Long-term effects of sheep grazing on giant hogweed (Heracleum mantegazzianum)

Hydrobiologia ◽  
1996 ◽  
Vol 340 (1-3) ◽  
pp. 277-284 ◽  
Author(s):  
Ulla Vogt Andersen ◽  
Birgitte Calov
Keyword(s):  
Sheep Grazing ◽  
Long Term Effects ◽  
Heracleum Mantegazzianum

scholarly journals Long-term effects of rotational prescribed burning and low-intensity sheep grazing on blanket-bog plant communities

2013 ◽  
Vol 50 (3) ◽  
pp. 625-635 ◽  
Author(s):  
Hyohyemi Lee ◽  
Josu G. Alday ◽  
Rob J. Rose ◽  
John O'Reilly ◽  
Rob H. Marrs
Keyword(s):  
Plant Communities ◽  
Prescribed Burning ◽  
Sheep Grazing ◽  
Long Term Effects ◽  
Low Intensity ◽  
Blanket Bog

Estimation of the Density of Feral Goats in Part of Arid South Australia by means of the Peterson Estimate

1984 ◽  
Vol 11 (1) ◽  
pp. 93 ◽  
Author(s):  
RP Henzell ◽  
PI McCloud
Keyword(s):  
South Australia ◽  
Grazing Pressure ◽  
Sheep Grazing ◽  
Long Term Effects ◽  
Arid Rangeland

The density of feral goats in about 234 km2 of arid rangeland used for sheep grazing in South Australia was estimated by means of a mark-resight technique. Marking and subsequent resighting were done at watering points. The Petersen estimate was 4.4 goats per square kilometre; adjustment to allow for nonrandom behaviour raised this estimate to 5.0 km-1. Maximum allowable sheep density is 12 km-2. The goat density we observed imposes an added burden on the vegetation. The densities of red and western grey kangaroos, when added together, approximate that of the goats. Rabbits are virtually absent. The long-term effects of the total grazing pressure on the vegetation cannot be predicted in detail but will probably be deleterious.

scholarly journals Long-Term Effects of Sheep Grazing in Various Densities on Marsh Properties and Vegetation Dynamics in Two Different Salt-Marsh Zones

2019 ◽  
Vol 43 (2) ◽  
pp. 298-315 ◽  
Author(s):  
J. P. Bakker ◽  
M. Schrama ◽  
P. Esselink ◽  
P. Daniels ◽  
N. Bhola ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Vegetation Dynamics ◽  
Sheep Grazing ◽  
Long Term Effects

The nutrition of ruminants grazing native and improved pastures. IV.* Long-term effects of the quantity of superphosphate applied on the nutritive value of the diet selected by sheep grazing a pasture originally sown to Phalaris aquatica and Trifolium repens

1979 ◽  
Vol 30 (3) ◽  
pp. 565 ◽  
Author(s):  
JP Langlands ◽  
JE Bowles ◽  
GE Donald
Keyword(s):  
Nitrogen Content ◽  
Trifolium Repens ◽  
Nutritive Value ◽  
Sheep Grazing ◽  
Long Term Effects ◽  
Phalaris Aquatica ◽  
Grazing Sheep

Small plots sown to Phalaris aquatica–Trifolium repens in 1967 were fertilized with either 0, 188 or 375 kg superphosphate ha-1 year-1 from 1967 to 1976; the plots were grazed uniformly between 1967 and 1975 and at three stocking intensities during 1975 and 1976. The composition of the forage on offer and of the diet selected by grazing sheep were measured at 2-monthly intervals during 1976. Phalaris largely died out from plots which did not receive superphosphate. Available forage, and its content of clover, nitrogen and most minerals were substantially greater on plots that received fertilizer, as were the digestibility and nitrogen content of the diet selected. The nutritive value of the diet selected was greatest on plots which received 375 kg superphosphate ha-1 year-1. The nitrogen content of the diet selected generally increased with increasing stocking intensity, but this trend was not evident for digestibility; interactions between the quantity of fertilizer applied and stocking intensity were not significant. Digestibility and nitrogen content of the diet varied between months, with the quantity of green forage and clover on offer, and with the nitrogen content of the available forage. __________________ *Part III, Aust. J. Agric. Res., 29, 1301 (1978).

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

Long-Term Effects of Head Lice Tx Unknown

2012 ◽  
Vol 43 (3) ◽  
pp. 42
Author(s):  
MITCHEL L. ZOLER
Keyword(s):  
Head Lice ◽  
Long Term Effects
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