Ribbon grass alluvial plain pastures in the Kimberley

Page last updated: Wednesday, 6 June 2018 - 1:36pm

There are many different pasture types in the pastoral rangelands in the Kimberley region of Western Australia. The Department of Primary Industries and Regional Development (DPIRD) provides this pasture information to be used as a reference for assessing pasture condition, and as a guide for pastoral station staff and others interested in the productivity and maintenance of the pastoral rangelands.

Assessments can be used to monitor the success of management and to set goals for improving rangeland condition.

Ribbon grass alluvial plain pastures

These pastures are part of the Kimberley 'black' soils group of pastures, and the perennial ribbon grass is the identifier grass. Use the interactive key to pasture condition to help identify pasture type.

Pastoral value

Ribbon grass alluvial plain pastures have a high pastoral value when in good condition. Ribbon grass plants can be killed by repeated prolonged heavy grazing, especially during dry years.

Occurrence

Ribbon grass alluvial plain pastures occur on level alluvial plains throughout the Kimberley. They are found on deep grey or brown cracking clays and occur as tussock grasslands, sometimes with a variable cover of trees, such as eucalypts and bauhinias. These pastures occupy a similar niche to Mitchell grass alluvial plain pastures. The main difference is that here Mitchell grasses are totally absent; additionally, some tree cover is a little more likely and gilgai microrelief is not always evident.

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Pasture condition

Good: When in good pasture condition, these pastures are dominated by ribbon grass. Bundle-bundle is also often present. Isolated plants of intermediate species, such as native millet (more common in higher rainfall areas), silky browntop or annual sorghum, may be present. There is little bare ground visible, unless the pasture is heavily grazed, and the plants appear vigorous.

Photograph of ribbon grass alluvial plain pasture in good condition
Figure 1 Ribbon grass alluvial plain pasture in good condition in the Kimberley (photograph taken May 2008). A High density and even spacing of ribbon grass plants, which appear healthy. B Only a small amount of undesirable species, such as feathertop. C The prickle bush growing in the background is an indicator of the heavy soils on which this pasture type is found; Mitchell grasses are not evident, confirming the pasture type determination; this pasture is lightly grazed, however, the high density of desirable species would still be obvious under a higher utilisation rate, so the condition would still be assessed as good.

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Fair: Prolonged heavy grazing on the preferred ribbon grass and bundle-bundle plants reduces their density and in fair condition, the intermediate species are more prominent. The lower density and smaller size of desirable plants allow an increase in undesirable plants, such as feathertop and rubber bush. Bare patches may become more obvious.

Photograph of ribbon grass alluvial plain pasture in fair condition
Figure 2 Ribbon grass alluvial plain pasture in fair condition in the Kimberley (photograph taken June 2008). A The density and vigour of desirable perennial grasses are reduced. B There is an increased number of undesirable plants, such as feathertop. C There are more patches with no perennial grass cover; Mitchell grass butts are not evident, confirming the pasture type.

Poor: In poor condition, ribbon grass and bundle-bundle plants are infrequent, often stunted and lacking vigour. Sometimes undesirable perennial species, such as feathertop, can dominate. Alternatively, there may be significant bare areas or large areas with annual grasses, such as Kimberley couch. Intermediate species have declined or may have been grazed out and grazing may even be evident on feathertop and rubber bush, which are species of low palatability.

Photograph of ribbon grass alluvial plain pasture in poor condition
Figure 3 Ribbon grass alluvial plain pasture in poor condition in the Kimberley (photograph taken May 2008). A Ribbon grass is sparse and stunted, showing evidence of heavy grazing. B The undesirable perennial, feathertop, remains. C There are large areas of bare ground; Mitchell grass butts are not evident, confirming the pasture type determination.

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Associated plants

Plants associated with ribbon grass alluvial plain pastures in the Kimberley

Common name

(link to DPIRD species page)

Scientific name

(link to FloraBase)

Life form
Desirable species    

Ribbon grass

Chrysopogon fallax

perennial

Bundle-bundle

Dichanthium fecundum

perennial

Queensland bluegrass

Dichanthium sericeum

annual or short-lived perennial

Native millet

Panicum decompositum

perennial

Intermediate species    

Silky browntop

Eulalia aurea

perennial

Flinders grasses

Iseilema spp.

annual

Wire grass, Northern Wanderrie grass

Eriachne obtusa

perennial

Black speargrass

Heteropogon contortus

perennial

White grass

Sehima nervosum

perennial

Neverfail

Eragrostis setifolia

perennial

Nineawns, bottlewashers, limestone grasses

Enneapogon spp.

annual or short-lived perennial

Kimberley couch

Cynodon convergens

annual

Annual sorghum

Sorghum stipoideum

annual

Sensitive plants

Neptunia spp.

perennial

Undesirable species    

Feathertop wiregrass

Aristida latifolia

perennial

Threeawn grasses

Aristida spp.

annual or perennial

Yellow daisy

Apowollastonia cylindrica

annual

Contact information

Matthew Fletcher
+61 (0)8 9166 4019
Kathryn Ryan
+61 (0)8 9166 4015