1、Designation:E 1983 98Standard Guide forAssessment of Wetland Functions1This standard is issued under the fixed designation E 1983;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indic
2、ates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide covers assisting wetland managers by pre-scribing a sequence of steps for defining and assessing wetlandfunctions.This guide also identifies properties th
3、at must beconsidered in the selection of a wetland assessment procedureto determine whether it will assist in satisfying the require-ments of wetland regulatory programs or produce valid designcriteria for planned wetlands,or both.This guide can helpwetland managers use existing assessment procedure
4、s moreeffectively during the decision-making process.The outcomeof the assessment is dependent on many factors including theselected procedure,the sampling design,and assumptions;therefore,decisions and assumptions made should be docu-mented throughout the process.While this guide is developedto ass
5、ist in satisfying the requirements of wetland regulatoryprograms,it can also be used in a variety of planning,management,and educational situations.1.2 The guide is not intended for use in assigning values towetland functions in terms of economic(for example,dollars)or other value units.However,the
6、information that is gatheredwhile assessing wetland functions may be useful in meetingthis objective when used in conjunction with other information(for example,see Refs(1)2and(2).1.3 This guide applies to assessment procedures designedfor application at the ecosystem scale.It does not address thele
7、ss commonly used landscape level models or the use ofwetland assessment procedures for cumulative impacts analy-sis(3-5).1.4 LimitationsThis guide does not include a standardwetland assessment procedure or models for assessing func-tion.This guide has been written primarily to complement andto aid i
8、n the selection of current procedures.There are severalprocedures for quantifying wetland functions and each hasbeen developed for specific purposes.The suitability of aprocedure depends on assessment objectives,wetland type,availability of applicable models given the wetland type andobjectives,and
9、policy of local decision makers.There arecontinuous efforts to develop new and improved methods thatcould override any one recommended standard procedure.1.5 The values stated in inch-pound units are to be regardedas the standard.The SI units given in parentheses are forinformation only.1.6 This sta
10、ndard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Terminology2.1 Definitions:2
11、.1.1 wetland assessment procedure,na definitive proce-dure for identifying,characterizing,or measuring the functionsthat a wetland performs,or a combination thereof.2.1.2 wetland functions,nthe physical,chemical,andbiological processes or attributes that contribute to the self-maintenance of wetland
12、 ecosystems(6)and(7).Wetlandfunctions result directly from the characteristics of a wetlandecosystem and the surrounding landscape and their interaction.2.1.2.1 DiscussionA wetland function is distinguishedfrom wetland value.Wetland functions are a direct result of thecharacteristics of a wetland an
13、d the surrounding landscape.Examples of functions include the removal of dissolvedsubstances,cycling of nutrients,maintenance of plant andanimal communities,and short-term storage of surface water.These functions provide benefits,goods,and services whichmay be assigned a value(economic or noneconomi
14、c)describ-ing the relative importance of a wetland function to anindividual or group of people.The values of wetlands areestimates,usually subjective,of the worth,merit,quality,orimportance of wetland functions(8).2.2 Definitions of Terms Specific to This StandardMost ofthe following definitions are
15、 from Refs(9)and(10).2.2.1 assessment model,na simple model that defines therelationship between ecosystem and landscape scale variablesand functional capacity of a wetland;it is used to derive ameasure of functional capacity(that is,the functional capacityindex).1This specification is under the jur
16、isdiction of ASTM Committee E50 onEnvironmental Assessment and is the direct responsibility of Subcommittee E50.02on Commercial Real Estate Transactions.Current edition approved Nov.10,1998.Published February 1999.2The boldface numbers given in parenthesis refer to a list of references at the endof the text.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.2.2.2 conceptual design,na design that provides a briefdescription of the planned