scholarly journals Remarks on the seasonal aspects of plant communities on cereal crop fields

2013 ◽  
Vol 37 (1) ◽  
pp. 91-112
Author(s):  
Jan T. Siciński
Keyword(s):  
Floristic Composition ◽  
Late Summer ◽  
Early Spring ◽  
Early Summer ◽  
Developmental Cycle ◽  
Vegetation Season ◽  
Crop Fields ◽  
Microclimatic Conditions ◽  
Cereal Fields ◽  
Developmental Phases

The present paper is a discussion on the external manifestations of periodicity in the appearance and various degrees of intensity of the developmental processes in communities of cereal fields. The result of these changes is a different appearance of the some community in the course of the annual developmental cycle. In the course of the vegetation season the particular species develop differently some flower in spring, the majority in summer and others as late as autumn. Observation of various associations with cereals indicates that some of them exhibit wide differences in the manifestation of development periodism. A larger or smaller number of stages and their shorter or longer duration may be observed. Floristically richer communities (large number of species represented by large number of individuals) show more pronounced developmental phases, whereas in poorer ones these phases are more uniformly distributed in the course of the vegetation season. Field communities developing in the poorest habitats exhibit fewer aspects, usually in summer. All Polish investigators agree as to the early spring, spring, early summer and late summer aspects. There are controversies concerning the autumn (stubblefield) aspect. The classification of stubble field phytocenoses as associations does not seem fully justified. This phytocenosis is a continuation of the development of the cereal including community under greatly changed light and microclimatic conditions. The floristic composition indicates a connection with a definite group of habitats, and thus, with communities of cereal crops.

scholarly journals Influence of a Municipal Solid Waste Landfill on the Surrounding Environment: Landfill Vegetation as a Potential Risk of Allergenic Pollen

2019 ◽  
Vol 16 (24) ◽  
pp. 5064 ◽  
Author(s):  
Magdalena Daria Vaverková ◽  
Dana Adamcová ◽  
Jan Winkler ◽  
Eugeniusz Koda ◽  
Jana Červenková ◽  
...  
Keyword(s):  
Plant Species ◽  
Low Cost ◽  
Late Summer ◽  
Cost Effective ◽  
Early Spring ◽  
Early Summer ◽  
Allergenic Pollen ◽  
Grass Species ◽  
Vegetation Monitoring ◽  
Growing Seasons

When the landfill use comes to end, important subsequent steps include aftercare, safety assurance, and ecological regeneration. Landfill revegetation is cost-effective and eco-friendly approach in the management of landfill areas, which serves the purpose of stabilization and provides a pleasant landscape. There are various vegetation types that can be planted, yet grass species are often used for low-cost reasons. Plants can be important sources of air pollution, particularly by grass pollen. The main goal of our study was to identify plant species that produce allergenic pollen. Long-term vegetation monitoring took place on three sites in the growing seasons of years 2008–2018. Studied objects were landfills located in the Czech Republic. The vegetation was assessed using a floristic survey of identified plant species. Plant species that produced allergens were recorded. During the monitoring, 298 plant species were determined. Plant species with allergenic pollen have a considerable share in the landfill vegetation. Thus, landfills are potential sources of various kinds of allergenic pollen. Moreover, our results indicated that there are three periods of pollen production: early spring, late spring, and early summer; late summer; and autumn. The second period is typical for the production of highly allergenic pollen by grasses. Most detected plant species with allergenic pollen are common for all monitored sites, which demonstrates that the vegetation of landfills is a significant source of allergenic pollen.

Sub-seasonal streamflow predictions by combining numerical weather models and re-analysis data in alpine catchments

2021 ◽  
Author(s):  
Mattia Zaramella ◽  
Susen Shtrestha ◽  
Mattia Callegari ◽  
Alice Crespi ◽  
Felix Greifeneder ◽  
...  
Keyword(s):  
Model Simulation ◽  
Late Summer ◽  
Analysis Data ◽  
Early Spring ◽  
Early Summer ◽  
Lead Times ◽  
Streamflow Prediction ◽  
Reanalysis Dataset ◽  
Numerical Weather ◽  
Basin Scale

<p>The European Center for Medium-Range Weather Forecasts (ECMWF) has presented in 2017 its latest seasonal forecasting system, SEAS5, available at 1° spatial resolution and daily timestep. More recently, in 2019, the ERA5 reanalysis dataset was released, replacing ERA Interim in providing climatic variables at a finer spatial and temporal resolution (30 km and hourly respectively). The use of such numerical weather predictions and re-analysis data has increased following the need for skills in planning water resources and preventing hydrogeological risk, as demanded by policy makers, energy stakeholders and public authorities. In this work, we apply at a sub-seasonal timescale the ECMWF-SEAS5 hindcast dataset to assess its prediction skills in the upper Adige river basin in the Eastern Italian Alps. The classical Extended Streamflow Prediction (ESP) framework was designated as a benchmark to assess ECMWF scores over the reference, a model simulation calibrated and validated on the runoff observed from 16 sub-basins and size spanning from 50 to 6900 km<sup>2</sup>. Before application, ECMWF was downscaled and adjusted to the ERA5 re-analysis data by means of a Quantile Mapping (QM) technique. The analysis was conducted over 23 hindcast years from 1993 to 2016 exploiting the semi-distributed basin-scale hydrological model (ICHYMOD). We showed that the sub seasonal QPF-based forecasts have advantages over the ESP, although, generally their skill deteriorates in lead times after day 15. Moreover, ECMWF predictions better perform during early-spring snowmelt and late summer. During late spring and early summer, the forecast skills of the two frameworks vary from basin to basin depending on specific features and lead times.  </p>

scholarly journals Population biology of eyeflukes in fish from a large fluvial ecosystem: the importance of gulls and habitat characteristics

2001 ◽  
Vol 79 (6) ◽  
pp. 1102-1113 ◽  
Author(s):  
D J Marcogliese ◽  
S Compagna ◽  
E Bergeron ◽  
J D McLaughlin
Keyword(s):  
Population Biology ◽  
Yellow Perch ◽  
Late Summer ◽  
Early Spring ◽  
Early Summer ◽  
Habitat Characteristics ◽  
Vitreous Humour ◽  
Late Fall ◽  
Golden Shiners ◽  
St Lawrence River

Spottail shiners (Notropis hudsonius) were monitored for eyeflukes monthly at four sites in the St. Lawrence River, Quebec, from spring through autumn in 1997 and 1998. In general, mean abundance of Diplostomum spp. in the lens of spottail shiners was highest at sites near large ring-billed gull (Larus delawarensis) colonies and was higher in 1998 than in 1997. Population studies demonstrated a major period of recruitment in the late summer – early autumn. Mean abundance increased between November and May, when sampling was logistically not possible, reflecting late-fall or early-spring recruitment. Golden shiners (Notemigonus crysoleucas) and small yellow perch (Perca flavescens) were monitored at a single site (Île aux Ours) in 1997 and 1998. Mean abundance of Diplostomum spp. in the lens of golden shiners at Île aux Ours was higher in 1998 than in 1997. Recruitment occurred in the early summer and between November and May, suggesting late-fall or early-spring transmission. Mean abundance decreased between August and October in both years. Yellow perch at Île aux Ours were infected with four different parasite species in their eyes. Mean abundance of Diplostomum spp. in the vitreous humour or retina increased during the summer and fall and then decreased between the fall and following spring. Diplostomum spp. in the lens increased in abundance in the early summer, and then decreased during the fall. Both Tylodelphys scheuringi and Neascus spp. in the vitreous humour were more abundant in 0+ than in 1+ perch. Mean abundance of T. scheuringi increased over the summer in 1997 and then dropped to zero in the same cohort over winter, suggesting that the parasite lives for only 1 year. Neascus spp. only were found in 1998. Distributional data, together with seasonal information, suggest that habitat characteristics contribute significantly to the abundance of Diplostomum spp. along the St. Lawrence River. Proximity to gull colonies enhances abundance, but higher rates of predation at wetland sites depress abundance and restrict the accumulation of parasites.

Flowering and shoot elongation of lychee in eastern Australia

2002 ◽  
Vol 53 (8) ◽  
pp. 977 ◽  
Author(s):  
T. Olesen ◽  
C. M. Menzel ◽  
N. Wiltshire ◽  
C. A. McConchie
Keyword(s):  
Late Summer ◽  
Weather Conditions ◽  
Shoot Elongation ◽  
Early Spring ◽  
Annual Number ◽  
Developmental Cycle ◽  
Winter Solstice ◽  
Mean Temperature ◽  
Eastern Australia ◽  
The Mean

We investigated the effects of the timing of shoot elongation on the flowering of lychee (Litchi chinensis Sonn.) in eastern Australia. Trees of cv. Kwai May Pink growing in Alstonville (lat. 28.9° S) were pruned during spring and summer, and subsequent shoot elongation was measured until the following spring. New shoots grew by discrete flushes, with the trees initiating 3, 2, or 1 vegetative shoots prior to winter, according to the pruning sequence. Shoots were vegetative when the mean temperature during early flush development was above 17-19°C, and floral at lower temperatures. Trees with successive flushes commencing in February (late summer) and June (early winter) were more likely to flower than trees with flushes commencing in April and August, because the weather conditions in June were cooler than those in August and more likely to favour induction. The importance of cool weather conditions during early flush development for floral determination was not significantly affected by the number of vegetative flushes to develop between pruning and winter. Having shown that the phase of recurrent flushing affects flowering, we sought to model the process in order to recognise reproductive and non-reproductive cycles along Australia's north-eastern seaboard, and to develop a management strategy for the promotion of flowering. From the results of the Alstonville pruning trial, the interval between successive flushes was regressed against the mean product of daily irradiation and mean daily temperature (°C.MJ/[m2.day]) during the interval. The regression was used in conjunction with long-term weather records to estimate the flush commencement dates required for the completion of 1 or 2 vegetative flushes by the winter solstice at different latitudes. The earliest date for the completion of 1 flush ranged from 16 February in northern New South Wales (lat. 30° S) to 13 March in northern Queensland (lat. 17° S). To test the model, a pruning trial was conducted near Mareeba (lat. 17° S). Trees pruned on 10 February, estimated to produce ≈ 1.5 flushes prior to winter (i.e. flushes in late autumn and early spring, but not in winter), flowered poorly and had low yields. In contrast, trees pruned on 11 March, estimated to produce 1 vegetative flush by winter, had good flowering and yields. Thus, strategic pruning after harvest can be used to manipulate flushing times, so that new, potentially flowering shoots emerge in winter. Cool temperatures are still required for successful flowering, and we provide estimates of the likelihood of such weather in the major growing areas by calculating the annual number of days with a mean temperature <20°C. For Cairns (lat. 16.9° S) the number of such days varied from 0 to 39 from 1888 to 1993, which is consistent with the irregular flowering of lychee in coastal northern Queensland. Our work is the first demonstration for any species that the phase of recurrent flushing affects flowering, and emphasises the interplay between a plant's endogenous developmental cycle and seasonal variations in weather.

Oribatida (Acari) associated with three species of Sphagnum at Spruce Hole Bog, New Hampshire, U.S.A.

1996 ◽  
Vol 74 (9) ◽  
pp. 1706-1712 ◽  
Author(s):  
Gay M. Donaldson
Keyword(s):  
New Hampshire ◽  
Water Surface ◽  
New Records ◽  
Oribatid Mite ◽  
Late Summer ◽  
Mite Species ◽  
Early Spring ◽  
Early Summer ◽  
Order Four ◽  
Oribatid Mite Species

In a topogenous, pond-border, moat bog in New Hampshire, 19 220 adult oribatid mites from 47 species were collected from 3 species of Sphagnum in the early spring, early summer, and late summer. The Sphagnum species were distributed along a gradient of increasing height above the water surface and decreasing shade in the order S. cuspidatum, S. recurvum, and S. magellanicum. Oribatid mite species diversity increased along this gradient in the same order. Four species of the genus Limnozetes were associated with Sphagnum spp. in this bog; they differed in habitat preference among the Sphagnum species. New records for New Hampshire were established for 19 oribatid mite species.

Foraging behaviour of beef cattle in the hilly terrain of a Mediterranean grassland

2012 ◽  
Vol 34 (2) ◽  
pp. 163 ◽  
Author(s):  
Z. Henkin ◽  
E. D. Ungar ◽  
A. Dolev
Keyword(s):  
Foraging Behaviour ◽  
Nutritive Value ◽  
Late Summer ◽  
Beef Cows ◽  
Early Morning ◽  
Grazing Pressure ◽  
Early Spring ◽  
Early Summer ◽  
Late Spring ◽  
Full Potential

The objective of this study was to determine the role of terrain in the foraging behaviour of beef cows grazing hilly Mediterranean grasslands. The study was conducted in eastern Galilee, Israel, during 2002 and 2003 on two similar 28-ha paddocks encompassing distinct terrain types in terms of slope and rock cover. The paddocks were continuously grazed by cows from mid winter (January–February) to autumn (September) at two different stocking rates (1.1 and 0.56 cows per ha). From early June to the end of September the cows were offered poultry litter ad libitum as a supplementary feed. The location and activity of cows were monitored with GPS collars during four periods in each year: early spring (February–March), late spring (April), early summer (June) and late summer (August). Herbage mass was measured at the beginning of each of these periods. During early and late spring, when the herbage mass and nutritive value of herbage were high, the cows spent 40–50% of the day grazing, with peaks in the morning and afternoon. In the dry, late summer period (August), grazing of the herbage was 20–22% of the day, occurring only in the early morning and late afternoon with sporadic bouts of grazing until midnight. In all periods the cows tended to prefer the flattest terrain sites. As the herbage mass declined to 1000–1500 kg ha–1, the exploitation of the pasture during grazing became increasingly similar among the different terrains. Even on relatively small paddocks, where grazing pressure was close to the full potential of the site, free-ranging cows tended to prefer less sloping and rocky sites. It is concluded that the grazing strategy of beef cows is determined by the interaction between terrain, the distribution of the herbage mass and the nutritive value of the herbage. As herbage mass declines during the growing season, the distribution of grazing becomes uniform and all terrain types are exploited.

scholarly journals SYMPTOM DEVELOPMENT AND TISSUE CONCENTRATIONS OF CHLORIDE AND BORON TOXICITY IN KIWIFRUIT

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1161c-1161
Author(s):  
Janine Hasey ◽  
K. Uriu ◽  
J. Pearson
Keyword(s):  
Late Summer ◽  
Sampling Procedure ◽  
Early Spring ◽  
Early Summer ◽  
Boron Toxicity ◽  
Symptom Development ◽  
Tissue Concentrations ◽  
Chloride Toxicity ◽  
High Boron ◽  
High Chloride

Chloride and boron toxicity symptoms and tissue concentrations were characterized and distinguished in kiwifruit. Dormant cane, bud, emerging leaves, blade and petiole samples were taken from February through October 1989 from three vineyards - a high chloride, a high boron and a low boron, low chloride control. Chloride toxicity symptoms started showing in early summer on basal leaves. By late summer, necrosis symptoms were on mid-shoot and leaves near the shoot terminal. In boron toxicity, interveinal chlorotic areas appeared first followed by marginal necrosis. Symptoms were seen on basal leaves in early spring, progressively affecting upper leaves by harvest. The high chloride vineyard accumulated chloride from early spring with the petiole concentrating more chloride than the blade. In the high boron vineyard, boron increased greatly in the blade but not in the petiole. Another sampling procedure other than mid-season leaf samples could be emerging leaves for detecting high chloride and dormant cane tips, buds or emerging leaves for high boron.

Seasonal changes in leaf and stem loline alkaloids in meadow fescue

2011 ◽  
Vol 62 (3) ◽  
pp. 261 ◽  
Author(s):  
Brian Patchett ◽  
Ravi Gooneratne ◽  
Lester Fletcher ◽  
Bruce Chapman
Keyword(s):  
Seasonal Changes ◽  
Seasonal Pattern ◽  
Late Summer ◽  
Early Spring ◽  
Early Summer ◽  
Sharp Decline ◽  
Meadow Fescue ◽  
Accumulation Pattern ◽  
Loline Alkaloids

Leaf and stem loline alkaloid concentration in 10 European meadow fescue (Festuca pratensis Huds.) lines grown in a field in Canterbury, New Zealand, were determined in samples collected six times between early spring 2004 and late autumn 2005. Significant differences in loline alkaloid concentrations were noted between lines and between harvest times. Higher total loline alkaloid concentrations (up to 4990 µg g–1) were found in stems compared to leaf (up to 1770 µg g–1). However, the seasonal accumulation pattern of different loline alkaloid concentrations in leaf and stem varied. In most lines, stem loline concentration peaked sharply in late spring and declined during early summer and autumn. The seasonal pattern of leaf loline alkaloid concentration followed the stem concentration except for a sharp decline in early summer followed by an increase in late summer. In most instances, the concentration of N-formyl loline was the highest > N-acetyl loline > N-acetyl norloline > N-methyl loline. The possible role of stem and leaf loline alkaloids to deter pasture-feeding insects is briefly discussed.

scholarly journals Temperature and light effects on Trichobilharzia szidati cercariae with implications for a risk analysis

2020 ◽  
Vol 62 (1) ◽  
Author(s):  
Azmi Al-Jubury ◽  
Per Kania ◽  
Anette Bygum ◽  
Kurt Buchmann
Keyword(s):  
Risk Analysis ◽  
Life Span ◽  
Intermediate Host ◽  
Lymnaea Stagnalis ◽  
Late Summer ◽  
Early Spring ◽  
Early Summer ◽  
Effect Of Temperature ◽  
The Public ◽  
Cercarial Dermatitis

Abstract Background Cercarial dermatitis (swimmer’s itch) caused by bird schistosome cercariae, released from intermediate host snails, is a common disorder also at higher latitudes. Several cases were observed in the artificial Danish freshwater Ringen Lake frequently used by the public for recreational purposes. The lake may serve as a model system when establishing a risk analysis for this zoonotic disease. In order to explain high risk periods we determined infection levels of intermediate host snails from early spring to late summer (March, June and August) and elucidated the effect of temperature and light on parasite shedding, behavior and life span. Results Field studies revealed no shedding snails in March and June but in late summer the prevalence of Trichobilharzia szidati infection (in a sample of 226 pulmonate Lymnaea stagnalis snails) reached 10%. When investigated under laboratory conditions the cercarial shedding rate (number of cercariae shed per snail per day) was positively correlated to temperature raising from a mean of 3000 (SD 4000) at 7 °C to a mean of 44,000 (SD 30,000) at 27 °C). The cercarial life span was inversely correlated to temperature but the parasites remained active for up to 60 h at 20 °C indicating accumulation of cercariae in the lake during summer periods. Cercariae exhibited positive phototaxy suggesting a higher pathogen concentration in surface water of the lake during daytime when the public visits the lake. Conclusion The only causative agent of cercarial dermatitis in Ringen Lake detected was T. szidati. The infection risk associated with aquatic activities is low during spring and early summer (March-June). In late summer the risk of infection is high since the release, behavior and life span of the infective parasite larvae have optimal conditions.

Migrations and Intermingling of Atlantic Cod (Gadus morhua) Stocks of the Newfoundland Area

1974 ◽  
Vol 31 (6) ◽  
pp. 1073-1092 ◽  
Author(s):  
Wilfred Templeman
Keyword(s):  
Gadus Morhua ◽  
East Coast ◽  
Atlantic Cod ◽  
Late Summer ◽  
Early Spring ◽  
Early Summer ◽  
Southeastern Part ◽  
Vertical Movements ◽  
Bank Stock ◽  
Avalon Peninsula

Commercial recaptures of 26% (22.5% in years after the tagging year) of 18,822 Atlantic cod (Gadus morhua) 50 cm or more in length that were tagged mainly in the feeding season at 13 localities in the Newfoundland area in 1954–55 elucidated migrations and intermingling of cod of various stocks or stock complexes. Cod of the northern Gulf of St. Lawrence stock migrated southward from the Strait of Belle Isle to winter on the northern side of Cabot Strait and vicinity, mingling there with the Burgeo Bank stock. Cod of the Newfoundland–Labrador complex tagged at three sites mingled along the east coast of Newfoundland and off southern Labrador and with cod of the northern Gulf stock near the Strait of Belle Isle, of the Avalon–Burin stock complex off the Avalon peninsula, and of a Grand Bank stock on the northern part of the bank. Though cod tagged off the Avalon peninsula and on St. Pierre Bank were recaptured mainly near the tagging sites, some moved as far north as Labrador, to the southern Grand Bank, and to Cabot Strait. Fish tagged on the northwestern Grand Bank were recaptured mainly at the tagging site but also elsewhere on the bank and off the east coast of Newfoundland. Those tagged on the Southeast Shoal of the Grand Bank were recaptured mainly on the southeastern part of the bank though some moved as far as southeastern Newfoundland. Those tagged on Burgeo Bank mingled with the Avalon–Burin stock complex, including the St. Pierre Bank component, but mainly with the Northern Gulf stock in winter–spring near Cabot Strait.Cod 90–129 cm long at tagging were recaptured at shorter distances from the tagging sites than 50–89-cm cod. Tagging–recapture distances also increased with increasing age for cod of the smaller length ranges on tagging. In their vertical movements, most tagged cod moved to shallow water in late spring or early summer and retreated gradually to deeper water from late summer to early spring. Some remained in deep water throughout the year.Recapture rates at different size ranges varied with area but were not greatly different at length ranges from 50–59 to 80–94 cm, which included 95% of the tagged cod.

Sign in / Sign up

Export Citation Format

Share Document