B. Economic Considerations 
Few, if any adequate economic studies have been done to compare 
the cost effectiveness of the presently operational detection-systems 
against remote sensing systems. What would be required for such a study 
would be total duplication of effort, except that one organization would 
carry on with the "old" method, and another organization would apply 
remote sensing methods, costs would be carefully accounted for, and the 
results would be evaluated by comparison of the effectiveness of each to 
complete the objectives of the survey. For example, see Can. Forestry 
Service (1975), where a list and description of disease, insect and other 
damaging impacts on the forest resource are given on a yearly basis. 
When the cost of monitoring exceeds the value of the resource 
being monitored, does monitoring stop? When damage is just beginning, 
the monetary value expended by remote sensing is very small relative to 
the total resource value. However, when the damage is extremely high 
and widespread, the cost of monitoring is still the same, but it may be 
higher than the value of the residual resource considered on a short- 
term basis only. In such a case the worth of the lost resource is 
greater than the cost of finding out what has been lost, and where the 
loss occurred. What is required is a governmental economic committment 
that would ideally have sufficient monetary allocations for adequate 
surveillance and subsequent interpretation of vegetation damage in 
susceptible zones at timely intervals. The economic committment could 
be extended to a global effort by the United Nations. Considered as an 
insurance program that is cashed in when the values saved from damage 
are those values that would have been lost if the program had not been 
in effect (Leuschner and Newton, 1974), the program would pay for itself. 
C. Detection Reliability 
We are beyond the point of film-filter studies, for "... 
damage assessment has become the largest single use for colour aerial 
photographs ..." (Myers 1974). A number of reports have indicated the 
operational nature of remote sensing and photo interpretation in all 
parts of the world (Annon 1972; Beaubein and Jobin 1974; Bradshaw 1974; 
Ciesla et al. 1971; Ciesla 1974; Kenneweg 1974; Murtha 1973; Nelson and 
Hartman 1975; Remeyn 1972; Sukhih and Sinitsin 1974). What needs to be 
demonstrated to the general user-community is the interpretation relia- 
bility and accuracy of the system. The remote sensing community has 
suffered from the over-selling of certain sensing systems by enthus- 
iastic individuals and agencies and consequently a "credibility-gap" 
has deyeloped between the remote sensing community and the user- 
community. Most of the over-selling has resulted from speculative 
statements made at the end of inconclusive studies and quoted out of 
context (Buys 1973). For the benefit of the "non-believers'" there have 
been few, if any, duplicated studies directed at assessing the accuracy