PLANT MORPHOGENESIS FOR SCIENTIFIC MANAGEMENT OF RANGE RESOURCES 



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General Environment 



Geography 



Australia's rangelands consist of a single vast 

 area (5,700,000 square kilometers) extending 

 more than 3,200 kilometers from east to west 

 and more than 2,000 kilometers from north to 

 south (figure 1). Its relatively low latitudes 

 (16°S. to 35°S.) are more akin to those of Mex- 

 ico than U.S.A. The highest point is 1,500 

 meters above sea level, but all the country used 

 for grazing lies between sea level and 700 meters. 

 No large, permanently flowing rivers, capable of 

 supporting irrigation agriculture, cross the area. 

 About half the area is drained by ephemeral 

 streams which flow toward internal drainage 

 basins; the remainder has no organized drain- 

 age system (8). The low relief is in marked 

 contrast to much of the U.S. rangelands; for ex- 

 ample, there are no mountain rangelands in Aus- 

 tralia suitable for summer use only. This partly 

 explains the lack of development of, or interest 

 in, seasonal grazing systems in Australia, al- 

 though such systems are widely used on similar 

 terrain in southern Africa. 



The human population is very low (about 

 300,000) and this, combined with the fact that 

 the area is broken by large areas of unoccu- 

 pied spinifex sand plains and dune fields, ex- 

 plains the poor communications and transport 

 systems. No railways or sealed (hard-surfaced) 

 roads cross the area in any direction; those 

 which do exist mainly link scattered mining 

 towns with coastal cities. As most of the ma- 

 terials required by the grazing industries have 

 to be brought from coastal cities and most of 

 the produce despatched to them, the poor trans- 

 port system and the long distances involved mean 

 that the industries have to bear high freight 

 costs. The freight problem is further aggravated 

 because little of the produce is used domestically, 

 most of it being exported from Australia and 

 sold on international markets. Compared with 

 the United States, the net result is relatively 

 high costs and lower return. 



Another aspect of the low population of 

 rangeland Australia is that there are no large 

 cities, no universities and only a few scattered 

 small research centers — a very different situa- 

 tion from the United States. 



Climate 



The whole of rangeland Australia is arid or 

 semiarid. In the north, rain falls only in the 

 summer, but in the remainder there is no well 

 defined rainy season, and rain may fall in 

 either summer or winter, or both, or neither (25). 

 Everywhere rainfall is erratic and, as the win- 

 ters are not cold enough to inhibit plant growth, 

 each fall of rain tends to produce a short, dis- 

 crete plant growth period; winter rainfall is 

 not accumulated in the soil to produce a reliable 

 spring growth period, as is common in the 

 U.S.A. 



Because of the short, erratic plant growing 

 periods, there is little in the way of regular 

 rhythms in the vegetation, which is probably 

 another reason for the lack of serious considera- 

 tion of seasonal grazing systems in the past. It 

 also means that any seasonal grazing strategies 

 developed in the future will need to be flexible, 

 and their application related more to actual 

 periods of rain than to a calender or seasonal 

 basis. An example of one such strategy is given 

 in Burrows' paper where, for control of Eremo- 

 phila gilesii, he recommends heavy stocking fol- 

 lowing any winter fall of rain greater than 40 

 mm. 



Another aspect of the erratic rainfall is that 

 long periods (greater than a year) without any 

 significant growing periods are common (9). 

 Any management strategies must take cogniz- 

 ance of this; an} 7 system designed to take ad- 

 vantage of seasonal characteristics or responses 

 of vegetation can only be superimposed on gen- 

 eral drought management strategies. 



Social And Political Aspects 



Most of Australia's rangelands are leased to 

 individuals or companies, from State govern- 

 ments or, in the Northern Territory, from the 

 Commonwealth. The stations are large and the 

 leases long term — 30 to 50 years, in some States 

 perpetual — (11). No counterpart exists in the 

 United States for this system of land tenure, but 

 in practice the long term leasehold system ap- 

 proaches that of private ownership in the United 

 States. In fact, the leaseholders are commonly 

 referred to as owners. In Australia's rangelands, 

 there is no equivalent of the U.S. Federal or 



