Abstract
Grazing the woodlands of semi-arid and arid Australia by domestic stock has extensively collapsed perennial *grass populations and thereby fostered woody plant increase. This study examined the pattern of grazing of individual grass plants by sheep in the landscape of a semi-arid woodland, and a model was developed describing the spatial and temporal influences on the grazing pressure placed on plants. Plants of two widespread perennial grass species differing in palatability, Eragrostis eriopoda and Thyridolepis mitchelliana, were examined weekly in two contrasting periods at the CSIRO Lake Mere Research Facility. The plants were located throughout the landscape in lightly- and heavily- stocked paddocks. Patterns of grazing in space and time were determined by examining the grazing of marked tillers. No preference was shown for previously ungrazed plants and only occasionally were previously grazed plants preferred. Thyridolepis mitchelliana plants were slightly preferred over E. eriopoda plants. Landscape zones receiving water and nutrients from elsewhere were preferred for grazing but the effect was weak. The foliage biomass of herbaceous plants in the immediate vicinity of a grass plant did not influence the number of tillers grazed nor the probability of the plant being grazed. Overall the defoliation of individual plants by sheep was weakly determined by landscape location, stocking level, plant species and prevailing forage on offer. The influence of spatial and temporal variation was small; random grazing of grass plants was the rule. This finding suggests that the grazing pressure on palatable perennial grasses in the paddocks of semi-arid woodlands will be similar across wooded landscapes and that spatial variability in plant mortality could be due to. the combined effect of plant water stress, which varies spatially and temporally, and grazing pressure which varies temporally but not spatially.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 10
Claim · model-written summary
Sheep showed no preference for previously ungrazed grass plants.
- Taxon
- Grassest0
- Interactor
- Sheep
Ovis ariest0herbivore - Outcome
- previously ungrazed plantse1
- Direction
- No preferencee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Grazing of Grasses by Sheep”
e1“No preference was shown for previously ungrazed plants”
Claim · model-written summary
Previously grazed grass plants were only occasionally preferred by sheep.
- Taxon
- Grassest0
- Interactor
- SheepOvis ariest0herbivore
- Outcome
- previously grazed plantse2
- Direction
- only occasionallye2
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Grazing of Grasses by Sheep”
e2“only occasionally were previously grazed plants preferred”
Claim · model-written summary
Thyridolepis mitchelliana plants were slightly preferred over E. eriopoda plants.
- Taxon
- Thyridolepis mitchelliana
.jpg?width=60)
Thyridolepis mitchellianae3 - Outcome
- preferrede3
- Direction
- slightly preferrede3
- Comparator
- E. eriopoda plantse3
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e3“Thyridolepis mitchelliana plants were slightly preferred over E. eriopoda plants”
Claim · model-written summary
Landscape zones receiving water and nutrients from elsewhere were preferred for grazing, but the effect was weak.
- Taxon
- Grassest0
- Interactor
- SheepOvis ariest0herbivore
- Outcome
- grazinge4
- Direction
- were preferrede4
- Qualifier
- the effect was weake4
- Setting
- Landscape zones receiving water and nutrients from elsewheree4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Grazing of Grasses by Sheep”
e4“Landscape zones receiving water and nutrients from elsewhere were preferred for grazing but the effect was weak”
Claim · model-written summary
Foliage biomass of herbaceous plants near a grass plant did not influence the number of tillers grazed or the probability of the plant being grazed.
- Taxon
- Grassest0
- Treatment
- foliage biomass of herbaceous plantse5
- Interactor
- SheepOvis ariest0herbivore
- Outcome
- number of tillers grazede5
- Direction
- did not influencee5
- Qualifier
- nor the probability of the plant being grazede5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Grazing of Grasses by Sheep”
e5“The foliage biomass of herbaceous plants in the immediate vicinity of a grass plant did not influence the number of tillers grazed nor the probability of the plant being grazed”
Claim · model-written summary
Defoliation of individual grass plants by sheep was weakly determined by landscape location, stocking level, plant species and prevailing forage.
- Taxon
- Grassest0
- Interactor
- sheepOvis ariese6herbivore
- Outcome
- defoliation of individual plants by sheepe6
- Qualifier
- weakly determined by landscape location, stocking level, plant species and prevailing forage on offere6
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Grazing of Grasses by Sheep”
e6“Overall the defoliation of individual plants by sheep was weakly determined by landscape location, stocking level, plant species and prevailing forage on offer”
Claim · model-written summary
The influence of spatial and temporal variation on grazing was small.
Verbatim
t0“Grazing of Grasses by Sheep”
e7“The influence of spatial and temporal variation was small”
Claim · model-written summary
Grazing of grass plants was random, the rule rather than an exception.
Verbatim
e0“random grazing of grass plants was the rule”
Claim · model-written summary
Grazing pressure on palatable perennial grasses in semi-arid woodland paddocks is suggested to be similar across wooded landscapes.
Verbatim
e0“the grazing pressure on palatable perennial grasses in the paddocks of semi-arid woodlands will be similar across wooded landscapes”
Claim · model-written summary
Spatial variability in plant mortality could be due to the combined effect of plant water stress and grazing pressure.
Verbatim
t0“Grazing of Grasses by Sheep”
e1“spatial variability in plant mortality could be due to. the combined effect of plant water stress, which varies spatially and temporally, and grazing pressure which varies temporally but not spatially”