This or any other evaluation system 

 nust play off bewildering detail against 

 simplifying integrations to facilitate the 

 decisionmaking process. The evaluator 

 must integrate mentally the information 

 about a number of different individual 

 species in order to make the decision. 

 The ideal solution is a compromise between 

 extremes - simple enough to allow a 

 decision to be made, but detailed enough 

 for the decisionmaker to feel confident 

 about it. 



All procedures developed to make 

 decisions about wetlands are based on 

 human values and human judgments about 

 what is good and what is not. They 

 reflect what humans think is important, 

 and that fact is a basic ingredient in all 

 management. In the case of HEP, the 

 procedures have been standardized, 

 individuals can be trained and certified 

 to carry them out, and reproducibility is 

 quite good. These facts often make us 

 forget the value-laden nature of the whole 

 enterprise. 



When habitat values are monetized for 

 benefit :cost analyses, a whole new set of 

 assumptions are superimposed on the 

 ecological evaluation. I do not intend to 

 discuss these because they are well 

 covered by several other authors (Shabman 

 and Batie 1978; McAllister igS'"). The 

 methodology has evolved from economic 

 theory that assumes that in a free economy 

 the market price reflects the value of a 

 commodity (the willingness-to-pay 



approach). 



This leads to real problems in 

 monetizing nonmarket commodities like pure 

 water and air, and in pricing marshes 

 whose monetary value in the marketplace is 

 determined by their value as real estate, 

 not their "free services" to society. 

 Consequently, attempts to monetize marsh 

 values have generally emphasized the 

 commercial "crops" from marshes - fish, 

 shellfish, furs, and recreational fishing 

 and hunting for which pricing 



methodologies are available. As Odum 

 (1979) pointed out, this kind of pricing 

 ignores ecosystem-level values related to 

 hydrology and productivity, and global 



values related to clean air and water and 

 other "life support" functions. 



One controversial approach uses the 

 idea that energy flow through an ecosystem 

 or the similar concept "embodied energy" 

 (the total energy required to produce the 

 commodity, Costanza 1980) is a valid index 

 of the totality of ecosystem functions; 

 and that furthermore, this index is 

 applicable to human systems as well. Thus 

 natural and human systems can be evaluated 

 on the basis of one common currency: 

 "embodied energy." (Since there is a 

 linear relationship between embodied 

 energy and dollars, that more familiar 

 currency can also be used.) 



The general response to this kind of 

 approach is probably fairly summed up by 

 Reppert and Sigleo (1979): "Certain 

 aspects of the evaluation structure .... 

 are too theoretical and unsubstantiated to 

 be considered for general application, 

 particularly those involving the analysis 

 of energy flows and the conversion of 

 energy values to monetary values." 

 However, in recent years both the 

 theoretical base and the methodology have 

 been much improved . 



Using better assumptions, Costanza 

 (1933) showed that the economist's 

 willingness-to-pay approach and energy 

 analysis converge to a surprising degree. 

 In Table 32 the average gross benefits 

 arrived at by summing the gross economic 

 value of different marsh resources 

 ($342/acre/yr) are roughly equivalent to 

 the latest value arrived at from the 

 embodied energy of biological productivity 

 ($300/acre/yr). This convergence suggests 

 an integrated methodological framework for 

 evaluation. The approach has the real 

 merit of being equally applicable to both 

 natural and human systems, but like e^ery 

 other approach it simplifies by converting 

 everything into one currency. 



Since the purpose of the exercise is 

 to compare apples to oranges or oil wells 

 to marshes, some kind of equivalence must 

 be established, but it seems to me 

 dangerous to lose sight of the real 



88 



