of the paper highlights his willingness to contribute his experience freely to the discussion of issues confronting rangeland managers: "In this paper I hope to lead you through the financial history of Willangee Station. Through decisions we made, the mistakes we have made, the lessions we have learnt, the debts we have taken on and the profits we have made. Our aim is to expose all of these factsso people may learn from them'. The paper, along with others presented at the Seminar, was published in the Australian Rangeland Journal. In 1980 Bill hosted a tour of Willangee by the Barrier Environment Group during a Conference on the theme'% the West Darling becoming a Desert?" By his actions, conservationists and graziers were brought together duringa period when conservation of Australia's arid lands was becoming a major issue. Through his leadership of the Broken Hill Branch of the Australian Rangeland Society, Bill has contributed greatly to the exchange of ideas between academics, the pastoralist community and conservationists. With such a wealth of knowledge of the district and its people Bill has been aguiding influence to the Broken Hill Branch, the Committee and its members. Aust. Rangel. J. 7(2) 1985, 64- 74 THE CASE FOR PRESCRIBED BURNING TO CONTROL SHRUBS IN EASTERN SEMI-ARID WOODLANDS K.C. Hodgkinson and G.N. Harrington CSIRO Division of Wildlife and Rangelands Research, Private Bag, P.O., Deniliquin, N.S. W. 2710 Abstract A theor) for shrub control by prescnbed burn~ng In semi-and woodlands of eastern Australla IS outlmed. Th~s theory IS based on ~nev~table shrub Increases wh~ch occur pnnc~pally by ep~sod~c, w~despread, mass establ~shment events Wet per~ods whlch foster shrub establ~shment also promote abundant grass growth pred~sposlng the plant community to be~ng burnt Fue then k~lls nearly all recently establ~shed shrubs and many of theadult shrubs, thereby con- trollmg the shrub populat~on Today, fire IS much less frequent and IS prevented altogether In some areas. Prescr~bed burn~ng before any potential wddflre season w~ll both control shrubs and hm~t the spread of wddfires Three constraints to the adopt~on of prescrtbed burn~ng are recogn~sed economlc benefits are ma~nly real~sed over a 10-20 year term: * grazlers have l~ttle experience and Infrequent opportunltles to learn about fire; grazlers are reluctant to accept the nsks associated with burnmg. If semi-and woodlands are to be burnt at a frequency necessary for shrub control. grazlng pressures may need to be reduced to husband the vlgour of perenn~al pasture plants Opponun~st~c burnlng should take place at times of w~despread shrub seedl~ngestabl~shment. Prescribed burnlng IS the only known method for broad-scale shrub control and relevant State departments and grazlers are urged to collaborate In prescr~bed burn~ng to a regonal strategy. rather than property by property

This article outlines the exploration and settlement of poplar box lands which followed the European occupation of the Australian continent in the mid-19th century, draws attention to the various fragments of historical information on substantial changes in the soils, vegetation and biota, and describes the role of European livestock (sheep, cattle, goats, rabbits) and fire in these changes.

The diet of sheep was recorded by direct observation in a shrub-dominated Eucalyptus populnea woodland between Nyngan and Bourke, N.S.W., on 7 occasions over a 2-year period. Different nutritional opportunities were provided by the effects of rainfall on 3 contrasting grazing treatments. The sheep did not graze equally over the whole area available but foraged selectively so that they encountered unacceptable plants rarely. In particular variable spear grass (Stipa variabilis) was avoided once the inflorescence had emerged and only extreme hunger pressured sheep into foraging in dead stands of this grass.matured, sheep ate firstly increasing quantities of perennial forbs and then mulga (Acacia aneura). When these foods were depleted, sheep subsisted on dead perennial grass, tree litter and broad leaf hopbush (Dodonaea vlscosa). All other shrub species were unacceptable. The ability of sheep to forage successfully during dry periods put excessive pressure on perennial grass, causing it to die out. I suggest this has contributed to the increased frequency of shrub establishment in the poplar box woodlands since they have been used for pastoral production.

Fire has been present during the evolution of poplar box communities and the flora is well adapted to fire. Broad fire regions are recognised on the basis of bioclimatic data and the effects of different fire regimcs on plant species and communities arc dis- cussed in relation to these regions. Grazing combined with the variable rainfall makes the accurate prediction of vegetation changes resulting from fire difficult. Fire is currently episodically associated with over-average rainfall in most areas as the predominant fuel is grass. Minimum fuel quantities of 100 g m-2 in pastures where fuel is continuous and 150 g m-' in pastures with discrete tussocks are required to carry a fire. Fire can drastically reduce shrub numbers, especially juvenile and seedling plants in the short term, but attitudes about using fire for shrub reduction vary from region to region according to the likelihood of growth or replacement pastures. Grazing control after burning to permit the recovery of the ground layer is difficult because of grazing by native herbivores. There is a need for further studies on fire behaviour and plant survivorship characteristics as affected by climate and native and domestic animal grazing.