Hard spinifex hill pastures in the Kimberley

Page last updated: Thursday, 23 May 2019 - 9:43am

There are many different pasture types in the pastoral rangelands in the Kimberley region of Western Australia. We provide 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.

Hard spinifex hill pastures

These pastures are part of the Kimberley red soil group - spinifex pastures, and hard spinifexes are the identifier grasses. Use the interactive key to pasture condition to help identify pasture type.

Pastoral value

Pastoral value is very low. Hard spinifex is unpalatable at most stages of growth, and palatable plants are too infrequent to support grazing for any length of time. The upper slopes of these pastures are largely inaccessible to livestock. Condition decline caused by grazing is most likely to be seen in the more-accessible areas of the pasture, such as shallow drainage lines where the more palatable plants tend to occur.

Occurrence

Hard spinifex hill pastures occur as hummock grasslands on hills and ranges in the Kimberley. They are found on shallow, rocky soils. Scattered shrubs and trees, such as snappy gum, may be present.

Pasture condition

Good: In good pasture condition, there is an even coverage of hard spinifex plants. A few desirable perennial grasses, annual grasses and herbs may be scattered among the spinifex clumps, but tend to be concentrated along the drainage lines (Figure 1).

Photograph of hard spinifex hill pasture in good condition
Figure 1 Hard spinifex hill pasture in good condition in the Kimberley (photograph taken May 2008).  A There is an even coverage of hard spinifex plants, considering the site is steep and stony.  B Bare areas are small and evenly distributed between spinifex hummocks.

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Fair: Hard spinifex hill pastures are not commonly seen in fair condition away from the creeklines. Grazing pressure is concentrated along creeklines in this pasture type and therefore decline in pasture condition will be most noticeable there. The coverage of spinifex plants away from the creeklines may appear patchy. Desirable species show reduced frequency and vigour, and undesirables make up an increased proportion of the non-spinifex species present.

Poor: Hard spinifex hill pastures are rarely seen in poor condition away from the creeklines. Desirable species are likely to be absent in poor condition. The risk of erosion in the creeklines is increased and only a few undesirable perennial and scattered annual grasses remain. There may be large bare areas between spinifex plants away from the creeklines.

Why no photos for fair and poor condition?

Hard spinifex hill pastures are usually only seen in good condition because they are unpalatable and grow in relatively inaccessable areas, therefore no photos of fair or poor condition are provided.

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Associated plants

Plants associated with hard spinifex hill pastures in the Kimberley
Common name
(link to DPIRD species page)

Scientific name

(link to FloraBase)

Life form
Desirable species    

Hard spinifexes

Triodia intermedia, Triodia wiseana and other hard Triodia spp.

perennial

Curly spinifex

Triodia bitextura

perennial

Ribbon grass

Chrysopogon fallax

perennial

Silky browntop

Eulalia aurea

perennial

White grass

Sehima nervosum

perennial

Intermediate species    

Black speargrass

Heteropogon contortus

perennial

Wire grass, Northern Wanderrie grass

Eriachne obtusa

perennial

Citronella grass

Cymbopogon bombycinus

perennial

Lovegrasses

Eragrostis spp.

annual or perennial

Annual sorghum

Sorghum stipoideum

annual

Undesirable species    

Threeawn grasses

Aristida spp.

annual or perennial

Contact information

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