Grazing management of natureal pastures at Trangie, NSW

1956 ◽  
Vol 7 (4) ◽  
pp. 233 ◽  
Author(s):  
EF Biddiscombe ◽  
RJ Hutchings ◽  
G Edgar ◽  
EG Cuthbertson
Keyword(s):  
Body Weight ◽  
Plant Density ◽  
Basal Area ◽  
Body Weight Loss ◽  
Perennial Grasses ◽  
Growth Stages ◽  
Natural Pasture ◽  
Continuous Grazing ◽  
Average Rainfall ◽  
Fleece Weight

Results of a 5-year grazing experiment on Stipa-Chlaris natural pasture are presented. Treatments were three rates of stocking each tested with continuous grazing, autumn deferment, and spring deferment. These were studied in relation to: (a) body weight and wool production of Merino wethers; (b) available feed; (c) density and basal area of the perennial grasses. Lighter stocking (one sheep/2 ac) showed little superiority in production per animal under the generally favourable rainfall conditions. There was only one interval of acute feed shortage in which heavier stocking (one sheep/ac) caused extreme body-weight loss and lower fleece weight. The spelling treatments gave no advantage over continuous grazing, either to sheep or to pasture. Effect of stocking rate on perennial grasses mainly depended upon the amount of rainfall received during certain growth stages of the species, e.g. the winter vegetative growth of Stipa, and the March-April maturation of Chloris and Digitaria. Generally, lighter stocking was favourable to plant density and basal area in seasons of average or below average rainfall; heavier stocking was best in wet seasons. Probable reasons for these relationships are discussed.

Impacts of level of utilisation by grazing on an Astrebla (Mitchell grass) grassland in north-western Queensland between 1984 and 2010. 1. Herbage mass and population dynamics of Astrebla spp.

2013 ◽  
Vol 35 (1) ◽  
pp. 1 ◽  
Author(s):  
D. M. Orr ◽  
D. G. Phelps
Keyword(s):  
Sustainable Management ◽  
Southern Oscillation ◽  
Basal Area ◽  
Major Change ◽  
Perennial Grasses ◽  
Seasonal Rainfall ◽  
Northern Australia ◽  
Average Rainfall ◽  
Recovery Study ◽  
North Western

Managing large variations in herbage production, resulting from highly variable seasonal rainfall, provides a major challenge for the sustainable management of Astrebla (Mitchell grass) grasslands in Australia. A grazing study with sheep was conducted between 1984 and 2010 on an Astrebla grassland in northern Queensland to describe the effects of a range of levels of utilisation of the herbage at the end of the summer growing season (April–May in northern Australia) on the sustainability of these grasslands. In unreplicated paddocks, sheep numbers were adjusted annually to achieve 0, 10, 20, 30, 50 and 80% utilisation of the herbage mass at the end of the summer over the ensuing 12 months. Higher levels of utilisation reduced both total and Astrebla spp. herbage mass because of the effects of higher utilisation on Astrebla spp. and this effect was accentuated by drought. The tussock density of Astrebla spp. varied widely among years but with few treatment differences until 2005 when density was reduced at the 50% level of utilisation. A major change in density resulted from a large recruitment of Astrebla spp. in 1989 that influenced its density for the remainder of the study. Basal area of the tussocks fluctuated among years, with increases due to rainfall and decreases during droughts. Seasonal rainfall was more influential than level of utilisation in changes to the basal area of perennial grasses. Drought resulted in the death of Astrebla spp. tussocks and this effect was accentuated at higher levels of utilisation. A series of three grazing exclosures were used to examine the recovery of the density and basal area of Astrebla spp. after it had been reduced by 80% utilisation over the preceding 9 years. This recovery study indicated that, although grazing exclusion was useful in the recovery of Astrebla spp., above-average rainfall was the major factor driving increases in the basal area of perennial grasses. Spring values of the Southern Oscillation Index and associated rainfall probabilities were considered to have potential for understanding the dynamics of Astrebla spp. It was concluded that Astrebla grassland remained sustainable after 26 years when grazed at up to 30% utilisation, while, at 50% utilisation, they became unsustainable after 20 years. Results from this study emphasised the need to maintain the population of Astrebla spp. tussocks.

Corrigendum to: Impacts of level of utilisation by grazing on an Astrebla (Mitchell grass) grassland in north-western Queensland between 1984 and 2010. 1. Herbage mass and population dynamics of Astrebla spp.

2014 ◽  
Vol 36 (3) ◽  
pp. 309
Author(s):  
D. M. Orr ◽  
D. G. Phelps
Keyword(s):  
Sustainable Management ◽  
Southern Oscillation ◽  
Basal Area ◽  
Major Change ◽  
Perennial Grasses ◽  
Seasonal Rainfall ◽  
Northern Australia ◽  
Average Rainfall ◽  
Recovery Study ◽  
North Western

Managing large variations in herbage production, resulting from highly variable seasonal rainfall, provides a major challenge for the sustainable management of Astrebla (Mitchell grass) grasslands in Australia. A grazing study with sheep was conducted between 1984 and 2010 on an Astrebla grassland in northern Queensland to describe the effects of a range of levels of utilisation of the herbage at the end of the summer growing season (April–May in northern Australia) on the sustainability of these grasslands. In unreplicated paddocks, sheep numbers were adjusted annually to achieve 0, 10, 20, 30, 50 and 80% utilisation of the herbage mass at the end of the summer over the ensuing 12 months. Higher levels of utilisation reduced both total and Astrebla spp. herbage mass because of the effects of higher utilisation on Astrebla spp. and this effect was accentuated by drought. The tussock density of Astrebla spp. varied widely among years but with few treatment differences until 2005 when density was reduced at the 50% level of utilisation. A major change in density resulted from a large recruitment of Astrebla spp. in 1989 that influenced its density for the remainder of the study. Basal area of the tussocks fluctuated among years, with increases due to rainfall and decreases during droughts. Seasonal rainfall was more influential than level of utilisation in changes to the basal area of perennial grasses. Drought resulted in the death of Astrebla spp. tussocks and this effect was accentuated at higher levels of utilisation. A series of three grazing exclosures were used to examine the recovery of the density and basal area of Astrebla spp. after it had been reduced by 80% utilisation over the preceding 9 years. This recovery study indicated that, although grazing exclusion was useful in the recovery of Astrebla spp., above-average rainfall was the major factor driving increases in the basal area of perennial grasses. Spring values of the Southern Oscillation Index and associated rainfall probabilities were considered to have potential for understanding the dynamics of Astrebla spp. It was concluded that Astrebla grassland remained sustainable after 26 years when grazed at up to 30% utilisation, while, at 50% utilisation, they became unsustainable after 20 years. Results from this study emphasised the need to maintain the population of Astrebla spp. tussocks.

The importance of plant density, plant basal area and plant mass per unit basal area as factors influencing the herbage mass of some native perennial grasses.

1982 ◽  
Vol 4 (2) ◽  
pp. 61 ◽  
Author(s):  
GM Lodge ◽  
AC Gleeson
Keyword(s):  
Plant Density ◽  
Basal Area ◽  
Perennial Grasses ◽  
Green Leaf ◽  
Relative Significance ◽  
Mass Estimate ◽  
Component Field ◽  
The Mean ◽  
The Individual ◽  
Green Stem

Four native perennial grasses, Aristida ramosa R.Br. (wire grass), Bothrioc.llloa macra (Steud) S.T. Blake (red grass), Spovo- bolus elongatus R.Br. (slender rats tail grass) and Stipa variabilis Hughes (corkscrew grass) were collected from 60 randomly allocated quadrats (0.16 m2) in a grazed unfertilized native pasture in November 1979. In each quadrat all plants of each species were counted, harvested individually and their basal areas were estimated. The mass of green leaf, green stem, dead herbage and total herbage of each species was estimated using the mean mass of the individual plants harvested in each of the quadrats. A method for determining the relative importance of the components of this herbage mass viz. plant density, basal area and mass per unit basal area is presented and these values are compared for each species. Plant density contributed significantly fP <0.05) to green leaf, green stem, dead and total herbage mass estimates of A. ramosa and S. elongatus; basal area to all herbage mass estimates of A. ramosa, S. elongatus and S. variabilis; and mass per unit basal area to all herbage mass estimates of A. ramosa and B. macra. The plant basal area of individual plants contributed signifi- cantly more (P <0.05) to the herbage mass estimate of S. vaviabilis and S, elongatus plants than did mass per unit basal area, whereas for B. rnacra mass per unit basal area was the significant (P < 0.05) component. Field procedures for estimating herbage mass and assessing the relative significance of its components are discussed and the extra time taken to collect plant density, plant basal area, and plant mass per unit basal area datais outlined.

Techniques for estimating plant basal area and assessing the herbage mass of some native perennial grasses.

1981 ◽  
Vol 3 (1) ◽  
pp. 83 ◽  
Author(s):  
GM Lodge ◽  
JA Taylor ◽  
RDB Whalley
Keyword(s):  
Plant Density ◽  
Unit Area ◽  
Basal Area ◽  
Ground Level ◽  
Field Studies ◽  
Fertilizer Application ◽  
Perennial Grasses ◽  
Individual Species ◽  
Laboratory Studies ◽  
Plant Parts

Techniques for using grid and unmarked transparent perspex overlays to estimate the area of tufted native perennial grasses were investigated in field and laboratory studies. Basal area was overestimated by using an unmarked overlay to trace the periphery of actual or atificial plant bases at ground level; this was caused by the amount of airspace included in the estimate. The compression of hand-held tufts reduced the airspace and improved the estimate of plant basal area. In the laboratory studies, the estimation by eye of filled cells in a transparent grid overlay was accurate over a range of areas from 0.02 to 10.39 cm2, although it required considerable operator training. Changes in herbage mass occur as a result of change in the number of plants per unit area (plant density), the basal area of individual plants or the plant mass per unit of basal area of individual plants. Field studies were undertaken at two sites to collect data on each of these components of herbage mass and to investigate whether or not such information could be used to estimate the herbage mass of individual species in a pasture. The relationship between the mass per unit basal area of certain plant parts would appear to have some potential for use in studies of the seasonal changes in various plant components, such as green leaf and stem. This relationship could be used to examine the response of some species to fertilizer application, grazing and defoliation and hence the process of change in species composition with management. Estimates of the herbage mass per unit area of individual native perennial grasses calculated from plant density, plant basal area and mass per unit of basal area data compared favourably with estimates of total herbage mass of individual species obtained from clipped quadrats. Suggested techniques for collecting data in the field and the time involved in sampling are discussed.

The role of plant mass, basal area and density in assessing the herbage mass response to fertility of some native perennial grasses.

1981 ◽  
Vol 3 (1) ◽  
pp. 92 ◽  
Author(s):  
GM Lodge
Keyword(s):  
Field Experiments ◽  
Plant Density ◽  
Basal Area ◽  
Perennial Grasses ◽  
Green Leaf ◽  
Density Data ◽  
Leaf Mass ◽  
Pot Culture

The effects of nitrogen (N) application and differing past fertilizer history on the ,preen leaf mass per plant, plant basal area, green leaf mass per unit of plant basal area and the plant density of some native perennial grasses were investigated in pot culture and field experiments. Data on each of these components of herbage mass were assessed, either individually or in combination with each other, as methods of evaluating the responsiveness of some native perennial grasses to increased fertility. Different mechanisms of increasing plant green leaf mass with applied N (pot culture) and superphosphate (field) were deter- mined in different species and these affected the relationship between green leaf mass anti basal area. Species such as Aristida ramosa and Bothriochloa macra increased their green leaf mass per unit of plant basal area but not their plant basal area. In the glasshouse the application of N significantly (P<0.05) increased the basal area of Chloris truncata, Eragrostis leptostachya, Dichanthium sericeum, Sporoholus elongatus, Danthonia linkii and Stipa variabilis. However, in the field long-term superphosphate application only significantly increased the basal area of C. truncata and D. linkii plants. In the field the mean densities of A. ramosa, D. sericeum and C. truncata plants growing at the unfertilized site were significantly higher than those at the fertilized site and the density of E. leptostachya plants was significantly higher (P<0.01) at the fertilized site. These data indicated that the use of either mass per plant, mass per unit basal area, plant basal area or plant density alone could bias the apparent responsiveness of some species to fertility. To accurately determine the effect of management on the herbage mass of individual native perennial grasses in the field either mass per plant and plant density data, or mass per unit basal area, basal area and plant density data should be combined.

Autecology of some natural pasture species at Trangie, N.S.W.

1954 ◽  
Vol 2 (1) ◽  
pp. 69 ◽  
Author(s):  
EF Biddiscombe ◽  
EG Cuthbertson ◽  
RJ Hutchings
Keyword(s):  
Seedling Survival ◽  
Basal Area ◽  
Late Summer ◽  
Climatic Conditions ◽  
Perennial Grasses ◽  
Annual Rainfall ◽  
Forage Production ◽  
Natural Pasture ◽  
Production Pattern ◽  
June July

Features of the autecology of four native perennial grasses (Stipa, Chloris, and Digitaria spp.) and an important group of winter annual species are reported from a 5-yr study of a naturaI pasture at Trangie, N.S.W. The investigation was mainly concerned with the response of the species to changes in seasonal climatic conditions. The study period (1948–52) was relatively moist (mean annual rainfall 25.6 in.) and the growing season (May–November) longer than average. Available moisture showed considerable variation in autumn and spring, and was the primary factor in the variable success of germination and seedling survival among the perennial grasses. Plant development in the perennial grasses is discussed for three study intervals, March 1948–50 (above average rainfall), March 1950–51 (recurrent flooding over 8 months), and March 1951–52 (including a long, dry summer) ; in all pkriods striking fluctuations were noted in persistency and basal area of established plants, particularly the small plants of each species. Available moisture is advanced as the principal factor controlling seasonal distribution of green forage production by the perennial grasses, temperature becoming limiting only at midwinter (June–July). All species conformed to a similar production pattern, showing a midsummer minimum (except in January 1951), late summer and spring peaks, and a midwinter trough. Flowering and maturation periods are listed for the perennial grasses, and infrequent but heavy seed production recorded for all species. Characteristic features of the root systems are discussed in relation to drought resistance and response to effective rainfall. Germination of Medicago spp. was most frequent in May and June (1-in. soil temperature 51–61°F), but was also successful in March, April, and July. Erodium cygnorum and Hordezcm leporinum favoured late February to early May (65–75°F) for germination. Among high populations percentage seedling survival was low, even in a very favourable season. Given adequate winter moisture (as in 1948 and 1949), Medicago spp. and E. cygnorum showed virtually an exponential increase in green forage production between May and September. The level of September production of these species is shown to be correlated with moisture availability in April. The principal factors ensuring regular recurrence of the winter annuals in pastures of the Trangie environment are outlined and discussed.

Floristic composition and pasture condition of Aristida/Bothriochloa pastures in central Queensland. II. Soil and pasture condition interactions

2015 ◽  
Vol 37 (2) ◽  
pp. 217
Author(s):  
R. G. Silcock ◽  
T. J. Hall ◽  
P. G. Filet ◽  
A. M. Kelly ◽  
D. Osten ◽  
...  
Keyword(s):  
Soil Type ◽  
Plant Density ◽  
Surface Condition ◽  
Good Condition ◽  
Basal Area ◽  
Ground Cover ◽  
Perennial Grasses ◽  
Tree Cover ◽  
Themeda Triandra ◽  
Heteropogon Contortus

Sustainable management of native pastures requires an understanding of what the bounds of pasture composition, cover and soil surface condition are for healthy pastoral landscapes to persist. A survey of 107 Aristida/Bothriochloa pasture sites in inland central Queensland was conducted. The sites were chosen for their current diversity of tree cover, apparent pasture condition and soil type to assist in setting more objective bounds on condition ‘states’ in such pastures. Assessors’ estimates of pasture condition were strongly correlated with herbage mass (r = 0.57) and projected ground cover (r = 0. 58), and moderately correlated with pasture crown cover (r = 0.35) and tree basal area (r = 0.32). Pasture condition was not correlated with pasture plant density or the frequency of simple guilds of pasture species. The soil type of Aristida/Bothriochloa pasture communities was generally hard-setting, low in cryptogam cover but moderately covered with litter and projected ground cover (30–50%). There was no correlation between projected ground cover of pasture and estimated ground-level cover of plant crowns. Tree basal area was correlated with broad categories of soil type, probably because greater tree clearing has occurred on the more fertile, heavy-textured clay soils. Of the main perennial grasses, some showed strong soil preferences, for example Tripogon loliiformis for hard-setting soils and Dichanthium sericeum for clays. Common species, such as Chrysopogon fallax and Heteropogon contortus, had no strong soil preference. Wiregrasses (Aristida spp.) tended to be uncommon at both ends of the estimated pasture condition scale whereas H. contortus was far more common in pastures in good condition. Sedges (Cyperaceae) were common on all soil types and for all pasture condition ratings. Plants identified as increaser species were Tragus australianus, daisies (Asteraceae) and potentially toxic herbaceous legumes such as Indigofera spp. and Crotalaria spp. Pasture condition could not be reliably predicted based on the abundance of a single species or taxon but there may be scope for using integrated data for four to five ecologically contrasting plants such as Themeda triandra with daisies, T. loliiformis and flannel weeds (Malvaceae).

1965-P: Glucagon Receptor Agonism Stimulates Body Weight Loss in Antibiotic Treatment in Obese Mice

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 1965-P
Author(s):  
TEAYOUN KIM ◽  
JESSICA P. ANTIPENKO ◽  
SHELLY NASON ◽  
NATALIE PRESEDO ◽  
WILLIAM J. VAN DER POL ◽  
...  
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Antibiotic Treatment ◽  
Body Weight Loss ◽  
Obese Mice ◽  
Glucagon Receptor

Relation between change in treatment for central diabetes insipidus and body weight loss

2018 ◽  
Vol 44 (1) ◽  
Author(s):  
Ayako Ito ◽  
Aya Nozaki ◽  
Ichiro Horie ◽  
Takao Ando ◽  
Atsushi Kawakami
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Diabetes Insipidus ◽  
Body Weight Loss ◽  
Central Diabetes Insipidus
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