PLANT MORPHOGENESIS AS THE BASIS FOR SCIENTIFIC 

 MANAGEMENT OF RANGE RESOURCES 



Proceedings of the Workshop of the United States-Australia Rangeland Panel, 



Berkeley, Calif., March 29-April 5, 1971 



INTRODUCTION 



By R. A. Perry * 



Australia and the United States both have 

 large areas of rangelands which in the past have 

 been used mainly for grazing stock, but which in 

 the future will be increasingly valuable for other 

 purposes, including recreation. The rangelands of 

 the two countries differ considerably in latitude, 

 topography, and climate, but the general prin- 

 ciples and importance of good range manage- 

 ment apply equally in both countries. 



The main objective of range management is 

 the maintenance of the natural resources on which 

 present and future productivity depend. Range 

 management is concerned with complex ecosys- 

 tems in which vegetation has a central role, in 

 that it both provides forage for animals and 

 protects the landscapes from wind and water 

 erosion. It is implicit that if vegetation is man- 

 aged correctly then so is the ecosystem. Manage- 

 ment of vegetation needs to be based on a 

 knowledge of the biology of the component spe- 

 cies, in relation to the physical and chemical en- 

 vironment and their reaction to grazing. 



The tolerance of ecosystems to utilization bj T 

 man, and their ability to regenerate following 

 misuse, decreases as the physical environment be- 

 comes more extreme, for example, as aridity or 

 slope increases. The more extreme the environ- 

 ment, the greater the need for careful manage- 

 ment and for flexibility in management systems. 

 Viewed against these considerations, the intensity 

 of stocking on many Australian rangelands is 

 too high and too inflexible, at least under existing 



1 Professor and Head, Department of Environmental 

 Biology, Australian National University, Canberra, A.C.T., 

 Australia. 



broad scale management practices. In many cases, 

 lower stocking intensities probably would be more 

 profitable in the long term. 



Normally the management of multispecifie 

 plant communities is concerned with maintaining 

 a balance between species. This particularly ap- 

 plies in the case of mixed woody and herbaceous 

 elements, where the desirable balance is one which 

 contains enough individuals of woody species to 

 provide landscape protection and reserve forage 

 in adverse periods, but not so many that they 

 seriously reduce herbaceous production at other 

 times. The balance needs to be maintained within 

 reasonably narrow limits, because if it is allowed 

 to swing too far towards undesirable species, it 

 is difficult to reverse by grazing management 

 alone. It is impossible to eliminate undesirable 

 species by any practical grazing management. 



Range management is commonly considered as 

 being concerned with native vegetation. However, 

 since new herbivores have been introduced to most 

 rangelands, scope exists for exploring plant gen- 

 etic material in terms of its grazing and nutrient 

 response and compatibility with other plant spe- 

 cies. Woody perennials may be more important 

 than they have been considered to be in the past. 



The primary tool of range management is graz- 

 ing control, involving variations in intensity of 

 use, season of use, distribution of animals, and 

 kind and class of animals. Other tools include 

 burning, selective biocides, mechanical treatments 

 to land or vegetation, and fertilizing. In Aus- 

 tralia, these all need assessing at more sophisti- 

 cated levels, particularly in matching specific 

 practices to individual sites and seasonal condi- 

 tions. 



