Chapter 8. — Multiple Resource Interactions 



In examining supply trends and opportunities to 

 enhance supplies of individual resources, the previous 

 chapters did not deal with the complex interactions 

 among resources because quantitative information on 

 renewable resource interactions is limited. Many 

 studies have examined the interaction between two 

 resources over a small geographic area. These studies 

 are of little use, however, in quantifying the impacts 

 of resource interactions for a national assessment. 

 In spite of the difficulty of quantifying multiresource 

 interactions, it is essential to understand the potential 

 impacts of meeting future demand for one resource on 

 the capacity to increase supplies of other resources. 

 Analyses suggest that, with more intensive manage- 

 ment, supplies can be increased to meet nearly all 

 renewable resource products, but still to be examined 

 is the potential for meeting the combination of 

 resource demands from the resource base at reason- 

 able cost or without extensive environmental degra- 

 dation. 



This chapter discusses the complexity of estimating 

 multiresource interactions, introduces an analytical 

 model which has the potential for quantifying these 

 interactions at regional and national levels, and 

 evaluates the capability of forest and range land to 

 increase supplies of renewable resource products. 



actions will affect the recreation resource, while at 

 the same time, recreation management activities will 

 affect timber production. These kinds of multiple 

 interactions are common on all forest and range lands. 

 To make a decision about the type of management 

 activities needed to obtain a given set of desired 

 outputs, the interactions among these uses must be 

 evaluated.' 



For each resource, various activities are carried out 

 as a part of management. Forexample, "timber stand 

 improvement" is a management activity — or, more 

 properly, a category of activities — commonly prac- 

 ticed as timber management. Each activity — directly 

 or in combination with other activities — is intended 

 to bring about specific results measured in terms such 

 as animal unit months, million cubic feet of timber, 

 or recreation visitor days. In addition to the primary 

 intended result, there is normally a wide array of 

 associated results. To carry the example further, 

 timber stand improvement might result in increasing 

 the forage available for wildlife and reducing the 

 length of time snow will remain on the ground as 

 well as the primary result of increasing net growth 

 of usable timber. 



Diagrammatically, these interactions can be illus- 

 trated as shown in figure 8.1. 



Complexity of Estimating Renewable 

 Resource Supplies 



The individual resources and uses discussed earlier 

 occur not in separate places on forest and range 

 lands, but rather in a great variety of combinations 

 and under a wide range of conditions. Land and 

 resource managers deal with this complexity along 

 with additional complicating factors such as different 

 ownerships and management goals. In some instances, 

 the production of two resources on an individual 

 unit of land is complementary. That is, management 

 activities to increase the production of one resource 

 will also increase the supply of the other. In other 

 instances, the two resources may be competitive. 

 Increases in the supply of one can only be accom- 

 pUshed at the cost of a reduction in the amount 

 available of the other. To fully evaluate the produc- 

 tive capacity of a tract of land, it may be necessary 

 to understand the interactions among several 

 resources. For example, it may be desirable to know 

 what combinations of timber forage for domestic live- 

 stock and forage for wildlife can be grown. Further, 

 it may be desirable to know the impact of these 

 various combinations on storm runoff and contri- 

 bution of sediment to an adjacent stream. On any 

 particular area, interactions occur simultaneously in 

 at least two directions. That is, timber management 



' Cooper, C. F. Ecosystem models in watershed management. In 

 The ecosystem concept in natural resource management. G. M. 

 Van Dyne (ed). Academic Press, New York. p. 309-324, 1969. 



Figure 8.1 



Land Capability 



Outdoor Recreation 



Wildlife and Fish 



L Range Grazing 



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Timber 



Water 



Environmental Impacts 



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