the United States for Med. The new niche of the introduced Haplotype M accounts for temperature fluctuations and increased precipitation. The introduced Med lineage has enlarged its original subtropical niche to the tropics-subtropics, invading regions with a high annual mean temperature (> ca. 10 °C) and high precipitation in the driest period. Human influence is an important factor for both niches. We suggest that an increase in precipitation in the 20th century, global warming and human-made habitats have shaped the invasive niches of the two lineages in the New World. However, as the invasions are ongoing and human and natural disturbances occur concomitantly, the future distribution ranges of the two lineages may diverge from the potential distribution ranges detected in this study. © 2013 John Wiley & Sons Ltd.

Substantial N2O emission during the initial period of the wheat season due to the conversion of winter-flooded paddy to rice-wheat rotation

Science.gov (United States)

Zhou, Wei; Lin, Shan; Wu, Lei; Zhao, Jingsong; Wang, Milan; Zhu, Bo; Mo, Yongliang; Hu, Ronggui; Chadwick, Dave; Shaaban, Muhammad

2017-12-01

Winter-flooded paddy is a typical rice-based cropping system to conserve water for the next rice growing season. Conversion of winter-flooded paddy to rice-wheat rotation has been widely adopted with the development of the water conservation infrastructure and the government's encouragement of winter agriculture in China in recent decades. However, the effects of this conversion on N2O emission are still not clear. Three winter-flooded paddy fields were studied in a split-plot design. One-half of each field was converted to rice-wheat rotation (RW), and the other half remained winter-flooded as rice-fallow (RF). Each plot of RW and RF was further divided into four subplots: three subplots for conventional N fertilizer application (RW-NC and RF-NC) and one for unfertilized treatment (RW-N0 and RF-N0). Conversion of RF-NC to RW-NC increased the N2O emission up to 6.6-fold in the first year and 4.4-fold in the second year. Moreover, N2O emissions for the entire wheat season were 1.74-3.74 kg N ha-1 and 0.24-0.31 kg N ha-1 from RW-NC and RW-N0, respectively, and accounted for 78%-94% and 78%-97% of the total annual amount. N2O emitted during the first 11-21 days of the wheat season from RW-NC was 1.48-3.28 kg N ha-1 and that from RW-N0 was 0.14-0.17 kg N ha-1, which contributed to 66%-82% and 45%-71% of the total annual amount, respectively. High N2O fluxes occurred when the soil water-filled pore space (WFPS) was in the range of 68%-72% and the ratio of available carbon to nitrogen in the soil was organic carbon (DOC) explained most of the variation of the N2O fluxes compared with the other measured environmental and soil factors. These findings suggest that the conversion of winter-flooded paddy to rice-wheat rotation increased N2O emissions that could be mitigated by controlling the soil moisture and ratio of available soil carbon to nitrogen.

Barriers to wheelchair use in the winter.

Science.gov (United States)

Ripat, Jacquie D; Brown, Cara L; Ethans, Karen D

2015-06-01

To test the hypothesis that challenges to community participation posed by winter weather are greater for individuals who use scooters, manual and power wheelchairs (wheeled mobility devices [WMDs]) than for the general ambulatory population, and to determine what WMD users identify as the most salient environmental barriers to community participation during the winter. Cross-sectional survey organized around 5 environmental domains: technological, natural, physical, social/attitudinal, and policy. Urban community in Canada. Convenience sample of WMD users or their proxy (N=99). Not applicable. Not applicable. Forty-two percent identified reduced outing frequency in winter months, associated with increased age (χ(3)=6.4, P=.04), lack of access to family/friends for transportation (χ(2)=8.1, P=.04), and primary type of WMD used in the winter (scooter χ(2)=8.8, P=.003). Most reported tires/casters becoming stuck in the snow (95%) or slipping on the ice (91%), difficulty ascending inclines/ramps (92%), and cold hands while using controls or pushing rims (85%); fewer identified frozen wheelchair/scooter batteries, seat cushions/backrests, or electronics. Sidewalks/roads were reported to be problematic by 99%. Eighty percent reported needing additional help in the winter. Limited community access in winter led to a sense of loneliness/isolation, and fear/anxiety related to safety. Respondents identified policies that limited participation during winter. People who use WMDs decrease their community participation in cold weather because of multiple environmental barriers. Clinicians, researchers, and policymakers can take a multidimensional approach to mitigate these barriers in order to enhance community participation by WMD users in winter. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

AGA predicts winter jump in residential gas price

International Nuclear Information System (INIS)

Anon.

1992-01-01

The American Gas Association predicts the average heating bill for residential gas consumers could increase by as much as 18% this winter. AGA Pres. Mike Baly said, Last year's winter was warmer than normal. If the 1992-93 winter is similar, AGA projects that residential natural gas heating bills will go up about 6%. If we see a return to normal winter weather, our projection show the average bill could rise by almost 18%

Assessment of winter fluxes of CO2 and CH4 in boreal forest soils of central Alaska estimated by the profile method and the chamber method: a diagnosis of methane emission and implications for the regional carbon budget

International Nuclear Information System (INIS)

Kim, Yongwon; Ueyama, Masahito; Harazono, Yoshinobu; Tanaka, Noriyuki; Nakagawa, Fumiko; Tsunogai, Urumu

2007-01-01

This research was carried out to estimate the winter fluxes of CO 2 and CH 4 using the concentration profile method and the chamber method in black spruce forest soils in central Alaska during the winter of 2004/5. The average winter fluxes of CO 2 and CH 4 by chamber and profile methods were 0.24 ± 0.06 (SE; standard error) and 0.21 ± 0.06 gCO 2 -C/m2/d, and 21.4 ± 5.6 and 21.4 ± 14 μgCH 4 -C/m2/hr. This suggests that the fluxes estimated by the two methods are not significantly different based on a one-way ANOVA with a 95% confidence level. The hypothesis on the processes of CH 4 transport/production/emission in underlying snow-covered boreal forest soils is proven by the pressure differences between air and in soil at 30 cm depth. The winter CO 2 emission corresponds to 23% of the annual CO 2 emitted from Alaska black spruce forest soils, which resulted in the sum of mainly root respiration and microbial respiration during the winter based on the (delta) 13 CO 2 of -2.25%. The average wintertime emissions of CO 2 and CH 4 were 49 ± 13 gCO 2 -C/m 2 /season and 0.11 ± 0.07 gCH 4 -C/m 2 /season, respectively. This implies that winter emissions of CO 2 and CH 4 are an important part of the annual carbon budget in seasonally snow-covered terrain of typical boreal forest soils

Causes of the mid-latitudinal daytime NmF2 semi-annual anomaly at solar minimum

Science.gov (United States)

Pavlov, A. V.

2018-04-01

Ionospheric ionosonde and radar observations and theoretical calculations of the F2-layer peak altitude, hmF2, and number density, NmF2, over Millstone Hill during winter, spring, summer, and autumn geomagnetically quiet time periods at low solar activity are used to study the causes of the observed daytime NmF2 semi-annual anomaly. It follows from the model simulations that this anomalous phenomenon arises in the ionosphere mainly as a result of seasonal variations of the following atmospheric parameters: (1) the plasma drift along geomagnetic field lines due to corresponding changes in neutral wind components, (2) temperature and number densities of the neutral atmosphere, and (3) an optical thickness of the atmosphere caused by the dependence of the solar zenith angle on the day of the year for the same solar local time. Seasonal variations of the production rate unexcited O+ ions due to chemical reactions involving electronically excited O+ ions contribute to the formation of the NmF2 semi-annual anomaly during the predominant part of the existence time of this anomalous phenomenon. However, these seasonal variations are not significant, and this mechanism should be considered only as an additional source of the NmF2 semi-annual anomaly during its time of existence. The reactions of unexcited O+ ions with vibrationally excited N2 and O2 cause only weak changes of NmF2 and these changes are close in magnitude at a given solar local time during the winter, spring, summer, and autumn daytime conditions under consideration. Ignoring these reactions cannot produce a significant impact on the formation of the NmF2 semi-annual anomaly.

Annual monsoon rains recorded by Jurassic dunes.

Science.gov (United States)

Loope, D B; Rowe, C M; Joeckel, R M

2001-07-05

Pangaea, the largest landmass in the Earth's history, was nearly bisected by the Equator during the late Palaeozoic and early Mesozoic eras. Modelling experiments and stratigraphic studies have suggested that the supercontinent generated a monsoonal atmospheric circulation that led to extreme seasonality, but direct evidence for annual rainfall periodicity has been lacking. In the Mesozoic era, about 190 million years ago, thick deposits of wind-blown sand accumulated in dunes of a vast, low-latitude desert at Pangaea's western margin. These deposits are now situated in the southwestern USA. Here we analyse slump masses in the annual depositional cycles within these deposits, which have been described for some outcrops of the Navajo Sandstone. Twenty-four slumps, which were generated by heavy rainfall, appear within one interval representing 36 years of dune migration. We interpret the positions of 20 of these masses to indicate slumping during summer monsoon rains, with the other four having been the result of winter storms. The slumped lee faces of these Jurassic dunes therefore represent a prehistoric record of yearly rain events.

Seasonal and inter-annual temperature variability in the bottom waters over the western Black Sea shelf

Directory of Open Access Journals (Sweden)

G. I. Shapiro

2011-09-01

Full Text Available Long-term changes in the state of the Bottom Shelf Water (BSW on the Western shelf of the Black Sea are assessed using analysis of intra-seasonal and inter-annual temperature variations. For the purpose of this study the BSW is defined as such shelf water mass between the seabed and the upper mixed layer (bounded by the σ_θ = 14.2 isopycnal which has limited ability to mix vertically with oxygen-rich surface waters during the warm season due to formation of a seasonal pycnocline. A long-term time series of temperature anomalies in the BSW is constructed from in-situ observations taken over the 2nd half of the 20th century. The BSW is shown to occupy nearly half of the shelf area during the summer stratification period (May–November.The results reveal a warm phase in the 1960s/70s, followed by a cold phase between 1985 and 1995 and a further warming after 1995. The transition between the warm and cold periods coincides with a regime shift in the Black Sea ecosystem. While it was confirmed that the memory of winter convection is well preserved over the following months in the deep sea, the signal of winter cooling in the BSW significantly reduces during the warm season. The potential of the BSW to ventilate horizontally during the warm season with the deep-sea waters is assessed using isopycnic analysis of temperature variations. It is shown that temperature in the BSW is stronger correlated with the temperature of Cold Intermediate Waters (CIW in the deep sea than with the severity of the previous winters, thus indicating that the isopycnal exchanges with the deep sea are more important for inter-annual/inter-decadal variability of the BSW on the western Black Sea shelf than effects of winter convection on the shelf itself.

Can GRACE detect winter snows in Japan?

Science.gov (United States)

Heki, Kosuke

2010-05-01

Current spatial resolution of the GRACE (Gravity Recovery and Climate Experiment) satellites is 300-400 km, and so its hydrological applications have been limited to continents and large islands. The Japanese Islands have width slightly smaller than this spatial resolution, but are known to show large amplitude seasonal changes in surface masses due mainly to winter snow. Such loads are responsible for seasonal crustal deformation observed with GEONET, a dense array of GPS (Global Positioning System) receivers in Japan (Heki, 2001). There is also a dense network of surface meteorological sensors for, e.g. snow depths, atmospheric pressures, etc. Heki (2004) showed that combined effects of surface loads, i.e. snow (predominant), atmosphere, soil moisture, dam impoundment, can explain seasonal crustal deformation observed by GPS to a large extent. The total weight of the winter snow in the Japanese Islands in its peak season may reach ~50 Gt. This is comparable to the annual loss of mountain glaciers in the Asian high mountains (Matsuo & Heki, 2010), and is above the detection level of GRACE. In this study, I use GRACE Level-2 Release-4 data from CSR, Univ. Texas, up to 2009 November, and evaluated seasonal changes in surface loads in and around the Japanese Islands. After applying a 350 km Gaussian filter and a de-striping filter, the peak-to-peak change of the water depth becomes ~4 cm in northern Japan. The maximum value is achieved in February-March. The region of large winter load spans from Hokkaido, Japan, to northeastern Honshu, which roughly coincides with the region of deep snow in Japan. Next I compiled snow depth data from surface meteorological observations, and converted them to loads using time-dependent snow density due to compaction. By applying the same spatial filter as the GRACE data, its spatial pattern becomes similar to the GRACE results. The present study suggests that GRACE is capable of detecting seasonal mass changes in an island arc not

Root development of fodder radish and winter wheat before winter in relation to uptake of nitrogen

DEFF Research Database (Denmark)

Wahlström, Ellen Margrethe; Hansen, Elly Møller; Mandel, A.

2015-01-01

occurred. Quantitative data is missing on N leaching of a catch crop compared to a winter cereal in a conventional cereal-based cropping system. The aim of the study was to investigate whether fodder radish (Raphanus sativus L.) (FR) would be more efficient than winter wheat (Triticum aestivum L.) (WW...

The meaning of nuclear winter

International Nuclear Information System (INIS)

Geiger, H.J.

1987-01-01

In this paper the author reviews the history and origins of the basic ideas underlying nuclear winter; and findings and predictions of several groups regarding this topic. The author reviews some of the further developments and scientific analyses regarding nuclear winter since the initial announcements of 1983, touching on some of the revisions and controversies and trying to indicate the current status of the field

Temporal modelling of ballast water discharge and ship-mediated invasion risk to Australia.

Science.gov (United States)

Cope, Robert C; Prowse, Thomas A A; Ross, Joshua V; Wittmann, Talia A; Cassey, Phillip

2015-04-01

Biological invasions have the potential to cause extensive ecological and economic damage. Maritime trade facilitates biological invasions by transferring species in ballast water, and on ships' hulls. With volumes of maritime trade increasing globally, efforts to prevent these biological invasions are of significant importance. Both the International Maritime Organization and the Australian government have developed policy seeking to reduce the risk of these invasions. In this study, we constructed models for the transfer of ballast water into Australian waters, based on historic ballast survey data. We used these models to hindcast ballast water discharge over all vessels that arrived in Australian waters between 1999 and 2012. We used models for propagule survival to compare the risk of ballast-mediated propagule transport between ecoregions. We found that total annual ballast discharge volume into Australia more than doubled over the study period, with the vast majority of ballast water discharge and propagule pressure associated with bulk carrier traffic. As such, the ecoregions suffering the greatest risk are those associated with the export of mining commodities. As global marine trade continues to increase, effective monitoring and biosecurity policy will remain necessary to combat the risk of future marine invasion events.

Clinical and epidemiological aspects of invasive Streptococcus pyogenes infections in Denmark during 2003 and 2004

DEFF Research Database (Denmark)

Luca-Harari, B.; Linden, M. van der; Staum-Kattoft, M.

2008-01-01

Active surveillance of invasive group A streptococcal (GAS) infections was conducted in Denmark during 2003 and 2004 as a part of the Strep-EURO initiative. The main objective was to improve understanding of the epidemiology of invasive GAS disease in Denmark. During the 2 years, 278 cases were...... reported, corresponding to a mean annual incidence of 2.6 cases per 100,000 inhabitants. The vast majority of isolates, 253 (91%), were from blood, with the remaining 25 (9%) being from cerebrospinal fluid, joints, or other normally sterile sites. The mean case fatality rate (CFR) was 20%, with the rate...... countries, GAS invasive disease shows a sustained, high endemicity, with involvement of both established and emerging streptococcal emm and T types Udgivelsesdato: 2008/1...

Sage-grouse habitat selection during winter in Alberta

Science.gov (United States)

Carpenter, Jennifer L.; Aldridge, Cameron L.; Boyce, Mark S.

2010-01-01

Greater sage-grouse (Centrocercus urophasianus) are dependent on sagebrush (Artemisia spp.) for food and shelter during winter, yet few studies have assessed winter habitat selection, particularly at scales applicable to conservation planning. Small changes to availability of winter habitats have caused drastic reductions in some sage-grouse populations. We modeled winter habitat selection by sage-grouse in Alberta, Canada, by using a resource selection function. Our purpose was to 1) generate a robust winter habitat-selection model for Alberta sage-grouse; 2) spatially depict habitat suitability in a Geographic Information System to identify areas with a high probability of selection and thus, conservation importance; and 3) assess the relative influence of human development, including oil and gas wells, in landscape models of winter habitat selection. Terrain and vegetation characteristics, sagebrush cover, anthropogenic landscape features, and energy development were important in top Akaike's Information Criterionselected models. During winter, sage-grouse selected dense sagebrush cover and homogenous less rugged areas, and avoided energy development and 2-track truck trails. Sage-grouse avoidance of energy development highlights the need for comprehensive management strategies that maintain suitable habitats across all seasons. ?? 2010 The Wildlife Society.

The Unusual Southern Hemisphere Stratosphere Winter of 2002

Science.gov (United States)

Newman, Paul A.; Nash, Eric R.

2003-01-01

The southern hemisphere stratospheric winter of 2002 was the most unusual winter yet observed in the southern hemisphere climate record. Temperatures near the edge of the Antarctic polar vortex were considerably warmer than normal over the entire course of the winter. The polar night jet was considerably weaker than normal, and was displaced more poleward than has been observed in previous winters. These record high temperatures and weak jet resulted from a series of wave events that took place over the course of the winter. The first large event occurred on 15 May, and the final warming occurred on 25 October. The propagation of these wave events from the troposphere is diagnosed from time series of Eliassen-Palm flux vectors. The wave events tended to occur irregularly over the course of the winter, and pre-conditioned the polar night jet for the extremely large wave event of 22 September. This large wave event resulted in the first ever observed major stratospheric warming in the southern hemisphere. This wave event split the Antarctic ozone hole. The combined effect of the wave events of the 2002 winter resulted in the smallest ozone hole observed since 1988.

Grassland birds wintering at U.S. Navy facilities in southern Texas

Science.gov (United States)

Woodin, Marc C.; Skoruppa, Mary Kay; Bryan, Pearce D.; Ruddy, Amanda J.; Hickman, Graham C.

2010-01-01

Grassland birds have undergone widespread decline throughout North America during the past several decades. Causes of this decline include habitat loss and fragmentation because of conversion of grasslands to cropland, afforestation in the East, brush and shrub invasion in the Southwest and western United States, and planting of exotic grass species to enhance forage production. A large number of exotic plant species, including grasses, have been introduced in North America, but most research on the effects of these invasions on birds has been limited to breeding birds, primarily those in northern latitudes. Research on the effects of exotic grasses on birds in winter has been extremely limited.This is the first study in southern Texas to examine and compare winter bird responses to native and exotic grasslands. This study was conducted during a period of six years (2003–2009) on United States Navy facilities in southern Texas including Naval Air Station–Corpus Christi, Naval Air Station–Kingsville, Naval Auxiliary Landing Field Waldron, Naval Auxiliary Landing Field Orange Grove, and Escondido Ranch, all of which contained examples of native grasslands, exotic grasslands, or both. Data from native and exotic grasslands were collected and compared for bird abundance and diversity; ground cover, vegetation density, and floristic diversity; bird and vegetation relationships; diversity of insects and arachnids; and seed abundance and diversity. Effects of management treatments in exotic grasslands were evaluated by comparing numbers and diversity of birds and small mammals in mowed, burned, and control areas.To determine bird abundance and bird species richness, birds were surveyed monthly (December–February) during the winters of 2003–2008 in transects (100 meter × 20 meter) located in native and exotic grasslands distributed at all five U.S. Navy facilities. To compare vegetation in native and exotic grasslands, vegetation characteristics were measured

Deer Wintering Areas

Data.gov (United States)

Vermont Center for Geographic Information — Deer winter habitat is critical to the long term survival of white-tailed deer (Odocoileus virginianus) in Vermont. Being near the northern extreme of the...

Distinct summer and winter bacterial communities in the active layer of Svalbard permafrost revealed by DNA- and RNA-based analyses

DEFF Research Database (Denmark)

Schostag, Morten; Stibal, Marek; Jacobsen, Carsten S.

2015-01-01

organic matter on the bacterial communities. The copy number of 16S rRNA genes and transcripts revealed no distinct seasonal changes indicating potential bacterial activity during winter despite soil temperatures well below -10ºC. Multivariate statistical analysis of the bacterial diversity data (DNA......The active layer of soil overlaying permafrost in the Arctic is subjected to dramatic annual changes in temperature and soil chemistry, which likely affect bacterial activity and community structure. We studied seasonal variations in the bacterial community of active layer soil from Svalbard (78º......N) by co-extracting DNA and RNA from 12 soil cores collected monthly over a year. PCR amplicons of 16S rRNA genes (DNA) and reverse transcribed transcripts (cDNA) were quantified and sequenced to test for the effect of low winter temperature and seasonal variation in concentration of easily degradable...

The role of adaptive trans-generational plasticity in biological invasions of plants.

Science.gov (United States)

Dyer, Andrew R; Brown, Cynthia S; Espeland, Erin K; McKay, John K; Meimberg, Harald; Rice, Kevin J

2010-03-01

High-impact biological invasions often involve establishment and spread in disturbed, high-resource patches followed by establishment and spread in biotically or abiotically stressful areas. Evolutionary change may be required for the second phase of invasion (establishment and spread in stressful areas) to occur. When species have low genetic diversity and short selection history, within-generation phenotypic plasticity is often cited as the mechanism through which spread across multiple habitat types can occur. We show that trans-generational plasticity (TGP) can result in pre-adapted progeny that exhibit traits associated with increased fitness both in high-resource patches and in stressful conditions. In the invasive sedge, Cyperus esculentus, maternal plants growing in nutrient-poor patches can place disproportional number of propagules into nutrient-rich patches. Using the invasive annual grass, Aegilops triuncialis, we show that maternal response to soil conditions can confer greater stress tolerance in seedlings in the form of greater photosynthetic efficiency. We also show TGP for a phenological shift in a low resource environment that results in greater stress tolerance in progeny. These lines of evidence suggest that the maternal environment can have profound effects on offspring success and that TGP may play a significant role in some plant invasions.

First record of the invasive diatom Didymosphenia geminata (Lyngbye) Schmidt in a Patagonian Andean river of Argentina

OpenAIRE

Sastre, Alicia Viviana; Santinelli, Norma Herminia; Bauer, Gabriel A.; Ayesterán, M. Gabriel; Uyua, Noelia Mariel

2017-01-01

The Futaleufú River, Argentina, was monitored monthly from June 2010 to August 2011, in order to detect the invasive diatom Didymosphenia geminata, which was previously observed in Chile. Plankton and periphyton samples were taken from 10 sites. Didymosphenia geminata was not found until late winter. In August 2010, the species was first detected at isolated points of the river but in spring and summer the algal coverage extended along several kilometers. The coverage of blooms, spread to dee...

Self-reinforcing impacts of plant invasions change over time.

Science.gov (United States)

Yelenik, Stephanie G; D'Antonio, Carla M

2013-11-28

Returning native species to habitats degraded by biological invasions is a critical conservation goal. A leading hypothesis poses that exotic plant dominance is self-reinforced by impacts on ecosystem processes, leading to persistent stable states. Invaders have been documented to modify fire regimes, alter soil nutrients or shift microbial communities in ways that feed back to benefit themselves over competitors. However, few studies have followed invasions through time to ask whether ecosystem impacts and feedbacks persist. Here we return to woodland sites in Hawai'i Volcanoes National Park that were invaded by exotic C4 grasses in the 1960s, the ecosystem impacts of which were studied intensively in the 1990s. We show that positive feedbacks between exotic grasses and soil nitrogen cycling have broken down, but rather than facilitating native vegetation, the weakening feedbacks facilitate new exotic species. Data from the 1990s showed that exotic grasses increased nitrogen-mineralization rates by two- to fourfold, but were nitrogen-limited. Thus, the impacts of the invader created a positive feedback early in the invasion. We now show that annual net soil nitrogen mineralization has since dropped to pre-invasion levels. In addition, a seedling outplanting experiment that varied soil nitrogen and grass competition demonstrates that the changing impacts of grasses do not favour native species re-establishment. Instead, decreased nitrogen availability most benefits another aggressive invader, the nitrogen-fixing tree Morella faya. Long-term studies of invasions may reveal that ecosystem impacts and feedbacks shift over time, but that this may not benefit native species recovery.

Probabilistic evaluation of decadal prediction skill regarding Northern Hemisphere winter storms

Directory of Open Access Journals (Sweden)

Tim Kruschke

2016-12-01

Full Text Available Winter wind storms related to intense extra-tropical cyclones are meteorological extreme events, often with major impacts on economy and human life, especially for Europe and the mid-latitudes. Hence, skillful decadal predictions regarding the frequency of their occurrence would be of great socio-economic value. The present paper extends the study of Kruschke et al. (2014 in several aspects. First, this study is situated in a more impact oriented context by analyzing the frequency of potentially damaging wind storm events instead of targeting at cyclones as general meteorological features which was done by Kruschke et al. (2014. Second, this study incorporates more data sets by analyzing five decadal hindcast experiments – 41 annual (1961–2001 initializations integrated for ten years each – set up with different initialization strategies. However, all experiments are based on the Max-Planck-Institute Earth System Model in a low-resolution configuration (MPI-ESM-LR. Differing combinations of these five experiments allow for more robust estimates of predictive skill (due to considerably larger ensemble size and systematic comparisons of the underlying initialization strategies. Third, the hindcast experiments are corrected for model bias and potential drifts over lead time by means of a novel parametric approach, accounting for non-stationary model drifts. We analyze whether skillful probabilistic three-category forecasts (enhanced, normal or decreased can be provided regarding winter (ONDJFM wind storm frequencies over the Northern Hemisphere (NH. Skill is assessed by using climatological probabilities and uninitialized transient simulations as reference forecasts. It is shown that forecasts of average winter wind storm frequencies for winters 2–5 and winters 2–9 are skillful over large parts of the NH. However, most of this skill is associated with external forcing from transient greenhouse gas and aerosol concentrations

Chapter 7: Migration and winter ecology

Science.gov (United States)

Deborah M. Finch; Jeffrey F. Kelly; Jean-Luc E. Cartron

2000-01-01

The willow flycatcher (Empidonax traillii) is a Neotropical migrant that breeds in North America, but winters in Central and northern South America. Little specific information is known about migration and wintering ecology of the southwestern willow flycatcher (E. t. extimus) (Yong and Finch 1997). Our report applies principally...

Effects of combustion emissions from the Eurasian continent in winter on seasonal δ 13C of elemental carbon in aerosols in Japan

Science.gov (United States)

Kawashima, Hiroto; Haneishi, Yuya

2012-01-01

We investigated suspended particulate matter (SPM, particles with a 100% cut-off aerodynamic diameter of 10 μm) and PM2.5 (particles with a 50% cut-off aerodynamic diameter of 2.5 μm) concentrations in aerosols sampled in Akita Prefecture, Japan, from April 2008 to January 2010, and the carbon isotope ratios (δ 13C) of elemental carbon (EC) in both SPM and PM2.5 and in samples from possible sources. We also determined the ion contents of SPM and estimated the back trajectories of air masses arriving at Akita Prefecture during the study period. The SPM concentration was very low (annual average, 15.2 μg m -3), and it tended to be higher in spring and lower in winter. We attributed the higher SPM in spring to dust storms brought from the Asian continent. The average annual PM2.5 concentration was 8.6 μg m -3. δ 13C of source samples (gasoline and diesel vehicle exhaust, fireplace soot, open biomass burning emissions, street dust, soil, charcoal, and coal) ranged from -34.7‰ to -1.8‰. δ 13C values of soot from gasoline light-duty (-24.4 ± 0.7‰) and passenger vehicles (-24.1 ± 0.6‰) were very similar to that of soot from all diesel vehicles (-24.3 ± 0.3‰). δ 13C was enriched in SPM in winter compared with summer values, moreover, only a slight seasonal trend was detected in δ 13C in PM2.5. From these data and the source results, we hypothesized that the enrichment of δ 13C of SPM and PM2.5 in winter was a long-range effect of overseas combustion processes such as coal combustion. In addition, δ 13C of SPM was correlated with Cl - and Mg 2+ contents in SPM, suggesting the influence of sea salt. We verified this hypothesis by back trajectory analyses. The results indicated a continental influence effects on EC of SPM and PM2.5 in winter.

Autumn Weather and Winter Increase in Cerebrovascular Disease Mortality

LENUS (Irish Health Repository)

McDonagh, R

2016-11-01

Mortality from cerebrovascular disease increases in winter but the cause is unclear. Ireland’s oceanic climate means that it infrequently experiences extremes of weather. We examined how weather patterns relate to stroke mortality in Ireland. Seasonal data for Sunshine (% of average), Rainfall (% of average) and Temperature (degrees Celsius above average) were collected for autumn (September-November) and winter (December-February) using official Irish Meteorological Office data. National cerebrovascular mortality data was obtained from Quarterly Vital Statistics. Excess winter deaths were calculated by subtracting (nadir) 3rd quarter mortality data from subsequent 1st quarter data. Data for 12 years were analysed, 2002-2014. Mean winter mortality excess was 24.7%. Winter mortality correlated with temperature (r=.60, p=0.04). Rise in winter mortality correlated strongly with the weather in the preceding autumn (Rainfall: r=-0.19 p=0.53, Temperature: r=-0.60, p=0.03, Sunshine, r=0.58, p=0.04). Winter cerebrovascular disease mortality appears higher following cool, sunny autum

Perspectives on screening winter-flood-tolerant woody species in the riparian protection forests of the three gorges reservoir.

Science.gov (United States)

Yang, Fan; Wang, Yong; Chan, Zhulong

2014-01-01

The establishment of riparian protection forests in the Three Gorges Reservoir (TGR) is an ideal measure to cope with the eco-environmental problems of the water-level fluctuation zone (WLFZ). Thus, the information for screening winter-flood-tolerant woody plant species is useful for the recovery and re-establishment of the riparian protection forests in the TGR WLFZ. Therefore, we discussed the possibilities of constructing and popularizing riparian protection forests in the TGR WLFZ from several aspects, including the woody plant species distribution in the WLFZ, the survival rate analyses of suitable candidate woody species under controlled flooding conditions, the survival rate investigation of some woody plant species planted in the TGR WLFZ, and the physiological responses of some woody plant species during the recovery stage after winter floods. The results of woody species investigation showed that most woody plant species that existed as annual seedlings in the TGR WLFZ are not suitable candidates for the riparian protection forests. However, arbor species (e.g., Salix matsudana, Populus×canadensis, Morus alba, Pterocarya stenoptera, Taxodium ascendens, and Metasequoia glyptostroboides) and shrub species (e.g., Salix variegata, Distylium chinensis, Lycium chinense, Myricaria laxiflora, and Rosa multiflora) might be considered suitable candidates for the riparian protection forests in the TGR WLFZ by survival rate analyses under controlled winter flooding conditions, and survival rate investigations of woody plant species planted in the TGR WLFZ, respectively. Physiological analyses showed that P.×canadensis, M. alba, L. chinense, and S. variegata could develop specific self-repairing mechanisms to stimulate biomass accumulation and carbohydrate synthesis via the increases in chlorophyll pigments and photosynthesis during recovery after winter floods. Our results suggested these woody plant species could endure the winter flooding stress and recover well

Perspectives on screening winter-flood-tolerant woody species in the riparian protection forests of the three gorges reservoir.

Directory of Open Access Journals (Sweden)

Fan Yang

Full Text Available The establishment of riparian protection forests in the Three Gorges Reservoir (TGR is an ideal measure to cope with the eco-environmental problems of the water-level fluctuation zone (WLFZ. Thus, the information for screening winter-flood-tolerant woody plant species is useful for the recovery and re-establishment of the riparian protection forests in the TGR WLFZ. Therefore, we discussed the possibilities of constructing and popularizing riparian protection forests in the TGR WLFZ from several aspects, including the woody plant species distribution in the WLFZ, the survival rate analyses of suitable candidate woody species under controlled flooding conditions, the survival rate investigation of some woody plant species planted in the TGR WLFZ, and the physiological responses of some woody plant species during the recovery stage after winter floods. The results of woody species investigation showed that most woody plant species that existed as annual seedlings in the TGR WLFZ are not suitable candidates for the riparian protection forests. However, arbor species (e.g., Salix matsudana, Populus×canadensis, Morus alba, Pterocarya stenoptera, Taxodium ascendens, and Metasequoia glyptostroboides and shrub species (e.g., Salix variegata, Distylium chinensis, Lycium chinense, Myricaria laxiflora, and Rosa multiflora might be considered suitable candidates for the riparian protection forests in the TGR WLFZ by survival rate analyses under controlled winter flooding conditions, and survival rate investigations of woody plant species planted in the TGR WLFZ, respectively. Physiological analyses showed that P.×canadensis, M. alba, L. chinense, and S. variegata could develop specific self-repairing mechanisms to stimulate biomass accumulation and carbohydrate synthesis via the increases in chlorophyll pigments and photosynthesis during recovery after winter floods. Our results suggested these woody plant species could endure the winter flooding stress

Inter-annual and spatial variability in hillslope runoff and mercury flux during spring snowmelt.

Science.gov (United States)

Haynes, Kristine M; Mitchell, Carl P J

2012-08-01

Spring snowmelt is an important period of mercury (Hg) export from watersheds. Limited research has investigated the potential effects of climate variability on hydrologic and Hg fluxes during spring snowmelt. The purpose of this research was to assess the potential impacts of inter-annual climate variability on Hg mobility in forested uplands, as well as spatial variability in hillslope hydrology and Hg fluxes. We compared hydrological flows, Hg and solute mobility from three adjacent hillslopes in the S7 watershed of the Marcell Experimental Forest, Minnesota during two very different spring snowmelt periods: one following a winter (2009-2010) with severely diminished snow accumulation (snow water equivalent (SWE) = 48 mm) with an early melt, and a second (2010-2011) with significantly greater winter snow accumulation (SWE = 98 mm) with average to late melt timing. Observed inter-annual differences in total Hg (THg) and dissolved organic carbon (DOC) yields were predominantly flow-driven, as the proportion by which solute yields increased was the same as the increase in runoff. Accounting for inter-annual differences in flow, there was no significant difference in THg and DOC export between the two snowmelt periods. The spring 2010 snowmelt highlighted the important contribution of melting soil frost in the timing of a considerable portion of THg exported from the hillslope, accounting for nearly 30% of the THg mobilized. Differences in slope morphology and soil depths to the confining till layer were important in controlling the large observed spatial variability in hydrological flowpaths, transmissivity feedback responses, and Hg flux trends across the adjacent hillslopes.

Winter climate variability and classification in the Bulgarian Mountainous Regions

International Nuclear Information System (INIS)

Petkova, Nadezhda; Koleva, Ekaterina

2004-01-01

The problems of snowiness and thermal conditions of winters are of high interest of investigations because of the more frequent droughts, occurred in the region. In the present study an attempt to reveal tendencies existing during the last 70 years of 20 th century in the course winter precipitation and,temperature as well as in some of the snow cover parameters. On the base of mean winter air temperature winters in the Bulgarian mountains were analyzed and classified. The main results of the study show that winter precipitation has decrease tendencies more significant in the highest parts of the mountains. On the other hand winter air temperature increases. It shows a relatively well-established maximum at the end of the studied period. In the Bulgarian mountains normal winters are about 35-40% of all winters. (Author)

Interim Report 'Winter smog and traffic'.

NARCIS (Netherlands)

Bloemen, H.; Blom, T.; Bogaard, van den C.; Boluyt, N.; Bree, van L.; Brunekreef, B.; Hoek, G.; Zee, van der S.

1994-01-01

This report presents a halfway score of the research project "Winter smog and Traffic", one of the themes of the research programme "Air Pollution and Health". A state of the art is presented of the health effects associated with exposure to winter smog and of the toxicological effects caused by the

Home advantage in the Winter Paralympic Games 1976-2014.

Science.gov (United States)

Wilson, Darryl; Ramchandani, Girish

2017-01-01

There is a limited amount of home advantage research concerned with winter sports. There is also a distinct lack of studies that investigate home advantage in the context of para sport events. This paper addresses this gap in the knowledge by examining home advantage in the Winter Paralympic Games. Using a standardised measure of success, we compared the performances of host nations at home with their own performances away from home between 1976 and 2014. Both country level and individual sport level analysis is conducted for this time period. Comparisons are also drawn with the Winter Olympic Games since 1992, the point from which both the Winter Olympic Games and the Winter Paralympic Games have been hosted by the same nations and in the same years. Clear evidence of a home advantage effect in the Winter Paralympic Games was found at country level. When examining individual sports, only alpine skiing and cross country skiing returned a significant home advantage effect. When comparing home advantage in the Winter Paralympic Games with the Winter Olympic Games for the last seven host nations (1992-2014), we found that home advantage was generally more pronounced (although not a statistically significant difference) in the case of the former. The causes of home advantage in the Winter Paralympic Games are unclear and should be investigated further.

Real-time weed detection, decision making and patch spraying in maize, sugarbeet, winter wheat and winter barley

DEFF Research Database (Denmark)

Gerhards, R; Christensen, Svend

2003-01-01

with weed infestation levels higher than the economic weed threshold; a review of such work is provided. This paper presents a system for site-specific weed control in sugarbeet (Beta vulgaris L.), maize (Zea mays L.), winter wheat (Triticum aestivum L.) and winter barley (Hordeum vulgare L.), including...

Prospective Surveillance of Invasive Group A Streptococcal Disease, Fiji, 2005–2007

Science.gov (United States)

Jenney, Adam; Kado, Joseph; Good, Michael F.; Batzloff, Michael; Waqatakirewa, Lepani; Mullholland, E. Kim; Carapetis, Jonathan R.

2009-01-01

We undertook a prospective active surveillance study of invasive group A streptococcal (GAS) disease in Fiji over a 23-month period, 2005–2007. We identified 64 cases of invasive GAS disease, which represents an average annualized all-ages incidence of 9.9 cases/100,000 population per year (95% confidence interval [CI] 7.6–12.6). Rates were highest in those >65 years of age and in those <5 years, particularly in infants, for whom the incidence was 44.9/100,000 (95% CI 18.1–92.5). The case-fatality rate was 32% and was associated with increasing age and underlying coexisting disease, including diabetes and renal disease. Fifty-five of the GAS isolates underwent emm sequence typing; the types were highly diverse, with 38 different emm subtypes and no particular dominant type. Our data support the view that invasive GAS disease is common in developing countries and deserves increased public health attention. PMID:19193265

Warmed Winter Water Temperatures Alter Reproduction in Two Fish Species

Science.gov (United States)

Firkus, Tyler; Rahel, Frank J.; Bergman, Harold L.; Cherrington, Brian D.

2018-02-01

We examined the spawning success of Fathead Minnows ( Pimephales promelas) and Johnny Darters ( Etheostoma nigrum) exposed to elevated winter water temperatures typical of streams characterized by anthropogenic thermal inputs. When Fathead Minnows were exposed to temperature treatments of 12, 16, or 20 °C during the winter, spawning occurred at 16 and 20 °C but not 12 °C. Eggs were deposited over 9 weeks before winter spawning ceased. Fathead Minnows from the three winter temperature treatments were then exposed to a simulated spring transition. Spawning occurred at all three temperature treatments during the spring, but fish from the 16° and 20 °C treatment had delayed egg production indicating a latent effect of warm winter temperatures on spring spawning. mRNA analysis of the egg yolk protein vitellogenin showed elevated expression in female Fathead Minnows at 16 and 20 °C during winter spawning that decreased after winter spawning ceased, whereas Fathead Minnows at 12 °C maintained comparatively low expression during winter. Johnny Darters were exposed to 4 °C to represent winter temperatures in the absence of thermal inputs, and 12, 16, and 20 °C to represent varying degrees of winter thermal pollution. Johnny Darters spawned during winter at 12, 16, and 20 °C but not at 4 °C. Johnny Darters at 4 °C subsequently spawned following a simulated spring period while those at 12, 16, and 20 °C did not. Our results indicate elevated winter water temperatures common in effluent-dominated streams can promote out-of-season spawning and that vitellogenin expression is a useful indicator of spawning readiness for fish exposed to elevated winter temperatures.

Winter barley mutants created in the Ukraine

International Nuclear Information System (INIS)

Zayats, O.M.

2001-01-01

Full text: Increasing fodder and protein production is one of the objectives of the development of agriculture in Ukraine. Higher productivity of fodder crops, due to new highly productive varieties, is the means to meet this aim. Winter barley is an important crop for fodder purposes. The climate of the Ukraine is favourable for growing this crop. The areas used for the growth of winter barley are however, small (500,000-550,000 ha) and there is a shortage of good quality varieties. The main aim of the work was therefore to create new varieties of highly productive winter barley, of good quality. The new varieties and mutation lines of winter barley were created under the influence of water solutions of N-nitroso-N-methylurea (NMH - 0,012, 0,005%), N-nitroso-N-ethylurea (NEH - 0,05; 0.025; 0,012%) ethyleneimine (EI - 0,02; 0,01; 0,005%) on winter barley seeds of the varieties of local and foreign selections. On the basis of many years of investigations (1984-94) the following mutations were described: hard-grained, winter-hardiness, earliness, middle-maturity, late-maturity, wide and large leaves, narrow leaves, multinodal, great number of leaves, great number of flowers, strong stem (lodging resistant), tallness, semi-dwarfness, dwarfness, and high productivity. Particularly valuable are mutants with high productivity of green bulk. Their potential yield is 70 t/ha. As a result of the work two varieties of winter barley 'Shyrokolysty' and 'Kormovy' were released into the State register of plant varieties of the Ukraine. The other valuable mutant genotypes are used in cross breeding programmes. (author)

Transmission of influenza reflects seasonality of wild birds across the annual cycle

Science.gov (United States)

Hill, Nichola J.; Ma, Eric J.; Meixell, Brandt W.; Lindberg, Mark S.; Boyce, Walter M.; Runstadler, Jonathan A.

2016-01-01

Influenza A Viruses (IAV) in nature must overcome shifting transmission barriers caused by the mobility of their primary host, migratory wild birds, that change throughout the annual cycle. Using a phylogenetic network of viral sequences from North American wild birds (2008–2011) we demonstrate a shift from intraspecific to interspecific transmission that along with reassortment, allows IAV to achieve viral flow across successive seasons from summer to winter. Our study supports amplification of IAV during summer breeding seeded by overwintering virus persisting locally and virus introduced from a wide range of latitudes. As birds migrate from breeding sites to lower latitudes, they become involved in transmission networks with greater connectivity to other bird species, with interspecies transmission of reassortant viruses peaking during the winter. We propose that switching transmission dynamics may be a critical strategy for pathogens that infect mobile hosts inhabiting regions with strong seasonality.

Impacts of winter NPO on subsequent winter ENSO: sensitivity to the definition of NPO index

Science.gov (United States)

Chen, Shangfeng; Wu, Renguang

2018-01-01

This study investigates the linkage between boreal winter North Pacific Oscillation (NPO) and subsequent winter El Niño-Southern Oscillation (ENSO) based on seven different NPO indices. Results show that the influence of winter NPO on the subsequent winter El Niño is sensitive to how the NPO is defined. A significant NPO-El Niño connection is obtained when the NPO-related anomalous cyclone over the subtropical North Pacific extends to near-equatorial regions. The anomalous cyclone induces warm sea surface temperature (SST) anomalies through modulating surface heat fluxes. These warm SST anomalies are able to maintain into the following spring and summer through an air-sea coupled process and in turn induce significant westerly wind anomalies over the tropical western Pacific. In contrast, the NPO-El Niño relationship is unclear when the NPO-related anomalous cyclone over the subtropical North Pacific is confined to off-equatorial regions and cannot induce significant warm SST anomalies over the subtropical North Pacific. The present study suggests that definitions of NPO should be taken into account when using NPO to predict ENSO. In particular, we recommend defining the NPO index based on the empirical orthogonal function technique over appropriate region that does not extend too far north.

Invasive Australian Acacia seed banks: Size and relationship with stem diameter in the presence of gall-forming biological control agents.

Directory of Open Access Journals (Sweden)

Matthys Strydom

Full Text Available Australian Acacia are invasive in many parts of the world. Despite significant mechanical and biological efforts to control their invasion and spread, soil-stored seed banks prevent their effective and sustained removal. In response South Africa has had a strong focus on employing seed reducing biological control agents to deal with Australian Acacia invasion, a programme that is considered as being successful. To provide a predictive understanding for their management, seed banks of four invasive Australian acacia species (Acacia longifolia, A. mearnsii, A. pycnantha and A. saligna were studied in the Western Cape of South Africa. Across six to seven sites for each species, seed bank sizes were estimated from dense, monospecific stands by collecting 30 litter and soil samples. Average estimated seed bank size was large (1017 to 17261 seed m-2 as was annual input into the seed bank, suggesting that these seed banks are not residual but are replenished in size annually. A clear relationship between seed bank size and stem diameter was established indicating that mechanical clearing should be conducted shortly after fire-stimulated recruitment events or within old populations when seed banks are small. In dense, monospecific stands seed-feeding biological control agents are not effective in reducing seed bank size.

Excess mortality in winter in Finnish intensive care.

Science.gov (United States)

Reinikainen, M; Uusaro, A; Ruokonen, E; Niskanen, M

2006-07-01

In the general population, mortality from acute myocardial infarctions, strokes and respiratory causes is increased in winter. The winter climate in Finland is harsh. The aim of this study was to find out whether there are seasonal variations in mortality rates in Finnish intensive care units (ICUs). We analysed data on 31,040 patients treated in 18 Finnish ICUs. We measured severity of illness with acute physiology and chronic health evaluation II (APACHE II) scores and intensity of care with therapeutic intervention scoring system (TISS) scores. We assessed mortality rates in different months and seasons and used logistic regression analysis to test the independent effect of various seasons on hospital mortality. We defined 'winter' as the period from December to February, inclusive. The crude hospital mortality rate was 17.9% in winter and 16.4% in non-winter, P = 0.003. Even after adjustment for case mix, winter season was an independent risk factor for increased hospital mortality (adjusted odds ratio 1.13, 95% confidence interval 1.04-1.22, P = 0.005). In particular, the risk of respiratory failure was increased in winter. Crude hospital mortality was increased during the main holiday season in July. However, the severity of illness-adjusted risk of death was not higher in July than in other months. An increase in the mean daily TISS score was an independent predictor of increased hospital mortality. Severity of illness-adjusted hospital mortality for Finnish ICU patients is higher in winter than in other seasons.

Field Evaluation of Highly Insulating Windows in the Lab Homes: Winter Experiment

Energy Technology Data Exchange (ETDEWEB)

Parker, Graham B.; Widder, Sarah H.; Bauman, Nathan N.

2012-06-01

This field evaluation of highly insulating windows was undertaken in a matched pair of 'Lab Homes' located on the Pacific Northwest National Laboratory (PNNL) campus during the 2012 winter heating season. Improving the insulation and solar heat gain characteristics of a home's windows has the potential to significantly improve the home's building envelope and overall thermal performance by reducing heat loss (in the winter), and cooling loss and solar heat gain (in the summer) through the windows. A high quality installation and/or window retrofit will also minimize or reduce air leakage through the window cavity and thus also contribute to reduced heat loss in the winter and cooling loss in the summer. These improvements all contribute to decreasing overall annual home energy use. Occupant comfort (non-quantifiable) can also be increased by minimizing or eliminating the cold 'draft' (temperature) many residents experience at or near window surfaces that are at a noticeably lower temperature than the room air temperature. Lastly, although not measured in this experiment, highly insulating windows (triple-pane in this experiment) also have the potential to significantly reduce the noise transmittance through windows compared to standard double-pane windows. The metered data taken in the Lab Homes and data analysis presented here represent 70 days of data taken during the 2012 heating season. As such, the savings from highly insulating windows in the experimental home (Lab Home B) compared to the standard double-pane clear glass windows in the baseline home (Lab Home A) are only a portion of the energy savings expected from a year-long experiment that would include a cooling season. The cooling season experiment will take place in the homes in the summer of 2012, and results of that experiment will be reported in a subsequent report available to all stakeholders.

Essential Outdoor Sun Safety Tips for Winter

Science.gov (United States)

... Weekend Warriors expand/collapse Vitamin D Essential Outdoor Sun Safety Tips for Winter Winter sports enthusiasts are ... skiing! Be Mindful of Time Spent in the Sun, Regardless of the Season If possible, ski early ...

Effects of winter temperature and summer drought on net ecosystem exchange of CO2 in a temperate peatland

Science.gov (United States)

Helfter, Carole; Campbell, Claire; Dinsmore, Kerry; Drewer, Julia; Coyle, Mhairi; Anderson, Margaret; Skiba, Ute; Nemitz, Eiko; Billett, Michael; Sutton, Mark

2014-05-01

Northern peatlands are one of the most important global sinks of atmospheric carbon dioxide (CO2); their ability to sequester C is a natural feedback mechanism controlled by climatic variables such as precipitation, temperature, length of growing season and period of snow cover. In the UK it has been predicted that peatlands could become a net source of carbon in response to climate change with climate models predicting a rise in global temperature of ca. 3oC between 1961-1990 and 2100. Land-atmosphere exchange of CO2in peatlands exhibits marked seasonal and inter-annual variations, which have significant short- and long-term effects on carbon sink strength. Net ecosystem exchange (NEE) of CO2 has been measured continuously by eddy-covariance (EC) at Auchencorth Moss (55° 47'32 N, 3° 14'35 W, 267 m a.s.l.), a temperate peatland in central Scotland, since 2002. Auchencorth Moss is a low-lying, ombrotrophic peatland situated ca. 20 km south-west of Edinburgh. Peat depth ranges from 5 m and the site has a mean annual precipitation of 1155 mm. The vegetation present within the flux measurement footprint comprises mixed grass species, heather and substantial areas of moss species (Sphagnum spp. and Polytrichum spp.). The EC system consists of a LiCOR 7000 closed-path infrared gas analyser for the simultaneous measurement of CO2 and water vapour and of a Gill Windmaster Pro ultrasonic anemometer. Over the 10 year period, the site was a consistent yet variable sink of CO2 ranging from -34.1 to -135.9 g CO2-C m-2 yr-1 (mean of -69.1 ± 33.6 g CO2-C m-2 yr-1). Inter-annual variability in NEE was positively correlated to the length of the growing seasons and mean winter air temperature explained 93% of the variability in summertime sink strength, indicating a phenological memory-effect. Plant development and productivity were stunted by colder winters causing a net reduction in the annual carbon sink strength of this peatland where autotrophic processes are thought to be

Land uses, fire, and invasion: Exotic annual Bromus and human dimensions

Science.gov (United States)

Pyke, David A.; Chambers, Jeanne C.; Beck, Jeffrey L.; Brooks, Matthew L.; Mealor, Brian A.

2016-01-01

Human land uses are the primary cause of the introduction and spread of exotic annual Bromusspecies. Initial introductions were likely linked to contaminated seeds used by homesteading farmers in the late 1880s and early 1900s. Transportation routes aided their spread. Unrestricted livestock grazing from the 1800s through the mid-1900s reduced native plant competitors leaving large areas vulnerable to Bromus dominance. Ecosystems with cooler and moister soils tend to have greater potential to recover from disturbances (resilience) and to be more resistant to Bromusinvasion and dominance. Warmer and drier ecosystems are less resistant to Bromus and are threatened by altered fire regimes which can lead to Bromus dominance, impacts to wildlife, and alternative stable states. Native Americans used fire for manipulating plant communities and may have contributed to the early dominance of Bromus in portions of California. Fire as a tool is now limited to site preparation for revegetation in most ecosystems where Bromus is a significant problem. Once Bromus dominates, breaking annual grass/fire cycles requires restoring fire-tolerant perennial grasses and forbs, which can compete with Bromus and resist its dominance. Current weed management policies often lack regulations to prevent further expansion of Bromus. Research is needed on how and where livestock grazing might help increase perennial grass and forb cover and density to create ecosystems that are more resistant to Bromus. Also, studies are needed to ascertain the role, if any, of oil and gas development in contributing to the spread of Bromus.

Invasive plants found in east Texas forests, 2009 forest inventory and analysis factsheet

Science.gov (United States)

Sonja N. Oswalt; Christopher M. Oswalt

2011-01-01

This science update provides information on the presence and cover of nonnative invasive plants found in forests of the eastern region of the State of Texas based on an annual inventory conducted by the Forest Inventory and Analysis (FIA) Program at the Southern Research Station of the U.S. Department of Agriculture Forest Service in cooperation with the Texas Forest...

Winter Season Mortality: Will Climate Warming Bring Benefits?

Science.gov (United States)

Kinney, Patrick L; Schwartz, Joel; Pascal, Mathilde; Petkova, Elisaveta; Tertre, Alain Le; Medina, Sylvia; Vautard, Robert

2015-06-01

Extreme heat events are associated with spikes in mortality, yet death rates are on average highest during the coldest months of the year. Under the assumption that most winter excess mortality is due to cold temperature, many previous studies have concluded that winter mortality will substantially decline in a warming climate. We analyzed whether and to what extent cold temperatures are associated with excess winter mortality across multiple cities and over multiple years within individual cities, using daily temperature and mortality data from 36 US cities (1985-2006) and 3 French cities (1971-2007). Comparing across cities, we found that excess winter mortality did not depend on seasonal temperature range, and was no lower in warmer vs. colder cities, suggesting that temperature is not a key driver of winter excess mortality. Using regression models within monthly strata, we found that variability in daily mortality within cities was not strongly influenced by winter temperature. Finally we found that inadequate control for seasonality in analyses of the effects of cold temperatures led to spuriously large assumed cold effects, and erroneous attribution of winter mortality to cold temperatures. Our findings suggest that reductions in cold-related mortality under warming climate may be much smaller than some have assumed. This should be of interest to researchers and policy makers concerned with projecting future health effects of climate change and developing relevant adaptation strategies.

Operational forecasting of daily temperatures in the Valencia Region. Part II: minimum temperatures in winter.

Science.gov (United States)

Gómez, I.; Estrela, M.

2009-09-01

Extreme temperature events have a great impact on human society. Knowledge of minimum temperatures during winter is very useful for both the general public and organisations whose workers have to operate in the open, e.g. railways, roadways, tourism, etc. Moreover, winter minimum temperatures are considered a parameter of interest and concern since persistent cold-waves can affect areas as diverse as public health, energy consumption, etc. Thus, an accurate forecasting of these temperatures could help to predict cold-wave conditions and permit the implementation of strategies aimed at minimizing the negative effects that low temperatures have on human health. The aim of this work is to evaluate the skill of the RAMS model in determining daily minimum temperatures during winter over the Valencia Region. For this, we have used the real-time configuration of this model currently running at the CEAM Foundation. To carry out the model verification process, we have analysed not only the global behaviour of the model for the whole Valencia Region, but also its behaviour for the individual stations distributed within this area. The study has been performed for the winter forecast period from 1 December 2007 - 31 March 2008. The results obtained are encouraging and indicate a good agreement between the observed and simulated minimum temperatures. Moreover, the model captures quite well the temperatures in the extreme cold episodes. Acknowledgement. This work was supported by "GRACCIE" (CSD2007-00067, Programa Consolider-Ingenio 2010), by the Spanish Ministerio de Educación y Ciencia, contract number CGL2005-03386/CLI, and by the Regional Government of Valencia Conselleria de Sanitat, contract "Simulación de las olas de calor e invasiones de frío y su regionalización en la Comunidad Valenciana" ("Heat wave and cold invasion simulation and their regionalization at Valencia Region"). The CEAM Foundation is supported by the Generalitat Valenciana and BANCAIXA (Valencia

Warmed Winter Water Temperatures Alter Reproduction in Two Fish Species.

Science.gov (United States)

Firkus, Tyler; Rahel, Frank J; Bergman, Harold L; Cherrington, Brian D

2018-02-01

We examined the spawning success of Fathead Minnows (Pimephales promelas) and Johnny Darters (Etheostoma nigrum) exposed to elevated winter water temperatures typical of streams characterized by anthropogenic thermal inputs. When Fathead Minnows were exposed to temperature treatments of 12, 16, or 20 °C during the winter, spawning occurred at 16 and 20 °C but not 12 °C. Eggs were deposited over 9 weeks before winter spawning ceased. Fathead Minnows from the three winter temperature treatments were then exposed to a simulated spring transition. Spawning occurred at all three temperature treatments during the spring, but fish from the 16° and 20 °C treatment had delayed egg production indicating a latent effect of warm winter temperatures on spring spawning. mRNA analysis of the egg yolk protein vitellogenin showed elevated expression in female Fathead Minnows at 16 and 20 °C during winter spawning that decreased after winter spawning ceased, whereas Fathead Minnows at 12 °C maintained comparatively low expression during winter. Johnny Darters were exposed to 4 °C to represent winter temperatures in the absence of thermal inputs, and 12, 16, and 20 °C to represent varying degrees of winter thermal pollution. Johnny Darters spawned during winter at 12, 16, and 20 °C but not at 4 °C. Johnny Darters at 4 °C subsequently spawned following a simulated spring period while those at 12, 16, and 20 °C did not. Our results indicate elevated winter water temperatures common in effluent-dominated streams can promote out-of-season spawning and that vitellogenin expression is a useful indicator of spawning readiness for fish exposed to elevated winter temperatures.

Winter Wonderlands

Science.gov (United States)

Coy, Mary

2011-01-01

Listening to people complain about the hardships of winter and the dreariness of the nearly constant gray sky prompted the author to help her sixth graders recognize and appreciate the beauty that surrounds them for nearly five months of the year in western New York. The author opines that if students could see things more artistically, the winter…

Increasing species richness of the macrozoobenthic fauna on tidal flats of the Wadden Sea by local range expansion and invasion of exotic species

NARCIS (Netherlands)

Beukema, J.; Dekker, R.

2011-01-01

A 40-y series of consistently collected samples (15 fixed sampling sites, constant sampled area of 15 × 0.95 m2, annual sampling only in late-winter/early-spring seasons, and consistent sieving and sorting procedures; restriction to 50 easily recognizable species) of macrozoobenthos on Balgzand, a

Evaluating the potential efficacy of invasive lionfish (Pterois volitans) removals.

Science.gov (United States)

Barbour, Andrew B; Allen, Micheal S; Allen, Michael S; Frazer, Thomas K; Sherman, Krista D

2011-05-10

The lionfish, Pterois volitans (Linnaeus) and Pterois miles (Bennett), invasion of the Western Atlantic Ocean, Caribbean Sea and Gulf of Mexico has the potential to alter aquatic communities and represents a legitimate ecological concern. Several local removal programs have been initiated to control this invasion, but it is not known whether removal efforts can substantially reduce lionfish numbers to ameliorate these concerns. We used an age-structured population model to evaluate the potential efficacy of lionfish removal programs and identified critical data gaps for future studies. We used high and low estimates for uncertain parameters including: length at 50% vulnerability to harvest (L(vul)), instantaneous natural mortality (M), and the Goodyear compensation ratio (CR). The model predicted an annual exploitation rate between 35 and 65% would be required to cause recruitment overfishing on lionfish populations for our baseline parameter estimates for M and CR (0.5 and 15). Lionfish quickly recovered from high removal rates, reaching 90% of unfished biomass six years after a 50-year simulated removal program. Quantifying lionfish natural mortality and the size-selective vulnerability to harvest are the most important knowledge gaps for future research. We suggest complete eradication of lionfish through fishing is unlikely, and substantial reduction of adult abundance will require a long-term commitment and may be feasible only in small, localized areas where annual exploitation can be intense over multiple consecutive years.

Modeling invasive alien plant species in river systems: Interaction with native ecosystem engineers and effects on hydro-morphodynamic processes

Science.gov (United States)

van Oorschot, M.; Kleinhans, M. G.; Geerling, G. W.; Egger, G.; Leuven, R. S. E. W.; Middelkoop, H.

2017-08-01

Invasive alien plant species negatively impact native plant communities by out-competing species or changing abiotic and biotic conditions in their introduced range. River systems are especially vulnerable to biological invasions, because waterways can function as invasion corridors. Understanding interactions of invasive and native species and their combined effects on river dynamics is essential for developing cost-effective management strategies. However, numerical models for simulating long-term effects of these processes are lacking. This paper investigates how an invasive alien plant species affects native riparian vegetation and hydro-morphodynamics. A morphodynamic model has been coupled to a dynamic vegetation model that predicts establishment, growth and mortality of riparian trees. We introduced an invasive alien species with life-history traits based on Japanese Knotweed (Fallopia japonica), and investigated effects of low- and high propagule pressure on invasion speed, native vegetation and hydro-morphodynamic processes. Results show that high propagule pressure leads to a decline in native species cover due to competition and the creation of unfavorable native colonization sites. With low propagule pressure the invader facilitates native seedling survival by creating favorable hydro-morphodynamic conditions at colonization sites. With high invader abundance, water levels are raised and sediment transport is reduced during the growing season. In winter, when the above-ground invader biomass is gone, results are reversed and the floodplain is more prone to erosion. Invasion effects thus depend on seasonal above- and below ground dynamic vegetation properties and persistence of the invader, on the characteristics of native species it replaces, and the combined interactions with hydro-morphodynamics.

The influence of the annual invasive plant, Impatiens glandulifera, on the sediment dynamics of inland watercourses in temperate regions

Science.gov (United States)

Dalvi, Shrutika; Greenwood, Philip

2016-04-01

Impatiens glandulifera (Common English Name - Himalayan Balsam) is a non native annual and highly invasive plant that was introduced into parts of Europe from the Himalaya during the nineteenth century as a colourful adornment to parks and gardens. This Plant colonises areas along the river banks, preferably wet, depositional sites, and displaces natural vegetation. The plant is killed by cold weather. The leaves area of riverbank previously occupied by the plant extremely vulnerable to soil erosion until new plant germinates in the following spring. Research work undertaken in the northwest Switzerland and the soutwestern United Kingdom established s link between accelerated soil erosion caused by Impatiens glandulifera and its detrimental impact on native biodiversity of riparian zone of river catchment area. This study focueses on the potential impact of such erosion on sediment quality. A priory reasoning suggests that the preference of Impatiens glandulifera on young depsotional sites near watercourses affects sediment quality. In this study, the results of a soil quality analysis along Impatiens glandulifera-contaminated river banks is presented. Soil physical and chemical properties are compared to non-affected sites to assess the potential impact of preferential erosion on water quality. In addtiion, soil surface profile (SSP) measuring based on by erosion pins, a micro profile bridge and a digital calliper at different selected locations along the riparian zone of river catchment area is used to determine erosion rates and determine sediment transfer from the riparian zone into the rivers.

Classification guide: Sochi 2014 Paralympic Winter Games

OpenAIRE

2014-01-01

The Sochi 2014 Paralympic Winter Games classification guide is designed to provide National Paralympic Committees (NPCs) and International Federations (IFs) with information about the classification policies and procedures that will apply to the Sochi 2014 Paralympic Winter Games.

Centralised electricity production from winter cereals biomass grown under central-northern Spain conditions: Global warming and energy yield assessments

International Nuclear Information System (INIS)

Sastre, C.M.; Maletta, E.; González-Arechavala, Y.; Ciria, P.; Santos, A.M.; Val, A. del; Pérez, P.; Carrasco, J.

2014-01-01

Highlights: • We assess the sustainability of electricity production from winter cereals biomass. • Productivity ranks are generated from different genotypes cultivated in real farms. • GHG and energy balances show better performance compared to natural gas electricity. • Cereals yields below 8 odt/ha do not accomplish objective 60% of GHG savings. • Marginal yields and sustainability criteria are discussed suggesting optimization. - Abstract: The goal of this paper is to assess the sustainability of electricity production from winter cereals grown in one of the most important Spanish agricultural areas, Castilla y León Region, situated in central-northern Spain. This study analyses greenhouse gases (GHG) emissions and energy balances of electricity production in a 25 MWe power plant that was powered using straw biomass from three annual winter cereals (rye, triticale and oat) grown as dedicated energy crops. The results of these analyses were compared with those of electricity produced from natural gas in Spanish power plants. Assessments were performed using a wide range of scenarios, mainly based on the biomass yield variability obtained in demonstration plots of twelve different winter cereal genotypes. Demonstration plots were established in two different locations (provinces of Soria and León) of the Castilla y León Region during two crop seasons (2009/2010 and 2010/2011) using common management practices and input rates for rain-fed agriculture in these regions. Our results suggest that production of electricity from winter cereals biomass combustion yielded considerable reductions in terms of GHG emissions when compared to electricity from natural gas. Nevertheless, the results show that low biomass yields that are relatively frequent for Spanish farmers on low productivity lands may produce no significant reductions in GHG in comparison with electricity from natural gas. Consequently, the agronomic management of winter cereals should be re

Winter chilling speeds spring development of temperate butterflies.

Science.gov (United States)

Stålhandske, Sandra; Gotthard, Karl; Leimar, Olof

2017-07-01

Understanding and predicting phenology has become more important with ongoing climate change and has brought about great research efforts in the recent decades. The majority of studies examining spring phenology of insects have focussed on the effects of spring temperatures alone. Here we use citizen-collected observation data to show that winter cold duration, in addition to spring temperature, can affect the spring emergence of butterflies. Using spatial mixed models, we disentangle the effects of climate variables and reveal impacts of both spring and winter conditions for five butterfly species that overwinter as pupae across the UK, with data from 1976 to 2013 and one butterfly species in Sweden, with data from 2001 to 2013. Warmer springs lead to earlier emergence in all species and milder winters lead to statistically significant delays in three of the five investigated species. We also find that the delaying effect of winter warmth has become more pronounced in the last decade, during which time winter durations have become shorter. For one of the studied species, Anthocharis cardamines (orange tip butterfly), we also make use of parameters determined from previous experiments on pupal development to model the spring phenology. Using daily temperatures in the UK and Sweden, we show that recent variation in spring temperature corresponds to 10-15 day changes in emergence time over UK and Sweden, whereas variation in winter duration corresponds to 20 days variation in the south of the UK versus only 3 days in the south of Sweden. In summary, we show that short winters delay phenology. The effect is most prominent in areas with particularly mild winters, emphasising the importance of winter for the response of ectothermic animals to climate change. With climate change, these effects may become even stronger and apply also at higher latitudes. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

Plant community resistance to invasion by Bromus species – the roles of community attributes, Bromus Interactions with plant communities, and Bromus traits

Science.gov (United States)

Chambers, Jeanne; Germino, Matthew; Belnap, Jayne; Brown, Cynthia; Schupp, Eugene W.; St. Clair, Samuel B

2016-01-01

The factors that determine plant community resistance to exotic annual Bromus species (Bromushereafter) are diverse and context specific. They are influenced by the environmental characteristics and attributes of the community, the traits of Bromus species, and the direct and indirect interactions of Bromus with the plant community. Environmental factors, in particular ambient and soil temperatures, have significant effects on the ability of Bromus to establish and spread. Seasonality of precipitation relative to temperature influences plant community resistance toBromus through effects on soil water storage, timing of water and nutrient availability, and dominant plant life forms. Differences among plant communities in how well soil resource use by the plant community matches resource supply rates can influence the magnitude of resource fluctuations due to either climate or disturbance and thus the opportunities for invasion. The spatial and temporal patterns of resource availability and acquisition of growth resources by Bromus versus native species strongly influence resistance to invasion. Traits of Bromus that confer a “priority advantage” for resource use in many communities include early-season germination and high growth and reproductive rates. Resistance to Bromus can be overwhelmed by high propagule supply, low innate seed dormancy, and large, if short-lived, seed banks. Biological crusts can inhibit germination and establishment of invasive annual plants, including several annual Bromus species, but are effective only in the absence of disturbance. Herbivores can have negative direct effects on Bromus, but positive indirect effects through decreases in competitors. Management strategies can be improved through increased understanding of community resistance to exotic annual Bromus species.

Proceedings of the 2001 Canadian society of petroleum geologists annual convention

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

Founded in 1927 as the Alberta Society of Petroleum Geologists, the Canadian Society of Petroleum Geologists is dedicated to promote and further the study of petroleum and natural gas geology and all the study fields related to it. Its 3300 members represent Canada and 30 other countries. The annual convention is held to provide a forum for the exchange of information on topics related to petroleum geology and to foster the spirit of scientific research with the members. Another objective of the Society and annual convention is to make the general public aware of the need for professional and well-trained scientists. In excess of 100 presentations were made at the 2001 annual convention on topics that included petroleum potential in Somalia, seismic imaging, faulting and fault seal, multi-scale reservoir compartmentalization, non-invasive geochemical and remote sensing methods, and much more. refs., tabs., figs.

Annual and interannual variations in global 6.5DWs from 20 to 110 km during 2002-2016 observed by TIMED/SABER

Science.gov (United States)

Huang, Y. Y.; Zhang, S. D.; Li, C. Y.; Li, H. J.; Huang, K. M.; Huang, C. M.

2017-08-01

Using version 2.0 of the TIMED/SABER kinetic temperature data, we have conducted a study on the annual and interannual variations of 6.5DWs at 20-110 km, from 52°S to 52°N for 2002-2016. First, we obtained global annual variations in the spectral power and amplitudes of 6.5DWs. We found that strong wave amplitudes emerged from 25°S/N to 52°S/N and peaked in the altitudes of the stratosphere, mesosphere, and the lower thermosphere. The annual variations in the 6.5DWs are similar in both hemispheres but different at various altitudes. At 40-50 km, the annual maxima emerge mostly in winters. In the MLT, annual peaks occurred twice every half year. At 80-90 km, 6.5DWs appeared mainly in equinoctial seasons and winters. At 100-110 km, 6.5DWs emerged mainly in equinoctial seasons. Second, we continued the study of the interannual variations in 6.5DW amplitudes from 2002 to 2016. Frequency spectra of the monthly mean amplitudes showed that main dynamics in the long-term variations of 6.5DWs were AO and SAO in both hemispheres. In addition, 4 month period signals were noticed in the MLT of the NH. The amplitudes of SAO and AO were obtained using a band-pass filter and were found to increase with altitude, as do the 6.5DW amplitudes. In both hemispheres, the relative importance of SAO and AO changes with altitude. At 40-50 and 100-110 km, AO play a dominant role, while at 80-90 km, they are weaker than SAO. Our results show that both the annual and interannual variations in 6.5DWs are mainly caused by the combined action of SAO and AO.

Hood River and Pelton Ladder monitoring and evaluation project and Hood River fish habitat project : annual progress report 1999-2000.; ANNUAL

International Nuclear Information System (INIS)

Lambert, Michael B.; McCanna, Joseph P.; Jennings, Mick

2001-01-01

The Hood River subbasin is home to four species of anadromous salmonids: chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), steelhead (Oncorhynchus mykiss), and sea run cutthroat trout (Salmo clarki). Indigenous spring chinook salmon were extirpated during the late 1960's. The naturally spawning spring chinook salmon currently present in the subbasin are progeny of Deschutes stock. Historically, the Hood River subbasin hatchery steelhead program utilized out-of-basin stocks for many years. Indigenous stocks of summer and winter steelhead were listed in March 1998 by National Marine Fisheries Service (NMFS) under the Endangered Species Act (ESA) as a ''Threatened'' Species along with similar genetically similar steelhead in the Lower Columbia Basin. This annual report summarizes work for two consecutive contract periods: the fiscal year (FY) 1999 contract period was 1 October, 1998 through 30 September, 1999 and 1 October, 1999 through 30 September, 2000 for FY 2000. Work implemented during FY 1999 and FY 2000 included (1) acclimation of hatchery spring chinook salmon and hatchery summer and winter steelhead smolts, (2) spring chinook salmon spawning ground surveys on the West Fork Hood River (3) genetic analysis of steelhead and cutthroat[contractual service with the ODFW], (4) Hood River water temperature studies, (5) Oak Springs Hatchery (OSH) and Round Butte Hatchery (RBH) coded-wire tagging and clipping evaluation, (6) preparation of the Hood River Watershed Assessment (Coccoli et al., December 1999) and the Fish Habitat Protection, Restoration, and Monitoring Plan (Coccoli et al., February 2000), (7) project implementation of early action habitat protection and restoration projects, (8) Pelton Ladder evaluation studies, (9) management oversight and guidance to BPA and ODFW engineering on HRPP facilities, and (10) preparation of an annual report summarizing project objectives for FY 1999 and FY 2000

Why is Taeniatherum caput-medusae (medusahead) Invasive in North America and not in its Native Eurasia?

Science.gov (United States)

Taeniatherum caput-medusae (medusahead) is an exotic annual grass introduced to North America in 1887 that has since invaded an estimated four million ha of rangelands. Contrary, in its native ranges of Eurasia, T. caput-medusae is not considered to be invasive. Why is it that T. caput-medusae expre...

Land uses, fire, and invasion: Exotic annual Bromus and human dimensions [Chapter 11

Science.gov (United States)

David A. Pyke; Jeanne C. Chambers; Jeffrey L. Beck; Matthew L. Brooks; Brian A. Mealor

2016-01-01

Human land uses are the primary cause of the introduction and spread of exotic annual Bromus species. Initial introductions were likely linked to contaminated seeds used by homesteading farmers in the late 1880s and early 1900s. Transportation routes aided their spread. Unrestricted livestock grazing from the 1800s through the mid-1900s reduced native plant competitors...

Invasive meningococcal disease epidemiology and control measures: a framework for evaluation

Directory of Open Access Journals (Sweden)

Coudeville L

2007-06-01

Full Text Available Abstract Background Meningococcal disease can have devastating consequences. As new vaccines emerge, it is necessary to assess their impact on public health. In the absence of long-term real world data, modeling the effects of different vaccination strategies is required. Discrete event simulation provides a flexible platform with which to conduct such evaluations. Methods A discrete event simulation of the epidemiology of invasive meningococcal disease was developed to quantify the potential impact of implementing routine vaccination of adolescents in the United States with a quadrivalent conjugate vaccine protecting against serogroups A, C, Y, and W-135. The impact of vaccination is assessed including both the direct effects on individuals vaccinated and the indirect effects resulting from herd immunity. The simulation integrates a variety of epidemiologic and demographic data, with core information on the incidence of invasive meningococcal disease and outbreak frequency derived from data available through the Centers for Disease Control and Prevention. Simulation of the potential indirect benefits of vaccination resulting from herd immunity draw on data from the United Kingdom, where routine vaccination with a conjugate vaccine has been in place for a number of years. Cases of disease are modeled along with their health consequences, as are the occurrence of disease outbreaks. Results When run without a strategy of routine immunization, the simulation accurately predicts the age-specific incidence of invasive meningococcal disease and the site-specific frequency of outbreaks in the Unite States. 2,807 cases are predicted annually, resulting in over 14,000 potential life years lost due to invasive disease. In base case analyses of routine vaccination, life years lost due to infection are reduced by over 45% (to 7,600 when routinely vaccinating adolescents 12 years of age at 70% coverage. Sensitivity analyses indicate that herd immunity plays

Hyperspectral Time Series Analysis of Native and Invasive Species in Hawaiian Rainforests

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Gregory P. Asner

2012-08-01

Full Text Available The unique ecosystems of the Hawaiian Islands are progressively being threatened following the introduction of exotic species. Operational implementation of remote sensing for the detection, mapping and monitoring of these biological invasions is currently hampered by a lack of knowledge on the spectral separability between native and invasive species. We used spaceborne imaging spectroscopy to analyze the seasonal dynamics of the canopy hyperspectral reflectance properties of four tree species: (i Metrosideros polymorpha, a keystone native Hawaiian species; (ii Acacia koa, a native Hawaiian nitrogen fixer; (iii the highly invasive Psidium cattleianum; and (iv Morella faya, a highly invasive nitrogen fixer. The species specific separability of the reflectance and derivative-reflectance signatures extracted from an Earth Observing-1 Hyperion time series, composed of 22 cloud-free images spanning a period of four years and was quantitatively evaluated using the Separability Index (SI. The analysis revealed that the Hawaiian native trees were universally unique from the invasive trees in their near-infrared-1 (700–1,250 nm reflectance (0.4 > SI > 1.4. Due to its higher leaf area index, invasive trees generally had a higher near-infrared reflectance. To a lesser extent, it could also be demonstrated that nitrogen-fixing trees were spectrally unique from non-fixing trees. The higher leaf nitrogen content of nitrogen-fixing trees was expressed through slightly increased separabilities in visible and shortwave-infrared reflectance wavebands (SI = 0.4. We also found phenology to be key to spectral separability analysis. As such, it was shown that the spectral separability in the near-infrared-1 reflectance between the native and invasive species groups was more expressed in summer (SI > 0.7 than in winter (SI < 0.7. The lowest separability was observed for March-July (SI < 0.3. This could be explained by the

AUTOMATIC CONTROL SYSTEM OF WINTER AUTOMOBILE-ROAD MAINTENANCE

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I. I. Leonovich

2008-01-01

Full Text Available In order to ensure a rational usage of financial and material resources directed on winter automobile-road maintenance in theRepublicofBelarusan automatic control system of winter maintenance is under its development and introduction.  The main purpose of the system is to obtain and use meteorological information on the state of a road network that allows to take necessary organizational and technological solutions ensuring safety and continuity of traffic during winter. This system also presupposes to ensure constant control over the state of roadway covering, expenditure of anti-glazed frost materials at all levels of management.The paper considers main aspects pertaining to introduction of the automatic control system of winter maintenance

Migratory timing, rate, routes and wintering areas of White-crested Elaenia (Elaenia albiceps chilensis, a key seed disperser for Patagonian forest regeneration.

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Susana Patricia Bravo

Full Text Available Migratory animals often play key ecological roles within the communities they visit throughout their annual journeys. As a consequence of the links between biomes mediated by migrants, changes in one biome could affect remote areas in unpredictable ways. Migratory routes and timing of most Neotropical austral migrants, which breed at south temperate latitudes of South America and overwinter closer to or within tropical latitudes of South America, have yet to be described in detail. As a result, our understanding about how these birds provide links between South American biomes is almost non-existent. White-crested Elaenia (Elaenia albiceps chilensis is a long-distance austral migrant that breeds in the Patagonian Forest biome and overwinters in tropical South America. Because this small flycatcher plays a key role in the regeneration of this ecosystem, our objective was to describe the annual cycle of White-crested elaenias to evaluate the degree of migratory connectivity between breeding and wintering areas and therefore to determine if there are specific biomes of northern South America linked by elaenias to Patagonian forests. Fifteen individuals were successfully tracked throughout a complete migration cycle using miniature light-level geolocators. All individuals resided and moved through the same general regions. During fall (March-April-May, elaenias were located in the Caatinga and the Atlantic Forest biomes, from Rio de Janeiro to the region near Salvador da Bahia, Brazil. During winter (June-July-Aug., birds were located further inland, within the Cerrado biome. Birds used three different routes during fall migration. Our results indicate that some individuals use a direct route, flying between 500-600 km/day, crossing desert and grasslands, while others took a detour, flying 100-200 km/day through forested areas with refueling opportunities. All birds used the Yunga forest during spring migration, with ten out of 15 individuals

Postharvest tillage reduces Downy Brome infestations in winter wheat

Science.gov (United States)

In the Pacific Northwest, downy brome continues to infest winter wheat producing regions especially in low-rainfall areas where the winter wheat-summer fallow rotation is the dominate production system. In Washington, a study was conducted for 2 years at each of two locations in the winter wheat -su...

How to Have a Healthy Winter | Poster

Science.gov (United States)

Without a doubt, winter is here. Between the icy weather and the recent hustle and bustle of the holidays, everyone is at an increased risk of getting sick. With that in mind, Occupational Health Services has a few simple tips for staying healthy this winter.

Risk management model of winter navigation operations

International Nuclear Information System (INIS)

Valdez Banda, Osiris A.; Goerlandt, Floris; Kuzmin, Vladimir; Kujala, Pentti; Montewka, Jakub

2016-01-01

The wintertime maritime traffic operations in the Gulf of Finland are managed through the Finnish–Swedish Winter Navigation System. This establishes the requirements and limitations for the vessels navigating when ice covers this area. During winter navigation in the Gulf of Finland, the largest risk stems from accidental ship collisions which may also trigger oil spills. In this article, a model for managing the risk of winter navigation operations is presented. The model analyses the probability of oil spills derived from collisions involving oil tanker vessels and other vessel types. The model structure is based on the steps provided in the Formal Safety Assessment (FSA) by the International Maritime Organization (IMO) and adapted into a Bayesian Network model. The results indicate that ship independent navigation and convoys are the operations with higher probability of oil spills. Minor spills are most probable, while major oil spills found very unlikely but possible. - Highlights: •A model to assess and manage the risk of winter navigation operations is proposed. •The risks of oil spills in winter navigation in the Gulf of Finland are analysed. •The model assesses and prioritizes actions to control the risk of the operations. •The model suggests navigational training as the most efficient risk control option.

Drought and Winter Drying (Pest Alert)

Science.gov (United States)

USDA Forest Service

Drought and winter drying have periodically caused major damage to trees. Drought reduces the amount of water available in the soil. In the case of winter drying, the water may be in the soil, but freezing of the soil makes the water unavailable to the tree. In both cases, more water is lost through transpiration than is available to the plant. Symptoms of drought and...

Relative importance of phosphorus, invasive mussels and climate for patterns in chlorophyll a and primary production in Lakes Michigan and Huron

Science.gov (United States)

Warner, David M.; Lesht, Barry M.

2015-01-01

1. Lakes Michigan and Huron, which are undergoing oligotrophication after reduction of phosphorus loading, invasion by dreissenid mussels and variation in climate, provide an opportunity to conduct large-scale evaluation of the relative importance of these changes for lake productivity. We used remote sensing, field data and an information-theoretic approach to identify factors that showed statistical relationships with observed changes in chlorophyll a (chla) and primary production (PP). 2. Spring phosphorus (TP), annual mean chla and PP have all declined significantly in both lakes since the late 1990s. Additionally, monthly mean values of chla have decreased in many but not all months, indicating altered seasonal patterns. The most striking change has been the decrease in chla concentration during the spring bloom. 3. Mean chlorophyll a concentration was 17% higher in Lake Michigan than in Lake Huron, and total production for 2008 in Lake Michigan (9.5 tg year 1 ) was 10% greater than in Lake Huron (7.8 tg year 1 ), even though Lake Michigan is slightly smaller (by 3%) than Lake Huron. Differences between the lakes in the early 1970s evidently persisted to 2008. 4. Invasive mussels influenced temporal trends in spring chla and annual primary production. However, TP had a greater effect on chla and primary production than did the mussels, and TP varied independently from them. Two climatic variables (precipitation and air temperature in the basins) influenced annual chla and annual PP, while the extent of ice cover influenced TP but not chla or primary production. Our results demonstrate that observed temporal patterns in chla and PP are the result of complex interactions of P, climate and invasive mussels.

Chemical ozone losses in Arctic and Antarctic polar winter/spring season derived from SCIAMACHY limb measurements 2002–2009

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T. Sonkaew

2013-02-01

Full Text Available Stratospheric ozone profiles are retrieved for the period 2002–2009 from SCIAMACHY measurements of limb-scattered solar radiation in the Hartley and Chappuis absorption bands of ozone. This data set is used to determine the chemical ozone losses in both the Arctic and Antarctic polar vortices by averaging the ozone in the vortex at a given potential temperature. The chemical ozone losses at isentropic levels between 450 K and 600 K are derived from the difference between observed ozone abundances and the ozone modelled taking diabatic cooling into account, but no chemical ozone loss. Chemical ozone losses of up to 30–40% between mid-January and the end of March inside the Arctic polar vortex are reported. Strong inter-annual variability of the Arctic ozone loss is observed, with the cold winters 2004/2005 and 2006/2007 showing chemical ozone losses inside the polar vortex at 475 K, where 1.7 ppmv and 1.4 ppmv of ozone were removed, respectively, over the period from 22 January to beginning of April and 0.9 ppmv and 1.2 ppmv, respectively, during February. For the winters of 2007/2008 and 2002/2003, ozone losses of about 0.8 ppmv and 0.4 ppmv, respectively are estimated at the 475 K isentropic level for the period from 22 January to beginning of April. Essentially no ozone losses were diagnosed for the relatively warm winters of 2003/2004 and 2005/2006. The maximum ozone loss in the SCIAMACHY data set was found in 2007 at the 600 K level and amounted to about 2.1 ppmv for the period between 22 January and the end of April. Enhanced losses close to this altitude were found in all investigated Arctic springs, in contrast to Antarctic spring. The inter-annual variability of ozone losses and PSC occurrence rates observed during Arctic spring is consistent with the known QBO effects on the Arctic polar vortex, with exception of the unusual Arctic winter 2008/2009.

The maximum total ozone mass loss of about 25 million tons was found in the

Intraspecific Autochthonous and Allochthonous Resource Use by Zooplankton in a Humic Lake during the Transitions between Winter, Summer and Fall.

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Martin Berggren

Full Text Available Seasonal patterns in assimilation of externally produced, allochthonous, organic matter into aquatic food webs are poorly understood, especially in brown-water lakes. We studied the allochthony (share biomass of terrestrial origin in cladoceran, calanoid and cyclopoid micro-crustacean zooplankton from late winter to fall during two years in a small humic lake (Sweden. The use of allochthonous resources was important for sustaining a small population of calanoids in the water column during late winter. However, in summer the calanoids shifted to 100% herbivory, increasing their biomass several-fold by making efficient use of the pelagic primary production. In contrast, the cyclopoids and cladocerans remained at high levels of allochthony throughout the seasons, both groups showing the mean allochthony of 0.56 (range in mean 0.17-0.79 and 0.34-0.75, for the respective group, depending on model parameters. Our study shows that terrestrial organic matter can be an important resource for cyclopoids and cladocerans on an annual basis, forming a significant link between terrestrial organic matter and the higher trophic levels of the food web, but it can also be important for sustaining otherwise herbivorous calanoids during periods of low primary production in late winter.

Global characteristics of extreme winters from a multi-millennial simulation

Energy Technology Data Exchange (ETDEWEB)

Hunt, B.G. [CSIRO Marine and Atmospheric Research, PO Box 1, Aspendale (Australia)

2011-10-15

Output from a multi-millennial simulation with the CSIRO Mark 2 coupled global climatic model has been analysed to determine the principal characteristics of extreme winters over the globe for ''present conditions''. Thus, this study is not concerned with possible changes in winter conditions associated with anthropogenically induced climatic change. Defining an extreme winter as having a surface temperature anomaly of below -2 standard deviations (sd) revealed a general occurrence rate over the globe of between 100 and 200 over a 6,000-year period of the simulation, with somewhat higher values over northwest North America. For temperature anomalies below -3 sd the corresponding occurrence rate drops to about 10. Spatial correlation studies revealed that extreme winters over regions in Europe, North America or Asia were very limited geographically, with time series of the surface temperature anomalies for these regions having mutual correlation coefficients of about 0.2. The temporal occurrence rates of winters (summers) having sd below -3 (above +3) were very asymmetric and sporadic, suggesting that such events arise from stochastic influences. Multi-year sequences of extreme winters were comparatively rare events. Detailed analysis revealed that the temporal and spatial evolution of the monthly surface temperature anomalies associated with an individual extreme winter were well replicated in the simulation, as were daily time series of such anomalies. Apart from an influence of the North Atlantic Oscillation on extreme winters in Europe, other prominent climatic oscillations were very poorly correlated with such winters. Rather modest winter temperature anomalies were found in the southern hemisphere. (orig.)

On the relation between ionospheric winter anomalies and solar wind

International Nuclear Information System (INIS)

Rumi, G.C.

2001-01-01

There are two different winter anomalies. A small one that appears in connection with ionization at relatively low latitudes in the bottom of the D-region of the ionosphere. There, the electron densities in the winter happen to be less than should be expected. On the other hand, the classic winter anomaly is present when in the winter the upper D-region, again at relatively low latitudes, has more ionization than should be expected. Both these effects are due to the slant compression of the geomagnetic field produced by the solar wind in the wind in the winter season (which is, of course, the summer season when reference is made to events in the other hemisphere). It is shown that the small winter anomaly is a consequence of a hemispheric imbalance in the flux of galactic cosmic rays determined by the obliquely distorted geomagnetic field. It is shown that the standard winter anomaly can be ascribed to the influx of a super solar wind, which penetrates into the Earth's polar atmosphere down to E-region, heights and, duly concentrated through a funneling action at the winter pole of the distorted geomagnetic field, slows down the winter polar vortex. An equatorward motion of the polar air with its content of nitric oxide brings about the excess of ionization in the upper D-region at lower latitudes. The experimentally observed rhythmic recurrence of the upper winter anomaly is correlated to a possible rhythmic recurrence of the super solar wind. The actual detection of the upper winter anomaly could yield some information on the velocity of the basic solar wind. A by-product of the present analysis, the determination of Γ, the coefficient of collisional detachment of the electrons from the O 2 - ions, is presented in the Appendix

On the relation between ionospheric winter anomalies and solar wind

Energy Technology Data Exchange (ETDEWEB)

Rumi, G.C. [Lecco, (Italy)

2001-06-01

There are two different winter anomalies. A small one that appears in connection with ionization at relatively low latitudes in the bottom of the D-region of the ionosphere. There, the electron densities in the winter happen to be less than should be expected. On the other hand, the classic winter anomaly is present when in the winter the upper D-region, again at relatively low latitudes, has more ionization than should be expected. Both these effects are due to the slant compression of the geomagnetic field produced by the solar wind in the wind in the winter season (which is, of course, the summer season when reference is made to events in the other hemisphere). It is shown that the small winter anomaly is a consequence of a hemispheric imbalance in the flux of galactic cosmic rays determined by the obliquely distorted geomagnetic field. It is shown that the standard winter anomaly can be ascribed to the influx of a super solar wind, which penetrates into the Earth's polar atmosphere down to E-region, heights and, duly concentrated through a funneling action at the winter pole of the distorted geomagnetic field, slows down the winter polar vortex. An equatorward motion of the polar air with its content of nitric oxide brings about the excess of ionization in the upper D-region at lower latitudes. The experimentally observed rhythmic recurrence of the upper winter anomaly is correlated to a possible rhythmic recurrence of the super solar wind. The actual detection of the upper winter anomaly could yield some information on the velocity of the basic solar wind. A by-product of the present analysis, the determination of {gamma}, the coefficient of collisional detachment of the electrons from the O{sub 2} {sup -} ions, is presented in the Appendix.

An Observational Study of Honey Bee Colony Winter Losses and Their Association with Varroa destructor, Neonicotinoids and Other Risk Factors

Science.gov (United States)

van der Zee, Romée; Gray, Alison; Pisa, Lennard; de Rijk, Theo

2015-01-01

This article presents results of an analysis of honey bee losses over the winter of 2011-2012 in the Netherlands, from a sample of 86 colonies, located at 43 apiaries. The apiaries were selected using spatially stratified random sampling. Colony winter loss data were collected and related to various measures of colony strength recorded in summer, as well as data from laboratory analysis of sample material taken from two selected colonies in each of the 43 apiaries. The logistic regression model which best explained the risk of winter loss included, in order of statistical importance, the variables (1) Varroa destructor mite infestation rate in October 2011, (2) presence of the cyano-substituted neonicotinoids acetamiprid or thiacloprid in the first 2 weeks of August 2011 in at least one of the honey bee matrices honey, bees or bee bread (pollen), (3) presence of Brassica napus (oilseed rape) or Sinapis arvensis (wild mustard) pollen in bee bread in early August 2011, and (4) a measure of the unexplained winter losses for the postal code area where the colonies were located, obtained from a different dataset. We consider in the discussion that reduced opportunities for foraging in July and August because of bad weather may have added substantially to the adverse effects of acetamiprid and thiacloprid. A novel feature of this work is its use of postal code random effects from two other independent datasets collected in the annual national monitoring by questionnaires of winter losses of honey bees in the Netherlands. These were used to plan the sample selection and also in the model fitting of the data in this study. It should however be noted that the results of the present pilot study are based on limited data, which may consequently reveal strong factors but fail to demonstrate possible interaction effects. PMID:26154346

An Observational Study of Honey Bee Colony Winter Losses and Their Association with Varroa destructor, Neonicotinoids and Other Risk Factors.

Directory of Open Access Journals (Sweden)

Romée van der Zee

Full Text Available This article presents results of an analysis of honey bee losses over the winter of 2011-2012 in the Netherlands, from a sample of 86 colonies, located at 43 apiaries. The apiaries were selected using spatially stratified random sampling. Colony winter loss data were collected and related to various measures of colony strength recorded in summer, as well as data from laboratory analysis of sample material taken from two selected colonies in each of the 43 apiaries. The logistic regression model which best explained the risk of winter loss included, in order of statistical importance, the variables (1 Varroa destructor mite infestation rate in October 2011, (2 presence of the cyano-substituted neonicotinoids acetamiprid or thiacloprid in the first 2 weeks of August 2011 in at least one of the honey bee matrices honey, bees or bee bread (pollen, (3 presence of Brassica napus (oilseed rape or Sinapis arvensis (wild mustard pollen in bee bread in early August 2011, and (4 a measure of the unexplained winter losses for the postal code area where the colonies were located, obtained from a different dataset. We consider in the discussion that reduced opportunities for foraging in July and August because of bad weather may have added substantially to the adverse effects of acetamiprid and thiacloprid. A novel feature of this work is its use of postal code random effects from two other independent datasets collected in the annual national monitoring by questionnaires of winter losses of honey bees in the Netherlands. These were used to plan the sample selection and also in the model fitting of the data in this study. It should however be noted that the results of the present pilot study are based on limited data, which may consequently reveal strong factors but fail to demonstrate possible interaction effects.

An Observational Study of Honey Bee Colony Winter Losses and Their Association with Varroa destructor, Neonicotinoids and Other Risk Factors.

Science.gov (United States)

van der Zee, Romée; Gray, Alison; Pisa, Lennard; de Rijk, Theo

2015-01-01

This article presents results of an analysis of honey bee losses over the winter of 2011-2012 in the Netherlands, from a sample of 86 colonies, located at 43 apiaries. The apiaries were selected using spatially stratified random sampling. Colony winter loss data were collected and related to various measures of colony strength recorded in summer, as well as data from laboratory analysis of sample material taken from two selected colonies in each of the 43 apiaries. The logistic regression model which best explained the risk of winter loss included, in order of statistical importance, the variables (1) Varroa destructor mite infestation rate in October 2011, (2) presence of the cyano-substituted neonicotinoids acetamiprid or thiacloprid in the first 2 weeks of August 2011 in at least one of the honey bee matrices honey, bees or bee bread (pollen), (3) presence of Brassica napus (oilseed rape) or Sinapis arvensis (wild mustard) pollen in bee bread in early August 2011, and (4) a measure of the unexplained winter losses for the postal code area where the colonies were located, obtained from a different dataset. We consider in the discussion that reduced opportunities for foraging in July and August because of bad weather may have added substantially to the adverse effects of acetamiprid and thiacloprid. A novel feature of this work is its use of postal code random effects from two other independent datasets collected in the annual national monitoring by questionnaires of winter losses of honey bees in the Netherlands. These were used to plan the sample selection and also in the model fitting of the data in this study. It should however be noted that the results of the present pilot study are based on limited data, which may consequently reveal strong factors but fail to demonstrate possible interaction effects.

Coming to grips with nuclear winter

International Nuclear Information System (INIS)

Scherr, S.J.

1985-01-01

This editorial examines the politics related to the concept of nuclear winter which is a term used to describe temperature changes brought on by the injection of smoke into the atmosphere by the massive fires set off by nuclear explosions. The climate change alone could cause crop failures and lead to massive starvation. The author suggests that the prospect of a nuclear winter should be a deterrent to any nuclear exchange

Quantification of seasonal to annual mass balances from glacier surface albedo derived from optical satellite images, application on 30 glaciers in the French Alps for the period 2000-2015.

Science.gov (United States)

Davaze, Lucas; Rabatel, Antoine; Arnaud, Yves; Sirguey, Pascal; Six, Delphine; Letreguilly, Anne; Dumont, Marie

2017-04-01

Increasing the number of glaciers monitored for surface mass balance is very challenging, especially using laborious methods based on in situ data. Complementary methods are therefore required to quantify the surface mass balance of unmonitored glaciers. The current study relies on the so-called albedo method, based on the analysis of albedo maps retrieved from optical satellite imagery acquired since 2000 by the MODIS sensor, onboard of TERRA satellite. Recent studies performed on single glaciers in the French Alps, the Himalayas or the Southern Alps of New Zealand revealed substantial relationships between summer minimum glacier-wide surface albedo and annual mass balance, because this minimum surface albedo is directly related to accumulation-area ratio and the equilibrium-line altitude. On the basis of 30 glaciers located in the French Alps where annual surface mass balance are available, our study conducted on the period 2000-2015 confirms the robustness and reliability of the relationship between the summer minimum surface albedo and the annual surface mass balance. At the seasonal scale, the integrated summer surface albedo is significantly correlated with the summer mass balance of the six glaciers seasonally surveyed. For the winter season, four of the six glaciers showed a significant correlation when linking the winter surface mass balance and the integrated winter surface albedo, using glacier-dependent thresholds to filter the albedo signal. Sensitivity study on the computed cloud detection algorithm revealed high confidence in retrieved albedo maps. These results are promising to monitor both annual and seasonal glacier-wide surface mass balances of individual glaciers at a regional scale using optical satellite images.

Winter/Summer Monsoon Experiment

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Winter/Summer Monsoon Experiment (MONEX) was conducted during the First Global GARP (Global Atmospheric Research Program) Experiment (FGGE). An international...

我的寒假%My Winter Holidays

Institute of Scientific and Technical Information of China (English)

无

2008-01-01

@@ Winter holidays have about twenty days.During winter holidays, I do all kinds of interesting thing.I like climbing the hill,because it can make me heMthy.I like fishing,it can give me a lot of fun.I like visiting some places of interest, it can enlarge my knowledge.

Response of soft winter wheat (Triticum aestivum L. to longtime enforced dormancy and time of spring vegetation recommencing

Directory of Open Access Journals (Sweden)

В. С. Хахула

2013-05-01

Full Text Available The article highlights the results of studying the soft winter wheat response to the duration of enforced winter dormancy and the time of vegetation recommencing, their impact on growth, development and the survival of the crops. It is found that the impact of those factors in the conditions of central Forest-Steppe of Ukraine is essential, which is to be taken into consideration when scheduling the measures of spring and summer care over the cultivated crops, in particular, where the spring extra nutrition takes place, pesticides and growth regulators are applied, the spaced planting resowing or partial resowing issues are to be settled down. The ecological effect of spring vegetation recommencing dates does not expose annually, therefore it is not always possible to predict the plant development type, but it is possible, nevertheless, to influence the processes of growth, development and survival of plants throughout spring-summer period and the development of their production capacity by means of introducing the intense technologies, optimization of mineral nutrition and the use of plant growth regulators, protection from rogues, diseases, pests.

Combined Use of Landsat-8 and Sentinel-2A Images for Winter Crop Mapping and Winter Wheat Yield Assessment at Regional Scale

Science.gov (United States)

Skakun, Sergii; Vermote, Eric; Roger, Jean-Claude; Franch, Belen

2017-01-01

Timely and accurate information on crop yield and production is critical to many applications within agriculture monitoring. Thanks to its coverage and temporal resolution, coarse spatial resolution satellite imagery has always been a source of valuable information for yield forecasting and assessment at national and regional scales. With availability of free images acquired by Landsat-8 and Sentinel-2 remote sensing satellites, it becomes possible to provide temporal resolution of an image every 3-5 days, and therefore, to develop next generation agriculture products at higher spatial resolution (10-30 m). This paper explores the combined use of Landsat-8 and Sentinel-2A for winter crop mapping and winter wheat yield assessment at regional scale. For the former, we adapt a previously developed approach for the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument at 250 m resolution that allows automatic mapping of winter crops taking into account a priori knowledge on crop calendar. For the latter, we use a generalized winter wheat yield forecasting model that is based on estimation of the peak Normalized Difference Vegetation Index (NDVI) from MODIS image time-series, and further downscaled to be applicable at 30 m resolution. We show that integration of Landsat-8 and Sentinel-2A improves both winter crop mapping and winter wheat yield assessment. In particular, the error of winter wheat yield estimates can be reduced up to 1.8 times compared to using a single satellite.

Combined Use of Landsat-8 and Sentinel-2A Images for Winter Crop Mapping and Winter Wheat Yield Assessment at Regional Scale

Directory of Open Access Journals (Sweden)

Sergii Skakun

2017-05-01

Full Text Available Timely and accurate information on crop yield and production is critical to many applications within agriculture monitoring. Thanks to its coverage and temporal resolution, coarse spatial resolution satellite imagery has always been a source of valuable information for yield forecasting and assessment at national and regional scales. With availability of free images acquired by Landsat-8 and Sentinel-2 remote sensing satellites, it becomes possible to provide temporal resolution of 3–5 days, and therefore, to develop next generation agriculture products at higher spatial resolution (10–30 m. This paper explores the combined use of Landsat-8 and Sentinel-2A for winter crop mapping and winter wheat yield assessment at regional scale. For the former, we adapt a previously developed approach for the Moderate Resolution Imaging Spectroradiometer (MODIS instrument at 250 m resolution that allows automatic mapping of winter crops taking into account a priori knowledge on crop calendar. For the latter, we use a generalized winter wheat yield forecasting model that is based on estimation of the peak Normalized Difference Vegetation Index (NDVI from MODIS image time-series, and further downscaled to be applicable at 30 m resolution. We show that integration of Landsat-8 and Sentinel-2A improves both winter crop mapping and winter wheat yield assessment. In particular, the error of winter wheat yield estimates can be reduced up to 1.8 times compared to using a single satellite.

Evaluating the potential efficacy of invasive lionfish (Pterois volitans removals.

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Andrew B Barbour

Full Text Available The lionfish, Pterois volitans (Linnaeus and Pterois miles (Bennett, invasion of the Western Atlantic Ocean, Caribbean Sea and Gulf of Mexico has the potential to alter aquatic communities and represents a legitimate ecological concern. Several local removal programs have been initiated to control this invasion, but it is not known whether removal efforts can substantially reduce lionfish numbers to ameliorate these concerns. We used an age-structured population model to evaluate the potential efficacy of lionfish removal programs and identified critical data gaps for future studies. We used high and low estimates for uncertain parameters including: length at 50% vulnerability to harvest (L(vul, instantaneous natural mortality (M, and the Goodyear compensation ratio (CR. The model predicted an annual exploitation rate between 35 and 65% would be required to cause recruitment overfishing on lionfish populations for our baseline parameter estimates for M and CR (0.5 and 15. Lionfish quickly recovered from high removal rates, reaching 90% of unfished biomass six years after a 50-year simulated removal program. Quantifying lionfish natural mortality and the size-selective vulnerability to harvest are the most important knowledge gaps for future research. We suggest complete eradication of lionfish through fishing is unlikely, and substantial reduction of adult abundance will require a long-term commitment and may be feasible only in small, localized areas where annual exploitation can be intense over multiple consecutive years.

Do invasive quagga mussels alter CO2 dynamics in the Laurentian Great Lakes?

Science.gov (United States)

Lin, Peng; Guo, Laodong

2016-12-01

The Laurentian Great Lakes have experienced unprecedented ecological and environmental changes, especially after the introduction of invasive quagga mussel (Dreissena rostriformis bugensis). While impacts on ecological functions have been widely recognized, the response of carbon dynamics to invasive species remains largely unknown. We report new CO2 data showing significant increases in pCO2 (up to 800 μatm in Lake Michigan) and CO2 emission fluxes in most of the Great Lakes compared to those prior to or during the early stage of the colonization of invasive quagga mussels. The increased CO2 supersaturation is most prominent in Lakes Huron and Michigan, followed by Lakes Ontario and Erie, but no evident change was observed in Lake Superior. This trend mirrors the infestation extent of invasive quagga mussels in the Great Lakes and is consistent with the decline in primary production and increase in water clarity observed pre- and post-Dreissena introduction, revealing a close linkage between invasive species and carbon dynamics. The Great Lakes have become a significant CO2 source to the atmosphere, emitting >7.7 ± 1.0 Tg-C annually, which is higher than the organic carbon burial rate in global inland-seas and attesting to the significant role of the Laurentian Great Lakes in regional/global CO2 budget and cycling.

Increasing species richness of the macrozoobenthic fauna on tidal flats of the Wadden Sea by local range expansion and invasion of exotic species

Science.gov (United States)

Beukema, J. J.; Dekker, R.

2011-06-01

A 40-y series of consistently collected samples (15 fixed sampling sites, constant sampled area of 15 × 0.95 m2, annual sampling only in late-winter/early-spring seasons, and consistent sieving and sorting procedures; restriction to 50 easily recognizable species) of macrozoobenthos on Balgzand, a tidal flat area in the westernmost part of the Wadden Sea (The Netherlands), revealed significantly increasing trends of species richness. Total numbers of species annually encountered increased from ~28 to ~38. Mean species density (number of species found per sampling site) increased from ~13 to ~18 per 0.95 m2. During the 40 years of the 1970-2009 period of observation, 4 exotic species invaded the area: (in order of first appearance) Ensis directus, Marenzelleria viridis, Crassostrea gigas, and Hemigrapsus takanoi. Another 5 species recently moved to Balgzand from nearby (subtidal) locations. Together, these 9 new species on the tidal flats explained by far most of the increase in total species numbers, but accounted for only one-third of the observed increase in species density (as a consequence of the restricted distribution of most of them). Species density increased particularly by a substantial number of species that showed increasing trends in the numbers of tidal flat sites they occupied. Most of these wider-spreading species were found to suffer from cold winters. During the 40-y period of observation, winter temperatures rose by about 2°C and cold winters became less frequent. The mean number of cold-sensitive species found per site significantly increased by almost 2 per 0.95 m2. Among the other species (not sensitive to low winter temperatures), 6 showed a rising and 2 a declining trend in number of occupied sites, resulting in a net long-term increase in species density amounting to another gain of 1.6 per 0.95 m2. Half of the 50 studied species did not show such long-term trend, nor were invaders. Thus, each of 3 groups (local or alien invaders/winter

Annual cycle energy system (ACES). Performance report, November 1977-September 1978

Energy Technology Data Exchange (ETDEWEB)

Holman, A.S.; Abbatiello, L.A.

1980-05-01

A single-family residence near Knoxville, Tennessee, is being used to demonstrate the energy-conserving features of the annual cycle energy system (ACES), an integrated heating and cooling system that utilizes a unidirectional heat pump and low-temperature thermal storage. A second house, the control house, is being used to compare the performance of the ACES with that of an electric-resistance heating and hot-water system combined with a central air conditioning system. The results of one year's operation, from November 1977 through mid-September 1978, showed that the ACES consumed 9012 kWhr of electricity and delivered 40.8 x 10/sup 6/ Btu (43.03 x 10/sup 9/J) of heating, 19.8 x 10/sup 6/ Btu (20.89 x 10/sup 9/J) of hot water, and 24.8 x 10/sup 6/ Btu (26.17 x 10/sup 9/J) of cooling; the annual coefficient of performance (COP) was 2.78. The control house consumed 20,523 kWhr of electricity and delivered 41.3 x 10/sup 6/ Btu (43.57 x 10/sup 9/J) of heating, 14.8 x 10/sup 6/ Btu (15.61 x 10/sup 9/J) of hot water, and 23.2 x 10/sup 6/ Btu (24.41 x 10/sup 9/J) of cooling; the annual COP was 1.13. These loads were delivered in a test year in which the heating season was one of the most severe in the past 20 years and the cooling season was normal. In addition, the ACES reduced peak utility system demands significantly: a reduction from 11.7 to 3.1 kW was achieved in the winter and from 4.1 to 0.7 kW in the summer. The only problems encountered were a heat leak into the storage bin that was twice the calculated value and control logic errors that produced excessive hot water in the winter, requiring extensive use of the night heat-rejection mode in the summer. These problems are currently being corrected.

A human breast cell model of pre-invasive to invasive transition

Energy Technology Data Exchange (ETDEWEB)

Bissell, Mina J; Rizki, Aylin; Weaver, Valerie M.; Lee, Sun-Young; Rozenberg, Gabriela I.; Chin, Koei; Myers, Connie A.; Bascom, Jamie L.; Mott, Joni D.; Semeiks, Jeremy R.; Grate, Leslie R.; Mian, I. Saira; Borowsky, Alexander D.; Jensen, Roy A.; Idowu, Michael O.; Chen, Fanqing; Chen, David J.; Petersen, Ole W.; Gray, Joe W.; Bissell, Mina J.

2008-03-10

A crucial step in human breast cancer progression is the acquisition of invasiveness. There is a distinct lack of human cell culture models to study the transition from pre-invasive to invasive phenotype as it may occur 'spontaneously' in vivo. To delineate molecular alterations important for this transition, we isolated human breast epithelial cell lines that showed partial loss of tissue polarity in three-dimensional reconstituted-basement membrane cultures. These cells remained non-invasive; however, unlike their non-malignant counterparts, they exhibited a high propensity to acquire invasiveness through basement membrane in culture. The genomic aberrations and gene expression profiles of the cells in this model showed a high degree of similarity to primary breast tumor profiles. The xenograft tumors formed by the cell lines in three different microenvironments in nude mice displayed metaplastic phenotypes, including squamous and basal characteristics, with invasive cells exhibiting features of higher grade tumors. To find functionally significant changes in transition from pre-invasive to invasive phenotype, we performed attribute profile clustering analysis on the list of genes differentially expressed between pre-invasive and invasive cells. We found integral membrane proteins, transcription factors, kinases, transport molecules, and chemokines to be highly represented. In addition, expression of matrix metalloproteinases MMP-9,-13,-15,-17 was up regulated in the invasive cells. Using siRNA based approaches, we found these MMPs to be required for the invasive phenotype. This model provides a new tool for dissection of mechanisms by which pre-invasive breast cells could acquire invasiveness in a metaplastic context.

Radiological and Environmental Research Division: ecology. Annual report, January-December 1982

International Nuclear Information System (INIS)

1983-09-01

This is the annual report of the Radiological and Environmental Division of the Argonne National Laboratory for 1982. Studies of the effects of ozone on crop growth and yield have been carried out by the Terrestrial Ecology Group for winter wheat and for sorghum. The Microcosms for Acid Rain Studies (MARS) facility was completed in the early summer. Controlled investigations of plant and soil responses in acid rain were initiated with crop plants grown in two different midwestern soil types. The Transuranics Group has found that the solubility and adsorptive behavior of plutonium previously observed at fallout concentrations in natural waters (approx. 10 -16 to 10 -18 M) is applicable at plutonium concentrations as high as 10 -8 M. The Lake Michigan eutrophication model has been adapted to operation in a Monte Carlo mode. Simulations based on yearly phosphorus loadings and winter conditions were selected at random from prescribed probability distributions and used to estimate some of the uncertainties associated with model forecasts of Lake Michigan water quality

Winter Ground Temperatures Control Snowmelt DOC Export From a Discontinuous Permafrost Watershed: A Multi-Year Perspective

Science.gov (United States)

Carey, S. K.

2006-12-01

For discontinuous and continuous permafrost watersheds, the largest mass flux of dissolved organic carbon (DOC) occurs during the snowmelt period. During this time, available allochtonous organic carbon that has accumulated over the winter in frozen organic soils is rapidly flushed to the basin outlet. While this process has been observed now in many river systems of different size and location, there have been few inter-annual reports on the mass of DOC loss and the factors controlling its variability during freshet. Hydrological and DOC fluxes were recorded for the 2002, 2003 and 2006 snowmelt season with supplementary over-winter data for an 8 square kilometer sub-basin (Granger Basin) of the Wolf Creek Research Basin, Yukon Territory, Canada. Granger Basin is an alpine catchment above treeline underlain with discontinuous permafrost (approximately 70 %) and has widespread surface organic soils up to 0.4 m in thickness. Pre-melt snow water equivalent varied widely throughout the basin, yet was greatest in 2006, followed by 2002 and 2003. Ground temperatures were notably colder throughout the 2003 winter compared with 2006 and 2002. For all years, discharge began in mid-May, and was a continuous event in 2002 and 2006. In 2003 four distinct melt-periods were observed due to rising and falling temperatures. During freshet, stream DOC concentration increased rapidly from 15 mg C/L on the first ascending limb of the hydrograph in each year. In 2003, DOC was largely flushed from the catchment several weeks prior to peak freshet. DOC concentration in wells and piezometers followed a similar pattern to streamflow DOC, with 2003 groundwater DOC concentrations less than 2002 and 2006. The total mass flux of DOC during freshet was 0.85, 0.45 and 1.01 g C/m2 for 2002, 2003 and 2006 respectively. Despite differences in pre-melt snow accumulation, the timing of melt and the volume of discharge, it appears that spring DOC export is largely controlled by over-winter ground

Wintering bald eagle trends in northern Arizona, 1975-2000

Science.gov (United States)

Teryl G. Grubb

2003-01-01

Between 1975 and 2000, 4,525 sightings of wintering bald eagles (Haliaeetus leucocephalus) were recorded at Mormon Lake in northern Arizona. Numbers of wintering eagles fluctuated little in the 20 years from 1975 through 1994 (5.5 ± 3.0 mean sightings per day). However, during the winters of 1995 through 1997 local record highs of 59 to 118 eagles...

Limnology of Sawtooth Lakes - 1995: Effects of winter limnology and lake fertilization on potential production of Snake River sockeye salmon

International Nuclear Information System (INIS)

Luecke, C.; Wurtsbaugh, W.A.; Budy, P.; Steinhart, G.B.; Slater, M.

1996-01-01

This Section II of the entire report describes the results of the limnological sampling conducted on Redfish, Altras, Pettit and Stanley Lakes from October 1994 through October 1995. Included are descriptions of winter limnological conditions and kokanee growth characteristics from 1993 to 1995, limnological conditions during the spring, summer and fall of 1995, comparison of characteristics among the four lakes; fertilization of Redfish Lake in 1995; effects of fertilization and effects of annual avriations in planktivorous fish abundance. Individual chapters and their subject areas are listed in following abstracts

Limnology of Sawtooth Lakes - 1995: Effects of winter limnology and lake fertilization on potential production of Snake River sockeye salmon

Energy Technology Data Exchange (ETDEWEB)

Luecke, C.; Wurtsbaugh, W.A.; Budy, P.; Steinhart, G.B.; Slater, M.

1996-05-01

This Section II of the entire report describes the results of the limnological sampling conducted on Redfish, Altras, Pettit and Stanley Lakes from October 1994 through October 1995. Included are descriptions of winter limnological conditions and kokanee growth characteristics from 1993 to 1995, limnological conditions during the spring, summer and fall of 1995, comparison of characteristics among the four lakes; fertilization of Redfish Lake in 1995; effects of fertilization and effects of annual avriations in planktivorous fish abundance. Individual chapters and their subject areas are listed in following abstracts.

Effects of sowing time on pink snow mould, leaf rust and winter damage in winter rye varieties in Finland

Directory of Open Access Journals (Sweden)

M. SERENIUS

2008-12-01

Full Text Available Disease infection in relation to sowing time of winter rye (Secale cereale was studied in southern Finland in order to compare overwintering capacity of modern rye varieties and to give recommendations for rye cultivation. This was done by using three sowing times and four rye varieties in field trials conducted at three locations in 1999–2001. The early sown rye (beginning of August was severely affected by diseases caused by Puccinia recondita and Microdochium nivale, whereas postponing sowing for two weeks after the recommended sowing time resulted in considerably less infection. The infection levels of diseases differed among rye varieties. Finnish rye varieties Anna and Bor 7068 were more resistant to snow mould and more winter hardy than the Polish variety Amilo, or the German hybrid varieties Picasso and Esprit. However, Amilo was the most resistant to leaf rust. In the first year snow mould appeared to be the primary cause of winter damage, but in the second year the winter damage was positively correlated with leaf rust. No significant correlation between frit fly infestation and winter damage or disease incidence of snow mould or leaf rust was established. The late sowing of rye (in the beginning of September is recommended in Finland, particularly with hybrid varieties, to minimize the need for chemical plant protection in autumn.;

Milk production, grazing behavior and nutritional status of dairy cows grazing two herbage allowances during winter

Directory of Open Access Journals (Sweden)

Miguel Ruiz-Albarran

2016-03-01

Full Text Available Winter grazing provides a useful means for increasing the proportion of grazed herbage in the annual diet of dairy cows. This season is characterized by low herbage growth rate, low herbage allowance, and low herbage intake and hence greater needs for supplements to supply the requirements of lactating dairy cows. The aim of this study was to determine the influence of herbage allowance (HA offered to autumn calving dairy cows grazing winter herbage on milk production, nutritional status, and grazing behavior. The study took 63 d using 32 multiparous Holstein-Friesian dairy cows. Prior to experimental treatment, milk production averaged 20.2 ± 1.7 kg d-1, body weight was 503 ± 19 kg, and days in milking were 103 ± 6. Experimental animals were randomly assigned to two treatments according to HA offered above ground level: low (17 kg DM cow-1 d-1 vs. high HA (25 kg DM cow¹ d¹. All cows were supplemented with grass silage supplying daily 6.25 and 4.6 kg DM of concentrate (concentrate commercial plus high corn moisture. Decreasing HA influenced positively milk production (+25%, milk protein (+20 kg, and milk fat (+17 kg per hectare; however no effects on milk production per cow or energy metabolic status were observed in the cows. In conclusion, a low HA showed to be the most significant influencing factor on milk and milk solids production per hectare in dairy cows grazing restricted winter and supplemented with grass silage and concentrate; but no effect on the milk production per cow was found.

Mapping of QTLs for leaf area and the association with winter ...

African Journals Online (AJOL)

Variations in plant architecture are often associated with the ability of plants to survive cold stress during winter. In studies of winter hardiness in lentil, it appeared that small leaf area was associated with improved winter survival. Based on this observation, the inheritance of leaf area and the relationship with winter ...

The Anomalous Winter of 1783-1784: Was the Laki Eruption or an Analog of the 2009-2010 Winter to Blame?

Science.gov (United States)

D'Arrigo, Rosanne; Seager, Richard; Smerdon, Jason E.; LeGrande, Allegra N.; Cook, Edward R.

2011-01-01

The multi ]stage eruption of the Icelandic volcano Laki beginning in June, 1783 is speculated to have caused unusual dry fog and heat in western Europe and cold in North America during the 1783 summer, and record cold and snow the subsequent winter across the circum-North Atlantic. Despite the many indisputable impacts of the Laki eruption, however, its effect on climate, particularly during the 1783.1784 winter, may be the most poorly constrained. Here we test an alternative explanation for the unusual conditions during this time: that they were caused primarily by a combined negative phase of the North Atlantic Oscillation (NAO) and an El Nino ]Southern Oscillation (ENSO) warm event. A similar combination of NAO ]ENSO phases was identified as the cause of record cold and snowy conditions during the 2009.2010 winter in Europe and eastern North America. 600-year tree-ring reconstructions of NAO and ENSO indices reveal values in the 1783.1784 winter second only to their combined severity in 2009.2010. Data sources and model simulations support our hypothesis that a combined, negative NAO ]ENSO warm phase was the dominant cause of the anomalous winter of 1783.1784, and that these events likely resulted from natural variability unconnected to Laki.

New gSSR and EST-SSR markers reveal high genetic diversity in the invasive plant Ambrosia artemisiifolia L. and can be transferred to other invasive Ambrosia species.

Science.gov (United States)

Meyer, Lucie; Causse, Romain; Pernin, Fanny; Scalone, Romain; Bailly, Géraldine; Chauvel, Bruno; Délye, Christophe; Le Corre, Valérie

2017-01-01

Ambrosia artemisiifolia L., (common ragweed), is an annual invasive and highly troublesome plant species originating from North America that has become widespread across Europe. New sets of genomic and expressed sequence tag (EST) based simple sequence repeats (SSRs) markers were developed in this species using three approaches. After validation, 13 genomic SSRs and 13 EST-SSRs were retained and used to characterize the genetic diversity and population genetic structure of Ambrosia artemisiifolia populations from the native (North America) and invasive (Europe) ranges of the species. Analysing the mating system based on maternal families did not reveal any departure from complete allogamy and excess homozygosity was mostly due the presence of null alleles. High genetic diversity and patterns of genetic structure in Europe suggest two main introduction events followed by secondary colonization events. Cross-species transferability of the newly developed markers to other invasive species of the Ambrosia genus was assessed. Sixty-five percent and 75% of markers, respectively, were transferable from A. artemisiifolia to Ambrosia psilostachya and Ambrosia tenuifolia. 40% were transferable to Ambrosia trifida, this latter species being seemingly more phylogenetically distantly related to A. artemisiifolia than the former two.

Nuclear Winter: Scientists in the Political Arena

Science.gov (United States)

Badash, Lawrence

2001-03-01

The nuclear winter phenomenon is used to illustrate the many paths by which scientific advice reaches decision makers in the United States government. Because the Reagan administration was hostile to the strategic policy that the scientific discovery seemed to demand, the leading proponent of nuclear winter, Carl Sagan, used his formidable talent for popularization to reach a larger audience.

The engineering approach to winter sports

CERN Document Server

Cheli, Federico; Maldifassi, Stefano; Melzi, Stefano; Sabbioni, Edoardo

2016-01-01

The Engineering Approach to Winter Sports presents the state-of-the-art research in the field of winter sports in a harmonized and comprehensive way for a diverse audience of engineers, equipment and facilities designers, and materials scientists. The book examines the physics and chemistry of snow and ice with particular focus on the interaction (friction) between sports equipment and snow/ice, how it is influenced by environmental factors, such as temperature and pressure, as well as by contaminants and how it can be modified through the use of ski waxes or the microtextures of blades or ski soles. The authors also cover, in turn, the different disciplines in winter sports:  skiing (both alpine and cross country), skating and jumping, bob sledding and skeleton, hockey and curling, with attention given to both equipment design and on the simulation of gesture and  track optimization.

Nuclear Winter: Implications for civil defense

Energy Technology Data Exchange (ETDEWEB)

Chester, C.V.; Perry, A.M.; Hobbs, B.F.

1988-05-01

''Nuclear Winter'' is the term given to the cooling hypothesized to occur in the Northern Hemisphere following a nuclear war as the result of the injection of smoke from burning cities into the atmosphere. The voluminous literature on this subject produced since the paper was published in 1983 by Turco, Toon, Ackerman, Pollack, and Sagen (TTAPS) has been reviewed. Three-dimensional global circulation models have resulted in reduced estimates of cooling---15 to 25/degree/C for a summer war and a few degrees for a winter war. More serious may be the possibility of suppression of convective precipitation by the altered temperature profiles in the atmosphere. However, very large uncertainties remain in input parameters, the models, and the results of calculations. We believe the state of knowledge about nuclear winter is sufficiently developed to conclude: Neither cold nor drought is likely to be a direct threat to human survival for populations with the wherewithal to survive normal January temperatures. The principal threat from nuclear winter is to food production, and this could present problems to third parties who are without food reserves. Loss of a crop year is neither a new nor an unexpected threat from nuclear war to the United States and the Soviet Union. Both have at least a year's food reserve at all times. Both face formidable organizational problems in distributing their reserves in a war-damaged environment. The consequences of nuclear winter could be expected to fall more heavily on the Soviet Union than the United States due to its higher latitude and less productive agriculture. This may be especially true if disturbances of rainfall amounts and distribution persist for more than a year.

Novel psychrotolerant picocyanobacteria isolated from Chesapeake Bay in the winter.

Science.gov (United States)

Xu, Yongle; Jiao, Nianzhi; Chen, Feng

2015-08-01

Picocyanobacteria are major primary producers in the ocean, especially in the tropical or subtropical oceans or during warm seasons. Many "warm" picocyanobacterial species have been isolated and characterized. However, picocyanobacteria in cold environments or cold seasons are much less studied. In general, little is known about the taxonomy and ecophysiology of picocyanobacteria living in the winter. In this study, 17 strains of picocyanobacteria were isolated from Chesapeake Bay, a temperate estuarine ecosystem, during the winter months. These winter isolates belong to five distinct phylogenetic lineages, and are distinct from the picocyanobacteria previously isolated from the warm seasons. The vast majority of the winter isolates were closely related to picocyanobacteria isolated from other cold environments like Arctic or subalpine waters. The winter picocyanobacterial isolates were able to maintain slow growth or prolonged dormancy at 4°C. Interestingly, the phycoerythrin-rich strains outperformed the phycocyanin-rich strains at cold temperature. In addition, winter picocyanobacteria changed their morphology when cultivated at 4°C. The close phylogenetic relationship between the winter picocyanobacteria and the picocyanobacteria living in high latitude cold regions indicates that low temperature locations select specific ecotypes of picocyanobacteria. © 2015 Phycological Society of America.

An induced mutant of Coastcross 1 Bermudagrass with improved winter hardiness

International Nuclear Information System (INIS)

Burton, G.W.; Constantin, M.J.; Dobson, J.W. Jr.; Hanna, W.W.; Powell, J.B.

1980-01-01

Coastcross 1 bermudagrass, a sterile F 1 hybrid, (Coastal x PI 255445) establishes faster, yields as much dry matter, is 12% more digestible, and gives 30-35% better daily gains and liveweight gains per ha when fed to cattle than does the Coastal clone but fails to develop rhizomes and lacks the winter hardiness of Coastal. To create a winter hardy mutant, 500,000 green stems were exposed to 7000 rad of 60 -Co rays at Oak Ridge, TN June 21, 1971 and were immediately planted at Blairsville, GA where relatively severe winters occur frequently. One of 4 plants surviving the 1971-72 winter was like Coastcross 1 in yield, in vitro dry matter digestibility and appearance in a 3-yr test during mild winters at Tifton, GA. Following the moderate winter of 1976-77, Coastcross 1-M3 yielded more than Coastcross 1 but only about half as much as Coastal. The severe winter of 1977-78 destroyed about 98% of the plants of Coastcross 1 and Coastcross 1-M3 but reduced the stand of Coastal very little. The small gain in winter hardiness by Coastcross 1-M3 suggests that several genes control the winter hardiness of well-established Coastal bermudagrass. (author)

Drifting algae and fish: Implications of tropical Sargassum invasion due to ocean warming in western Japan

Science.gov (United States)

Yamasaki, Mami; Aono, Mikina; Ogawa, Naoto; Tanaka, Koichiro; Imoto, Zenji; Nakamura, Yohei

2014-06-01

Evidence is accumulating that the invasion and extinction of habitat-forming seaweed species alters coastal community structure and ecological services, but their effects on the pelagic environment have been largely ignored. Thus, we examined the seasonal occurrence patterns of indigenous temperate and invasive tropical drifting algae and associated fish species every month for 2 years (2009-2011) in western Japan (Tosa Bay), where a rapid shift from temperate to tropical Sargassum species has been occurring in the coastal area since the late 1980s due to rising seawater temperatures. Of the 19 Sargassum species (31.6%) in drifting algae, we found that six were tropical species, whereas a study in the early 1980s found only one tropical species among 12 species (8.3%), thereby suggesting an increase in the proportion of tropical Sargassum species in drifting algae during the last 30 years. Drifting temperate algae were abundantly present from late winter to summer, whereas tropical algal clumps occurred primarily during summer. In the warm season, fish assemblages did not differ significantly between drifting temperate and tropical algae, suggesting the low host-algal specificity of most fishes. We also found that yellowtail juveniles frequently aggregated with drifting temperate algae from late winter to spring when drifting tropical algae were unavailable. Local fishermen collect these juveniles for use as aquaculture seed stock; therefore, the occurrence of drifting temperate algae in early spring is important for local fisheries. These results suggest that the further extinction of temperate Sargassum spp. may have negative impacts on the pelagic ecosystem and associated regional fisheries.

Arctic tundra shrub invasion and soot deposition: Consequences for spring snowmelt and near-surface air temperatures

Science.gov (United States)

Strack, John E.; Pielke, Roger A.; Liston, Glen E.

2007-12-01

Invasive shrubs and soot pollution both have the potential to alter the surface energy balance and timing of snow melt in the Arctic. Shrubs reduce the amount of snow lost to sublimation on the tundra during the winter leading to a deeper end-of-winter snowpack. The shrubs also enhance the absorption of energy by the snowpack during the melt season by converting incoming solar radiation to longwave radiation and sensible heat. Soot deposition lowers the albedo of the snow, allowing it to more effectively absorb incoming solar radiation and thus melt faster. This study uses the Colorado State University Regional Atmospheric Modeling System version 4.4 (CSU-RAMS 4.4), equipped with an enhanced snow model, to investigate the effects of shrub encroachment and soot deposition on the atmosphere and snowpack in the Kuparuk Basin of Alaska during the May-June melt period. The results of the simulations suggest that a complete invasion of the tundra by shrubs leads to a 2.2°C warming of 3 m air temperatures and a 108 m increase in boundary layer depth during the melt period. The snow-free date also occurred 11 d earlier despite having a larger initial snowpack. The results also show that a decrease in the snow albedo of 0.1, owing to soot pollution, caused the snow-free date to occur 5 d earlier. The soot pollution caused a 1.0°C warming of 3 m air temperatures and a 25 m average deepening of the boundary layer.

Winter Bottom Trawl Survey

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Winter Bottom Trawl Survey was initiated in 1992 and covered offshore areas from the Mid-Atlantic to Georges Bank. Inshore strata were covered...

Severe European winters in a secular perspective

Science.gov (United States)

Hoy, Andreas; Hänsel, Stephanie

2017-04-01

Temperature conditions during the winter time are substantially shaped by a strong year-to-year variability. European winters since the late 1980s - compared to previous decades and centuries - were mainly characterised by a high temperature level, including recent record-warm winters. Yet, comparably cold winters and severe cold spells still occur nowadays, like recently observed from 2009 to 2013 and in early 2017. Central England experienced its second coldest December since start of observations more than 350 years ago in 2010, and some of the lowest temperatures ever measured in northern Europe (below -50 °C in Lapland) were recorded in January 1999. Analysing thermal characteristics and spatial distribution of severe (historical) winters - using early instrumental data - helps expanding and consolidating our knowledge of past weather extremes. This contribution presents efforts towards this direction. We focus on a) compiling and assessing a very long-term instrumental, spatially widespread and well-distributed, high-quality meteorological data set to b) investigate very cold winter temperatures in Europe from early measurements until today. In a first step, we analyse the longest available time series of monthly temperature averages within Europe. Our dataset extends from the Nordic countries up to the Mediterranean and from the British Isles up to Russia. We utilise as much as possible homogenised times series in order to ensure reliable results. Homogenised data derive from the NORDHOM (Scandinavia) and HISTALP (greater alpine region) datasets or were obtained from national weather services and universities. Other (not specifically homogenised) data were derived from the ECA&D dataset or national institutions. The employed time series often start already during the 18th century, with Paris & Central England being the longest datasets (from 1659). In a second step, daily temperature averages are involved. Only some of those series are homogenised, but

Polar bears experience skeletal muscle atrophy in response to food deprivation and reduced activity in winter and summer

Science.gov (United States)

Whiteman, John P.; Harlow, Henry J.; Durner, George M.; Regehr, Eric V.; Rourke, Bryan C.; Robles, Manuel; Amstrup, Steven C.; Ben-David, Merav

2017-01-01

When reducing activity and using stored energy during seasonal food shortages, animals risk degradation of skeletal muscles, although some species avoid or minimize the resulting atrophy while experiencing these conditions during hibernation. Polar bears may be food deprived and relatively inactive during winter (when pregnant females hibernate and hunting success declines for other demographic groups) as well as summer (when sea ice retreats from key foraging habitats). We investigated muscle atrophy in samples of biceps femoris collected from free-ranging polar bears in the Southern Beaufort Sea (SBS) throughout their annual cycle. Atrophy was most pronounced in April–May as a result of food deprivation during the previous winter, with muscles exhibiting reduced protein concentration, increased water content, and lower creatine kinase mRNA. These animals increased feeding and activity in spring (when seal prey becomes more available), initiating a period of muscle recovery. During the following ice melt of late summer, ~30% of SBS bears abandon retreating sea ice for land; in August, these ‘shore’ bears exhibited no muscle atrophy, indicating that they had fully recovered from winter food deprivation. These individuals subsequently scavenged whale carcasses deposited by humans and by October, had retained good muscle condition. In contrast, ~70% of SBS bears follow the ice north in late summer, into deep water with less prey. These ‘ice’ bears fast; by October, they exhibited muscle protein loss and rapid changes in myosin heavy-chain isoforms in response to reduced activity. These findings indicate that, unlike other bears during winter hibernation, polar bears without food in summer cannot mitigate atrophy. Consequently, prolonged summer fasting resulting from climate change-induced ice loss creates a risk of greater muscle atrophy and reduced abilities to travel and hunt.

Polar bears experience skeletal muscle atrophy in response to food deprivation and reduced activity in winter and summer

Science.gov (United States)

Harlow, Henry J.; Durner, George M.; Regehr, Eric V.; Rourke, Bryan C.; Robles, Manuel; Amstrup, Steven C.; Ben-David, Merav

2017-01-01

Abstract When reducing activity and using stored energy during seasonal food shortages, animals risk degradation of skeletal muscles, although some species avoid or minimize the resulting atrophy while experiencing these conditions during hibernation. Polar bears may be food deprived and relatively inactive during winter (when pregnant females hibernate and hunting success declines for other demographic groups) as well as summer (when sea ice retreats from key foraging habitats). We investigated muscle atrophy in samples of biceps femoris collected from free-ranging polar bears in the Southern Beaufort Sea (SBS) throughout their annual cycle. Atrophy was most pronounced in April–May as a result of food deprivation during the previous winter, with muscles exhibiting reduced protein concentration, increased water content, and lower creatine kinase mRNA. These animals increased feeding and activity in spring (when seal prey becomes more available), initiating a period of muscle recovery. During the following ice melt of late summer, ~30% of SBS bears abandon retreating sea ice for land; in August, these ‘shore’ bears exhibited no muscle atrophy, indicating that they had fully recovered from winter food deprivation. These individuals subsequently scavenged whale carcasses deposited by humans and by October, had retained good muscle condition. In contrast, ~70% of SBS bears follow the ice north in late summer, into deep water with less prey. These ‘ice’ bears fast; by October, they exhibited muscle protein loss and rapid changes in myosin heavy-chain isoforms in response to reduced activity. These findings indicate that, unlike other bears during winter hibernation, polar bears without food in summer cannot mitigate atrophy. Consequently, prolonged summer fasting resulting from climate change-induced ice loss creates a risk of greater muscle atrophy and reduced abilities to travel and hunt. PMID:28835844

Polar bears experience skeletal muscle atrophy in response to food deprivation and reduced activity in winter and summer.

Science.gov (United States)

Whiteman, John P; Harlow, Henry J; Durner, George M; Regehr, Eric V; Rourke, Bryan C; Robles, Manuel; Amstrup, Steven C; Ben-David, Merav

2017-01-01

When reducing activity and using stored energy during seasonal food shortages, animals risk degradation of skeletal muscles, although some species avoid or minimize the resulting atrophy while experiencing these conditions during hibernation. Polar bears may be food deprived and relatively inactive during winter (when pregnant females hibernate and hunting success declines for other demographic groups) as well as summer (when sea ice retreats from key foraging habitats). We investigated muscle atrophy in samples of biceps femoris collected from free-ranging polar bears in the Southern Beaufort Sea (SBS) throughout their annual cycle. Atrophy was most pronounced in April-May as a result of food deprivation during the previous winter, with muscles exhibiting reduced protein concentration, increased water content, and lower creatine kinase mRNA. These animals increased feeding and activity in spring (when seal prey becomes more available), initiating a period of muscle recovery. During the following ice melt of late summer, ~30% of SBS bears abandon retreating sea ice for land; in August, these 'shore' bears exhibited no muscle atrophy, indicating that they had fully recovered from winter food deprivation. These individuals subsequently scavenged whale carcasses deposited by humans and by October, had retained good muscle condition. In contrast, ~70% of SBS bears follow the ice north in late summer, into deep water with less prey. These 'ice' bears fast; by October, they exhibited muscle protein loss and rapid changes in myosin heavy-chain isoforms in response to reduced activity. These findings indicate that, unlike other bears during winter hibernation, polar bears without food in summer cannot mitigate atrophy. Consequently, prolonged summer fasting resulting from climate change-induced ice loss creates a risk of greater muscle atrophy and reduced abilities to travel and hunt.

Regional greenhouse gas emissions from cultivation of winter wheat and winter rapeseed for biofuels in Denmark

DEFF Research Database (Denmark)

Elsgaard, Lars; Olesen, Jørgen E; Hermansen, John Erik

2013-01-01

Biofuels from bioenergy crops may substitute a significant part of fossil fuels in the transport sector where, e.g., the European Union has set a target of using 10% renewable energy by 2020. Savings of greenhouse gas emissions by biofuels vary according to cropping systems and are influenced...... by such regional factors as soil conditions, climate and input of agrochemicals. Here we analysed at a regional scale the greenhouse gas (GHG) emissions associated with cultivation of winter wheat for bioethanol and winter rapeseed for rapeseed methyl ester (RME) under Danish conditions. Emitted CO2 equivalents...

Assessing meteorological key factors influencing crop invasion by pollen beetle (

Directory of Open Access Journals (Sweden)

Jürgen Junk

2016-09-01

Full Text Available The pollen beetle, Meligethes aeneus F. (Coleoptera: Nitidulidae, is a severe pest of winter oilseed rape. A phenological model to forecast the first spring invasion of crops in Luxembourg by M. aeneus was developed in order to provide a tool for improving pest management and for assessing the potential effects of climate change on this pest. The model was derived using long-term, multi-site observational datasets of pollen beetle migration and meteorological data, as the timing of crop invasion is determined mainly by meteorological variables. Daily values of mean air and soil temperature, accumulated sunshine duration and precipitation were used to create a threshold-based model to forecast crop invasion. Minimising of the root mean squared error (RMSE of predicted versus observed migration dates was used as the quality criterion for selecting the optimum combination of threshold values for meteorological variables. We identified mean air temperature 8.0 °C, mean soil temperature 4.6 °C, and sunshine duration of 3.4 h as the best threshold values, with a cut-off of 1 mm precipitation and with no need for persistence of those conditions for more than one day (RMSE=9.3days$RMSE=9.3\\,\\text{days}$. Only in six out of 30 cases, differences between observed and predicted immigration dates were >5$>5$ days. In the future, crop invasion by pollen beetles will probably be strongly affected by changes in air temperature and precipitation related to climate change. We used a multi-model ensemble of 15 regional climate models driven by the A1B emission scenario to assess meteorological changes in two 30‑year future periods, near future (2021–2050 and far future (2069–2098 in comparison with the reference period (1971–2000. Air temperature and precipitation were predicted to increase in the first three months of each year, both in the near future and the far future. The pollen beetle migration model indicated that this change would

Invasion by nonnative brook trout in Panther Creek, Idaho: Roles of local habitat quality, biotic resistance, and connectivity to source habitats

Science.gov (United States)

Benjamin, Joseph R.; Dunham, Jason B.; Dare, M.R.

2007-01-01

Theoretical models and empirical evidence suggest that the invasion of nonnative species in freshwaters is facilitated through the interaction of three factors: habitat quality, biotic resistance, and connectivity. We measured variables that represented each factor to determine which were associated with the occurrence of nonnative brook trout Salvelinus fontinalis in Panther Creek, a tributary to the Salmon River, Idaho. Habitat variables included measures of summer and winter temperature, instream cover, and channel size. The abundance of native rainbow trout Oncorhynchus mykiss within sampled sites was used as a measure of biotic resistance. We also considered the connectivity of sample sites to unconfined valley bottoms, which were considered habitats that may serve as sources for the spread of established populations of brook trout. We analyzed the occurrence of small (<150‐mm [fork length]) and large (≥150‐mm) brook trout separately, assuming that the former represents an established invasion while accounting for the higher potential mobility of the latter. The occurrence of small brook trout was strongly associated with the proximity of sites to large, unconstrained valley bottoms, providing evidence that such habitats may serve as sources for the spread of brook trout invasion. Within sites, winter degree‐days and maximum summer temperature were positively associated with the occurrence of small brook trout. The occurrence of large brook trout was not related to any of the variables considered, perhaps due to the difficulty of linking site‐specific habitat factors to larger and more mobile individuals. The abundance of rainbow trout was not conclusively associated with the occurrence of either small or large brook trout, providing little support for the role of biotic resistance. Overall, our results suggest that source connectivity and local habitat characteristics, but not biotic resistance, influence the establishment and spread of

The influence of winter swimming on the rheological properties of blood.

Science.gov (United States)

Teległów, Aneta; Dąbrowski, Zbigniew; Marchewka, Anna; Tyka, Aleksander; Krawczyk, Marcin; Głodzik, Jacek; Szyguła, Zbigniew; Mleczko, Edward; Bilski, Jan; Tyka, Anna; Tabarowski, Zbigniew; Czepiel, Jacek; Filar-Mierzwa, Katarzyna

2014-01-01

The aim of this study was to analyze the changes in blood rheology resulting from regular winter swimming. The study was carried out on 12 male winter swimmers. Venous blood for morphological, biochemical and rheological analysis was sampled twice from each winter swimmer - at the beginning of the season and after its completion. There were no significant changes detected in the median values of most blood morphological parameters. The only exception pertained to MCHC which was significantly lower after the season. Winter swimming entailed significant decrease in median elongation index values at shear stress levels of 0.30 Pa and 0.58 Pa, and significant increase in median values of this parameter at shear stress levels ≥1.13 Pa. No significant changes were observed in winter swimmers' median values of aggregation indices and plasma viscosity. The median level of glucose was lower post winter swimming in comparison to the pre-seasonal values. In contrast, one season of winter swimming did not influence swimmers' median value of fibrinogen concentration. In summary, this study revealed positive effects of winter swimming on the rheological properties of blood, manifested by an increase in erythrocyte deformability without accompanying changes in erythrocyte aggregation.

Mortality impact of extreme winter temperatures

Science.gov (United States)

Díaz, Julio; García, Ricardo; López, César; Linares, Cristina; Tobías, Aurelio; Prieto, Luis

2005-01-01

During the last few years great attention has been paid to the evaluation of the impact of extreme temperatures on human health. This paper examines the effect of extreme winter temperature on mortality in Madrid for people older than 65, using ARIMA and GAM models. Data correspond to 1,815 winter days over the period 1986 1997, during which time a total of 133,000 deaths occurred. The daily maximum temperature (Tmax) was shown to be the best thermal indicator of the impact of climate on mortality. When total mortality was considered, the maximum impact occured 7 8 days after a temperature extreme; for circulatory diseases the lag was between 7 and 14 days. When respiratory causes were considered, two mortality peaks were evident at 4 5 and 11 days. When the impact of winter extreme temperatures was compared with that associated with summer extremes, it was found to occur over a longer term, and appeared to be more indirect.

Increasing Winter Maximal Metabolic Rate Improves Intrawinter Survival in Small Birds.

Science.gov (United States)

Petit, Magali; Clavijo-Baquet, Sabrina; Vézina, François

Small resident bird species living at northern latitudes increase their metabolism in winter, and this is widely assumed to improve their chances of survival. However, the relationship between winter metabolic performance and survival has yet to be demonstrated. Using capture-mark-recapture, we followed a population of free-living black-capped chickadees (Poecile atricapillus) over 3 yr and evaluated their survival probability within and among winters. We also measured the size-independent body mass (M s ), hematocrit (Hct), basal metabolic rate (BMR), and maximal thermogenic capacity (Msum) and investigated how these parameters influenced survival within and among winters. Results showed that survival probability was high and constant both within (0.92) and among (0.96) winters. They also showed that while M s , Hct, and BMR had no significant influence, survival was positively related to Msum-following a sigmoid relationship-within but not among winter. Birds expressing an Msum below 1.26 W (i.e., similar to summer levels) had a winter. Our data therefore suggest that black-capped chickadees that are either too slow or unable to adjust their phenotype from summer to winter have little chances of survival and thus that seasonal upregulation of metabolic performance is highly beneficial. This study is the first to document in an avian system the relationship between thermogenic capacity and winter survival, a proxy of fitness.

Range expansion of invasive shrubs: implication for crown fire risk in forestlands of the southern USA.

Science.gov (United States)

Wang, Hsiao-Hsuan; Wonkka, Carissa L; Grant, William E; Rogers, William E

2016-01-01

Non-native plant invasions and changing management activities have dramatically altered the structure and composition of forests worldwide. Invasive shrubs and fire suppression have led to increased densification and biomass accumulation in forest ecosystems of the southeastern USA. Notably, Chinese and European privets are rapid growing, shade-tolerant shrubs which number among the most aggressive invasive species in these forests. Privet encroachment has caused losses of native diversity, alteration of ecosystem processes and changes in community structure. The latter has become manifest through decreases in fine herbaceous fuels concurrent with increases in coarse woody fuels in forest understoreys. These alterations in fuel structure will potentially lead to less frequent, but more severe forest fires, which threaten important forest resources during extreme weather conditions. Drawing on extensive data sets compiled by the US Forest Service, we integrated statistical forecasting and analytical techniques within a spatially explicit, agent-based, simulation framework to predict potential range expansion of Chinese and European privet (Ligustrum sinenseandL. vulgare) and the associated increase in crown fire risk over the next two decades in forestlands of Mississippi and Alabama. Our results indicate that probability of invasion is positively associated with elevation, adjacency (within 300 m) to water bodies, mean daily maximum temperature, site productivity and private land ownership, and is negatively associated with slope, stand age, artificial regeneration, distance to the nearest road and fire disturbance. Our projections suggest the total area invaded will increase from 1.36 to ≈31.39% of all forestlands in Mississippi and Alabama (≈7 million hectares) and the annual frequency of crown fires in these forestlands will approximately double within the next two decades. Such time series projections of annual range expansions and crown fire frequency

Lake Pend Oreille Predation Research, Annual Report 2002-2003.

Energy Technology Data Exchange (ETDEWEB)

Bassista, Thomas

2004-02-01

During August 2002 we conducted a hydroacoustic survey to enumerate pelagic fish >406 mm in Lake Pend Oreille, Idaho. The purpose of this survey was to determine a collective lakewide biomass estimate of pelagic bull trout Salvelinus confluentus, rainbow trout Oncorhynchus mykiss, and lake trout S. namaycush and compare it to pelagic prey (kokanee salmon O. nerka) biomass. By developing hydroacoustic techniques to determine the pelagic predator to prey ratio, we can annually monitor their balance. Hydroacoustic surveys were also performed during December 2002 and February 2003 to investigate the effectiveness of autumn and winter surveys for pelagic predators. The inherent problem associated with hydroacoustic sampling is the inability to directly identify fish species. Therefore, we utilized sonic tracking techniques to describe rainbow trout and lake trout habitat use during our winter hydroacoustic survey to help identify fish targets from the hydroacoustic echograms. During August 2002 we estimated there were 39,044 pelagic fish >406 mm in Lake Pend Oreille (1.84 f/ha). Based on temperature and depth utilization, two distinct groups of pelagic fish >406 mm were located during August; one group was located between 10 and 35 m and the other between 40 and 70 m. The biomass for pelagic fish >406 mm during August 2002 was 73 t (metric ton). This would account for a ratio of 1 kg of pelagic predator for every 2.63 kg of kokanee prey, assuming all pelagic fish >406 mm are predators. During our late fall and winter hydroacoustic surveys, pelagic fish >406 mm were observed at lake depths between 20 and 90 m. During late fall and winter, we tracked three rainbow trout (168 habitat observations) and found that they mostly occupied pelagic areas and predominantly stayed within the top 10 m of the water column. During late fall (one lake trout) and winter (four lake trout), we found that lake trout (184 habitat observations) utilized benthic-nearshore areas 65% of the time

Winter cover crop effect on corn seedling pathogens

Science.gov (United States)

Cover crops are an excellent management tool to improve the sustainability of agriculture. Winter rye cover crops have been used successfully in Iowa corn-soybean rotations. Unfortunately, winter rye cover crops occasionally reduce yields of the following corn crop. We hypothesize that one potential...

Impact of an invasive weed, Parthenium hysterophorus, on a pasture community in south east Queensland, Australia.

Science.gov (United States)

Nguyen, Thi; Bajwa, Ali Ahsan; Belgeri, Amalia; Navie, Sheldon; O'Donnell, Chris; Adkins, Steve

2017-12-01

Parthenium weed is a highly invasive alien species in more than 40 countries around the world. Along with severe negative effects on human and animal health and crop production, it also causes harm to ecosystem functioning by reducing the native plant species biodiversity. However, its impacts on native plant species, especially in pasture communities, are less known. Given parthenium weed causes substantial losses to Australian pastures' productivity, it is crucial to estimate its impact on pasture communities. This study evaluates the impact of parthenium weed upon species diversity in a pasture community at Kilcoy, south east Queensland, Australia. Sub-sites containing three levels of parthenium weed density (i.e. high, low and zero) were chosen to quantify the above- and below-ground plant community structure. Species richness, diversity and evenness were all found to be significantly reduced as the density of parthenium weed increased; an effect was evident even when parthenium weed was present at relatively low densities (i.e. two plants m -2 ). This trend was observed in the summer season as well as in winter season when this annual weed was absent from the above-ground plant community. This demonstrates the strong impact that parthenium weed has upon the community composition and functioning throughout the year. It also shows the long-term impact of parthenium weed on the soil seed bank where it had displaced several native species. So, management options used for parthenium weed should also consider the reduction of parthenium weed seed bank along with controlling its above-ground populations.

Short-term cropland responses to temperature extreme events during late winter

Science.gov (United States)

De Simon, G.; Alberti, G.; Delle Vedove, G.; Peressotti, A.; Zaldei, A.; Miglietta, F.

2013-08-01

In recent years, several studies have focused on terrestrial ecosystem response to extreme events. Most of this research has been conducted in natural ecosystems, but few have considered agroecosystems. In this study, we investigated the impact of a manipulated warmer or cooler late winter/early spring on the carbon budget and final harvest of a soybean crop (Glycine max (L.) Merr.). Soil temperature was altered by manipulating soil albedo by covering the soil surface with a layer of inert silica gravel. We tested three treatments - cooling (Co), warming (W), mix (M) - and control (C). An automated system continuously measured soil heterotrophic respiration (Rh), soil temperature profiles, and soil water content across the entire year in each plot. Phenological phases were periodically assessed and final harvest was measured in each plot. Results showed that treatments had only a transient effect on daily Rh rates, which did not result in a total annual carbon budget significantly different from control, even though cooling showed a significant reduction in final harvest. We also observed anticipation in emergence in both W and M treatments and a delay in emergence for Co. Moreover, plant density and growth increased in W and M and decreased in Co. In conclusion, from the results of our experiment we can assert that an increase in the frequency of both heat and cold waves is unlikely to have large effects on the overall annual carbon balance of irrigated croplands.

Reindeer (Rangifer tarandus and climate change: Importance of winter forage

Directory of Open Access Journals (Sweden)

Thrine Moen Heggberget

2002-06-01

Full Text Available As a consequence of increasing greenhouse gas concentrations, climate change is predicted to be particularly pronounced, although regionally variable, in the vast arctic, sub-arctic and alpine tundra areas of the northern hemisphere. Here, we review winter foraging conditions for reindeer and caribou (Rangifer tarandus living in these areas, and consider diet, forage quality and distribution, accessibility due to snow variation, and effects of snow condition on reindeer and caribou populations. Finally, we hypothesise how global warming may affect wild mountain reindeer herds in South Norway. Energy-rich lichens often dominate reindeer and caribou diets. The animals also prefer lichens, and their productivity has been shown to be higher on lichen-rich than on lichen-poor ranges. Nevertheless, this energy source appears to be neither sufficient as winter diet for reindeer or caribou (at least for pregnant females nor necessary. Some reindeer and caribou populations seem to be better adapted to a non-lichen winter diet, e.g. by a larger alimentary tract. Shrubs appear to be the most common alternative winter forage, while some grasses appear to represent a good, nutritionally-balanced winter diet. Reindeer/caribou make good use of a wide variety of plants in winter, including dead and dry parts that are digested more than expected based on their fibre content. The diversity of winter forage is probably important for the mineral content of the diet. A lichen-dominated winter diet may be deficient in essential dietary elements, e.g. minerals. Sodium in particular may be marginal in inland winter ranges. Our review indicates that most Rangifer populations with lichen-dominated winter diets are either periodically or continuously heavily harvested by humans or predators. However, when population size is mainly limited by food, accessible lichen resources are often depleted. Plant studies simulating climatic change indicate that a warmer, wetter

The annual planktonic protist community structure in an ice-free high Arctic fjord (Adventfjorden, West Spitsbergen)

Science.gov (United States)

Kubiszyn, A. M.; Wiktor, J. M.; Wiktor, J. M.; Griffiths, C.; Kristiansen, S.; Gabrielsen, T. M.

2017-05-01

We investigated the size and trophic structure of the annual planktonic protist community structure in the ice-free Adventfjorden in relation to environmental factors. Our high-resolution (weekly to monthly) study was conducted in 2012, when warm Atlantic water was advected into the fjord in winter and summer. We observed a distinct seasonality in the protist communities. The winter protist community was characterised by extremely low levels of protist abundance and biomass (primarily Dinophyceae, Ciliophora and Bacillariophyceae) in a homogenous water column. In the second half of April, the total protist abundance and biomass rapidly increased, thus initiating the spring bloom in a still well-mixed water column. The spring bloom was initially dominated by the prymnesiophyte Phaeocystis pouchetii and Bacillariophyceae (primarily from the genera Thalassiosira, Fragilariopsis and Chaetoceros) and was later strictly dominated by Phaeocystis colonies. When the bloom terminated in mid-June, the community shifted towards flagellates (Dinophyceae, Ciliophora, Cryptophyceae and nanoflagellates 3-7 μm in size) in a stratified, nutrient-depleted water column. Decreases in the light intensity decreased the protist abundance and biomass, and the fall community (Dinophyceae, Cryptophyceae and Bacillariophyceae) was followed by the winter community.

Planning of traumatological hospital resources for a major winter sporting event as illustrated by the 2005 Winter Universiad.

Science.gov (United States)

Oberladstaetter, J; Kamelger, F S; Rosenberger, R; Dallapozza, Ch; Struve, P; Luger, T; Fink, Ch; Attal, R

2009-03-01

The 22nd Student World Winter Games took place in January 2005 in Innsbruck and Seefeld, Austria. Exactly 1,500 athletes of 50 nationalities competed in 69 events in ten winter sports. A total number of 750 functionaries, 800 volunteers and 85,000 spectators participated in the second largest winter sports event behind the Olympic winter games. The aim of this study was to evaluate the needed resources to ensure traumatological care for an event of that size. At the medical "call-center" all consultations, as well as patient data, diagnosis, and medical treatment were recorded using a preset protocol. Further, all patients treated in the University Hospital Innsbruck were registered with an emphasis on trauma patients. Forty-eight of 65 patients transported to the hospital as a result of the Universiade were trauma patients, 37 of whom were athletes. The gender distribution was 34:14 (m:f). Ice hockey players had the highest rate of injury (25% of all injured athletes), followed by alpine skiers (20.8% of injured athletes). The highest ISS was nine. Forty-three patients got ambulatory treatment, five were admitted to the hospital and surgical treatment was conducted in three cases. Mean patient number was 4.8 per day. No additional personnel, structural, or technical hospital resources were needed to accommodate a large winter sports event like the Universiad. Thus, a level-B trauma center with an emergency room and independent traumatological department with around the clock surgical capability seems to be sufficient to provide traumatological care for an event of this size if the possibility of patient transport to a larger facility exists in the case of catastrophic events.

Aircraft measurements to characterize polluted winter boundary layers: Overview of twin otter flights during the Utah Winter Fine Particulate Matter Study

Science.gov (United States)

Brown, S. S.; Baasandorj, M.; Franchin, A.; Middlebrook, A. M.; Goldberger, L.; Thornton, J. A.; Dube, W. P.; McDuffie, E. E.; Womack, C.; Fibiger, D. L.; Moravek, A.; Clark, J. C.; Murphy, J. G.; Mitchell, R.

2017-12-01

Winter air pollution is a significant public health concern. In many regions of the U.S., Europe and Asia, wintertime particulate matter concentrations exceed national and / or international air quality standards. Winter air pollution also represents a scientific challenge because these events occur during stagnation events in shallow, vertically stratified boundary layers whose composition is difficult to probe from surface level measurements. Chemical processes responsible for the conversion of primary emissions to secondary pollutants such as ammonium nitrate aerosol vary with height above ground level. Sources of oxidants are poorly understood and may result from both local chemical production and mixing between shallow inversion layers and background air. During the Utah Winter Fine Particulate Study (UWFPS) in January - February 2017, the NOAA twin otter executed 23 research flights with a payload designed to characterize the formation of ammonium nitrate aerosol in three mountain valleys of northern Utah (Salt Lake, Cache, and Utah). These valleys are subject to periodic episodes of winter aerosol pollution well in excess of U.S. national ambient air quality standards. This presentation will describe the measurement strategy of the twin otter flights to address the specific features of aerosol pollution within winter boundary layer of this region. This strategy is relevant to understanding the broader issue of winter air pollution in other regions and potentially to the design of future studies. The presentation will summarize findings from UWFPS related to boundary layer structure, emissions and chemical processes responsible for ammonium nitrate aerosol in this region.

Investigation the Concentration and Trend of Winter Precipitation of Iranian Border Stations over the Last Half Century

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Keyvan Khalili

2017-02-01

Full Text Available Introduction: Climate change in the current era is a very important environmental challenge. Our understanding of the impacts of human activities on the environment, especially those related to global warming caused by increased greenhouse gases indicates that, most probably, a number of hydro-climatic parameters are changing. Based on the scientific reports, the average temperature of the earth has increased about 0.6 degrees centigrade over the 20th century and it is expected that the amount of evaporation continues to rise. In this case, the atmosphere would be able to transport larger amounts of water vapor, influencing the amount of atmospheric precipitations (21. Low precipitation and its severe fluctuations in the daily, seasonal and annual time scales are the intrinsic characteristics of Iran’s climates. Based on the research background, it seems that no comprehensive study has been conducted on concentration of winter precipitation in Iran. The aim of this study is to calculate the concentration and Trend of precipitation of Iranian border stations over the last half-century. Materials and Methods: Iran with an area of over16480000 square kilometers is situated in the northern hemisphere and southwest of Asia. Almost all parts of Iran have four seasons. In general, a year can be divided into two warm and cold seasons. In this study, 18 stations were selected among more than 200 synoptic stations existing in the country, for investigating the concentration and precipitation trend. PCI Index The PCI index has been proposed as an index of precipitation concentration. The seasonal scales of this index are calculated as equation 1(18: (1 Where Pi is the amount of monthly precipitation in the ith month. Based on the proposed formula, the minimum value of theoretical PCI is 8.3, indicating absolute uniformity in the precipitation concentration (i.e. the same amount of precipitation occurs every month. Trend analysis The aim of process test

Winter-APK voor bijen : Helpt u deze winter mee bij het praktijkonderzoek?

NARCIS (Netherlands)

Som de Cerff, B.; Cornelissen, B.; Moens, F.

2013-01-01

Om de risico’s van een aanrijding bij sneeuw en gladheid te verminderen, laten steeds meer automobilisten bij het monteren van winterbanden ook een wintercontrole uitvoeren. Zou een dergelijke controle voor de winter ook schade aan onze volken in de vorm van wintersterfte kunnen verminderen? Dat zou

The casual, naturalised and invasive alien flora of Zimbabwe based on herbarium and literature records

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Alfred Maroyi

2012-01-01

Full Text Available Zimbabwe’s casual, naturalised and invasive alien plant species were analysed with regard to their habit, origin, mode or purpose of introduction and their invasion status in the country. This alien flora of 391 taxa belonged to 239 genera and 73 families, corresponding to 6.6% of the total flora of Zimbabwe. Of these, 153 (39.1% plant species were casual aliens, 154 (39.4% were naturalised and 84 (21.5% were invasive species. Most invasions in terms of numbers of alien species were in the central and eastern parts of the country. Asteraceae (53 species, Poaceae (48 species and Fabaceae sensu lato (49 species families were prominent in all the floristic regions of the country. Annual and perennial herbaceous species formed the majority of life forms of the casual, naturalised and invasive alien flora of Zimbabwe. Genera with the highest number of alien species were Ipomoea with nine species, Acacia and Euphorbia with eight species each, Chenopodium and Senna with seven species each, Eucalyptus with six species, Oenothera, Physalis and Solanum with five species each. More than 49.6% of the alien plants in Zimbabwe originated primarily from South, Central and North America, followed by Europe (24.6%, Asia (23.8%, Africa (10.5% and Australasia (5.9%.Conservation implications: This research provides baseline information and historical invasion patterns of casual, naturalised and invasive alien flora in Zimbabwe. This inventory is a crucial starting point in trying to understand and initiate the management of biological invasions. This is also important for monitoring new introductions and management of existing alien plants in Zimbabwe.

STIMULATION OF RESISTANCE OF BEE FAMILIES DURING WINTERING

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nicolae eremia

2013-10-01

Full Text Available Honey bees use as food nectar, honey, pollen and bee bread. They collect nectar and pollen on flowers, that process in food - honey and bee bread. Food provides the bees body with energy due to carbohydrates, proteins, enzymes, lipids, vitamins, minerals. The goal of the studies was to stimulate the bees’ resistance during wintering against nesemosa disease in bee families’ survival after winter time and productivity increasing. There was established that the optimal dose of feed additive Pramix Bionorm P (symbiotic complex, in reserves supplementing of food of bee families during autumn is 150 mg of sugar syrup. There was revealed that using of the feed additive Pramix Bionorm P (symbiotic complex, in bees feeding for reserves supplementing of bees food ensures a stimulating of resistance at wintering of bees, decreases the quantity of used honey during wintering at one space between honey combs populated with bees, as well increases the productivity.

European seasonal mortality and influenza incidence due to winter temperature variability

Science.gov (United States)

Rodó, X.; Ballester, J.; Robine, J. M.; Herrmann, F. R.

2017-12-01

Recent studies have vividly emphasized the lack of consensus on the degree of vulnerability (sensu IPCC) of European societies to current and future winter temperatures. Here we consider several climate factors, influenza incidence and daily numbers of deaths to characterize the relationship between winter temperature and mortality in a very large ensemble of European regions representing more than 400 million people. Analyses highlight the strong association between the year-to-year fluctuations in winter mean temperature and mortality, with higher seasonal cases during harsh winters, in all of the countries except the United Kingdom, the Netherlands and Belgium. This spatial distribution contrasts with the well-documented latitudinal orientation of the dependency between daily temperature and mortality within the season. A theoretical framework is proposed to reconcile the apparent contradictions between recent studies, offering an interpretation to regional differences in the vulnerability to daily, seasonal and long-term winter temperature variability. Despite the lack of a strong year-to-year association between winter mean values in some countries, it can be concluded that warmer winters will contribute to the decrease in winter mortality everywhere in Europe. More information in Ballester J, et al. (2016) Nature Climate Change 6, 927-930, doi:10.1038/NCLIMATE3070.

Migration and wintering sites of Pelagic Cormorants determined by satellite telemetry

Science.gov (United States)

Hatch, Shyla A.; Gill, V.A.; Mulcahy, D.M.

2011-01-01

Factors affecting winter survival may be key determinants of status and population trends of seabirds, but connections between breeding sites and wintering areas of most populations are poorly known. Pelagic Cormorants (Phalacrocorax pelagicus; N= 6) surgically implanted with satellite transmitters migrated from a breeding colony on Middleton Island, northern Gulf of Alaska, to wintering sites in southeast Alaska and northern British Columbia. Winter locations averaged 920 km (range = 600-1190 km) from the breeding site. Migration flights in fall and spring lasted ???5 d in four instances. After reaching wintering areas, cormorants settled in narrowly circumscribed inshore locations (~10-km radius) and remained there throughout the nonbreeding period (September- March). Two juveniles tagged at the breeding colony as fledglings remained at their wintering sites for the duration of the tracking interval (14 and 22 mo, respectively). Most cormorants used multiple sites within their winter ranges for roosting and foraging. Band recoveries show that Pelagic Cormorants in southern British Columbia and Washington disperse locally in winter, rather than migrating like the cormorants in our study. Radio-tagging and monitoring cormorants and other seabirds from known breeding sites are vital for understanding migratory connectivity and improving conservation strategies for local populations. ?? 2011 The Authors. Journal of Field Ornithology ?? 2011 Association of Field Ornithologists.

Environmental research program: FY 1987, annual report

International Nuclear Information System (INIS)

1988-03-01

This multidisciplinary research program includes fundamental and applied research in physics, chemistry, engineering, and biology, as well as research on the development of advanced methods of measurement and analysis. The Program's Annual Report contains summaries of research performed during FY 1987 in the areas of atmospheric aerosols, flue gas chemistry, combustion, membrane bioenergetics, and analytical chemistry. The main research interests of the Atmospheric Aerosol Research group concern the chemical and physical processes that occur in haze, clouds, and fogs. For their studies, the group is developing novel analytical and research methods for characterizing aerosol species. Aerosol research is performed in the laboratory and in the field. Studies of smoke emissions from fires and their possible effects on climatic change, especially as related to nuclear winter, are an example of the collaboration between the Atmospheric Aerosol Research and Combustion Research Groups

Environmental research program: FY 1987, annual report

Energy Technology Data Exchange (ETDEWEB)

1988-03-01

This multidisciplinary research program includes fundamental and applied research in physics, chemistry, engineering, and biology, as well as research on the development of advanced methods of measurement and analysis. The Program's Annual Report contains summaries of research performed during FY 1987 in the areas of atmospheric aerosols, flue gas chemistry, combustion, membrane bioenergetics, and analytical chemistry. The main research interests of the Atmospheric Aerosol Research group concern the chemical and physical processes that occur in haze, clouds, and fogs. For their studies, the group is developing novel analytical and research methods for characterizing aerosol species. Aerosol research is performed in the laboratory and in the field. Studies of smoke emissions from fires and their possible effects on climatic change, especially as related to nuclear winter, are an example of the collaboration between the Atmospheric Aerosol Research and Combustion Research Groups.

Comparison of Selected Morphological, Rheological and Biochemical Parameters of Winter Swimmers' Blood at the End of One Winter Swimming Season and at the Beginning of Another.

Science.gov (United States)

Teległów, Aneta; Marchewka, Jakub; Tabarowski, Zbigniew; Rembiasz, Konrad; Głodzik, Jacek; Scisłowska-Czarnecka, Anna

2015-01-01

The aim of the study was to examine potential differences in the morphological, rheological and biochemical blood parameters of winter swimmers who remained physically active during the period between the end of one winter swimming season and the beginning of another. The study included a group of healthy winter swimmers (n = 17, all between 30 and 60 years of age). Six months following the end of winter season, the levels of mean corpuscular hemoglobin concentration and mean corpuscular hemoglobin turned out to be significantly higher, while erythrocyte count and hematocrit level significantly lower than at the baseline. Moreover, the break in winter swimming was reflected by a significant increase in median erythrocyte elongation index at all shear stress levels ≥ 1.13 Pa. The only significant changes in biochemical parameters of the blood pertained to an increase in the concentration of transferrin and to a decrease in the total protein, albumin and beta-1 globulin concentrations. Seasonal effort of winter swimmers between the end of one winter swimming season and the beginning of another has a positive influence on morphological, rheological and biochemical blood parameters.

Polar vortex evolution during Northern Hemispheric winter 2004/05

Directory of Open Access Journals (Sweden)

T. Chshyolkova

2007-06-01

Full Text Available As a part of the project "Atmospheric Wave Influences upon the Winter Polar Vortices (0–100 km" of the CAWSES program, data from meteor and Medium Frequency radars at 12 locations and MetO (UK Meteorological Office global assimilated fields have been analyzed for the first campaign during the Northern Hemispheric winter of 2004/05. The stratospheric state has been described using the conventional zonal mean parameters as well as Q-diagnostic, which allows consideration of the longitudinal variability. The stratosphere was cold during winter of 2004/05, and the polar vortex was relatively strong during most of the winter with relatively weak disturbances occurring at the end of December and the end of January. For this winter the strongest deformation with the splitting of the polar vortex in the lower stratosphere was observed at the end of February. Here the results show strong latitudinal and longitudinal differences that are evident in the stratospheric and mesospheric data sets at different stations. Eastward winds are weaker and oscillations with planetary wave periods have smaller amplitudes at more poleward stations. Accordingly, the occurrence, time and magnitude of the observed reversal of the zonal mesospheric winds associated with stratospheric disturbances depend on the local stratospheric conditions. In general, compared to previous years, the winter of 2004/05 could be characterized by weak planetary wave activity at stratospheric and mesospheric heights.

Radio frequency energy for non-invasive and minimally invasive skin tightening.

Science.gov (United States)

Mulholland, R Stephen

2011-07-01

This article reviews the non-invasive and minimally invasive options for skin tightening, focusing on peer-reviewed articles and presentations and those technologies with the most proven or promising RF non-excisional skin-tightening results for excisional surgeons. RF has been the mainstay of non-invasive skin tightening and has emerged as the "cutting edge" technology in the minimally invasive skin-tightening field. Because these RF skin-tightening technologies are capital equipment purchases with a significant cost associated, this article also discusses some business issues and models that have proven to work in the plastic surgeon's office for non-invasive and minimally invasive skin-tightening technologies. Copyright © 2011 Elsevier Inc. All rights reserved.

Features of annual and semiannual variations derived from the global ionospheric maps of total electron content

Directory of Open Access Journals (Sweden)

B. Zhao

2008-01-01

Full Text Available In the present work we use the NASA-JPL global ionospheric maps of total electron content (TEC, firstly to construct TEC maps (TEC vs. magnetic local time MLT, and magnetic latitude MLAT in the interval from 1999 to 2005. These TEC maps were, in turn, used to estimate the annual-to-mean amplitude ratio, A₁, and the semiannual-to-mean amplitude ratio, A₂, as well as the latitudinal symmetrical and asymmetrical parts, A' and A" of A₁. Thus, we investigated in detail the TEC climatology from maps of these indices, with an emphasis on the quantitative presentation for local time and latitudinal changes in the seasonal, annual and semiannual anomalies of the ionospheric TEC. Then we took the TEC value at 14:00 LT to examine various anomalies at a global scale following the same procedure. Results reveal similar features appearing in NmF2, such as that the seasonal anomaly is more significant in the near-pole regions than in the far-pole regions and the reverse is true for the semiannual anomaly; the winter anomaly has least a chance to be observed at the South America and South Pacific areas. The most impressive feature is that the equinoctial asymmetry is most prominent at the East Asian and South Australian areas. Through the analysis of the TIMED GUVI columnar [O/N2] data, we have investigated to what extent the seasonal, annual and semiannual variations can be explained by their counterparts in [O/N2]. Results revealed that the [O/N2] variation is a major contributor to the daytime winter anomaly of TEC, and it also contributes to some of the semiannual and annual anomalies. The contribution to the anomalies unexplained by the [O/N2] data could possibly be due to the dynamics associated with thermospheric winds and electric fields.

Overhead irrigation increased winter chilling and floral bud ...

African Journals Online (AJOL)

Eucalyptus nitens requires a sufficiently cold winter to produce flower buds. In areas in South Africa where E. nitens commercial plantations as well as breeding and production seed orchards are located, winter chilling is often insufficient for floral bud initiation. Hence, under such conditions, E. nitens floral bud and seed ...

Disentangling Environmental and Anthropogenic Impacts on the Distribution of Unintentionally Introduced Invasive Alien Insects in Mainland China.

Science.gov (United States)

Zhao, Cai-Yun; Li, Jun-Sheng; Xu, Jing; Liu, Xiao-Yan

2017-05-01

Globalization increases the opportunities for unintentionally introduced invasive alien species, especially for insects, and most of these species could damage ecosystems and cause economic loss in China. In this study, we analyzed drivers of the distribution of unintentionally introduced invasive alien insects. Based on the number of unintentionally introduced invasive alien insects and their presence/absence records in each province in mainland China, regression trees were built to elucidate the roles of environmental and anthropogenic factors on the number distribution and similarity of species composition of these insects. Classification and regression trees indicated climatic suitability (the mean temperature in January) and human economic activity (sum of total freight) are primary drivers for the number distribution pattern of unintentionally introduced invasive alien insects at provincial scale, while only environmental factors (the mean January temperature, the annual precipitation and the areas of provinces) significantly affect the similarity of them based on the multivariate regression trees. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

Does Wyoming's Core Area Policy Protect Winter Habitats for Greater Sage-Grouse?

Science.gov (United States)

Smith, Kurt T.; Beck, Jeffrey L.; Pratt, Aaron C.

2016-10-01

Conservation reserves established to protect important habitat for wildlife species are used world-wide as a wildlife conservation measure. Effective reserves must adequately protect year-round habitats to maintain wildlife populations. Wyoming's Sage-Grouse Core Area policy was established to protect breeding habitats for greater sage-grouse ( Centrocercus urophasianus). Protecting only one important seasonal habitat could result in loss or degradation of other important habitats and potential declines in local populations. The purpose of our study was to identify the timing of winter habitat use, the extent which individuals breeding in Core Areas used winter habitats, and develop resource selection functions to assess effectiveness of Core Areas in conserving sage-grouse winter habitats in portions of 5 Core Areas in central and north-central Wyoming during winters 2011-2015. We found that use of winter habitats occured over a longer period than current Core Area winter timing stipulations and a substantial amount of winter habitat outside of Core Areas was used by individuals that bred in Core Areas, particularly in smaller Core Areas. Resource selection functions for each study area indicated that sage-grouse were selecting habitats in response to landscapes dominated by big sagebrush and flatter topography similar to other research on sage-grouse winter habitat selection. The substantial portion of sage-grouse locations and predicted probability of selection during winter outside small Core Areas illustrate that winter requirements for sage-grouse are not adequately met by existing Core Areas. Consequently, further considerations for identifying and managing important winter sage-grouse habitats under Wyoming's Core Area Policy are warranted.

Seasonal Changes in Atmospheric Noise Levels and the Annual Variation in Pigeon Homing Performance

Science.gov (United States)

Hagstrum, J. T.; McIsaac, H. P.; Drob, D. P.

2015-12-01

The remarkable navigational ability of homing pigeons (Columba livia) is influenced by a number of factors, an unknown one of which causes the "Wintereffekt"1 or annual variation in homing performance. Minima in homeward orientation and return speeds have been observed in winter, with maxima in summer, during repetitive pigeon releases from single sites near experimental lofts in Wilhelmshaven, Göttingen, and Munich, Germany, and near Pisa, Italy1-4. Overall the annual variation is more pronounced in northern Germany than Italy4, and both mature and juvenile cohorts respond to this seasonal factor. Older, more experienced pigeons are better at compensating for its effects than naïve ones, but are still affected after numerous releases. The narrow low-frequency band of atmospheric background noise (microbaroms; 0.1-0.3 Hz) also varies with an annual cycle that generally has higher amplitudes in winter than in summer depending on location5. In addition, homing pigeons, and possibly other birds, apparently use infrasonic signals of similar frequency as navigational cues6, and a seasonal variation in background noise levels could cause corresponding changes in signal-to-noise ratios and thus in homing performance. The annual variation in homing performance, however, was not observed during long-term pigeon releases at two sites in eastern North America. The annual and geographic variability in homing performance in the northern hemisphere can be explained to a first order by seasonal changes in infrasonic noise sources related to ocean storm activity, and to the direction and intensity of stratospheric winds. In addition, increased dispersion in departure bearings of individual birds for some North American releases were likely caused by additional infrasonic noise associated with severe weather events during tornado and Atlantic hurricane seasons. 1Kramer, G. & von Saint Paul, U., J. Ornithol. 97, 353-370 (1956); 2Wallraff, H. G., Z. Tierpsychol. 17, 82-113 (1960

The Japanese alga Polysiphonia morrowii (Rhodomelaceae, Rhodophyta) on the South Atlantic Ocean: first report of an invasive macroalga inhabiting oyster reefs

Science.gov (United States)

Croce, M. Emilia; Parodi, Elisa R.

2014-06-01

Conspicuous tufts of the filamentous algae Polysiphonia Greville inhabit the reefs of Crassostrea gigas on the Atlantic Patagonian coast. The population was recorded for the first time in 1994 and identified as P. argentinica. This study exhaustively investigated the morphology and reproduction of specimens and the seasonality of the population. The results revealed the identity of the specimens as the invasive Japanese macroalga Polysiphonia morrowii Harvey, on the basis of several striking features: the setaceous and tufted thalli, the corymbose growing apices, the endogenous axillary branches, the urceolate cystocarps and the sharply pointed branches. Sexual reproduction was evidenced; however, fertile male gametophytes were absent in the samples. The population was found almost all year round, but its abundance became higher in autumn and winter. The present study constitutes the first record of this invasive macroalga on the South Atlantic Ocean; the fourth record of an exotic macroalgal species on the Atlantic Patagonian coast; and the first record of an invasive species related to the establishment of C. gigas in Atlantic Patagonia.

Do cheatgrass, snake river wheatgrass, and crested wheatgrass sense different availabilities of N and P in soils conditioned by a cheatgrass invasion?

Science.gov (United States)

Long-term invasion by cheatgrass often increases availability of soil N and P thereby fostering increased competitive ability. We designed an experiment to test if cheatgrass (exotic annual), Snake River wheatgrass (native perennial), and crested wheatgrass (exotic perennial) all benefit from this e...

Neurotic psychopathology and alexithymia among winter swimmers and controls--a prospective study.

Science.gov (United States)

Lindeman, Sari; Hirvonen, Jorma; Joukamaa, Matti

2002-05-01

Random samples of 25 voluntary Finnish winter swimmers (7 males, 18 females) and 11 controls (3 males, 8 females were followed prospectively during the winter season from October 1999 to May 2000 to (determine whether winter swimming is beneficial for mental well-being, as many of its practitioners claim. The Crown-Crisp Experimental Index (CCEI) was used for measuring free-floating anxiety, phobic anxiety, obsessionality, depression, somatic anxiety and hysteria, and the 20-item version of the Toronto Alexithymia Scale (TAS-20) for measuring alexithymia. Self-reported somatic and mental health and the reasons for and the frequency of winter-swimming were asked, too. As resealed by open questions, the winter swimmers reported positive effects of winter swimming. Several of the swimmers also told that they had started winter swimming to improve their physical and mental health. Their experience was that the swimming had relieved physical symptoms and made their mood more positive. However, we found no major differences between winter swimmers and controls in any CCEI or TAS variables. The structured questionnaires do not necessarily, however, reach subjective feelings and experiences.

Nuclear Winter: The implications for civil defense

International Nuclear Information System (INIS)

Chester, C.V.; Perry, A.M.; Hobbs, B.F.

1987-01-01

''Nuclear Winter'' is the term given to hypothesized cooling in the northern hemisphere following a nuclear war due to injection of smoke from burning cities into the atmosphere. The voluminous literature on this subject produced since the original paper in 1983 by Turco, Toon, Ackerman, Pollack, and Sagen (TTAPS) has been reviewed. The widespread use of 3-dimensional global circulation models have resulted in reduced estimates of cooling; 15 to 25 0 C for a summer war and a few degrees for a winter war. More serious may be the possibility of suppression of convective precipitation by the altered temperature profiles in the atmosphere. However, very large uncertainties remain in input parameters, the models, and the results of calculations. We believe the state of knowledge about nuclear winter is sufficiently developed to conclude: Neither cold nor drought are likely to be direct threats to human survival for populations with the wherewithal to survive normal January temperatures; The principal threat from nuclear winter is to food production, and could present problems to third parties without food reserves; and Loss of a crop year is neither a new nor unexpected threat from nuclear war to the US and the Soviet Union. Both have at least a year's food reserve at all times. Both face formidable organizational problems in distributing their reserves in a war-damaged environment. The consequences of nuclear winter could be expected to fall more heavily on the Soviet Union than the US due to its higher latitude and less productive agriculture. This may be especially true if disturbances of rainfall amounts and distribution persist for more than a year. 6 refs

Interference competition between an invasive parakeet and native bird species at feeding sites.

Science.gov (United States)

Le Louarn, Marine; Couillens, Bertrand; Deschamps-Cottin, Magali; Clergeau, Philippe

2016-01-01

Interference competition has proved to be a factor of successful establishment of invasive species. This type of competition may have a stronger impact when native species have temporal niche overlap with the invasive species. The ring-necked parakeet Psittacula krameri has been successfully introduced in many countries and its interspecific agonistic behavior has already been reported. The purpose of this study is to analyze the territorial and preemptive interference competition between the ring-necked parakeet and native bird species in a recently colonized area. We used an empirical approach by recording video sequences in gardens equipped with bird feeders in winter. Our results showed that the ring-necked parakeet was the most frequent species at the feeders. Several native species showed temporal niche overlap with the ring-necked parakeet, the highest overlap being with the starling Sturnus vulgaris . The starling was also the species most impacted by interference competition with the parakeet. Our study suggests that, by being most frequently present at the feeders, by demonstrating the most agonistic behavior and by hindering access to food of the other species, the ring-necked parakeet is a superior competitor and may compete with native bird species.

CAN WINTER DEPRESSION BE PREVENTED BY LIGHT TREATMENT

NARCIS (Netherlands)

MEESTERS, Y; LAMBERS, PA; JANSEN, JHC; BOUHUYS, AL; BEERSMA, DGM; VANDENHOOFDAKKER, RH

1991-01-01

The administration of light at the development of the first signs of a winter depression appears to prevent it from developing into a full-blown depression. No patient from a group of 10 treated in this way developed any signs of depression during the rest of the winter season, while five of seven

Can winter depression be prevented by light treatment?

NARCIS (Netherlands)

Meesters, Ybe; Lambers, Petrus A.; Jansen, Jacob; Bouhuys, Antoinette L.; Beersma, Domien G.M.; Hoofdakker, Rutger H. van den

1991-01-01

The administration of light at the development of the first signs of a winter depression appears to prevent it from developing into a full-blown depression. No patient from a group of 10 treated in this way developed any signs of depression during the rest of the winter season, while five of seven

National Nuclear Security Administration Nonproliferation Graduate Fellowship Program Annual Report in Brief: October 2007 - May 2008

Energy Technology Data Exchange (ETDEWEB)

Berkman, Clarissa O.; Fankhauser, Jana G.; Sandusky, Jessica A.

2009-05-01

This abbreviated Annual Report covers program activities of the National Nuclear Security Administration (NNSA) Nonproliferation Graduate Fellowship Program (NGFP) from October 2007 through May 2008--the timeframe between the last Annual Report (which covered activities through September 2007) and the next report (which will begin with June 2008 activities). In that timeframe, the NGFP continued building a solid foundation as the program began reaping the benefits of recently implemented changes. This report is organized by Fellowship class and the pertinent program activities for each, including: October 2007 Recruiting events and final applications (Class of 2008) Winter 2007 Selection and hiring (Class of 2008) Spring 2008 Career development roundtables (Class of 2007) Orientation planning (Class of 2008) Recruitment planning and university outreach (Class of 2009) May 2008 Closing ceremony (Class of 2007)

Are cold winters in Europe associated with low solar activity?

International Nuclear Information System (INIS)

Lockwood, M; Harrison, R G; Woollings, T; Solanki, S K

2010-01-01

Solar activity during the current sunspot minimum has fallen to levels unknown since the start of the 20th century. The Maunder minimum (about 1650-1700) was a prolonged episode of low solar activity which coincided with more severe winters in the United Kingdom and continental Europe. Motivated by recent relatively cold winters in the UK, we investigate the possible connection with solar activity. We identify regionally anomalous cold winters by detrending the Central England temperature (CET) record using reconstructions of the northern hemisphere mean temperature. We show that cold winter excursions from the hemispheric trend occur more commonly in the UK during low solar activity, consistent with the solar influence on the occurrence of persistent blocking events in the eastern Atlantic. We stress that this is a regional and seasonal effect relating to European winters and not a global effect. Average solar activity has declined rapidly since 1985 and cosmogenic isotopes suggest an 8% chance of a return to Maunder minimum conditions within the next 50 years (Lockwood 2010 Proc. R. Soc. A 466 303-29): the results presented here indicate that, despite hemispheric warming, the UK and Europe could experience more cold winters than during recent decades.

Invasion dynamics of Pinus elliottii Engelm. on restinga under a restoration process inside Parque Florestal do Rio Vermelho, Florianópolis, SC

Directory of Open Access Journals (Sweden)

Kurt Bourscheid

2010-06-01

Full Text Available Species invasion in natural communities is considered a great threat to global biodiversity. The second biggest cause of extinction worldwide is related to invasive species action, which is only smaller than habitat loss and fragmentation. The objective of this study was to quantify the levels of Pinus elliottii Engelm. var. elliottii infestation in Parque Florestal do Rio Vermelho, Florianópolis, SC, Brazil. One year after the clearance of one hectare of Pinus, 100 plots were set to evaluate Pinus regeneration. Semestral evaluations were made between the winter of 2003 and the summer of 2005. Population density showed significant differences (p<0.05, varying from 19,617 plants/ha to 166,624 plants/ha. The border effect became strong after the winter of 2004 and the emergence rate increased significantly. The zones closest to the of fungus on Jatropha curcas seeds. The physiological quality was preserved during the cryoconservation. border showed the highest population densities, reaching 362,268 plants/ha on the first 10m from the border. The mean population density of each zone resulted in a decreasing exponential equation where there were 569,598 plants/ha on the zone closest to the border and 43,768 plants/ha on the border’s furthest zone. This led to the recommendation to cut all Young 2 plants about every 4 years in order to control the reinfestation.

Going outside in Winter: A Qualitative Study of Preschool Dressing Routines

Science.gov (United States)

Hatcher, Beth; Squibb, Betsy

2011-01-01

The exploratory study focused on describing typical routines of preparing for winter outdoor play with preschool children and their teachers. Naturalistic observations, interviews and photographs resulted in extensive examples of children's development in cognitive understanding of winter and winter-related concepts. Observations of teachers and…

The risk of establishment of aquatic invasive species: joining invasibility and propagule pressure.

Science.gov (United States)

Leung, Brian; Mandrak, Nicholas E

2007-10-22

Invasive species are increasingly becoming a policy priority. This has spurred researchers and managers to try to estimate the risk of invasion. Conceptually, invasions are dependent both on the receiving environment (invasibility) and on the ability to reach these new areas (propagule pressure). However, analyses of risk typically examine only one or the other. Here, we develop and apply a joint model of invasion risk that simultaneously incorporates invasibility and propagule pressure. We present arguments that the behaviour of these two elements of risk differs substantially--propagule pressure is a function of time, whereas invasibility is not--and therefore have different management implications. Further, we use the well-studied zebra mussel (Dreissena polymorpha) to contrast predictions made using the joint model to those made by separate invasibility and propagule pressure models. We show that predictions of invasion progress as well as of the long-term invasion pattern are strongly affected by using a joint model.

Genetic differentiation between sympatric and allopatric wintering populations of Snow Geese

Science.gov (United States)

Humphries, E.M.; Peters, J.L.; Jonsson, J.E.; Stone, R.; Afton, A.D.; Omland, K.E.

2009-01-01

Blackwater National Wildlife Refuge on the Delmarva Peninsula, Maryland, USA has been the wintering area of a small population of Lesser Snow Geese (Chen caerulescens caerulescens; LSGO) since the 1930s. Snow Geese primarily pair in wintering areas and gene flow could be restricted between this and other LSGO wintering populations. Winter pair formation also could facilitate interbreeding with sympatric but morphologically differentiated Greater Snow Geese (C. c. atlantica; GSGO).We sequenced 658 bp of the mitochondrial DNA control region for 68 Snow Geese from East Coast and Louisiana wintering populations to examine the level of genetic differentiation among populations and subspecies. We found no evidence for genetic differentiation between LSGO populations but, consistent with morphological differences, LSGO and GSGO were significantly differentiated. We also found a lack of genetic differentiation between different LSGO morphotypes from Louisiana. We examined available banding data and found the breeding range of Delmarva LSGO overlaps extensively with LSGO that winter in Louisiana, and documented movements between wintering populations. Our results suggest the Delmarva population of LSGO is not a unique population unit apart from Mid-Continent Snow Geese. ?? 2009 by the Wilson Ornithological Society.

Declining trends in invasive orthopedic interventions for people with hemophilia enrolled in the Universal Data Collection program (2000–2010)

Science.gov (United States)

TOBASE, P.; LANE, H.; SIDDIQI, A.-E-A.; INGRAM-RICH, R.; WARD, R. S.

2016-01-01

Introduction Recurrent joint hemarthroses due to hemophilia (Factor VIII and Factor IX deficiency) often lead to invasive orthopedic interventions to decrease frequency of bleeding and/or to alleviate pain associated with end-stage hemophilic arthropathy. Aim Identify trends in invasive orthopedic interventions among people with hemophilia who were enrolled in the Universal Data Collection (UDC) program during the period 2000–2010. Methods Data were collected from 130 hemophilia treatment centers in the United States annually during the period 2000–2010, in collaboration with the Centers for Disease Control and Prevention (CDC). The number of visits in which an invasive orthopedic intervention was reported was expressed as a proportion of the total visits in each year of the program. Invasive orthopedic interventions consisted of arthroplasty, arthrodesis, and synovectomy. Joints included in this study were the shoulder, elbow, hip, knee, and ankle. Results A 5.6% decrease in all invasive orthopedic interventions in all joints of people with hemophilia enrolled in the UDC program over the 11-year study period was observed. Conclusions These data reflect a declining trend in invasive orthopedic interventions in people with hemophilia. Further research is needed to understand the characteristics that may influence invasive orthopedic interventions. PMID:27030396

Biological soil crusts are the main contributor to winter soil respiration in a temperate desert ecosystem of China

Science.gov (United States)

He, M. Z.

2012-04-01

Aims Biological soil crusts (BSCs) are a key biotic component of desert ecosystems worldwide. However, most studies carried out to date on carbon (fluxes) in these ecosystems, such as soil respiration (RS), have neglected them. Also, winter RS is reported to be a significant component of annual carbon budget in other ecosystems, however, we have less knowledge about winter RS of BSCs in winter and its contribution to carbon cycle in desert regions. Therefore, the specific objectives of this study were to: (i) quantify the effects of different BSCs types (moss crust, algae crust, physical crust) on the winter RS; (ii) explore relationships of RS against soil temperature and water content for different BSCs, and (iii) assess the relative contribution of BSCs to the annual amount of C released by RS at desert ecosystem level. Methods Site Description The study sites are located at the southeast fringe of the Tengger Desert in the Shapotou region of the Ningxia Hui Autonomous Region [37°32'N and 105°02'E, at 1340 m above mean sea level (a.m.s.l.)], western China. The mean daily temperature in January is -6.9°C , while it is 24.3°C in July. The mean annual precipitation is 186 mm, approximately 80% of which falls between May and September. The annual potential evaporation is 2800 mm. The landscape of the Shapotou region is characterized by large and dense reticulate barchans chains of sand dunes that migrate south-eastward at a velocity of 3-6 m per year. The soil is loose, infertile and mobile and can thus be classified as orthic sierozem and Aeolian sandy soil. Additionally, the soil has a consistent gravimetric water content that ranges from 3 to 4%. The groundwater in the study area is too deep (>60 m) to support large areas of the native vegetation cover; therefore, precipitation is usually the only source of freshwater. The predominant native plants are Hedysarum scoparium Fisch. and Agriophyllum squarrosum Moq., Psammochloa cillosa Bor, which scattered

Comparative anatomy of invasive and non-invasive species in the ...

African Journals Online (AJOL)

The foliar and stem micromorphological study of the invasive and non-invasive species were undertaken using Light Microscope (LM). The occurrence of vessels in the pillar of the abundant sclerenchyma tissues are important component of the skeletal system in the invasive species. The prominent tiles of parenchymatous ...

Preventing a new invasive alien plant from entering and spreading in the Euro-Mediterranean region: The case study of Parthenium hysterophorus

NARCIS (Netherlands)

Brunel, S.; Panetta, D.; Fried, G.; Kriticos, D.; Prasad, R.; Oude Lansink, A.G.J.M.; Shabbir, A.; Yaacoby, T.

2014-01-01

Parthenium or famine weed (Parthenium hysterophorus L.) is an annual plant originating from the Americas, which is a major invasive alien plant in almost all continents. While the deleterious impacts of the species on agriculture, human and animal health have been well documented, information on the

Downtown People Mover (DPM) Winterization Test Demonstration : Otis Elevator

Science.gov (United States)

1982-01-01

The Otis Elevator Company Transportation Technology Division (OTIS-TTD) Downtown People Mover (DPM) Winterization Test Demonstration Final Report covers the 1978-79 and 1979-80 winter periods. Tests were performed at the Otis test track in Denver, Co...

Small Winter Thunderstorm with Sprites and Strong Positive Discharge

Science.gov (United States)

Suzuki, Tomoyuki; Hayakawa, Masashi; Michimoto, Koichiro

A sprite campaign was conducted in the Hokuriku area of Japan during a winter of 2004/2005. On the basis of a combined analysis of the data from various instruments (CCD cameras, radar, VHF/LF∼MF lightning mapping system, field mill network, and ELF detector), we studied meteorological and electrical structures for winter thunderstorms and sprite-producing positive discharge. Typical winter sprite parent thunderstorms had a meso-scale cloud area with embedded small convective cells. Some small winter thunderstorms accompanied by the most frequent sprite events were found to cause 2∼3 sprite events during a short interval of about 3∼5 min. When the sprites were observed, the extent of the convective cells at 20 dBZ counter was atmost ∼20 × 20 km. The VHF sources associated with sprites were located near south of the convective cell and were mapped within very small areas of at most ∼10 × 10 km. This fact shows that some small winter thunderstorms can generate large positive charge associated with sprites. We will present the analysis of such a small thunderstorms with sprites and positive lightning discharges.

Kleptoparasitism by bald eagles wintering in south-central Nebraska

Science.gov (United States)

Jorde, Dennis G.; Lingle, G.R.

1988-01-01

Kleptoparasitism on other raptors was one means by which Bald Eagles (Haliaeetus leucocephalus) secured food along the North Platte and Platte rivers during the winters of 1978-1980. Species kelptoparasitized were Ferruginous Hawk (Buteo regalis), Red-tailed Hawk (B. jamaicensis), Rough-legged Hawk (B. lagopus), Golden Eagle (Aquila chrysaetos), and Bald Eagle. Stealing of prey occurred more often during the severe winter of 1978-1979 when ice cover restricted eagles from feeding on fish than during the milder winter of 1979-1980. Kleptoparasitism occurred principally in agricultural habitats where large numbers of Mallards (Anas platyrhynchos) were foraging. Subadults watched adults steal food and participated in food-stealing with adults, which indicated interspecific kleptoparasitism may be a learned behavior. We suggest factors that may favor interspecific kleptoparasitism as a foraging strategy of Bald Eagles in obtaining waterfowl during severe winters.

Trait differences between naturalized and invasive plant species independent of residence time and phylogeny.

Science.gov (United States)

Gallagher, R V; Randall, R P; Leishman, M R

2015-04-01

The ability to predict which alien plants will transition from naturalized to invasive prior to their introduction to novel regions is a key goal for conservation and has the potential to increase the efficacy of weed risk assessment (WRA). However, multiple factors contribute to plant invasion success (e.g., functional traits, range characteristics, residence time, phylogeny), and they all must be taken into account simultaneously in order to identify meaningful correlates of invasion success. We compiled 146 pairs of phylogenetically paired (congeneric) naturalized and invasive plant species in Australia with similar minimum residence times (i.e., time since introduction in years). These pairs were used to test for differences in 5 functional traits (flowering duration, leaf size, maximum height, specific leaf area [SLA], seed mass) and 3 characteristics of species' native ranges (biome occupancy, mean annual temperature, and rainfall breadth) between naturalized and invasive species. Invasive species, on average, had larger SLA, longer flowering periods, and were taller than their congeneric naturalized relatives. Invaders also exhibited greater tolerance for different environmental conditions in the native range, where they occupied more biomes and a wider breadth of rainfall and temperature conditions than naturalized congeners. However, neither seed mass nor leaf size differed between pairs of naturalized and invasive species. A key finding was the role of SLA in distinguishing between naturalized and invasive pairs. Species with high SLA values were typically associated with faster growth rates, more rapid turnover of leaf material, and shorter lifespans than those species with low SLA. This suite of characteristics may contribute to the ability of a species to transition from naturalized to invasive across a wide range of environmental contexts and disturbance regimes. Our findings will help in the refinement of WRA protocols, and we advocate the inclusion

Winter severity determines functional trait composition of phytoplankton in seasonally ice-covered lakes.

Science.gov (United States)

Özkundakci, Deniz; Gsell, Alena S; Hintze, Thomas; Täuscher, Helgard; Adrian, Rita

2016-01-01

How climate change will affect the community dynamics and functionality of lake ecosystems during winter is still little understood. This is also true for phytoplankton in seasonally ice-covered temperate lakes which are particularly vulnerable to the presence or absence of ice. We examined changes in pelagic phytoplankton winter community structure in a north temperate lake (Müggelsee, Germany), covering 18 winters between 1995 and 2013. We tested how phytoplankton taxa composition varied along a winter-severity gradient and to what extent winter severity shaped the functional trait composition of overwintering phytoplankton communities using multivariate statistical analyses and a functional trait-based approach. We hypothesized that overwintering phytoplankton communities are dominated by taxa with trait combinations corresponding to the prevailing winter water column conditions, using ice thickness measurements as a winter-severity indicator. Winter severity had little effect on univariate diversity indicators (taxon richness and evenness), but a strong relationship was found between the phytoplankton community structure and winter severity when taxon trait identity was taken into account. Species responses to winter severity were mediated by the key functional traits: motility, nutritional mode, and the ability to form resting stages. Accordingly, one or the other of two functional groups dominated the phytoplankton biomass during mild winters (i.e., thin or no ice cover; phototrophic taxa) or severe winters (i.e., thick ice cover; exclusively motile taxa). Based on predicted milder winters for temperate regions and a reduction in ice-cover durations, phytoplankton communities during winter can be expected to comprise taxa that have a relative advantage when the water column is well mixed (i.e., need not be motile) and light is less limiting (i.e., need not be mixotrophic). A potential implication of this result is that winter severity promotes different

Allelopathic potential of segetal and ruderal invasive alien plants

Directory of Open Access Journals (Sweden)

Nenad Novak

2018-06-01

Full Text Available At the global level, the invasion of alien organisms is considered the second largest threat to biodiversity. The assumption is that the high allelopathic potential is one of the features that helps invasive plant species to spread to new areas. Allelopathic potential of 8 invasive plant species (donor species and their impact on test-species was determined in the study. Donor species were velvetleaf (Abutilon theophrasti Med., ragweed (Ambrosia elatior L., jimsonweed (Datura stramonium L., common cocklebur (Xanthium strumarium L., tree of heaven (Ailanthus altissima (Mill. Swingle, indigo bush (Amorpha fruticosa L., Japanese knotweed (Reynoutria japonica Houtt. and giant goldenrod (Solidago gigantea Aiton. Three cultivated plant species from 3 different plant families were used as test-species. Test-species were: oat (Avena sativa L., oilseed rape (Brassica napus subsp. oleifera and sunflower (Helianthus annuus L.. Water extracts made of whole plants of donor species were applied to the seeds of the test-species. High allelopathic potential was proven for all species included in experiment. Allelopathic effects were exclusively negative. Impact on germination for all species was much lower in relation to the impact on the radicle and shoot length of the test-species. Perennial donor species had a stronger allelopathic potential than annual donor species. Tree of heaven was the species with the strongest allelopathic potential. Its extracts inhibited germination, radicle and shoot length of oilseed rape by 19%, 94.88% and 98.91% respectively.

Winter School Les Houches

CERN Document Server

Lannoo, Michel; Bastard, Gérald; Voos, Michel; Boccara, Nino

1986-01-01

The Winter School held in Les Houches on March 12-21, 1985 was devoted to Semiconductor Heterojunctions and Superlattices, a topic which is recognized as being now one of the most interesting and active fields in semiconductor physics. In fact, following the pioneering work of Esaki and Tsu in 1970, the study of these two-dimensional semiconductor heterostructures has developed rapidly, both from the point of view of basic physics and of applications. For instance, modulation-doped heterojunctions are nowadays currently used to investigate the quantum Hall effect and to make very fast transistors. This book contains the lectures presented at this Winter School, showing in particular that many aspects of semiconductor heterojunctions and super­ lattices were treated, extending from the fabrication of these two-dimensional systems to their basic properties and applications in micro-and opto-electron­ ics. Among the subjects which were covered, one can quote as examples: molecular beam epitaxy and metallorgani...

Editorial - The winter Atomiades

CERN Multimedia

Staff Association

2011-01-01

As we wrote in our previous editorial, the Staff Association gives direct support to sports events, such as the Atomiades, a section of the Association of Sports Communities of European Research Institutes, which brings together sportsmen and women from 38 European research centres in 13 countries (Austria, Belgium, Czech Republic, United Kingdom, Finland, France, Germany, Hungary, Italy, Luxemburg, the Netherlands, Russia, and Switzerland). The summer Atomiades take place between the months of June and September every three years. Thirteen such events have taken place since 1973, the last one in June 2009 in Berlin. As far as the winter Atomiades are concerned, also organized every three years, and alternating with the summer Atomiades, there have been eleven since 1981, the last one at the end of January this year in neighbouring France. The following article tells the wonderful adventure of the CERN staff who took part in this event. A positive outcome for CERN skiers at the winter Atomiades The 11t...

Impact of warm winters on microbial growth

Science.gov (United States)

Birgander, Johanna; Rousk, Johannes; Axel Olsson, Pål

2014-05-01

Growth of soil bacteria has an asymmetrical response to higher temperature with a gradual increase with increasing temperatures until an optimum after which a steep decline occurs. In laboratory studies it has been shown that by exposing a soil bacterial community to a temperature above the community's optimum temperature for two months, the bacterial community grows warm-adapted, and the optimum temperature of bacterial growth shifts towards higher temperatures. This result suggests a change in the intrinsic temperature dependence of bacterial growth, as temperature influenced the bacterial growth even though all other factors were kept constant. An intrinsic temperature dependence could be explained by either a change in the bacterial community composition, exchanging less tolerant bacteria towards more tolerant ones, or it could be due to adaptation within the bacteria present. No matter what the shift in temperature tolerance is due to, the shift could have ecosystem scale implications, as winters in northern Europe are getting warmer. To address the question of how microbes and plants are affected by warmer winters, a winter-warming experiment was established in a South Swedish grassland. Results suggest a positive response in microbial growth rate in plots where winter soil temperatures were around 6 °C above ambient. Both bacterial and fungal growth (leucine incorporation, and acetate into ergosterol incorporation, respectively) appeared stimulated, and there are two candidate explanations for these results. Either (i) warming directly influence microbial communities by modulating their temperature adaptation, or (ii) warming indirectly affected the microbial communities via temperature induced changes in bacterial growth conditions. The first explanation is in accordance with what has been shown in laboratory conditions (explained above), where the differences in the intrinsic temperature relationships were examined. To test this explanation the

Responses to invasion and invader removal differ between native and exotic plant groups in a coastal dune.

Science.gov (United States)

Magnoli, Susan M; Kleinhesselink, Andrew R; Cushman, J Hall

2013-12-01

The spread of exotic, invasive species is a global phenomenon that is recognized as a major source of environmental change. Although many studies have addressed the effects of exotic plants on the communities they invade, few have quantified the effects of invader removal on plant communities, or considered the degree to which different plant groups vary in response to invasion and invader removal. We evaluated the effects of an exotic succulent, iceplant (Carpobrotus edulis), on a coastal dune plant community in northern California, as well as the community responses to its removal. To assess possible mechanisms by which iceplant affects other plants, we also evaluated its above- and belowground influences on the germination and growth of a dominant exotic annual grass, Bromus diandrus. We found that iceplant invasion was associated with reduced native plant cover as well as increased cover and density of some exotic plants-especially exotic annual grasses. However, iceplant removal did not necessarily lead to a reversal of these effects: removal increased the cover and density of both native and exotic species. We also found that B. diandrus grown in iceplant patches, or in soil where iceplant had been removed, had poorer germination and growth than B. diandrus grown in soil not influenced by iceplant. This suggests that the influence of iceplant on this dune plant community occurs, at least in part, due to belowground effects, and that these effects remain after iceplant has been removed. Our study demonstrates the importance of considering how exotic invasive plants affect not only native species, but also co-occurring exotic taxa. It also shows that combining observational studies with removal experiments can lead to important insights into the influence of invaders and the mechanisms of their effects.

A meta-analysis of trait differences between invasive and non-invasive plant species

OpenAIRE

van Kleunen, Mark; Weber, Ewald; Fischer, Markus

2010-01-01

A major aim in ecology is identifying determinants of invasiveness. We performed a meta-analysis of 117 field or experimental-garden studies that measured pair-wise trait differences of a total of 125 invasive and 196 non-invasive plant species in the invasive range of the invasive species. We tested whether invasiveness is associated with performance-related traits (physiology, leaf-area allocation, shoot allocation, growth rate, size and fitness), and whether such associations depend on typ...

A winter severity index for the state of Maine.

Science.gov (United States)

2009-01-01

Winter maintenance in the Sate of Maine consumes around twenty percent of the Bureau of : Maintenance and Operations budget each year. Costs are directly related to the length and severity : of a winter season. In addition, the cost of materials and ...

The role of composition, invasives, and maintenance emissions on urban forest carbon stocks.

Science.gov (United States)

Horn, Josh; Escobedo, Francisco J; Hinkle, Ross; Hostetler, Mark; Timilsina, Nilesh

2015-02-01

There are few field-based, empirical studies quantifying the effect of invasive trees and palms and maintenance-related carbon emissions on changes in urban forest carbon stocks. We estimated carbon (C) stock changes and tree maintenance-related C emissions in a subtropical urban forest by re-measuring a subsample of residential permanent plots during 2009 and 2011, using regional allometric biomass equations, and surveying residential homeowners near Orlando, FL, USA. The effect of native, non-native, invasive tree species and palms on C stocks and sequestration was also quantified. Findings show 17.8 tC/ha in stocks and 1.2 tC/ha/year of net sequestration. The most important species both by frequency of C stocks and sequestration were Quercus laurifolia Michx. and Quercus virginiana Mill., accounting for 20% of all the trees measured; 60% of carbon stocks and over 75% of net C sequestration. Palms contributed to less than 1% of the total C stocks. Natives comprised two-thirds of the tree population and sequestered 90% of all C, while invasive trees and palms accounted for 5 % of net C sequestration. Overall, invasive and exotic trees had a limited contribution to total C stocks and sequestration. Annual tree-related maintenance C emissions were 0.1% of total gross C sequestration. Plot-level tree, palm, and litter cover were correlated to C stocks and net sequestration. Findings can be used to complement existing urban forest C offset accounting and monitoring protocols and to better understand the role of invasive woody plants on urban ecosystem service provision.

Terrestrial animals as invasive species and as species at risk from invasions

Science.gov (United States)

Deborah M. Finch; Dean Pearson; Joseph Wunderle; Wayne Arendt

2010-01-01

Including terrestrial animal species in the invasive species strategy plan is an important step in invasive species management. Invasions by nonindigenous species threaten nearly 50 percent of imperiled native species in the United States and are the Nation's second leading cause of species endangerment. Invasion and conversion of native habitats by exotic species...

Is Switzerland suitable for the invasion of Aedes albopictus [corrected]?

Science.gov (United States)

Neteler, Markus; Metz, Markus; Rocchini, Duccio; Rizzoli, Annapaola; Flacio, Eleonora; Engeler, Luca; Guidi, Valeria; Lüthy, Peter; Tonolla, Mauro

2013-01-01

Over the last 30 years, the Asian tiger mosquito, Aedes albopictus, has rapidly spread around the world. The European distribution comprises the Mediterranean basin with a first appearance in Switzerland in 2003. Early identification of the most suitable areas in Switzerland allowing progressive invasion by this species is considered crucial to suggest adequate surveillance and control plans. We identified the most suitable areas for invasion and establishment of Ae. albopictus in Switzerland. The potential distribution areas linked to the current climatic suitability were assessed using remotely sensed land surface temperature data recorded by the MODIS satellite sensors. Suitable areas for adult survival and overwintering of diapausing eggs were also identified for future climatic conditions, considering two different climate change scenarios (A1B, A2) for the periods 2020-2049 and 2045-2074. At present, the areas around Lake Geneva in western Switzerland provide suitable climatic conditions for Ae. albopictus. In northern Switzerland, parts of the Rhine valley, around Lake Constance, as well as the surroundings of Lake Neuchâtel, appear to be suitable for the survival at least of adult Ae. albopictus. However, these areas are characterized by winters currently being too cold for survival and development of diapausing eggs. In southern Switzerland, Ae. albopictus is already well-established, especially in the Canton of Ticino. For the years 2020-2049, the predicted possible spread of the tiger mosquito does not differ significantly from its potential current distribution. However, important expansions are obtained if the period is extended to the years 2045-2074, when Ae. albopictus may invade large new areas. Several parts of Switzerland provide suitable climatic conditions for invasion and establishment of Ae. albopictus. The current distribution and rapid spread in other European countries suggest that the tiger mosquito will colonize new areas in Switzerland

Exotic Annual Grasses in Western Rangelands: Predicting Resistance and Resilience of Native Ecosystems to Invasion (Draft)

National Research Council Canada - National Science Library

Belnap, Jayne; Evans, R. D; Phillips, Susan L; Reheis, Merith; Reynolds, Rich; Sanford, Robert; Webb, Bruce

2004-01-01

Bromus tectorum (hereafter referred to as Bromus) is a non-native annual grass from the Mediterranean region that arrived in the United States in the late 19th century and soon spread throughout the western states...

Is the alpine divide becoming more permeable to biological invasions? - Insights on the invasion and establishment of the Walnut Husk Fly, Rhagoletis completa (Diptera: Tephritidae) in Switzerland.

Science.gov (United States)

Aluja, M; Guillén, L; Rull, J; Höhn, H; Frey, J; Graf, B; Samietz, J

2011-08-01

The Walnut Husk Fly, Rhagoletis completa Cresson (Diptera: Tephritidae), is native to North America (Midwestern US and north-eastern Mexico) and has invaded several European countries in the past decades by likely crossing the alpine divide separating most parts of Switzerland from Italy. Here, we determined its current distribution in Switzerland by sampling walnuts (Juglans regia L.) in ecologically and climatically distinct regions along potential invasion corridors. R. completa was found to be firmly established in most low altitude areas of Switzerland where walnuts thrive, but notably not a single parasitoid was recovered from any of the samples. Infested fruit was recovered in 42 of the 71 localities that were surveyed, with mean fruit infestation rate varying greatly among sites. The incidence of R. completa in Switzerland is closely related to meteorological mean spring temperature patterns influencing growing season length, but not to winter temperatures, reflecting survival potential during hibernation. Importantly, areas in which the fly is absent correspond with localities where the mean spring temperatures fall below 7°C. Historical data records show that the natural cold barrier around the Alpine divide in the central Swiss Alps corresponding to such minimal temperatures has shrunk significantly from a width of more than 40 km before 1990 to around 20 km after 2000. We hypothesize on possible invasion/expansion routes along alpine valleys, dwell on distribution patterns in relation to climate, and outline future research needs as the incursion of R. completa into Switzerland; and, more recently, other European countries, such as Germany, Austria, France and Slovenia, represent an example of alien species that settle first in the Mediterranean Basin and from there become invasive by crossing the Alps.

Invasive Species Science Branch: research and management tools for controlling invasive species

Science.gov (United States)

Reed, Robert N.; Walters, Katie D.

2015-01-01

Invasive, nonnative species of plants, animals, and disease organisms adversely affect the ecosystems they enter. Like “biological wildfires,” they can quickly spread and affect nearly all terrestrial and aquatic ecosystems. Invasive species have become one of the greatest environmental challenges of the 21st century in economic, environmental, and human health costs, with an estimated effect in the United States of more than $120 billion per year. Managers of the Department of the Interior and other public and private lands often rank invasive species as their top resource management problem. The Invasive Species Science Branch of the Fort Collins Science Center provides research and technical assistance relating to management concerns for invasive species, including understanding how these species are introduced, identifying areas vulnerable to invasion, forecasting invasions, and developing control methods. To disseminate this information, branch scientists are developing platforms to share invasive species information with DOI cooperators, other agency partners, and the public. From these and other data, branch scientists are constructing models to understand and predict invasive species distributions for more effective management. The branch also has extensive herpetological and population biology expertise that is applied to harmful reptile invaders such as the Brown Treesnake on Guam and Burmese Python in Florida.

Invasive Candidiasis

Science.gov (United States)

... Waterborne, and Environmental Diseases Mycotic Diseases Branch Invasive Candidiasis Recommend on Facebook Tweet Share Compartir Global Emergence ... antifungal drugs. Learn more about C. auris Invasive candidiasis is an infection caused by a yeast (a ...

Intraspecies differenes in phenotypic plasticity: Invasive versus non-invasive populations of Ceratophyllum demersum

DEFF Research Database (Denmark)

Hyldgaard, Benita; Brix, Hans

2012-01-01

High phenotypic plasticity has been hypothesized to affect the invasiveness of plants, as high plasticity may enlarge the breath of environments in which the plants can survive and reproduce. Here we compare the phenotypic plasticity of invasive and non-invasive populations of the same species...... hypothesized that the phenotypic plasticity in fitness-related traits like growth and photosynthesis were higher in the invasive than in the non-invasive population. The invasive population acclimated to elevated temperatures through increased rates of photosynthesis (range: Pamb: 8–452 mol O2 g−1 DM h−1......-harvesting complex. Hence, the invasive population of C. demersum from New Zealand had higher phenotypic plasticity in response to temperature than the non-invasive Danish population. This might be the result of genetic evolution since its introduction to New Zealand five decades ago, but further studies are needed...

Latitudinal trends in human primary activities: characterizing the winter day as a synchronizer.

Science.gov (United States)

Martín-Olalla, José María

2018-03-28

This work analyzes time use surveys from 19 countries (17 European and 2 American) in the middle latitude (38-61 degree) accounting for 45% of world population in this range. Time marks for primary activities are contrasted against light/dark conditions. The analysis reveals winter sunrise synchronizes labor start time below 54 degree, occurring within winter civil twilight. Winter sunset is a source of synchronization for labor end times. Winter terminator punctuate meal times in Europe: dinner occurs 3 h after winter sunset time within 1 h; 40% narrower than variability of dinner local times. The sleep-wake cycle of laborers is shown to be related to winter sunrise whereas standard population's appears to be irrespective of latitude. The significance of the winter terminator depends on two competing factors average labor time (~7 h30 m) and the shortest photoperiod. Winter terminator gains significance when both roughly matches. That is within a latitude range from 38 degree to 54 degree. The significance of winter terminator as a source of synchronization is also related to contemporary year round time schedules: the shortest photoperiod represents the worst case scenario the society faces.

Winter active bumblebees (Bombus terrestris achieve high foraging rates in urban Britain.

Directory of Open Access Journals (Sweden)

Ralph J Stelzer

2010-03-01

Full Text Available Foraging bumblebees are normally associated with spring and summer in northern Europe. However, there have been sightings of the bumblebee Bombus terrestris during the warmer winters in recent years in southern England. But what floral resources are they relying upon during winter and how much winter forage can they collect?To test if urban areas in the UK provide a rich foraging niche for bees we set up colonies of B. terrestris in the field during two late winter periods (2005/6 & 2006/7 in London, UK, and measured their foraging performance. Fully automatic radio-frequency identification (RFID technology was used in 2006/7 to enable us to record the complete foraging activity of individually tagged bees. The number of bumblebees present during winter (October 2007 to March 2008 and the main plants they visited were also recorded during transect walks. Queens and workers were observed throughout the winter, suggesting a second generation of bee colonies active during the winter months. Mass flowering shrubs such as Mahonia spp. were identified as important food resources. The foraging experiments showed that bees active during the winter can attain nectar and pollen foraging rates that match, and even surpass, those recorded during summer.B. terrestris in the UK are now able to utilise a rich winter foraging resource in urban parks and gardens that might at present still be under-exploited, opening up the possibility of further changes in pollinator phenology.

Winter active bumblebees (Bombus terrestris) achieve high foraging rates in urban Britain.

Science.gov (United States)

Stelzer, Ralph J; Chittka, Lars; Carlton, Marc; Ings, Thomas C

2010-03-05

Foraging bumblebees are normally associated with spring and summer in northern Europe. However, there have been sightings of the bumblebee Bombus terrestris during the warmer winters in recent years in southern England. But what floral resources are they relying upon during winter and how much winter forage can they collect? To test if urban areas in the UK provide a rich foraging niche for bees we set up colonies of B. terrestris in the field during two late winter periods (2005/6 & 2006/7) in London, UK, and measured their foraging performance. Fully automatic radio-frequency identification (RFID) technology was used in 2006/7 to enable us to record the complete foraging activity of individually tagged bees. The number of bumblebees present during winter (October 2007 to March 2008) and the main plants they visited were also recorded during transect walks. Queens and workers were observed throughout the winter, suggesting a second generation of bee colonies active during the winter months. Mass flowering shrubs such as Mahonia spp. were identified as important food resources. The foraging experiments showed that bees active during the winter can attain nectar and pollen foraging rates that match, and even surpass, those recorded during summer. B. terrestris in the UK are now able to utilise a rich winter foraging resource in urban parks and gardens that might at present still be under-exploited, opening up the possibility of further changes in pollinator phenology.

10-Year Mortality Outcome of a Routine Invasive Strategy Versus a Selective Invasive Strategy in Non-ST-Segment Elevation Acute Coronary Syndrome: The British Heart Foundation RITA-3 Randomized Trial.

Science.gov (United States)

Henderson, Robert A; Jarvis, Christopher; Clayton, Tim; Pocock, Stuart J; Fox, Keith A A

2015-08-04

The RITA-3 (Third Randomised Intervention Treatment of Angina) trial compared outcomes of a routine early invasive strategy (coronary arteriography and myocardial revascularization, as clinically indicated) to those of a selective invasive strategy (coronary arteriography for recurrent ischemia only) in patients with non-ST-segment elevation acute coronary syndrome (NSTEACS). At a median of 5 years' follow-up, the routine invasive strategy was associated with a 24% reduction in the odds of all-cause mortality. This study reports 10-year follow-up outcomes of the randomized cohort to determine the impact of a routine invasive strategy on longer-term mortality. We randomized 1,810 patients with NSTEACS to receive routine invasive or selective invasive strategies. All randomized patients had annual follow-up visits up to 5 years, and mortality was documented thereafter using data from the Office of National Statistics. Over 10 years, there were no differences in mortality between the 2 groups (all-cause deaths in 225 [25.1%] vs. 232 patients [25.4%]: p = 0.94; and cardiovascular deaths in 135 [15.1%] vs. 147 patients [16.1%]: p = 0.65 in the routine invasive and selective invasive groups, respectively). Multivariate analysis identified several independent predictors of 10-year mortality: age, previous myocardial infarction, heart failure, smoking status, diabetes, heart rate, and ST-segment depression. A modified post-discharge Global Registry of Acute Coronary Events (GRACE) score was used to calculate an individual risk score for each patient and to form low-risk, medium-risk, and high-risk groups. Risk of death within 10 years varied markedly from 14.4 % in the low-risk group to 56.2% in the high-risk group. This mortality trend did not depend on the assigned treatment strategy. The advantage of reduced mortality of routine early invasive strategy seen at 5 years was attenuated during later follow-up, with no evidence of a difference in outcome at 10 years

Warmer and wetter winters: characteristics and implications of an extreme weather event in the High Arctic

International Nuclear Information System (INIS)

Hansen, Brage B; Isaksen, Ketil; Benestad, Rasmus E; Kohler, Jack; Pedersen, Åshild Ø; Loe, Leif E; Coulson, Stephen J; Larsen, Jan Otto; Varpe, Øystein

2014-01-01

One predicted consequence of global warming is an increased frequency of extreme weather events, such as heat waves, droughts, or heavy rainfalls. In parts of the Arctic, extreme warm spells and heavy rain-on-snow (ROS) events in winter are already more frequent. How these weather events impact snow-pack and permafrost characteristics is rarely documented empirically, and the implications for wildlife and society are hence far from understood. Here we characterize and document the effects of an extreme warm spell and ROS event that occurred in High Arctic Svalbard in January–February 2012, during the polar night. In this normally cold semi-desert environment, we recorded above-zero temperatures (up to 7 °C) across the entire archipelago and record-breaking precipitation, with up to 98 mm rainfall in one day (return period of >500 years prior to this event) and 272 mm over the two-week long warm spell. These precipitation amounts are equivalent to 25 and 70% respectively of the mean annual total precipitation. The extreme event caused significant increase in permafrost temperatures down to at least 5 m depth, induced slush avalanches with resultant damage to infrastructure, and left a significant ground-ice cover (∼5–20 cm thick basal ice). The ground-ice not only affected inhabitants by closing roads and airports as well as reducing mobility and thereby tourism income, but it also led to high starvation-induced mortality in all monitored populations of the wild reindeer by blocking access to the winter food source. Based on empirical-statistical downscaling of global climate models run under the moderate RCP4.5 emission scenario, we predict strong future warming with average mid-winter temperatures even approaching 0 °C, suggesting increased frequency of ROS. This will have far-reaching implications for Arctic ecosystems and societies through the changes in snow-pack and permafrost properties. (letter)

Warmer and wetter winters: characteristics and implications of an extreme weather event in the High Arctic

Science.gov (United States)

Hansen, Brage B.; Isaksen, Ketil; Benestad, Rasmus E.; Kohler, Jack; Pedersen, Åshild Ø.; Loe, Leif E.; Coulson, Stephen J.; Larsen, Jan Otto; Varpe, Øystein

2014-11-01

One predicted consequence of global warming is an increased frequency of extreme weather events, such as heat waves, droughts, or heavy rainfalls. In parts of the Arctic, extreme warm spells and heavy rain-on-snow (ROS) events in winter are already more frequent. How these weather events impact snow-pack and permafrost characteristics is rarely documented empirically, and the implications for wildlife and society are hence far from understood. Here we characterize and document the effects of an extreme warm spell and ROS event that occurred in High Arctic Svalbard in January-February 2012, during the polar night. In this normally cold semi-desert environment, we recorded above-zero temperatures (up to 7 °C) across the entire archipelago and record-breaking precipitation, with up to 98 mm rainfall in one day (return period of >500 years prior to this event) and 272 mm over the two-week long warm spell. These precipitation amounts are equivalent to 25 and 70% respectively of the mean annual total precipitation. The extreme event caused significant increase in permafrost temperatures down to at least 5 m depth, induced slush avalanches with resultant damage to infrastructure, and left a significant ground-ice cover (˜5-20 cm thick basal ice). The ground-ice not only affected inhabitants by closing roads and airports as well as reducing mobility and thereby tourism income, but it also led to high starvation-induced mortality in all monitored populations of the wild reindeer by blocking access to the winter food source. Based on empirical-statistical downscaling of global climate models run under the moderate RCP4.5 emission scenario, we predict strong future warming with average mid-winter temperatures even approaching 0 °C, suggesting increased frequency of ROS. This will have far-reaching implications for Arctic ecosystems and societies through the changes in snow-pack and permafrost properties.

The decline in winter excess mortality in The Netherlands

NARCIS (Netherlands)

Kunst, A. E.; Looman, C. W.; Mackenbach, J. P.

1991-01-01

In most countries, numbers of deaths rise considerably during the winter season. This winter excess in mortality has, however, been declining during recent decades. The causes of this decline are hardly known. This paper attempts to derive a number of hypotheses on the basis of a detailed

Genetic architecture of winter hardiness and frost tolerance in triticale.

Directory of Open Access Journals (Sweden)

Wenxin Liu

Full Text Available Abiotic stress experienced by autumn-sown crops during winter is of great economic importance as it can have a severe negative impact on yield. In this study, we investigated the genetic architecture of winter hardiness and frost tolerance in triticale. To this end, we used a large mapping population of 647 DH lines phenotyped for both traits in combination with genome-wide marker data. Employing multiple-line cross QTL mapping, we identified nine main effect QTL for winter hardiness and frost tolerance of which six were overlapping between both traits. Three major QTL were identified on chromosomes 5A, 1B and 5R. In addition, an epistasis scan revealed the contribution of epistasis to the genetic architecture of winter hardiness and frost tolerance in triticale. Taken together, our results show that winter hardiness and frost tolerance are complex traits that can be improved by phenotypic selection, but also that genomic approaches hold potential for a knowledge-based improvement of these important traits in elite triticale germplasm.

A comparison of pine and spruce in recovery from winter stress; changes in recovery kinetics, and the abundance and phosphorylation status of photosynthetic proteins during winter.

Science.gov (United States)

Merry, Ryan; Jerrard, Jacob; Frebault, Julia; Verhoeven, Amy

2017-09-01

During winter evergreens maintain a sustained form of thermal energy dissipation that results in reduced photochemical efficiency measured using the chlorophyll fluorescence parameter Fv/Fm. Eastern white pine (Pinus strobus L.) and white spruce [Picea glauca (Moench) Voss] have been shown to differ in their rate of recovery of Fv/Fm from winter stress. The goal of this study was to monitor changes in photosynthetic protein abundance and phosphorylation status during winter recovery that accompany these functional changes. An additional goal was to determine whether light-dependent changes in light harvesting complex II (LHCII) phosphorylation occur during winter conditions. We used a combination of field measurements and recovery experiments to monitor chlorophyll fluorescence and photosynthetic protein content and phosphorylation status. We found that pine recovered three times more slowly than spruce, and that the kinetics of recovery in spruce included a rapid and slow component, while in pine there was only a rapid component to recovery. Both species retained relatively high amounts of the light harvesting protein Lhcb5 (CP26) and the PsbS protein during winter, suggesting a role for these proteins in sustained thermal dissipation. Both species maintained high phosphorylation of LHCII and the D1 protein in darkness during winter. Pine and spruce differed in the kinetics of the dephosphorylation of LHCII and D1 upon warming, suggesting the rate of dephosphorylation of LHCII and D1 may be important in the rapid component of recovery from winter stress. Finally, we demonstrated that light-dependent changes in LHII phosphorylation do not continue to occur on subzero winter days and that needles are maintained in a phosphorylation pattern consistent with the high light conditions to which those needles are exposed. Our results suggest a role for retained phosphorylation of both LHCII and D1 in maintenance of the photosynthetic machinery in a winter conformation

Annual and semiannual variations in the ionospheric F2-layer: II. Physical discussion

Directory of Open Access Journals (Sweden)

H. Rishbeth

2000-08-01

Full Text Available The companion paper by Zou et al. shows that the annual and semiannual variations in the peak F2-layer electron density (NmF2 at midlatitudes can be reproduced by a coupled thermosphere-ionosphere computational model (CTIP, without recourse to external influences such as the solar wind, or waves and tides originating in the lower atmosphere. The present work discusses the physics in greater detail. It shows that noon NmF2 is closely related to the ambient atomic/molecular concentration ratio, and suggests that the variations of NmF2 with geographic and magnetic longitude are largely due to the geometry of the auroral ovals. It also concludes that electric fields play no important part in the dynamics of the midlatitude thermosphere. Our modelling leads to the following picture of the global three-dimensional thermospheric circulation which, as envisaged by Duncan, is the key to explaining the F2-layer variations. At solstice, the almost continuous solar input at high summer latitudes drives a prevailing summer-to-winter wind, with upwelling at low latitudes and throughout most of the summer hemisphere, and a zone of downwelling in the winter hemisphere, just equatorward of the auroral oval. These motions affect thermospheric composition more than do the alternating day/night (up-and-down motions at equinox. As a result, the thermosphere as a whole is more molecular at solstice than at equinox. Taken in conjunction with the well-known relation of F2-layer electron density to the atomic/molecular ratio in the neutral air, this explains the F2-layer semiannual effect in NmF2 that prevails at low and middle latitudes. At higher midlatitudes, the seasonal behaviour depends on the geographic latitude of the winter downwelling zone, though the effect of the composition changes is modified by the large solar zenith angle at midwinter. The zenith angle effect is especially important in longitudes far from the magnetic poles. Here, the downwelling occurs

75 FR 4842 - Winter Use Plan, Environmental Impact Statement, Yellowstone National Park

Science.gov (United States)

2010-01-29

... DEPARTMENT OF THE INTERIOR National Park Service Winter Use Plan, Environmental Impact Statement... to prepare an Environmental Impact Statement for a Winter Use Plan, Yellowstone National Park... Park Service (NPS) is preparing an Environmental Impact Statement (EIS) for a Winter Use Plan for...

The elusive gene for keratolytic winter erythema | Hull | South ...

African Journals Online (AJOL)

Keratolytic winter erythema (KWE), also known as Oudtshoorn skin disease, is characterised by a cyclical disruption of normal epidermal keratinisation affecting primarily the palmoplantar skin with peeling of the palms and soles, which is worse in the winter. It is a rare monogenic, autosomal dominant condition of unknown ...

An Annual Plant Growth Proxy in the Mojave Desert Using MODIS-EVI Data.

Science.gov (United States)

Wallace, Cynthia S A; Thomas, Kathryn A

2008-12-03

In the arid Mojave Desert, the phenological response of vegetation is largely dependent upon the timing and amount of rainfall, and maps of annual plant cover at any one point in time can vary widely. Our study developed relative annual plant growth models as proxies for annual plant cover using metrics that captured phenological variability in Moderate-Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) satellite images. We used landscape phenologies revealed in MODIS data together with ecological knowledge of annual plant seasonality to develop a suite of metrics to describe annual growth on a yearly basis. Each of these metrics was applied to temporally-composited MODIS-EVI images to develop a relative model of annual growth. Each model was evaluated by testing how well it predicted field estimates of annual cover collected during 2003 and 2005 at the Mojave National Preserve. The best performing metric was the spring difference metric, which compared the average of three spring MODIS-EVI composites of a given year to that of 2002, a year of record drought. The spring difference metric showed correlations with annual plant cover of R² = 0.61 for 2005 and R² = 0.47 for 2003. Although the correlation is moderate, we consider it supportive given the characteristics of the field data, which were collected for a different study in a localized area and are not ideal for calibration to MODIS pixels. A proxy for annual growth potential was developed from the spring difference metric of 2005 for use as an environmental data layer in desert tortoise habitat modeling. The application of the spring difference metric to other imagery years presents potential for other applications such as fuels, invasive species, and dust-emission monitoring in the Mojave Desert.

An Annual Plant Growth Proxy in the Mojave Desert Using MODIS-EVI Data

Directory of Open Access Journals (Sweden)

Kathryn A. Thomas

2008-12-01

Full Text Available In the arid Mojave Desert, the phenological response of vegetation is largely dependent upon the timing and amount of rainfall, and maps of annual plant cover at any one point in time can vary widely. Our study developed relative annual plant growth models as proxies for annual plant cover using metrics that captured phenological variability in Moderate-Resolution Imaging Spectroradiometer (MODIS Enhanced Vegetation Index (EVI satellite images. We used landscape phenologies revealed in MODIS data together with ecological knowledge of annual plant seasonality to develop a suite of metrics to describe annual growth on a yearly basis. Each of these metrics was applied to temporally-composited MODIS-EVI images to develop a relative model of annual growth. Each model was evaluated by testing how well it predicted field estimates of annual cover collected during 2003 and 2005 at the Mojave National Preserve. The best performing metric was the spring difference metric, which compared the average of three spring MODIS-EVI composites of a given year to that of 2002, a year of record drought. The spring difference metric showed correlations with annual plant cover of R2 = 0.61 for 2005 and R2 = 0.47 for 2003. Although the correlation is moderate, we consider it supportive given the characteristics of the field data, which were collected for a different study in a localized area and are not ideal for calibration to MODIS pixels. A proxy for annual growth potential was developed from the spring difference metric of 2005 for use as an environmental data layer in desert tortoise habitat modeling. The application of the spring difference metric to other imagery years presents potential for other applications such as fuels, invasive species, and dust-emission monitoring in the Mojave Desert.

Genetic gains in wheat in Turkey: Winter wheat for dryland conditions

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Mesut Keser

2017-12-01

Full Text Available Wheat breeders in Turkey have been developing new varieties since the 1920s, but few studies have evaluated the rates of genetic improvement. This study determined wheat genetic gains by evaluating 22 winter/facultative varieties released for rainfed conditions between 1931 and 2006. The study was conducted at three locations in Turkey during 2008–2012, with a total of 21 test sites. The experimental design was a randomized complete block with four replicates in 2008 and 2009 and three replicates in 2010–2012. Regression analysis was conducted to determine genetic progress over time. Mean yield across all 21 locations was 3.34 t ha−1, but varied from 1.11 t ha−1 to 6.02 t ha−1 and was highly affected by moisture stress. Annual genetic gain was 0.50% compared to Ak-702, or 0.30% compared to the first modern landmark varieties. The genetic gains in drought-affected sites were 0.75% compared to Ak-702 and 0.66% compared to the landmark varieties. Modern varieties had both improved yield potential and tolerance to moisture stress. Rht genes and rye translocations were largely absent in the varieties studied. The number of spikes per unit area decreased by 10% over the study period, but grains spike−1 and 1000-kernel weight increased by 10%. There were no significant increases in harvest index, grain size, or spike fertility, and no significant decrease in quality over time. Future use of Rht genes and rye translocations in breeding programs may increase yield under rainfed conditions. Keywords: Genetic gain, Rainfed wheat production, Winter wheat, Yield

Spirit's Winter Work Site

Science.gov (United States)

2006-01-01

[figure removed for brevity, see original site] Annotated Version This portion of an image acquired by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment camera shows the Spirit rover's winter campaign site. Spirit was parked on a slope tilted 11 degrees to the north to maximize sunlight during the southern winter season. 'Tyrone' is an area where the rover's wheels disturbed light-toned soils. Remote sensing and in-situ analyses found the light-toned soil at Tyrone to be sulfate rich and hydrated. The original picture is catalogued as PSP_001513_1655_red and was taken on Sept. 29, 2006. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.

Comparison of snowpack and winter wet-deposition chemistry in the Rocky Mountains, USA: implications for winter dry deposition

Science.gov (United States)

Clow, David W.; Ingersoll, George P.; Mast, M. Alisa; Turk, John T.; Campbell, Donald H.

Depth-integrated snowpack chemistry was measured just prior to maximum snowpack depth during the winters of 1992-1999 at 12 sites co-located with National Atmospheric Deposition Program/National Trend Network (NADP/NTN) sites in the central and southern Rocky Mountains, USA. Winter volume-weighted mean wet-deposition concentrations were calculated for the NADP/NTN sites, and the data were compared to snowpack concentrations using the paired t-test and the Wilcoxon signed-rank test. No statistically significant differences were indicated in concentrations of SO 42- or NO 3- ( p>0.1). Small, but statistically significant differences ( p⩽0.03) were indicated for all other solutes analyzed. Differences were largest for Ca 2+ concentrations, which on average were 2.3 μeq l -1 (43%) higher in the snowpack than in winter NADP/NTN samples. Eolian carbonate dust appeared to influence snowpack chemistry through both wet and dry deposition, and the effect increased from north to south. Dry deposition of eolian carbonates was estimated to have neutralized an average of 6.9 μeq l -1 and a maximum of 12 μeq l -1 of snowpack acidity at the southernmost sites. The good agreement between snowpack and winter NADP/NTN SO 42- and NO 3- concentrations indicates that for those solutes the two data sets can be combined to increase data density in high-elevation areas, where few NADP/NTN sites exist. This combination of data sets will allow for better estimates of atmospheric deposition of SO 42- and NO 3- across the Rocky Mountain region.

Evaluation of a model for predicting Avena fatua and Descurainia sophia seed emergence in winter rapeseed

Energy Technology Data Exchange (ETDEWEB)

Aboutalebian, M.A.; Nazari, S.; Gonzalez-Andujar, J.L.

2017-07-01

Avena fatua and Descurainia sophia are two important annual weeds throughout winter rapeseed (Brassica napus L.) production systems in the semiarid region of Iran. Timely and more accurate control of both species may be developed if there is a better understanding of its emergence patterns. Non-linear regression techniques are usually unable to accurately predict field emergence under such environmental conditions. The objectives of this research were to evaluate the emergence patterns of A. fatua and D. sophia and determine if emergence could be predicted using cumulative soil thermal time in degree days (CTT). In the present work, cumulative seedling emergence from a winter rapeseed field during 3 years data set was fitted to cumulative soil CTT using Weibull and Gompertz functions. The Weibull model provided a better fit, based on coefficient of determination (R2sqr), root mean square of error (RMSE) and Akaike index (AICd), compared to the Gompertz model between 2013 and 2016 seasons for both species. Maximum emergence of A. fatua occured 70-119 days after sowing or after equals 329-426 °Cd, while in D. sophia it occurred 119-134 days after sowing rapeseed equals 373-470 °Cd. Both models can aid in the future study of A. fatua and D. sophia emergence and assist growers and agricultural professionals with planning timely and more accurate A. fatua and D. sophia control.

Comparative proteomics reveals the physiological differences between winter tender shoots and spring tender shoots of a novel tea (Camellia sinensis L.) cultivar evergrowing in winter.

Science.gov (United States)

Liu, Shengjie; Gao, Jiadong; Chen, Zhongjian; Qiao, Xiaoyan; Huang, Hualin; Cui, Baiyuan; Zhu, Qingfeng; Dai, Zhangyan; Wu, Hualing; Pan, Yayan; Yang, Chengwei; Liu, Jun

2017-11-20

A recently discovered tea [Camellia sinensis (L.) O. Kuntze] cultivar can generate tender shoots in winter. We performed comparative proteomics to analyze the differentially accumulated proteins between winter and spring tender shoots of this clonal cultivar to reveal the physiological basis of its evergrowing character during winter. We extracted proteins from the winter and spring tender shoots (newly formed two leaves and a bud) of the evergrowing tea cultivar "Dongcha11" respectively. Thirty-three differentially accumulated high-confidence proteins were identified by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF / TOF MS). Among these, 24 proteins had increased abundance while nine showed were decreased abundance in winter tender shoots as compared with the spring tender shoots. We categorized the differentially accumulated proteins into eight critical biological processes based on protein function annotation including photosynthesis, cell structure, protein synthesis & destination, transporters, metabolism of sugars and polysaccharides, secondary metabolism, disease/defense and proteins with unknown functions. Proteins with increased abundance in winter tender shoots were mainly related to the processes of photosynthesis, cytoskeleton and protein synthesis, whereas those with decreased abundance were correlated to metabolism and the secondary metabolism of polyphenolic flavonoids. Biochemical analysis showed that the total contents of soluble sugar and amino acid were higher in winter tender shoots while tea polyphenols were lower as compared with spring tender shoots. Our study suggested that the simultaneous increase in the abundance of photosynthesis-related proteins rubisco, plastocyanin, and ATP synthase delta chain, metabolism-related proteins eIF4 and protease subunits, and the cytoskeleton-structure associated proteins phosphatidylinositol transfer protein and profilin may be because of the adaptation of the

Annual crop type classification of the U.S. Great Plains for 2000 to 2011

Science.gov (United States)

Howard, Daniel M.; Wylie, Bruce K.

2014-01-01

The purpose of this study was to increase the spatial and temporal availability of crop classification data. In this study, nearly 16.2 million crop observation points were used in the training of the US Great Plains classification tree crop type model (CTM). Each observation point was further defined by weekly Normalized Difference Vegetation Index, annual climate, and a number of other biogeophysical environmental characteristics. This study accounted for the most prevalent crop types in the region, including, corn, soybeans, winter wheat, spring wheat, cotton, sorghum, and alfalfa. Annual CTM crop maps of the US Great Plains were created for 2000 to 2011 at a spatial resolution of 250 meters. The CTM achieved an 87 percent classification success rate on 1.8 million observation points that were withheld from model training. Product validation was performed on greater than 15,000 county records with a coefficient of determination of R2 = 0.76.

Threshold sensitivity of shallow Arctic lakes and sublake permafrost to changing winter climate

Science.gov (United States)

Arp, Christopher D.; Jones, Benjamin M.; Grosse, Guido; Bondurant, Allen C.; Romanovksy, Vladimir E.; Hinkel, Kenneth M.; Parsekian, Andrew D.

2016-01-01

Interactions and feedbacks between abundant surface waters and permafrost fundamentally shape lowland Arctic landscapes. Sublake permafrost is maintained when the maximum ice thickness (MIT) exceeds lake depth and mean annual bed temperatures (MABTs) remain below freezing. However, declining MIT since the 1970s is likely causing talik development below shallow lakes. Here we show high-temperature sensitivity to winter ice growth at the water-sediment interface of shallow lakes based on year-round lake sensor data. Empirical model experiments suggest that shallow (1 m depth) lakes have warmed substantially over the last 30 years (2.4°C), with MABT above freezing 5 of the last 7 years. This is in comparison to slower rates of warming in deeper (3 m) lakes (0.9°C), with already well-developed taliks. Our findings indicate that permafrost below shallow lakes has already begun crossing a critical thawing threshold approximately 70 years prior to predicted terrestrial permafrost thaw in northern Alaska.

Annual modulation of non-volcanic tremor in northern Cascadia

Science.gov (United States)

Pollitz, Fred; Wech, Aaron G.; Kao, Honn; Burgmann, Roland

2013-01-01

Two catalogs of episodic tremor events in northern Cascadia, one from 2006 to 2012 and the other from 1997 to 2011, reveal two systematic patterns of tremor occurrence in southern Vancouver Island: (1) most individual events tend to occur in the third quarter of the year; (2) the number of events in prolonged episodes (i.e., episodic tremor and slip events), which generally propagate to Vancouver Island from elsewhere along the Cascadia subduction zone, is inversely correlated with the amount of precipitation that occurred in the preceding 2 months. We rationalize these patterns as the product of hydrologic loading of the crust of southern Vancouver Island and the surrounding continental region, superimposed with annual variations from oceanic tidal loading. Loading of the Vancouver Island crust in the winter (when the land surface receives ample precipitation) and unloading in the summer tends to inhibit and enhance downdip shear stress, respectively. Quantitatively, for an annually variable surface load, the predicted stress perturbation depends on mantle viscoelastic rheology. A mechanical model of downdip shear stress on the transition zone beneath Vancouver Island—driven predominantly by the annual hydrologic cycle—is consistent with the 1997–2012 tremor observations, with peak-to-peak downdip shear stress of about 0.4 kPa. This seasonal dependence of tremor occurrence appears to be restricted to southern Vancouver Island because of its unique situation as an elongated narrow-width land mass surrounded by ocean, which permits seasonal perturbations in shear stress at depth.

Learning at old age: a study on winter bees

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Andreas Behrends

2010-04-01

Full Text Available Ageing is often accompanied by a decline in learning and memory abilities across the animal kingdom. Understanding age-related changes in cognitive abilities is therefore a major goal of current research. The honey bee is emerging as a novel model organism for age-related changes in brain function, because learning and memory can easily be studied in bees under controlled laboratory conditions. In addition, genetically similar workers naturally display life expectancies from six weeks (summer bees to six months (winter bees. We studied whether in honey bees, extreme longevity leads to a decline in cognitive functions. Six-month-old winter bees were conditioned either to odours or to tactile stimuli. Afterwards, long-term memory and discrimination abilities were analysed. Winter bees were kept under different conditions (flight /no flight opportunity to test for effects of foraging activity on learning performance. Despite their extreme age, winter bees did not display an age-related decline in learning or discrimination abilities, but had a slightly impaired olfactory long-term memory. The opportunity to forage indoors led to a slight decrease in learning performance. This suggests that in honey bees, unlike in most other animals, age per se does not impair associative learning. Future research will show which mechanisms protect winter bees from age-related deficits in learning.

[Winter sport injuries in childhood (author's transl)].

Science.gov (United States)

Hausbrandt, D; Höllwarth, M; Ritter, G

1979-01-01

3374 accidents occurring on the field of sport during the years 1975--1977 accounted for 19% of all accidents dealt with at the Institute of Kinderchirurgie in Graz. 51% of the accidents were caused by the typical winter sports: skiing, tobogganing, ice-skating and ski-jumping with skiing accounting for 75% of the accidents. The fracture localization typical of the different kinds of winter sport is dealt with in detail. The correct size and safety of the equipment were found to be particularly important in the prevention of such accidents in childhood.

Nuclear winter: The evidence and the risks

International Nuclear Information System (INIS)

Greene, O.

1985-01-01

Global concern over nuclear extinction, centered on the holocaust itself, now has turned to the more terrifying consequences of a post-war nuclear winter: ''the long-term effects - destruction of the environment, spread of epidemic diseases, contamination by radioactivity, and ... collapse of agriculture-[that] would spread famine and death to every country.'' Nuclear Winter, the latest in a series of studies by a number of different groups is clinical, analytical, systematic, and detailed. Two physicists and biologist analyze the effects on the climate, plants, animals, and living systems; the human costs; the policy implications

Mixed cropping of annual feed legumes with barley improves feed quantity and crude protein content under dry-land conditions

Directory of Open Access Journals (Sweden)

Khoshnood Alizadeh

2013-01-01

Full Text Available The objective of this research is to determine a suitable mixture of annual feed legumes and barley as a winter crop under dry-land conditions. Seeds of Hungarian vetch (cv. 2670, smooth vetch (cv. Maragheh, and local varieties of grass pea and field pea were mixed with barley (cv. Abidar in a 1:1 ratio and were tested, along with related monoculture. All legumes in the mixture survived winter while legumes alone, except Hungarian vetch, did not survive in the cold areas. The maximum fresh and dry forage yields (56 and 15 ton ha-1 respectively were obtained from a mixture of smooth vetch and barley in provinces with mild winter and more than 400 mm of rainfall. The mixture of barley and smooth vetch resulted in the highest mean crude protein content (17%. Autumn seeding of smooth vetch and barley in a 1:1 ratio produced more than 2 ton ha-1 of dry biomass with good quality in all studied areas and thus could serve as an alternative cropping system after wheat/barley in cold and semi-cold dry land.

THE EVOLUTION OF THE WINTER PARALYMPIC GAMES AND SPORTS

Directory of Open Access Journals (Sweden)

Vasilios Giovanis

2015-03-01

Full Text Available Purpose: The aim of this research was to record and the evolution of the winter paralympic games and sports since 1976 until 2010. The history of the Winter Paralympic Games is relatively recent compared to that one of the Olympic Games. The first Games were held in 1976 in Ornskoldsvik, Sweden and the most recent, 38 years later in 2014, in Sochi, Russia. This article will examine the Winter Paralympic Games up until the ones in 2010 in Vancouver, Canada. During these years, there have been many changes in relation to the Games itself, the governing body of the Paralympic Movement, the sports’ facilities, the sports involved and sports’ categories. The motivation for writing this paper was the need to record and gather all of these items in one paper. Gathering information for the Winter Paralympic Games will be an important theoretical background. This information will create a database for the structure of the governing body of the Paralympic Games, for the organization of the Games [Local Organizing Committee (LOC, venues and equipment], for the evolution of the Winter Paralympic Sports and the categories of the athletes, as well as the evolution of the athletes’ and sports’ participation. Material : The research material that was used was mainly from the bibliography and records of the International Paralympic Committee (IPC, from the Official Post Games Reports and the Internet, while the research method that was used was descriptive. Moreover, the use of diagrams will depict the distribution of the participation of athletes and countries in each Games. Results : The participation of countries grew continuously and steadily from 16 to 44, during the years of 1976 to 2010 respectively. Regarding the athletes’ participation, starting in the first Games with 198 athletes, they reached the number of 502 in the 2010 Vancouver Winter Paralympic Games. The participation percentages of the athletes coming from Europe constituted the bulk

Annual and semiannual variations in the ionospheric F2-layer. I. Modelling

Directory of Open Access Journals (Sweden)

L. Zou

2000-08-01

Full Text Available Annual, seasonal and semiannual variations of F2-layer electron density (NmF2 and height (hmF2 have been compared with the coupled thermosphere-ionosphere-plasmasphere computational model (CTIP, for geomagnetically quiet conditions. Compared with results from ionosonde data from midlatitudes, CTIP reproduces quite well many observed features of NmF2, such as the dominant winter maxima at high midlatitudes in longitude sectors near the magnetic poles, the equinox maxima in sectors remote from the magnetic poles and at lower latitudes generally, and the form of the month-to-month variations at latitudes between about 60°N and 50°S. CTIP also reproduces the seasonal behaviour of NmF2 at midnight and the summer-winter changes of hmF2. Some features of the F2-layer, not reproduced by the present version of CTIP, are attributed to processes not included in the modelling. Examples are the increased prevalence of the winter maxima of noon NmF2 at higher solar activity, which may be a consequence of the increase of F2-layer loss rate in summer by vibrationally excited molecular nitrogen, and the semiannual variation in hmF2, which may be due to tidal effects. An unexpected feature of the computed distributions of NmF2 is an east-west hemisphere difference, which seems to be linked to the geomagnetic field configuration. Physical discussion is reserved to the companion paper by Rishbeth et al.Key words: Atmospheric composition and structure (thermosphere-composition and chemistry - Ionosphere (mid-latitude ionosphere; modelling and forecasting

Influence of richness and seeding density on invasion resistance in experimental tallgrass prairie restorations

Science.gov (United States)

Nemec, Kristine T.; Allen, Craig R.; Helzer, Christopher J.; Wedin, David A.

2013-01-01

In recent years, agricultural producers and non-governmental organizations and agencies have restored thousands of hectares of cropland to grassland in the Great Plains of the United States. However, little is known about the relationships between richness and seeding density in these restorations and resistance to invasive plant species. We assessed the effects of richness and seeding density on resistance to invasive and other unseeded plant species in experimental tallgrass prairie plots in central Nebraska. In 2006, twenty-four 55 m × 55 m plots were planted with six replicates in each of four treatments: high richness (97 species typically planted by The Nature Conservancy), at low and high seeding densities, and low richness (15 species representing a typical Conservation Reserve Program mix, CP25), at low and high seeding densities. There was a significant negative relationship between richness and basal cover of unseeded perennial forbs/legumes and unseeded perennial/annual grasses, abundance of bull thistle (Cirsium vulgare), and the number of inflorescences removed from smooth brome (Bromus inermis) transplants. Invasion resistance may have been higher in the high richness treatments because of the characteristics of the dominant species in these plots or because of greater interspecific competition for limiting resources among forbs/legumes with neighboring plants belonging to the same functional group. Seeding density was not important in affecting invasion resistance, except in the cover of unseeded grasses. Increasing seed mix richness may be more effective than increasing the seeding density for decreasing invasion by unseeded perennial species, bull thistle, and smooth brome.

Communicating Certainty About Nuclear Winter

Science.gov (United States)

Robock, A.

2013-12-01

I have been spending much of my time in the past several years trying to warn the world about the continuing danger of nuclear weapons, and that the solution is a rapid reduction in the nuclear arsenal. I feel that a scientist who discovers dangers to society has an ethical duty to issue a warning, even if the danger is so scary that it is hard for people to deal with. The debate about nuclear winter in the 1980s helped to end the nuclear arms race, but the planet still has enough nuclear weapons, even after reductions planned for 2017 under the New START treaty, to produce nuclear winter, with temperatures plunging below freezing in the summer in major agricultural regions, threatening the food supply for most of the planet. New research by myself, Brian Toon, Mike Mills, and colleagues over the past six years has found that a nuclear war between any two countries, such as India and Pakistan, using 50 atom bombs each of the size dropped on Hiroshima could produce climate change unprecedented in recorded human history, and a world food crisis because of the agricultural effects. This is much less than 1% of the current global arsenal. Communicating certainty - what we know for sure - has been much more effective than communicating uncertainty. The limited success I have had has come from persistence and serendipity. The first step was to do the science. We have published peer-reviewed articles in major journals, including Science, Nature, Proceedings of the National Academy of Sciences, Journal of Geophysical Research, Atmospheric Chemistry and Physics, Physics Today, and Climatic Change. But policymakers do not read these journals. Through fairly convoluted circumstances, which will be described in this talk, we were able to get papers published in Scientific American and the Bulletin of Atomic Scientists. I have also published several encyclopedia articles on the subject. As a Lead Author of Chapter 8 (Radiative Forcing) of the recently published Fifth Assessment

Addressing challenges for youths with mobility devices in winter conditions.

Science.gov (United States)

Morales, Ernesto; Lindsay, Sally; Edwards, Geoffrey; Howell, Lori; Vincent, Claude; Yantzi, Nicole; Gauthier, Véronique

2018-01-01

Winter-related research about the experience of navigating in the urban context has mostly focused on the elderly population with physical disabilities. The aim of this project was to explore potential design solutions to enhance young people's mobility devices and the built environment to improve accessibility and participation in winter. A multi-method qualitative design process included the following steps: (1) in-depth interviews; (2) photo elicitation; (3) individual co-design sessions; and (4) group co-design sessions (i.e., focus group). The participants were 13 youths (nine males and four females), aged 12-21, who used a wheelchair (12 power chair users and one manual wheelchair), for some with their parents, others without their parents, according to the parents' willingness to participate or not in the study (n = 13). The first two authors conducted group co-design sessions with mechanical engineers and therapists/clinicians in two Canadian cities to discuss the feasibility of the designs. Results (findings): The youths and their parents reported different winter-related challenges and proposed specific design solutions to enhance their participation and inclusion in winter activities. Seven of these designs were presented at two group co-design sessions of therapists/clinicians and engineers. Two designs were found to be feasible: (1) a traction device for wheelchairs in snow and (2) a mat made of rollers to clean snow and dirt from tires. The results of this research highlight the frustrations and challenges youths who use wheelchairs encounter in winter and a need for new solutions to ensure greater accessibility in winter. Therapists/clinicians and designers should address winter-related accessibility problems in areas with abundant snow. Implications for Rehabilitation Several studies show that current urban contexts do not necessarily respond accurately to the needs of individuals with limited mobility. Winter-related research about the

Winter survival of Scots pine seedlings under different snow conditions.

Science.gov (United States)

Domisch, Timo; Martz, Françoise; Repo, Tapani; Rautio, Pasi

2018-04-01

Future climate scenarios predict increased air temperatures and precipitation, particularly at high latitudes, and especially so during winter. Soil temperatures, however, are more difficult to predict, since they depend strongly on the fate of the insulating snow cover. 'Rain-on-snow' events and warm spells during winter can lead to thaw-freeze cycles, compacted snow and ice encasement, as well as local flooding. These adverse conditions could counteract the otherwise positive effects of climatic changes on forest seedling growth. In order to study the effects of different winter and snow conditions on young Scots pine (Pinus sylvestris L.) seedlings, we conducted a laboratory experiment in which 80 1-year-old Scots pine seedlings were distributed between four winter treatments in dasotrons: ambient snow cover (SNOW), compressed snow and ice encasement (ICE), flooded and frozen soil (FLOOD) and no snow (NO SNOW). During the winter treatment period and a 1.5-month simulated spring/early summer phase, we monitored the needle, stem and root biomass of the seedlings, and determined their starch and soluble sugar concentrations. In addition, we assessed the stress experienced by the seedlings by measuring chlorophyll fluorescence, electric impedance and photosynthesis of the previous-year needles. Compared with the SNOW treatment, carbohydrate concentrations were lower in the FLOOD and NO SNOW treatments where the seedlings had almost died before the end of the experiment, presumably due to frost desiccation of aboveground parts during the winter treatments. The seedlings of the ICE treatment showed dead needles and stems only above the snow and ice cover. The results emphasize the importance of an insulating and protecting snow cover for small forest tree seedlings, and that future winters with changed snow patterns might affect the survival of tree seedlings and thus forest productivity.

Traveling to Canada for the Vancouver 2010 Winter Olympic and Paralympic Games.

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Heggie, Travis W

2009-07-01

The 21st Winter Olympic Games will be held in Vancouver, British Columbia, Canada from February 12 to 28, 2010. Following the Winter Olympic Games, the Winter Paralympic Games will be held from March 12 to 21, 2010. There will be 86 winter sporting events hosted in Vancouver with 5500 athletes staying in two Olympic Villages. Another 2800 members of the media, 25,000 volunteers, and 1 million spectators are expected in attendance. This paper reviews health and safety issues for all travelers to Canada for the 2010 Vancouver Winter Olympic Games with a specific focus on pre-travel planning, road and transportation safety in British Columbia, natural and environmental hazards, Olympic medical facilities, safety and security, and infectious disease.

Assessing distributions of two invasive species of contrasting habits in future climate.

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Panda, Rajendra Mohan; Behera, Mukunda Dev; Roy, Partha Sarathi

2018-05-01

Understanding the impact of climate change on species invasion is crucial for sustainable biodiversity conservation. Through this study, we try to answer how species differing in phenological cycles, specifically Cassia tora and Lantana camara, differ in the manner in which they invade new regions in India in the future climate. Since both species occupy identical niches, exploring their invasive potential in different climate change scenarios will offer critical insights into invasion and inform ecosystem management. We use three modelling protocols (i.e., maximum entropy, generalised linear model and generalised additive model) to predict the current distribution. Projections are made for both moderate (A1B) and extreme (A2) IPCC (Intergovernmental Panel on Climate Change) scenarios for the year 2050 and 2100. The study reveals that the distributions of C. tora (annual) and L. camara (perennial) would depend on the precipitation of the warmest quarter and moisture availability. C. tora may demonstrate physiological tolerance to the mean diurnal temperature range and L. camara to the solar radiation. C. tora may invade central India, while L. camara may invade the Western Himalaya, parts of the Eastern Himalaya and the Western Ghats. The distribution ranges of both species could shift in the northern and north-eastern directions in India, owing to changes in moisture availability. The possible alterations in precipitation regimes could lead to water stress, which might have cascading effects on species invasion. L. camara might adapt to climate change better compared with C. tora. This comparative analysis of the future distributions of two invasive plants with contrasting habits demonstrates that temporal complementarity would prevail over the competition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Winter in the Ouachitas--a severe winter storm signature in Pinus echinata in the Ouachita Mountains of Oklahoma and Arkansas, USA

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Douglas J. Stevenson; Thomas B. Lynch; Pradip Saud; Robert Heineman; Randal Holeman; Dennis Wilson; Keith Anderson; Chris Cerny; James M. Guldin

2016-01-01

Each year severe winter storms (≈ice storms) damage trees throughout the southern USA. Arkansas and Oklahoma have a history of severe winter storms. To extend that history back beyond the reach of written records, a distinctive tree ring pattern or signature is needed. Storm-caused breakage, branch loss and bending stress provide that signature. We found a severe storm...

Research on spatial distribution of photosynthetic characteristics of Winter Wheat

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Yan, Q. Q.; Zhou, Q. Y.; Zhang, B. Z.; Han, X.; Han, N. N.; Li, S. M.

2018-03-01

In order to explore the spatial distribution of photosynthetic characteristics of winter wheat leaf, the photosynthetic rate on different parts of leaf (leaf base-leaf middle-leaf apex) and that on each canopy (top layer-middle layer-bottom layer) leaf during the whole growth period of winter wheat were measured. The variation of photosynthetic rate with PAR and the spatial distribution of winter wheat leaf during the whole growth periods were analysed. The results showed that the photosynthetic rate of different parts of winter wheat increased with the increase of PAR, which was showed as leaf base>leaf middle>leaf apex. In the same growth period, photosynthetic rate in different parts of the tablet was showed as leaf middle>leaf base>leaf apex. For the different canopy layer of winter wheat, the photosynthetic rate of the top layer leaf was significantly greater than that of the middle layer and lower layer leaf. The photosynthetic rate of the top layer leaf was the largest in the leaf base position. The photosynthetic rate of leaf of the same canopy layer at different growth stages were showed as tasseling stage >grain filling stage > maturation stage.

Invasive clonal plant species have a greater root-foraging plasticity than non-invasive ones.

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Keser, Lidewij H; Dawson, Wayne; Song, Yao-Bin; Yu, Fei-Hai; Fischer, Markus; Dong, Ming; van Kleunen, Mark

2014-03-01

Clonality is frequently positively correlated with plant invasiveness, but which aspects of clonality make some clonal species more invasive than others is not known. Due to their spreading growth form, clonal plants are likely to experience spatial heterogeneity in nutrient availability. Plasticity in allocation of biomass to clonal growth organs and roots may allow these plants to forage for high-nutrient patches. We investigated whether this foraging response is stronger in species that have become invasive than in species that have not. We used six confamilial pairs of native European clonal plant species differing in invasion success in the USA. We grew all species in large pots under homogeneous or heterogeneous nutrient conditions in a greenhouse, and compared their nutrient-foraging response and performance. Neither invasive nor non-invasive species showed significant foraging responses to heterogeneity in clonal growth organ biomass or in aboveground biomass of clonal offspring. Invasive species had, however, a greater positive foraging response in terms of root and belowground biomass than non-invasive species. Invasive species also produced more total biomass. Our results suggest that the ability for strong root foraging is among the characteristics promoting invasiveness in clonal plants.

Comparing Model Ozone Loss during the SOLVE and SOLVE-2 Winters

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Drdla, K.

2003-01-01

Model simulations have been used to analyze the factors influencing ozone loss during the 1999-2000 and 2002-2003 js. For both winters, the evolution of the Arctic vortex from November to April has been simulated using a trajectory-based microphysical and photochemical model. Extensive PSC formation and strong ozone depletion are evident in both winters. However, the ozone loss begins earlier in the 2002-2003 winter, with significant ozone depletion by early January. Analysis of the model results shows that during December 2002 not only cold temperatures but also the vortex structure was critical, allowing PSC-processed air parcels to experience significant solar exposure. The resultant ozone loss can be differentiated from ozone loss that occurs in the springtime, in particular because of the continued exposure to PSCs. For example, chlorine reactivation by the PSCs causes ozone loss to be insensitive to denitrification. Therefore, diagnosing the extent of ozone loss early in the winter is critical In understanding the overall winter-long ozone depletion.

46 CFR 42.30-10 - Southern Winter Seasonal Zone.

Science.gov (United States)

2010-10-01

... Island; thence the rhumb line to Black Rock Point on Stewart Island; thence the rhumb line to the point... BY SEA Zones, Areas, and Seasonal Periods § 42.30-10 Southern Winter Seasonal Zone. (a) The northern boundary of the Southern Winter Seasonal Zone is the rhumb line from the east coast of the American...

Evaluation of winter resistance of age-1+ galician carp in Рrikarpattya ponds

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I. Hrytsynyak

2018-03-01

Full Text Available Purpose. To evaluate the winter resistance of age-1+ Galician carp in pond conditions of the Prykarpattya region. Methodology. Analysis of the winter resistance of age-1+ Galician carp was carried out at the base of the fish farm “Korop” during 2015-2017. Wintering took place in a 2.5 ha pond. Hydrochemical parameters were determined using general chemical tests. The temperature and oxygen regimes of water in ponds were determined by a thermo-oximeter. The material for the study were age-1+ Galician carp. Determination of fish culture parameters of the preparedness for wintering of the Galician carp was carried out according to the instructions for organizing the wintering of fish seeds in ponds. To analyze the physiological preparedness of carp for wintering, the method of zootechnical analysis was used. Findings. The stocking density of age-1+ Galician carp in the wintering pond was 1000 kg/ha. The average individual weight of fish seeds ranged from 1650 g during 2015-2016 season and 1760 g during 2016-2017. The condition factor of age-1+ Galician carp was within the normative values. During the wintering season, the chemical composition of the meat-fillet of the Galician carp at the second year of culturing was within the normative parameters. During wintering, the environmental conditions corresponded to the necessary fish culture requirements. The dissolved oxygen content in water during the winter period did not exceed the critical limits. The water temperature ranged from 1 ° C to 8 ° C. As a result of fish harvesting in the wintering pond, 1483 and 1291 specimens of age-2 Galician carp were obtained in 2016 and 2017, respectively. The average individual weight of fish was 1450 ± 191 g and 1528 ± 124 g. The total yield from wintering exceeded 90%. Originality. For the first time, an evaluation of winter resistance of age-1+ Galician carp in pond conditions of the Prykarpattya region was carried out. Practical value. The results of

Over-winter ecology of Oncorhynchus nerka in the Sawtooth Valley Lakes

Energy Technology Data Exchange (ETDEWEB)

Steinhart, G.B.; Wurtsbaugh, W.A.

1996-05-01

Included in this section of the report on limnology of Lakes in the Snake River Plain are descriptions of winter limnological conditions and kokanee growth characteristics from 1993 to 1995. The winter is usually a very harsh period for animals, and little is know about the over-winter ecology os sockeye salmon. They are active a temperatures below 4 F. The chapter discusses methods and results. 14 figs, 4 tabs.

Over-winter ecology of Oncorhynchus nerka in the Sawtooth Valley Lakes

International Nuclear Information System (INIS)

Steinhart, G.B.; Wurtsbaugh, W.A.

1996-01-01

Included in this section of the report on limnology of Lakes in the Snake River Plain are descriptions of winter limnological conditions and kokanee growth characteristics from 1993 to 1995. The winter is usually a very harsh period for animals, and little is know about the over-winter ecology os sockeye salmon. They are active a temperatures below 4 F. The chapter discusses methods and results. 14 figs, 4 tabs

Establishing Winter Origins of Migrating Lesser Snow Geese Using Stable Isotopes

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Viviane Hénaux

2012-06-01

Full Text Available Increases in Snow Goose (Chen caerulescens populations and large-scale habitat changes in North America have contributed to the concentration of migratory waterfowl on fewer wetlands, reducing resource availability, and enhancing risks of disease transmission. Predicting wintering locations of migratory individuals is critical to guide wildlife population management and habitat restoration. We used stable carbon (δ13C, nitrogen (δ15N, and hydrogen (δ2H isotope ratios in muscle tissue of wintering Snow Geese to discriminate four major wintering areas, the Playa Lake Region, Texas Gulf Coast, Louisiana Gulf Coast, and Arkansas, and infer the wintering locations of individuals collected later during the 2007 and 2008 spring migrations in the Rainwater Basin (RWB of Nebraska. We predicted the wintering ground derivation of migrating Snow Geese using a likelihood-based approach. Our three-isotope analysis provided an efficient discrimination of the four wintering areas. The assignment model predicted that 53% [95% CI: 37-69] of our sample of Snow Geese from the RWB in 2007 had most likely originated in Louisiana, 38% [23-54] had wintered on Texas Gulf Coast, and 9% [0-20] in Arkansas; the assessment suggested that 89% [73-100] of our 2008 sample had most likely come from Texas Gulf Coast, 9% [0-27] from Louisiana Gulf Coast, and 2% [0-9] from Arkansas. Further segregation of wintering grounds and additional sampling of spring migrating Snow Geese would refine overall assignment and help explain interannual variations in migratory connectivity. The ability to distinguish origins of northbound geese can support the development of spatially-adaptive management strategies for the midcontinent Snow Goose population. Establishing migratory connectivity using isotope assignment techniques can be extended to other waterfowl species to determine critical habitat, evaluate population energy requirements, and inform waterfowl conservation and management

Climate change affects winter chill for temperate fruit and nut trees.

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Luedeling, Eike; Girvetz, Evan H; Semenov, Mikhail A; Brown, Patrick H

2011-01-01

Temperate fruit and nut trees require adequate winter chill to produce economically viable yields. Global warming has the potential to reduce available winter chill and greatly impact crop yields. We estimated winter chill for two past (1975 and 2000) and 18 future scenarios (mid and end 21st century; 3 Global Climate Models [GCMs]; 3 greenhouse gas emissions [GHG] scenarios). For 4,293 weather stations around the world and GCM projections, Safe Winter Chill (SWC), the amount of winter chill that is exceeded in 90% of all years, was estimated for all scenarios using the "Dynamic Model" and interpolated globally. We found that SWC ranged between 0 and about 170 Chill Portions (CP) for all climate scenarios, but that the global distribution varied across scenarios. Warm regions are likely to experience severe reductions in available winter chill, potentially threatening production there. In contrast, SWC in most temperate growing regions is likely to remain relatively unchanged, and cold regions may even see an increase in SWC. Climate change impacts on SWC differed quantitatively among GCMs and GHG scenarios, with the highest GHG leading to losses up to 40 CP in warm regions, compared to 20 CP for the lowest GHG. The extent of projected changes in winter chill in many major growing regions of fruits and nuts indicates that growers of these commodities will likely experience problems in the future. Mitigation of climate change through reductions in greenhouse gas emissions can help reduce the impacts, however, adaption to changes will have to occur. To better prepare for likely impacts of climate change, efforts should be undertaken to breed tree cultivars for lower chilling requirements, to develop tools to cope with insufficient winter chill, and to better understand the temperature responses of tree crops.

On the winter anomaly of the night-to-day ratio of ozone in the middle to upper mesosphere in middle to high latitudes

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Sonnemann, G. R.; Hartogh, P.; Jarchow, Ch.; Grygalashvyly, M.; Berger, U.

Long-term measurements of ozone by means of the microwave technique performed at Lindau (51.66°N, 10.13°E), Germany, revealed a winter anomaly of the night-to-day ratio (NDR) which is more clearly pronounced as the so-called tertiary nighttime ozone maximum. The domain of occurrence also differs somewhat from that of the nighttime ozone enhancement. The maximum winter-to-summer ratio amounts to a value of two to three in 70 km height. The annual variation of the NDR is modulated by oscillations of planetary time scale. 3D-calculations on the basis of the advanced GCM LIMA essentially reflect the observations but also show some typical differences which probably result from a somewhat too humid model atmosphere in middle latitudes. We analyzed the most important impacts on the middle mesospheric ozone. The strongest impacts are connected with the annual variation of water vapor and the so-called Doppler-Sonnemann effect considering the influence of the zonal wind on the chemistry due to the fact that ozone is subjected to an effective dissociation longer than molecular oxygen for an increasing solar zenith angle. Because of that the net odd oxygen production decreases faster than the formation of atomic oxygen from ozone which is involved in an odd oxygen destructing catalytic cycle. A shortening of the time of sunset by a west wind regime increases the nighttime ozone level relatively, whereas the daytime ozone is less influenced by the zonal wind in the domain considered.

Is Switzerland Suitable for the Invasion of Aedes albopictus?

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Neteler, Markus; Metz, Markus; Rocchini, Duccio; Rizzoli, Annapaola; Flacio, Eleonora; Engeler, Luca; Guidi, Valeria; Lüthy, Peter; Tonolla, Mauro

2013-01-01

Background Over the last 30 years, the Asian tiger mosquito, Aedes albopictus, has rapidly spread around the world. The European distribution comprises the Mediterranean basin with a first appearance in Switzerland in 2003. Early identification of the most suitable areas in Switzerland allowing progressive invasion by this species is considered crucial to suggest adequate surveillance and control plans. Methodology/Principal Findings We identified the most suitable areas for invasion and establishment of Ae. albopictus in Switzerland. The potential distribution areas linked to the current climatic suitability were assessed using remotely sensed land surface temperature data recorded by the MODIS satellite sensors. Suitable areas for adult survival and overwintering of diapausing eggs were also identified for future climatic conditions, considering two different climate change scenarios (A1B, A2) for the periods 2020–2049 and 2045–2074. At present, the areas around Lake Geneva in western Switzerland provide suitable climatic conditions for Ae. albopictus. In northern Switzerland, parts of the Rhine valley, around Lake Constance, as well as the surroundings of Lake Neuchâtel, appear to be suitable for the survival at least of adult Ae. albopictus. However, these areas are characterized by winters currently being too cold for survival and development of diapausing eggs. In southern Switzerland, Ae. albopictus is already well-established, especially in the Canton of Ticino. For the years 2020–2049, the predicted possible spread of the tiger mosquito does not differ significantly from its potential current distribution. However, important expansions are obtained if the period is extended to the years 2045–2074, when Ae. albopictus may invade large new areas. Conclusions/Significance Several parts of Switzerland provide suitable climatic conditions for invasion and establishment of Ae. albopictus. The current distribution and rapid spread in other European

Nitrous oxide emission from highland winter wheat field after long-term fertilization

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X. R. Wei

2010-10-01

Full Text Available Nitrous oxide (N₂O is an important greenhouse gas. N₂O emissions from soils vary with fertilization and cropping practices. The response of N₂O emission to fertilization of agricultural soils plays an important role in global N₂O emission. The objective of this study was to assess the seasonal pattern of N₂O fluxes and the annual N₂O emissions from a rain-fed winter wheat (Triticum aestivum L. field in the Loess Plateau of China. A static flux chamber method was used to measure soil N₂O fluxes from 2006 to 2008. The study included 5 treatments with 3 replications in a randomized complete block design. Prior to initiating N₂O measurements the treatments had received the same fertilization for 22 years. The fertilizer treatments were unfertilized control (CK, manure (M, nitrogen (N, nitrogen + phosphorus (NP, and nitrogen + phosphorus + manure (NPM. Soil N₂O fluxes in the highland winter wheat field were highly variable temporally and thus were fertilization dependent. The highest fluxes occurred in the warmer and wetter seasons. Relative to CK, m slightly increased N₂O flux while N, NP and NPM treatments significantly increased N₂O fluxes. The fertilizer induced increase in N₂O flux occurred mainly in the first 30 days after fertilization. The increases were smaller in the relatively warm and dry year than in the cold and wet year. Combining phosphorous and/or manure with mineral N fertilizer partly offset the nitrogen fertilizer induced increase in N₂O flux. N₂O fluxes at the seedling stage were mainly controlled by nitrogen fertilization, while fluxes at other plant growth stages were influenced by plant and environmental conditions. The cumulative N₂O emissions were always higher in the fertilized treatments than in the non-fertilized treatment (CK. Mineral and manure

Effects of prescribed burns on wintering cavity-nesting birds

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Heather L. Bateman; Margaret A. O' Connell

2006-01-01

Primary cavity-nesting birds play a critical role in forest ecosystems by excavating cavities later used by other birds and mammals as nesting or roosting sites. Several species of cavity-nesting birds are non-migratory residents and consequently subject to winter conditions. We conducted winter bird counts from 1998 to 2000 to examine the abundance and habitat...

Do traits of invasive species influence decomposition and soil respiration of disturbed ecosystems?

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Wells, A. J.; Balster, N. J.

2009-12-01

Large-scale landscape disturbances typically alter the terrestrial carbon cycle leading to shifts in pools of soil carbon. Restoration of disturbed landscapes with prairie vegetation has thus been practiced with the intent of increasing carbon accrual in soils. However, since disturbed soils are prone to invasion by non-native invasive species, many ecological restorations have resulted in unexpected outcomes, which may be explained by differences in plant traits such as tissue quality and biomass allocation. Typically, the tissue of invasive species has lower C:N ratios relative to native species, and consequently, faster decomposition rates, which potentially can alter the balance in soil carbon. The primary objective of this research was to compare the effects of native prairie species versus non-native invasive species on the carbon cycling within a novel environment: a recently dewatered basin in southwestern Wisconsin following dam removal. We hypothesized that a higher invasive to native species ratio would result in faster litter decomposition and a higher rate of soil respiration. To test this hypothesis, we seeded newly exposed sediments with native prairie seeds in 2005, annually collected aboveground plant biomass (by species per plot), calculated decomposition rate of native and invasive litter (underneath both canopy types), and measured soil respiration during the growing season of 2009. After four years of seeding, the aboveground biomass of the native vegetation has increased significantly (p invasive species biomass has decreased from 459 to 296 g m-2. Senesced tissue from mixed native species had a higher C:N ratio, 27:1 (43% C: 1.6% N), than tissue from mixed invasive species, 24:1 (35% C: 1.5% N). However, after 7 months, we found that the rate of decomposition depended on both litter type and plant canopy type (p invasive plant tissue had a slightly faster decomposition rate than the native litter and this rate was elevated under invasive

Life in Ice: Microbial Growth Dynamics and Greenhouse Gas Production During Winter in a Thermokarst Bog Revealed by Stable Isotope Probing Targeted Metagenomics

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Blazewicz, S.; White, R. A., III; Tas, N.; Euskirchen, E. S.; Mcfarland, J. W.; Jansson, J.; Waldrop, M. P.

2016-12-01

Permafrost contains a reservoir of frozen C estimated to be twice the size of the current atmospheric C pool. In response to changing climate, permafrost is rapidly warming which could result in widespread seasonal thawing. When permafrost thaws, soils that are rich in ice and C often transform into thermokarst wetlands with anaerobic conditions and significant production of atmospheric CH4. While most C flux research in recently thawed permafrost concentrates on the few summer months when seasonal thaw has occurred, there is mounting evidence that sizeable portions of annual CO2 and CH4 efflux occurs over winter or during a rapid burst of emissions associated with seasonal thaw. A potential mechanism for such efflux patterns is microbial activity in frozen soils over winter where gasses produced are partially trapped within ice until spring thaw. In order to better understand microbial transformation of soil C to greenhouse gas over winter, we applied stable isotope probing (SIP) targeted metagenomics combined with process measurements and field flux data to reveal activities of microbial communities in `frozen' soil from an Alaskan thermokarst bog. Field studies revealed build-up of CO2 and CH4 in frozen soils suggesting that microbial activity persisted throughout the winter in soils poised just below the freezing point. Laboratory incubations designed to simulate in-situ winter conditions (-1.5 °C and anaerobic) revealed continuous CH4 and CO2 production. Strikingly, the quantity of CH4 produced in 6 months in frozen soil was equivalent to approximately 80% of CH4 emitted during the 3 month summer `active' season. Heavy water SIP targeted iTag sequencing revealed growing bacteria and archaea in the frozen anaerobic soil. Growth was primarily observed in two bacterial phyla, Firmicutes and Bacteroidetes, suggesting that fermentation was likely the major C mineralization pathway. SIP targeted metagenomics facilitated characterization of the primary metabolic

A winter chronicle. The coldness of the winter in the Federal Republic of Germany between 1960/61 and 2007/2008; Eine Winterchronik. Die Kaelte der Winter in Deutschland von 1960/61 bis 2007/08