scholarly journals Habitat use of wild boar in a French agroecosystem from late winter to early summer

1991 ◽  
Vol 36 ◽  
pp. 119-129 ◽  
Author(s):  
Jean-François Gerard ◽  
Bruno Cargnelutti ◽  
François Spitz ◽  
Gilbert Valet ◽  
Thierry Sardin
Keyword(s):  
Habitat Use ◽  
Wild Boar ◽  
Early Summer ◽  
Late Winter

scholarly journals Late-winter habitat use by the Fisher, Pekania pennanti (Erxleben, 1777), in the Boreal Plains Ecozone of northwestern Saskatchewan, Canada

2014 ◽  
Vol 128 (3) ◽  
pp. 272 ◽  
Author(s):  
Gilbert Proulx
Keyword(s):  
Habitat Use ◽  
Deciduous Forest ◽  
Late Winter ◽  
Larix Laricina ◽  
Forest Stands ◽  
Habitat Types ◽  
Winter Habitat ◽  
Boreal Plains ◽  
Pekania Pennanti ◽  
Crown Closure

Late-winter habitat use by the Fisher, Pekania pennanti (Erxleben, 1777) in northwestern Saskatchewan was assessed in February 2009, 2011, and 2012. A total of 78 Fisher tracks were recorded over 60 300 m of snowshoe surveys. Fisher tracks were significantly less frequent than expected in Tamarack (Larix laricina [Du Roi] K. Koch) stands with > 40% crown closure and mainly 0–10 m trees (P < 0.05) and in open areas. Fishers used other habitat types equal to availability, including muskeg and coniferous, mixed, and deciduous forest stands. Maintaining mosaics of forest stands of different seral stages interspersed with muskeg would meet the late-winter habitat needs of Fishers in the Boreal Plains Ecozone of northwestern Saskatchewan.

scholarly journals Climatic influence on the composition of snow cover at Austre Okstindbreen, Norway, 1989 and 1990

1994 ◽  
Vol 19 ◽  
pp. 1-6 ◽  
Author(s):  
He Yuanqing ◽  
Wilfred H. Theakstone
Keyword(s):  
Snow Cover ◽  
North Atlantic ◽  
Early Summer ◽  
Late Winter ◽  
Crustal Material ◽  
Air Masses ◽  
The North ◽  
Air Temperatures ◽  
Winter Snow ◽  
Marine Source

Winter snow cover at Austre Okstindbreen is influenced strongly by patterns of atmospheric circulation, and by air temperatures during precipitation. Differences of circulation over the North Atlantic and Scandinavia during the winters of 1988–89 and 1989–90 were reflected in the ionic and isotopic composition of snow that accumulated at the glacier. Early summer ablation did not remove, or smooth out, all the initial stratigraphic differences. In the first half of the 1988–89 winter, most air masses took a relatively short route between a marine source and Okstindan; late winter snowfalls were from air masses which had taken a longer continental route. The snow that accumulated in the first half of the 1989–90 winter was associated with air masses which had followed longer continental routes, and so brought higher concentrations of impurities from forests, lakes and crustal material. The ablation season began earlier in 1990 than in 1989, and summer winds and rain supplied more impurities to the snowpack surface.

scholarly journals Compost and soil moisture effects on seasonal carbon and nitrogen dynamics, greenhouse gas fluxes and global warming potential of semi-arid soils

2019 ◽  
Vol 8 (S1) ◽  
pp. 367-376 ◽  
Author(s):  
Mavis Badu Brempong ◽  
Urszula Norton ◽  
Jay B. Norton
Keyword(s):  
Global Warming ◽  
Soil Moisture ◽  
Global Warming Potential ◽  
Carbon Dioxide Emissions ◽  
Inorganic Nitrogen ◽  
Early Summer ◽  
Late Spring ◽  
Late Winter ◽  
Normal Soil ◽  
Soil Inorganic

Abstract Purpose An 8-week incubation study was conducted to monitor soil inorganic nitrogen (N), dissolved organic carbon (DOC), greenhouse gases (GHG) [CO2, N2O and CH4] and cumulative global warming potential (GWP) in dryland soil. Methods Soil was amended with variable rates of compost (zero, 15, 30 and 45 dry Mg ha−1) and soil moistures [5% (dry), 7% (normal) and 14% (wet) water filled pore space (WFPS)] and experienced biweekly temperature transitions from 5 °C (late winter) to 10 °C (early spring) to 15 °C (late spring) to 25 °C (early summer). Results The addition of 30 and 45 Mg ha−1 compost enhanced N mineralization with 13% more soil inorganic N (7.49 and 7.72 µg Ng−1 day−1, respectively) during early summer compared with lower compost rates. Normal and wet soils had 35% more DOC in the late spring (an average of 34 µg g−1 day−1) compared to the dry WFPS, but transitioning from late spring to early summer, DOC at all soil WFPS levels increased. Highest rates of compost were not significant sources of GHG with normal soil WFPS, compared with lower compost rates. Carbon dioxide emissions increased by 59 and 15%, respectively, as soil WFPS increased from dry to normal and normal to wet. Soils with normal WFPS were the most effective CH4 sink. Conclusion One-time application of high compost rates to dryland soils leads to enhanced N and C mineralization under normal soil moisture and warmer temperature of the summer but will not pose significant global warming dangers to the environment through GHG emissions since soils are rarely wet.

Behaviour, habitat associations, and intrasexual differences of female Stone’s sheep

2006 ◽  
Vol 84 (8) ◽  
pp. 1187-1201 ◽  
Author(s):  
Andrew B.D. Walker ◽  
Katherine L. Parker ◽  
Michael P. Gillingham
Keyword(s):  
Habitat Use ◽  
Predation Risk ◽  
Growing Season ◽  
Early Summer ◽  
Habitat Associations ◽  
Phenological Stage ◽  
Shrub Species ◽  
Lichen Cover ◽  
Ovis Dalli ◽  
Maternal Status

Stone’s sheep ( Ovis dalli stonei Allen, 1897) in northern British Columbia segregate sexually during most of the year, and intrasexually between maternal and nonmaternal females during spring and early summer. Our objective was to quantify intrasexual habitat use of female Stone’s sheep relative to maternal status using measures of behaviour and habitat use. We reviewed three hypotheses of intersexual segregation (predation-risk, forage-selection, and activity-budget hypotheses) to determine if they also explained intrasexual segregation of female Stone’s sheep. Female Stone’s sheep spent the majority of their active time foraging. Nursery groups spent shorter durations of time active, more time active in solid rock escape features, and less time active in shrub habitat than nonmaternal groups. The best predictive model describing intrasexual differences incorporated distance to nearest escape feature and size of nearest escape feature. Regardless of maternal status, female Stone’s sheep used low-elevation plant communities early in the growing season that were characterized by more shrub species and increased cover. As the growing season progressed, they tracked a phenological stage, moving up in elevation and associating with communities that contained increasing amounts of moss and lichen cover. The patterns in behaviour, habitat use, and vegetation associations between intrasexual groups of Stone’s sheep were best characterized by the predation-risk hypothesis.

Performance of breeding ewes on lucerne-subterranean clover pastures

1985 ◽  
Vol 25 (4) ◽  
pp. 758 ◽  
Author(s):  
DG Hall ◽  
EC Wolfe ◽  
BR Cullis
Keyword(s):  
New South ◽  
Subterranean Clover ◽  
Early Summer ◽  
Late Winter ◽  
Wagga Wagga ◽  
Pasture Production ◽  
South Wales ◽  
Sheep Production ◽  
Lamb Growth

Pasture production, ewe and lamb growth, ewe wool production and diet quality were studied on lucerne-subterranean clover pastures at Wagga Wagga, New South Wales. Lucerne was sown at rates of 0.75 to 3.0 kg/ha, and the pastures were rotationally grazed with Border Leicester x Merino ewes at 9.6 or 12.7 sheep/ha, the ewes lambing in August- September. Lucerne density declined by 45% over the 3 years on all treatments. The clover cultivar sown, Woogenellup, had low persistence, particularly at 12.7 sheep/ha. The density of lucerne had little effect on annual wool and lamb production, although the ewes grew faster on the denser lucerne in summer and the sparser lucerne in winter. At 12- 7 sheep/ha, there was an extra 19% total lamb weight by the end of November and an extra 22% of finer wool (1 �m) annually, but the fleeces had a higher proportion of wool tenderness. The major limitations of the lucerne-subterranean clover pastures to sheep production were the low quality of the diet in early summer, and low pasture production in late winter. In early summer the lucerne was rapidly consumed, leaving only moderate quality clover and grass residues, which limited lamb growth, while in winter pregnancy toxaemia occurred, fleeces were tender and wool growth was low, particularly during a drought in 1976.

Some Aspects of the Ecology of Lake Macquarie, N.S.W., with Regard to an Alleged Depletion of Fish. V. Chlorophyll Distribution

1959 ◽  
Vol 10 (3) ◽  
pp. 316
Author(s):  
PS Davis
Keyword(s):  
Surface Waters ◽  
Vertical Profile ◽  
Chlorophyll Concentration ◽  
Euphotic Zone ◽  
Early Summer ◽  
Late Winter ◽  
Light Penetration ◽  
Chlorophyll Distribution ◽  
The Mean ◽  
Made In

The chlorophyll a in samples from five stations in Lake Macquarie was determined over the period July 1955 to November 1956. The mean surface value for the four stations within the lake proper was 1.26 mg/m³. The vertical profile at one station was studied and the mean of these profile values was 1.23 mg/m³. Throughout the period of the survey chlorophyll concentrations in the lake varied from 0.1 to 4.0 mg/m³. The lowest values were found in the late winter and early summer (November) and the peaks during spring and autumn. The chlorophyll concentration in the surface waters of Lake Macquarie was shown to be significantly higher than that of the marine water entering the lake, but lower than that of a comparison station in the Hawkesbury River. One series of light penetration measurements made in December 1956 showed that all the water in the lake, and all but one section of Dora Creek, lay within the euphotic zone.

Canopy nectar production and the impact of logging and climate in Grey Ironbark Eucalyptus paniculata (Smith) forests

2009 ◽  
Vol 15 (4) ◽  
pp. 287 ◽  
Author(s):  
Bradley S. Law ◽  
Mark Chidel
Keyword(s):  
Feeding Activity ◽  
Negative Relationship ◽  
Limited Resource ◽  
Early Summer ◽  
Late Winter ◽  
Nectar Production ◽  
Management Actions ◽  
Logged Forest ◽  
The Impact ◽  
Regrowth Forest

Nectar in tall forest canopies is a significant, but poorly quantified, resource for Australian fauna, as well as the European Honeybee Apis mellifera. We investigated the impact of logging on nectar production in the canopy of Grey Ironbark Eucalyptus paniculata (Smith) forests in southern Australia. Using cherry-pickers and cranes we measured nectar production in large and small trees in replicate sites in each of recently logged, young regrowth and old regrowth forest over three consecutive years (2004?2006). We focused on over-night nectar production, although nectar was produced during both the day and night. Logging history and tree size, when considered individually, had no significant effect on nectar production per flower, although the two factors showed a significant interaction. However, these differences were relatively minor in comparison to the negative relationship with drought. Little nectar was produced per flower under any logging history in drought. During good conditions nectar production varied depending on logging history. When scaled up to the forest stand, logging history had a marked effect on nectar production with old regrowth forest producing seven times as much sugar per ha as recently logged forest. Young regrowth forest 15?20 years old produced nectar quantities intermediate between that of recently logged forest and regrowth forest. At the compartment scale, current practices require the retention of old forest and the typical extent of this retention reduced the difference between old regrowth forest and recently logged forest to a factor of two times. Nectar production per flower was low and a limited resource in autumn 2004 and late-winter 2005, but was copious and in surplus in early summer 2006. Nectar standing crops at the flower scale appeared to be determined by an interaction between environmental conditions (drought) that negatively influenced nectar production and the feeding activity of flower visitors at the time, which itself is affected by prevailing temperatures and nectar attributes, such as sugar concentration and regional nectar availability. We suggest that management actions should focus on minimising nectar depletion in poor flowering years when the nectar resource is limiting.

scholarly journals Predicting Melt Pond Fraction on Landfast Snow Covered First Year Sea Ice from Winter C-Band SAR Backscatter Utilizing Linear, Polarimetric and Texture Parameters

2018 ◽  
Vol 10 (10) ◽  
pp. 1603 ◽  
Author(s):  
Saroat Ramjan ◽  
Torsten Geldsetzer ◽  
Randall Scharien ◽  
John Yackel
Keyword(s):  
Sea Ice ◽  
Regression Models ◽  
Incidence Angle ◽  
Early Summer ◽  
Aerial Photographs ◽  
Late Winter ◽  
First Year ◽  
Melt Pond ◽  
Texture Parameters ◽  
Snow Thickness

Early-summer melt pond fraction is predicted using late-winter C-band backscatter of snow-covered first-year sea ice. Aerial photographs were acquired during an early-summer 2012 field campaign in Resolute Passage, Nunavut, Canada, on smooth first-year sea ice to estimate the melt pond fraction. RADARSAT-2 Synthetic Aperture Radar (SAR) data were acquired over the study area in late winter prior to melt onset. Correlations between the melt pond fractions and late-winter linear and polarimetric SAR parameters and texture measures derived from the SAR parameters are utilized to develop multivariate regression models that predict melt pond fractions. The results demonstrate substantial capability of the regression models to predict melt pond fractions for all SAR incidence angle ranges. The combination of the most significant linear, polarimetric and texture parameters provide the best model at far-range incidence angles, with an R 2 of 0.62 and a pond fraction RMSE of 0.09. Near- and mid- range incidence angle models provide R 2 values of 0.57 and 0.61, respectively, with an RMSE of 0.11. The strength of the regression models improves when SAR parameters are combined with texture parameters. These predictions also serve as a proxy to estimate snow thickness distributions during late winter as higher pond fractions evolve from thinner snow cover.

Some remarks on the ecology of Echinorhynchus salmonis Muller 1784

1970 ◽  
Vol 48 (2) ◽  
pp. 317-321 ◽  
Author(s):  
Shibru Tedla ◽  
C. H. Fernando
Keyword(s):  
Yellow Perch ◽  
Rapid Development ◽  
Perca Fluviatilis ◽  
Early Summer ◽  
Late Winter ◽  
Breeding Cycle ◽  
Intermediate Hosts ◽  
Egg Maturation ◽  
Perch Perca Fluviatilis ◽  
Bodies Of Water

The acanthocephalan Echinorhynchus salmonis showed a marked seasonality of occurrence in the yellow perch Perca fluviatilis in the Bay of Quinte, Lake Ontario. The incidence of the parasite started increasing in autumn and reached a peak in late winter. It started decreasing in March and fell to zero in August or September. Such seasonality has been previously observed for acanthocephalans in bodies of water which freeze, as does the Bay of Quinte. There is a single egg maturation period for the parasite in early summer, after which the parasites die. Infestation of intermediate hosts occurs in spring when the population of the hosts is high. The subsequent warm period ensures rapid development of the parasite. Within the fish the parasite is less affected by the lower temperatures prevailing in winter. No influence was apparent between the maturity and seasonality of the parasite and the food and breeding cycle of the fish.

Life cycles of four species of Pseudocalanus in Nova Scotia

1989 ◽  
Vol 67 (3) ◽  
pp. 552-558 ◽  
Author(s):  
I. A. McLaren ◽  
Estelle Laberge ◽  
C. J. Corkett ◽  
J.-M. Sévigny
Keyword(s):  
Life Cycle ◽  
Nova Scotia ◽  
First Generation ◽  
Early Summer ◽  
Life Cycles ◽  
The Arctic ◽  
Late Winter ◽  
Early Winter ◽  
Temperature Dependent ◽  
Scotian Shelf

The primarily arctic Pseudocalanus acuspes, relict in Bedford Basin, Nova Scotia, produces a first generation (G1) in late winter; most G1 individuals mature in late spring. The G1 then produces a G2, most of which "rest" in copepodite stages III and IV until early winter. These stages store large amounts of lipid in early summer, which slowly diminish subsequently. A small number of G2 individuals continue to develop at temperature-dependent rates, maturing in early autumn and producing G3 adults in November. Copepodites developing in winter and spring store less lipid. The primarily arctic Pseudocalanus minutus, rare in Bedford Basin and on the Scotia Shelf, is strictly annual, developing to a lipid-filled copepodite stage V after spawning in late winter. The arctic–temperate Pseudocalanus newmani is abundant on the Scotian Shelf, but may not be self-sustaining when advected into Bedford Basin. It stores little lipid and appears to have at least three mature generations at temperature-dependent intervals over Browns Bank between May and November. It may rest in winter, or its life-cycle synchrony by spring could result from food-limited development during winter. The temperate Pseudocalanus moultoni appears to have a life cycle similar to that of P. newmani, but was less common during summer on Browns Bank. These life cycles are appropriately adapted to the geographical ranges of the species, and show some parallels with species of Calanus.

Sign in / Sign up

Export Citation Format

Share Document