Plants

Good rains that can fall at any time of the year

 changes everything along the The Oodnadatta Track

In late autumn and winter they turn enormous stretches of country side into spectacular landscapes of colour.

Dunes and sandy plains might be covered in carpets of numerous varities of annual flowers - yellow, white and  pink daisies, the spectacular regal birdflower or blue cattle bush. Summer rains produce brilliant spreads of Sturt Desert Pea and Swainsona peas of orange, white, pink and purple hues. 

Why is there such a wonderful variety of plants?

Climate, landforms and soil types determine where and when plants will grow.

the climate in this country is erratic. So, to survive, plants have evolved in many different ways. Soil types vary - ranging from clays to sandy loams; from sand plains to limestone and saline soils; from alluvial soils associated with swamps and watercourses to rocky ridges, hill slopes and hard gibber country. All are habitats for different plants where the distribution varies greatly.

Germination

Plants out here can be quite particular about when they germinate and grow. Grasses and some wildflowers usually germinate after summer rains; short -lived herbs and most wildflowers are prevelent following winter rains. The Sturt Desert Pea germinates only after summer rains, when the ground is warm. It is also programmed not to germinate in the same area in two consecutive years even when rainfall is apparently adequate and seed is on the ground.

Seeds can remain dormant in the ground protected by their tough outer coverings for many years until the right conditions return to trigger germination. Temperature affects germination. Bladder Saltbush will not germinate above a certain temperature to avoid " cooking " in the heat. Timing can be very specific. For instance you'll see button grass, a favourite summer grass and not only for beef cattle but also the native birds , following rain events in February, when optimum ground temperatures and rainfall are likely to conincide. 

How plants survive

Dry times are a normal part of the climate cycle out here and most plants are drought evading. Drought-resistant perennials are present all the time. Tall shrubs and trees maximise their access to water by a combination of shallow roots to capitalise on light rains, and a deep tap root system to reach the deeper reservoirs of moisture. In exceptionally dry times most most arid perennial plants will cease growing. Some partially or completely shed leaves to preserve nutrients and energy.

Livestock enjoy variety

The Oodnadatta Track is home to some of the finest grazing in Australia. It's ability to produce beef cattle is quite incredible.  Stock have greater choice of feed in the pastoral country than in the more settled farming lands. Livestock find a whole range of grasses, shrubs, herbs, forbs and trees are palatable.

Most grasses, especially the dominant Mitchell grasses which grow after summer rains, are excellent cattle fodder. Good seasons can also produce an abundance of the fleshy-leaved plants munyeroo and native spinach. These are particularily useful because on a diet of these moisture-laden plants livestock can spend extended periods of time away from their watering points.  For a more detailed description of the plants and their locations through Allandale, please visit  Land Systems

Want to know more?

Visit the Australian Arid lands Botanic Gardens at Port Augusta - the ideal place to learn more about the hugerange of arid plants the grow along the Oodnadatta Track in the South Australian Outback.

 Information courtesy of the following organisations

Arid Areas Catchment Water Board

Government of South Australia

South Australian Tourism Commission

Western Mining