Relationships between the effects of insect herbivory and sheep grazing on seasonal changes in an early successional plant community

Oecologia ◽  
1987 ◽  
Vol 71 (2) ◽  
pp. 245-253 ◽  
Author(s):  
C. W. D. Gibson ◽  
V. K. Brown ◽  
M. Jepsen
Keyword(s):  
Plant Community ◽  
Seasonal Changes ◽  
Insect Herbivory ◽  
Sheep Grazing ◽  
Successional Plant

Seasonal changes in plasma concentrations of proteins, urea, glucose, calcium and phosphorus in sheep grazing a hill pasture and their relationship to changes in body composition

1974 ◽  
Vol 83 (1) ◽  
pp. 161-169 ◽  
Author(s):  
A. R. Sykes ◽  
A. C. Field
Keyword(s):  
Body Composition ◽  
Early Pregnancy ◽  
Seasonal Changes ◽  
Plasma Concentrations ◽  
Late Pregnancy ◽  
Albumin Concentration ◽  
Sheep Grazing ◽  
Plasma Albumin ◽  
Plasma Urea ◽  
Plasma Albumin Concentration

SUMMARYThe seasonal changes in plasma concentrations of albumin, globulin, transferrin, urea, Ca, P and glucose were measured in 59 Scottish Blackface sheep grazing a hill pasture. The sheep were classified according to age and state of permanent incisor dentition into four groups. Sheep were slaughtered at mating (November), mid-lactation (June) and in the late dry period (November), and the changes in plasma constituents related to changes in body composition. A protein-free supplement was offered during late pregnancy.Another group of sheep was used in the subsequent year to investigate the significance of helminth infections on such pastures.Plasma albumin concentration fell from 32·0 g/1 in all sheep in early pregnancy to 17·5–19·5 g/1 in late pregnancy and early lactation in 5½- to 6½-year-old animals. Younger animals (2½ year old) maintained higher (23·0 g/1) levels at these latter times. The extent of the decrease in plasma albumin concentration of the groups was related to the loss of N from their soft tissues during the same period.Plasma volume increased from 2·10 to 2·491 between early pregnancy and midlactation (45 and 66 ml/kg body weight respectively). The increase in volume was considered to account for the reduction in the concentration of plasma globulin which took place during this period.Plasma urea-N concentrations were extremely low (50—60mg/l) between February and April and had fallen from their highest values (240 mg/1) in August to 150 mg/1 by the following November. It is argued that the fall in albumin concentration which occurred in early pregnancy, coupled with the extremely low urea-N concentration, reflects a very low digestible crude protein intake during most of pregnancy.Transferrin concentration followed a similar seasonal pattern to urea. The concentration was extremely low in February (2·2–2·4 g/1), highest in August (3·45 g/1) and had fallen by November (3·0 g/1). The value of transferrin as a nutritional index is discussed.Regular dosing with anthelminthic of sheep on these pastures had a beneficial effect on plasma albumin concentrations, particularly during critical nutritional periods, namely late pregnancy and lactation.Plasma glucose, Ca and P concentrations were of no value in monitoring the nutritional status of the animal with respect to these nutrients.

Comparison of Markovian matrix models of a primary successional plant community

1998 ◽  
Vol 107 (1) ◽  
pp. 93-102 ◽  
Author(s):  
W.Michael Childress ◽  
Charles M Crisafulli ◽  
Edward J Rykiel Jr
Keyword(s):  
Matrix Models ◽  
Plant Community ◽  
Successional Plant

scholarly journals Fine‐root traits are linked to species dynamics in a successional plant community

Ecology ◽  
2019 ◽  
Vol 100 (3) ◽  
Author(s):  
Joshua S. Caplan ◽  
Scott J. Meiners ◽  
Habacuc Flores‐Moreno ◽  
M. Luke McCormack
Keyword(s):  
Plant Community ◽  
Fine Root ◽  
Root Traits ◽  
Species Dynamics ◽  
Successional Plant

Urinary sediments in sheep feeding on oestrogenic clover. V.* Seasonal changes in the excretion of components of calculi and sediments

1976 ◽  
Vol 27 (6) ◽  
pp. 867 ◽  
Author(s):  
MC Nottle
Keyword(s):  
Urinary Tract ◽  
Seasonal Changes ◽  
Urinary Tract Obstruction ◽  
Trifolium Subterraneum ◽  
Biochanin A ◽  
Sheep Grazing ◽  
Urolithin A ◽  
Urolithin B ◽  
Layer Chromatography ◽  
Clover Pasture

Urine collections (24-hr) were made at 14-day intervals from early July to late October on six sheep grazing a pasture with oestrogenic Trifolium subterraneum cv. Dinninup dominant. Thin-layer chromatography was used to estimate urinary concentrations of formononetin, equol and 4'-O-methyl equol and to demonstrate the presence of benzocoumarins (urolithins A and B), biochanin A, indigotin and indirubin, which have been found in calculi or sediments from sheep grazing oestrogenic clover pastures. Formononetin levels ranged from 0.6 to 1.0mg% until late August and then from 1.2 to 1.7 mg %, the latter level occurring in late September. Equol concentration fluctuated between 8 and 15 mg % for the first eight collections but in the last two, in early and late October, levels reached 30 and 60 mg % respectively. The concentration of 4'-O-methyl equol ranged from 3 to 8 mg % until mid August and attained a peak of 29 mg % in late August. Between early September and early October values ranged from 15 to 23 mg % but by late October only trace amounts were present. Urolithin B appeared in all or most samples at each collection but urolithin A occurred in relatively few samples per collection until mid September. From mid September to late October the highest concentrations of both urolithins were attained. Indigotin generally occurred in only one urine at each collection but from mid August to mid September it was present in three or four urines per collection. Indirubin was present in all urines in all collections except the last, when it was present in only one urine. Biochanin A was detected only in urines collected in late September and early October. The relevance of these results to the period of formation of different calculi or sediments found in sheep grazing oestrogenic clover pasture and the implications of the metabolism of formononetin to equol and 4'-O-methyl equol in relation to urinary tract obstruction are discussed. ________________ *Part IV, Aust. J. Agric. Res., 26: 313 (1975).

Resource dynamics in an early-successional plant community are influenced by insect exclusion

2004 ◽  
Vol 36 (11) ◽  
pp. 1817-1826 ◽  
Author(s):  
Martin Schädler ◽  
Jörn Alphei ◽  
Stefan Scheu ◽  
Roland Brandl ◽  
Harald Auge
Keyword(s):  
Plant Community ◽  
Resource Dynamics ◽  
Successional Plant ◽  
Insect Exclusion

scholarly journals Effect of insect herbivory on plant community dynamics under contrasting water availability levels

2018 ◽  
Vol 106 (5) ◽  
pp. 1819-1828 ◽  
Author(s):  
Giovanni Tamburini ◽  
Elena Dani ◽  
Riccardo Bommarco ◽  
Lorenzo Marini
Keyword(s):  
Plant Community ◽  
Water Availability ◽  
Community Dynamics ◽  
Insect Herbivory ◽  
Plant Community Dynamics

Insect herbivory and the plant community

1982 ◽  
pp. 49-54
Author(s):  
I. D. Hodkinson ◽  
M. K. Hughes
Keyword(s):  
Plant Community ◽  
Insect Herbivory
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