Spring Time Research Articles

Identifying the Driving Factors of Water Quality in a Sub-Watershed of the Republican River Basin, Kansas USA.

Studies have shown that the agricultural expansion and land use changes in the Midwest of the U.S. are major drivers for increased nonpoint source pollution throughout the regional river systems. In this study, we empirically examined the relationship of planted area and production of three dominant crops with nitrate flux in the Republican River, Kansas, a sub-watershed of Mississippi River Basin. Our results show that land use in the region could not explain the observed changes in nitrate flux in the river. Instead, after including explanatory variables such as precipitation, growing degree days, and well water irrigation in the regression model we found that irrigation and spring precipitation could explain >85% of the variability in nitrate flux from 2000 to 2014. This suggests that changes in crop acreage and production alone cannot explain variability in nitrate flux. Future agricultural policy for the region should focus on controlling both the timing and amount of fertilizer applied to the field to reduce the potential leaching of excess fertilizer through spring time runoff and/or over-irrigation into nearby river systems.

The Prevalence of Cryptocaryon irritans in wild marine ornamental fish from Vietnam

Wild-caught ornamental marine fish from NhaTrang (Khanh Hoa) and Ha Long (Quang Ninh) in Vietnam were examined over the three sampling batches corresponding to the spring, summer and autumn times for the prevalence of Cryptocaryon irritans. Out of a total of 211 fish (15 species), 143 (67.7 %) were found to be infected with the mean intensity of 7.67 parasites per field of view (x4 magnification). The prevalence of C. irritans in fish caught during the spring (91.0 3% on average) was significantly higher than that of the fish caught during the summer (39.29 %). A wide variation in the prevalence of the parasite was shown among the fish species. The highest prevalence and intensity of the infection occurred in Plataxteira, Diodon holocanthus, Paracanthurus hepatusat 100 % of infection and density of 12 parasites/field of view (x4 magnification) while and the lowest prevalence of C. irritans appeared on Rhinecanthus aculeatus, Zancluscornutus, and Zebrasoma veliferum with less than 50% of fish infected. Clinical signs of fish infected of C. irritans showed such as tiny white spots on skin, gills, and fins; ragged fins, changes in skin colour, cloudy eyes and increase mucus production.

Invasion of the European Mink in Omsk Oblast

The invasion of the European mink Mustela lutreola in Omsk oblast continued about 100 years; it was reported for the first time in 1886 and last in 1984. Changes in numbers of the European mink in Omsk oblast were in a direct weak relationship to abiotic factors, such as indicators of solar activity (W, Wolf number) and different moisture conditions within the territory and water level in water bodies. Changes in the area of distribution and population density were in a weak relationship to the timing of spring and fall onsets and the amount of precipitation and snow cover in winter. The average annual harvest amount from professional hunting was rated at ~25% of the individuals living within the territory.

Perennial ground cover plants as floral resources for urban pollinators: A case of Geranium species

Urban green areas, due to their high plant diversity, can be supportive as floral resources (nectar and/or pollen) to wild and managed pollinating insects. This research aims towards understanding the contribution of ornamental ground cover perennials as a food source for urban pollinators. We compare floral phenology and abundance, nectar and pollen production, and insect visitation to flowers of Geranium macrorrhizum, G. platypetalum and G. sanguineum, planted in the botanical garden of Lublin, SE Poland. The investigation revealed that the studied hardy geraniums exhibit many features valuable for pollinators, including large floral display (G. macrorrhizum and G. platypetalum), extended flowering period (G. sanguineum) and ample nectar and pollen reward (G. macrorrhizum). They can supply urban pollinators with a high quality food during spring and early summer time, i.e. the period of high food demand by many bee species. Moreover, hardy geraniums might be valuable plants for urban beekeeping as they are eagerly visited by honeybees. The investigated ground cover plants could therefore be considered in future city plantings.

Hydrochemical Characteristic of the Littoral Zone of Lake Onega

The article presents the results of hydrochemical studies of two areas, open and closed, in the littoral zone of Lake Onega, carried out in 2013–2014. The results show that water of river and slope runoff, enriched with both biogenic elements and allochthonous organic matter, persist over a long time in spring in the littoral zone. In the summer, water chemistry at open shores is similar to that in lake pelagic zone, while the closed areas of littoral zone show the effect of biological processes. In the period of autumn homothermy, river and slope waters have no considerable effect on coastal water quality.

The Influence of Treatment Timing and Shrub Size on Chinese Privet (Ligustrum sinense) Control with Cut Stump Herbicide Treatments in the Southeastern United States

AbstractSince its introduction to the United States in 1852, Chinese privet (Ligustrum sinenseLour.) has spread throughout the Southeast, invading many natural areas. Manual control by cutting or shredding is one of the most common strategies many land managers employ. However, rapid sprouting from the root collar and lateral roots commonly results in poor control. Cutting followed by either glyphosate or triclopyr application to the stumps is generally effective, but the efficacy of these herbicides in relation to treatment timing andL. sinenseroot collar diameter has not been evaluated. The objective of this experiment was to determine the effectiveness of glyphosate and triclopyr cut stump treatments compared with cutting alone at spring and fall timings across a range ofL. sinensesize classes. Studies were conducted at two locations in Auburn, AL. Treatments included cut stump+no herbicide, cut stump+ glyphosate (120 g L−1), or cut stump+triclopyr (90 g L−1). Treatments were applied to at least 50 experimental units each at April and November timings. Root collar diameter was recorded for each stem, stems were cut 2.5 cm above the ground, and herbicide treatments were applied within 30 s.Ligustrum sinensemortality and sprouting were quantified 6, 12, and 18 mo after treatment. Both glyphosate and triclopyr amine were very effective in controllingL. sinenseat both spring and fall timings. However, glyphosate provided slightly better results than triclopyr when lateral sprouting was included. Application timing also was significant, with a lower percentage of sprouting following November treatments than April treatments. Stem size influenced treatment success, as larger stumps tended to sprout more than smaller stumps. These results indicateL. sinensecan be controlled with cut stump herbicide treatment using either glyphosate or triclopyr with spring or fall timings at concentrations much lower than typically used.

Springtime Peaks and Christmas Troughs: A National Longitudinal Population-Based Study into Suicide Incidence Time Trends in the Netherlands.

Time trends are one of the most studied phenomena in suicide research; however, evidence for time trends in the Dutch population remains understudied. Insight into time trends can contribute to the development of effective suicide prevention strategies. Time trends in national daily and monthly data of 33,224 suicide events that occurred in the Netherlands from 1995 to 2015 were examined, as well as the influence of age, gender, and province, in a longitudinal population-based design with Poisson regression analyses and Bayesian change point analyses. Suicide incidence among Dutch residents increased from 2007 until 2015 by 38%. Suicide rates peak in spring, up to 8% higher than in summer (p < 0.001). Suicide incidence was 42% lower at Christmas, compared to the December-average (IRR = 0.580, p < 0.001). After Christmas, a substantial increase occurred on January 1, which remained high during the first weeks of the new year. Suicide occurred more than twice as often in men than in women. For both genders, the results indicated a spring time peak in suicide incidence and a trough at Christmas. Suicide rates were highest in the elderly (age group, 80+), and no evidence was found of a differential effect by season in the age groups with regard to suicide incidence. No interaction effect was found with regard to province of residence for both season and Christmas, indicating that no evidence was found that these time trends had differential effects in the Dutch provinces in terms of suicide incidence. Evidence was found for time trends in suicide incidence in the Netherlands. It is recommended to plan (mental) health care services to be available especially at high-risk moments, at spring time, and in the beginning of January. Further research is needed to explore the protective effect of Christmas in suicide incidence.

Atmospheric Inputs of Nitrogen, Carbon, and Phosphorus across an Urban Area: Unaccounted Fluxes and Canopy Influences

AbstractRates of atmospheric deposition are declining across the United States, yet urban areas remain hotspots of atmospheric deposition. While past studies show elevated rates of inorganic nitrogen (N) deposition in cities, less is known about atmospheric inputs of organic N, organic carbon (C), and organic and inorganic phosphorus (P), all of which can affect ecosystem processes, water quality, and air quality. Further, the effect of the tree canopy on amounts and forms of nutrients reaching urban ground surfaces is not well‐characterized. We measured growing season rates of total N, organic C, and total P in bulk atmospheric inputs, throughfall, and soil solution around the greater Boston area. We found that organic N constitutes a third of total N inputs, organic C inputs are comparable to rural inputs, and inorganic P inputs are 1.2 times higher than those in sewage effluent. Atmospheric inputs are enhanced two‐to‐eight times in late spring and are elevated beneath tree canopies, suggesting that trees augment atmospheric inputs to ground surfaces. Additionally, throughfall inputs may directly enter runoff when trees extend above impervious surfaces, as is the case with 26.1% of Boston's tree canopy. Our results indicate that the urban atmosphere is a significant source of elemental inputs that may impact urban ecosystems and efforts to improve water quality, particularly in terms of P. Further, as cities create policies encouraging tree planting to provide ecosystem services, locating trees above permeable surfaces to reduce runoff nutrient loads may be essential to managing urban biogeochemical cycling and water quality.

Evaluation of Two-Ship Collision Severity using Ordered Probit Approaches

This study develops an ordered probit model to evaluate the factors influencing two-ship collision severity using ten years’ ship collision accident data from Fujian sea areas. The model results show that the involvement of big ships has the largest impact in increasing the probability of a serious or very serious accident, followed by the involvement of fishing vessels. There will be a bigger probability of a serious accident if both ships involved in the collision are cargo ships. We found that the season of spring, poor visibility and night time periods are more likely to be factors in high severity levels of ship collision. The results also reveal that lookout failure plays a decisive role in increasing serious accident risk compared with other types of human errors. The results of this study may be beneficial for policy-makers in proposing efficient strategies to reduce the likelihood of serious ship collisions.

Measurements of ammonia concentration in buildings of pig enterprises in Greece.

The concentration of ammonia was measured in the air space of 180 houses of 30 pig enterprises in Greece during an 8-month period by using tubes that chemically bind atmospheric ammonia. The mean overall ammonia concentration was 24.6 ppm (10-52 ppm). The mean ammonia concentration according to the age group of the animals was 26.4 ppm in finishing pig houses, 26.2 ppm in growers' pig houses, 22.6 ppm in flat-deck units and 19.8 ppm in farrowing houses (p&lt;0.05). With regard to the type of the floor, the mean ammonia concentration was 28.0 ppm in concrete-floored houses and 21.4 ppm in slatted-floored ones (p&lt;0.05), and as regards the season of the year, higher concentrations were measured at winter time (27.7 ppm) compared to those seen during spring (24.5 ppm) and summer time (21.1 ppm) (p&lt;0.05). The findings are discussed in relation to the adverse effects that ammonia may have for pig's health and production.

Down to the wire: late season changes in sex expression in a sexually labile tree species, Acer pensylvanicum (Sapindaceae)

In sexually plastic Acer pensylvanicum, determination of sex can occur extremely late, within three weeks of spring flowering. Physical damage causing complete vascular tissue severance results in increased female expression. Species with environmental sex determination are rare amongst angiosperms but widely distributed across taxa. The timing of floral development in species that change sex based on environmental cues is unexplored. We investigated the timing of differentiation of sexual organs in buds of Acer pensylvanicum, an understory tree in eastern North America with environmental sex determination. We collected branches from individuals at three collection times in the early spring of 2016 and kept them in a warm greenhouse until anthesis. All individuals exhibited complete or partial female inflorescences in the greenhouse in one or more collection. However, none of these same individuals produced only female flowers in the field. Unlike many other woody species that differentiate bud sexual primordia 9–12 months prior to flowering, A. pensylvanicum may differentiate the sexual organs in its flower buds as late as three weeks prior to anthesis. In a separate series of branch collections in 2017, we found that the stress response to cutting leads to increased female sex expression in branches, while earlier warm temperatures (e.g., those caused by growing in a protected greenhouse environment) or increased carbohydrate availability does not. Given the labile sex determination system of A. pensylvanicum, the ability to delay differentiation of buds into male or female until shortly before spring flowering would allow individual trees to respond to sex-determining damage cues as late as mid-spring. This supports the hypothesis that A. pensylvanicum may not exhibit the lag-time characteristic of temperate spring and early-summer flowering woody species and may change sex expression in response to stress.

THE IMPACT OF USING COMBINATIONS OF N, S AND B IN OILSEED RAPE - BRASSICA NAPUS L. ON QUANTITATIVE PROPERTIES OF SEED

As a result of the use of the following elements - nitrogen (N), sulphur (S) and boron (B) - quantitative properties of two genotypes of oilseed rape - Brassica napus L., Zorica (variety) and Rohan (hybrid) were determined. The main purpose of the study was determination of the production mode, set in both genotypes of oilseed rape versus managing various nutrients. An experiment was set in the Skopje region, on total experimental area of 650m2. For this purpose, the following combinations of fertilizers were used: N1 with 110 kg/ha nitrogen, N2 with 150 kg/ha nitrogen, S1 with 30 kg/ha sulphur, S2 with 70 kg/ha sulphur, B1 with 1.0 kg/ha boron, and B2 with 2.0 kg/ha boron (at spring time, foliar application) versus standard variant: N:P:K in the ratio 10:20:30 (N 50kg/ha, 90 kg/ha P2O5 and 180 kg/ha K2O) used in autumn. During the experiment the following parameters were monitored: height of plants (cm), number of branches per plant, number of pods per plant, length of pod (cm), number of seeds in the silique, and seed yield (t/ha). From the combinations of nutrients and variations that have been set in terms of genotypes, the results of yield showed statistical significance at level of 0.05 from variants N2PK, N2PK+S2+B2 in variety Zorica and N1PK+S1+B1 in the hybrid Rohan.

Influence of precipitation on bacterial structure in a typical karst spring, SW China

Micro-organisms are major components in the environment, which play a key role in groundwater environment. This study aims to investigate the bacterial diversity over time in a typical karst spring named S31 and its response to hydrogeochemical parameters. Quantitative PCR and 16S rRNA high-throughput sequencing was adopted to detect changes of the bacterial community structure. For the correlations between hydrogeochemical parameters and predominant phyla, redundancy analysis were adopted. According to the results, hydrochemical characteristics were controlled by carbonate equilibrium system and dynamic groundwater transformation which was influenced distinctly by precipitation. In addition, the redundancy analysis indicates that HCO3-, Ca2+, Eh, temperature and cumulative precipitation are the most important hydrogeochemical and environmental parameters to determine the bacterial community structures. That is to say, temperature can influence bacterial abundance by controlling dissolved oxygen content. Precipitation is another important factor which determines the community composition and bacterial structure directly or indirectly. Moreover, acidobacteria, proteobacteria, and bacteroidetes play key roles in response to the environmental factors in the groundwater of karst zones.

Diverse Responses of Vegetation Phenology to Climate Change in Different Grasslands in Inner Mongolia during 2000–2016

Vegetation phenology in temperate grasslands is highly sensitive to climate change. However, it is still unclear how the timing of vegetation phenology events (especially for autumn phenology) is altered in response to climate change across different grassland types. In this study, we investigated variations of the growing season start (SOS) and end (EOS), derived from Moderate Resolution Imaging Spectroradiometer (MODIS) data (2000–2016), for meadow steppe, typical steppe, and desert steppe in the Inner Mongolian grassland of Northern China. Using gridded climate data (2000–2015), we further analyzed correlations between SOS/EOS and pre-season average air temperature and total precipitation (defined as 90-day period prior to SOS/EOS, i.e., pre-SOS/EOS) in each grid. The results showed that both SOS and EOS occurred later in desert steppe (day of year (doy) 114 and 312) than in meadow steppe (doy 109 and 305) and typical steppe (doy 111 and 307); namely, desert steppe has a relatively late growing season than meadow steppe and typical steppe. For all three grasslands, SOS was mainly controlled by pre-SOS precipitation with the sensitivity being largest in desert steppe. EOS was closely connected with pre-EOS air temperature in meadow steppe and typical steppe, but more closely related to pre-EOS precipitation in desert steppe. During 2000–2015, SOS in typical steppe and desert steppe has significantly advanced by 2.2 days and 10.6 days due to a significant increase of pre-SOS precipitation. In addition, EOS of desert steppe has also significantly advanced by 6.8 days, likely as a result from the combined effects of elevated preseason temperature and precipitation. Our study highlights the diverse responses in the timing of spring and autumn phenology to preceding temperature and precipitation in different grassland types. Results from this study can help to guide grazing systems and to develop policy frameworks for grasslands protection.

Long-term changes in the seasonal timing of landbird migration on the Pacific Flyway

ABSTRACT The seasonal phenology of latitudinal movements is one of the key life-history traits of migratory birds. We used quantile regression to examine long-term changes in the timing of spring and autumn migration in 5 species of migratory passerine birds captured at a banding station in northern California, USA, over a 22 yr period from 1987 to 2008. Our 5 study species included 3 short-distance migrants, Pacific-slope Flycatcher (Empidonax difficilis), Orange-crowned Warbler (Oreothlypis celata), and Wilson's Warbler (Cardellina pusilla); and 2 long-distance migrants, Swainson's Thrush (Catharus ustulatus) and Yellow Warbler (Setophaga petechia). Median timing of migration advanced in spring for 2 of the 5 species (−2.5 days decade−1) but was delayed during autumn migration for 3 of the species (+2.9 days decade−1). The duration of the migration period also became compressed in some species but more protracted in others. We tested whether annual variation in migration timing was related to 3 indices ...

Confirmation of Elevated Methane Emissions in Utah's Uintah Basin With Ground‐Based Observations and a High‐Resolution Transport Model

AbstractLarge CH4 leak rates have been observed in the Uintah Basin of eastern Utah, an area with over 10,000 active and producing natural gas and oil wells. In this paper, we model CH4 concentrations at four sites in the Uintah Basin and compare the simulated results to in situ observations at these sites during two spring time periods in 2015 and 2016. These sites include a baseline location (Fruitland), two sites near oil wells (Roosevelt and Castlepeak), and a site near natural gas wells (Horsepool). To interpret these measurements and relate observed CH4 variations to emissions, we carried out atmospheric simulations using the Stochastic Time‐Inverted Lagrangian Transport model driven by meteorological fields simulated by the Weather Research and Forecasting and High Resolution Rapid Refresh models. These simulations were combined with two different emission inventories: (1) aircraft‐derived basin‐wide emissions allocated spatially using oil and gas well locations, from the National Oceanic and Atmospheric Administration (NOAA), and (2) a bottom‐up inventory for the entire U.S., from the Environmental Protection Agency (EPA). At both Horsepool and Castlepeak, the diurnal cycle of modeled CH4 concentrations was captured using NOAA emission estimates but was underestimated using the EPA inventory. These findings corroborate emission estimates from the NOAA inventory, based on daytime mass balance estimates, and provide additional support for a suggested leak rate from the Uintah Basin that is higher than most other regions with natural gas and oil development.

Evolutionary dynamics of the leaf phenological cycle in an oak metapopulation along an elevation gradient.

It has been predicted that environmental changes will radically alter the selective pressures on phenological traits. Long-lived species, such as trees, will be particularly affected, as they may need to undergo major adaptive change over only one or a few generations. The traits describing the annual life cycle of trees are generally highly evolvable, but nothing is known about the strength of their genetic correlations. Tight correlations can impose strong evolutionary constraints, potentially hampering the adaptation of multivariate phenological phenotypes. In this study, we investigated the evolutionary, genetic and environmental components of the timing of leaf unfolding and senescence within an oak metapopulation along an elevation gradient. Population divergence, estimated from insitu and common-garden data, was compared to expectations under neutral evolution, based on microsatellite markers. This approach made it possible (1) to evaluate the influence of genetic correlation on multivariate local adaptation to elevation and (2) to identify traits probably exposed to past selective pressures due to the colder climate at high elevation. The genetic correlation was positive but very weak, indicating that genetic constraints did not shape the local adaptation pattern for leaf phenology. Both spring and fall (leaf unfolding and senescence, respectively) phenology timings were involved in local adaptation, but leaf unfolding was probably the trait most exposed to climate change-induced selection. Our data indicated that genetic variation makes a much smaller contribution to adaptation than the considerable plastic variation displayed by a tree during its lifetime. The evolutionary potential of leaf phenology is, therefore, probably not the most critical aspect for short-term population survival in a changing climate.

Marked reduction in demographic rates and reduced fitness advantage for early breeding is not linked to reduced thermal matching of breeding time.

Warmer springs may cause animals to become mistimed if advances of spring timing, including available resources and of timing of breeding occur at different speed. We used thermal sums (cumulative sum of degree days) during spring to describe the thermal progression (timing) of spring and investigate its relationship to breeding phenology and demography of a long‐distant migrant bird, the northern wheatear (Oenanthe oenanthe L.). We first compare 20‐year trends in spring timing, breeding time, selection for breeding time, and annual demographic rates. We then explicitly test whether annual variation in selection for breeding time and demographic rates associates with the degree of phenological matching between breeding time and thermal progression of spring. Both thermal progression of spring and breeding time of wheatears advanced in time during the study period. But despite breeding on average 7 days earlier with respect to date, wheatears bred about 4 days later with respect to thermal spring progression. Over the same time period, selection for breeding time changed from distinct within‐season advantage of breeding early to no or very weak advantage. Furthermore, demographic rates (nest success, fledgling production, recruitment, adult survival) and nestling weight declined markedly by 16%–79%. Those temporal trends suggest that a reduced degree of phenological matching may affect within‐season fitness advantage of early breeding and population demographic rates. In contrast, when we investigate links based on annual variation, we find no significant relationship between either demographic rates or fitness advantage of early breeding with annual variation in the degree of phenological matching. Our results show that corresponding temporal trends in phenological matching, selection for breeding time and demographic rates are inconclusive evidence for demographic effects of changed phenological matching. Instead, we suggest that the trends in selection for breeding time and demographic rates are due to a general deterioration of the breeding environment.

RADON SURVEY IN SCHOOL AND ESTIMATION OF EFFECTIVE DOSE USING CORRECTED RADON CONCENTRATION.

Radon exposure in schools is different from that in dwellings because the residence pattern is very different each other. So, when effective dose is calculated in schools, different approach should be considered from in dwellings. The aim of this study was to estimate actual effective dose due to inhaled radon considering the residence time in schools. It could help avoid overestimation when effective dose is calculated in schools. The range of radon concentration in 376 schools was 18.1-2810 Bq m-3 and that of annual effective dose was estimated 0.0902-8.92 mSv y-1 considering the residence time in spring and autumn semesters.

Evaluation of Herbicides for Ground Ivy (Glechoma hederacea L.) Control at Two Application Timings

Ground ivy (Glechoma hederacea L.) is a creeping perennial broadleaf species that is difficult to control in turf. The efficacy of spring herbicide applications has received limited investigation. Further, comparisons between commonly used and effective herbicide treatments are limited. Field experiments were conducted to determine the influence of herbicide selection and fall and spring application timings on the control of ground ivy across three separate environments located across Indiana and Tennessee. Herbicides containing 2,4‐D, fluroxypyr, triclopyr, iodosulfuron, thiencarbazone, and aminocyclopyrachlor or mixtures of these active ingredients had the greatest control of ground ivy (&gt;53%) at both timings. With the exception of metsulfuron and fluroxypyr, most of the herbicides provided consistent ground ivy control when applied in either the fall or the spring. Differences in ground ivy control between herbicides were much greater than differences between spring and fall application timings. This research indicates that proper herbicide selection has a larger influence on ground ivy control than application timing.