1、Designation: E 1923 97 (Reapproved 2003)Standard Guide forSampling Terrestrial and Wetlands Vegetation1This standard is issued under the fixed designation E 1923; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last rev
2、ision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers environmental studies such as riskassessments, planning projects, or research typically includingcharacteri
3、zation of ecological resources. Compliance withfederal statutes (for example, National Environmental PolicyAct 1970, (NEPA); Comprehensive Environmental Response,Compensation and Liability Act 1981, (CERCLA: with itsRemedial Investigation/Feasibility (RI/FS) and Natural Re-source Damage Assessment (
4、NRDA) components); ResourceConservation Recovery Act (RCRA), and Federal Insecticide,Fungicide, and Rodenticide Act, (FIFRA) as well as stateregulations addressing projects such as hazardous waste siteassessments and environmental impact analysis often requirescharacterization of vegetation. This gu
5、ide presents a frame-work for selection of terrestrial vegetation sampling methodsbased on project-specific objectives. Method-specific practicesare associated with this basic guide as annexes.1.2 As with any data gathering activity, the value ofinformation is affected by the strategy and sampling d
6、esign.Determining the number of sample points, temporal and spatiallocation of sample points, relationships among samplingpoints, and the correspondence of other sampling activities areimportant considerations. Strengths and limitations of variousmethods are described in general terms in this guide.
7、 However,the key issues linked to data quality relate to the specificquestion being addressed and the adequacy of the field sam-pling plan.1.3 The values stated in SI units are to be regarded as thestandard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated w
8、ith 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. Referenced Documents2.1 No related ASTM standards on field sampling areavailable.2.2 This guide is intend
9、ed only as a framework for vegeta-tion sampling, not as an in-depth discussion of methodology.Greig-Smith (1)2provided a detailed theoretical treatment ofvegetation sampling. Other excellent treatments of vegetationsampling, typically with fewer theoretical considerations, arealso available. The use
10、r of this guide is referred to generalliterature on field sampling methods and designs (2-8).3. Terminology3.1 The words “must,” “should,” “may,” “can,” and “might”have specific meanings in this guide. “Must” is used to expressan absolute requirement, that is, to state that the test ought tobe desig
11、ned to satisfy the specified condition, unless thepurpose of the test requires a different design. “Should” is usedto state that the specified condition is recommended and oughtto be met if possible. Although violation of one “should” israrely a serious matter, violation of several will often render
12、 theresults questionable. “May” is used to mean “is (are) allowedto,” “can” is used to mean “is (are) able to,” and “might” isused to mean “could be possible.” Thus, the distinctionbetween “may” and “can” is preserved, and “might” is neverused as a synonym for either “may” or “can.”3.2 Definitions o
13、f Terms Specific to This Standard: Consis-tent use of terminology is essential for any vegetation samplingeffort. Below is a list of terms that are used in this guide, aswell as others that may be encountered commonly during thecourse of vegetation sampling. This list is not exhaustive, andit includ
14、es terms that do not apply to every project or method.Definitions are from Barbour et al. (9) and Hanson (10),ortheauthor of this guide.3.2.1 abundancethe number of individuals of one taxonin an area; equivalent to the term density as used in botanicalliterature (relative abundance = density).3.2.2
15、associationa particular type of community withrelatively consistent floristic composition, a uniform physiog-nomy, and a distribution characteristic of a particular habitat.3.2.3 basal areathe cross-sectional area of a tree trunk at1.4 m (4.5 ft) above ground (see diameter at breast height).3.2.4 ba
16、sal area factor (BAF)in variable radius sampling,the number that is multiplied by the number of tallies to obtainbasal area in m2/ha or ft2/ac.1This guide is under the jurisdiction of ASTM Committee E47 on BiologicalEffects and Environmental Fate and is the direct responsibility of SubcommitteeE47.0
17、2 on Terrestrial Assessment and Toxicology.Current edition approved May 10, 2003. Published August 2003. Originallyapproved in 1997. Previous edition approved in 1997 as E 1923 97.2The boldface numbers given in parentheses refer to a list of references at theend of the text.1Copyright ASTM Internati
18、onal, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.2.5 biomassthe mass of vegetation per unit area.3.2.6 canopythe uppermost layer, consisting of branchesand leaves of trees and shrubs, in a forest or woodland.3.2.7 communitya group of interacting plant (or a
19、nimal)populations in a defined area.3.2.8 constancythe percentage of all relevs that contain agiven taxon (see Annex A1 for description of relev method).3.2.9 coverthe area of ground covered by plants of one ormore taxa.3.2.10 densitythe number of plants rooted in a given area.3.2.11 diameter at bre
20、ast height (DBH)the widest point ofa tree trunk measured 1.4 m (4.5 ft) above the ground.3.2.12 dominancea measure of a taxons contribution tocover or basal area in a community (physiognomic domi-nance), or a taxons impact on the reproduction and continuedexistence of a community (sociologic dominan
21、ce).3.2.13 ecosystema biological community plus thephysical-chemical environment in a particular area.3.2.14 floraa list of all the taxa in an area.3.2.15 forba non-graminoid herbaceous plant.3.2.16 frequencythe percentage of total sampling unitsthat contains at least one rooted individual of a give
22、n taxon, ameasure of uniformity of a taxons distribution.3.2.17 geographic information system (GIS)an integratedspatial data base and mapping system in which geographicalinformation can be used to produce digital maps, manipulatespatial data, and model spatial information. Allows overlay oflayers of
23、 information, such as habitats or plant ranges.3.2.18 global positioning system (GPS)a survey system inwhich a GPS unit is used to receive signals from satellites.Signals are then interpreted to provide information such aslatitude and longitude, or bearings for navigation, positioning,or mapping.3.2
24、.19 graminoida grass (Poaceae), sedge (Cyperaceae),or rush (Juncaceae).3.2.20 herba plant with one or more stems that die backto the ground each year (that is, graminoids and forbs).3.2.21 importancethe relative contribution of a taxon to acommunity; defined as the sum of relative cover, relativeden
25、sity, and relative frequency.3.2.22 importance percentagethe mean of the normalizeddensity, cover, and frequency values, ona0to100%scale.3.2.23 physiognomythe surface features of an area.3.2.24 populationa group of individuals of the samespecies occupying a habitat small enough to permit interbreed-
26、ing.3.2.25 presencethe percentage of all stands that contain agiven taxon.3.2.26 quadratan area of any shape that can be delineatedin vegetation so that cover can be estimated, plants counted, ortaxa listed.3.2.27 releva method to survey vegetation in a struc-tured, subjective manner that generates
27、categorical descriptionsof species abundance, dominance, and sociability.3.2.28 rhizospherean unspecified volume of soil closelysurrounding plant roots.3.2.29 remote sensingthe use of satellites or high-altitudephotography to measure geographic patterns such as vegeta-tion.3.2.30 shrubwoody plant ty
28、pically smaller than a treewhen both are mature (typically with DBH 2 to 3 m tall when mature (typically DBH $10cm). Should be defined specifically at start of project.4. Sampling Approaches4.1 Vegetation sampling methods can be divided into twobroad divisions, namely (a) those that use a defined pl
29、ot orarea; and (b) the plotless methods that have no defined area.Regardless of the method used, the information obtained insampling includes a list of species and some measure of thedominant taxa. With defined area plots, direct measures ofcover, size of individuals, numbers of individuals, or biom
30、assof each taxa are possible. Subsequent calculations allow theinformation to be presented in normalized or relative terms.The plotless methods, except for the point-quarters method,generate only normalized or relative comparisons of taxa.Therefore, if a measure of the number of individuals per unit
31、area (that is, plant density) is needed, one should not use aline-intercept or point-frame method. In general, the definedarea methods require a greater level of effort per unit data thanthe plotless methods.4.1.1 Defined area methods employ discrete sampling plots.The shape of the plot may be circu
32、lar, square, or rectangular.Key factors regarding choice of the shape relate to thevegetation conditions and terrain. Circular plots are delineatedin the field by using a center post and a measuring device(meter tape, rope, pipe, or stick) as a radial arm to trace thecircumference. Alternatively, a
33、rigid hoop may be placed in thefield. Tall vegetation or rugged terrain impede efforts toestablish good boundaries of circular plots. Square or rectan-gular plots are more easily placed in the field as straight linesand are typically easier to establish compared to arcs. For agiven area, a circular
34、plot has less perimeter than a square plotwhich has less perimeter than a rectangular plot. Consequently,E 1923 97 (2003)2in an ideal situation, circular plots would present fewer“edge-related” sampling decisions and therefore make theeffort more objective. However, as field conditions compro-mise t
35、he ability to place circular plots, this advantage is quicklylost.4.1.2 Plotless methods range from relatively loosely struc-tured reconnaissance strategies to rigorous techniques thatemploy either dimensionless points, as in various line andpoint-sampling methods, or geometric relationships that fa
36、ctorsize and distance into the measures, as in the variable radiustechnique.5. Significance and Use5.1 Vegetation sampling is useful for investigating plantsuccession and community composition for a variety of pur-poses including land use planning, resource surveys, assess-ment of vegetation respons
37、e to toxic materials and otherenvironmental stresses, and for ecological research (11).6. Interference6.1 Topography, vegetation type to be sampled, and skill ofpersonnel are the main limitations in vegetation sampling.Rock outcrops, steep slopes, and open water limit the effec-tiveness of all metho
38、ds discussed here, but study areas can bedesigned to avoid potential problem areas with a limitedamount of bias (see Section 9). Limited sight distances due totopography or dense vegetation may cause difficulties inplacing transects, defining plot areas, and sighting vegetation invariable radius sam
39、pling. Impenetrable vegetation, such asblackberry or floating bogs, may impede establishment of linetransects or points. Beyond these physical interference factors,caution should be exercised to understand spatial distributionpatterns inherent in many vegetation types. Aggregate orpatchy distributio
40、n of plants may limit the validity of certaincalculations of density, frequency, or dominance. Project-specific quality assurance plans should address each of thepotential interference factors (physical as well as biological)that might confound sampling efforts. See Annex A6 for furtherdiscussion of
41、 the limitations of each method.7. Sampling Materials7.1 Field Notebooks/Data SheetsProper recording of dataand observations is essential for any vegetation samplingeffort. Field notebooks or data sheets, or both, should beuseable in all expected weather conditions, and waterproof inkshould be used
42、when possible. Field notebooks should containconsecutively pre-numbered pages, and notebooks should beproject-specific. Daily observations should include personnel,weather, date, time, location, and any other observations ofconditions that may affect the project. All mistakes should becrossed out wi
43、th a single line, initialed, and dated. Data sheetsshould be photocopied weekly and stored separately fromoriginals to avoid costly loss of data and time.7.2 Site Maps, Aerial Photos, Compass, and GPS(Optional)Topographic maps and aerial photos can be usedin designing a study to identify sampling ar
44、eas, vegetationtypes, and access to a study area before field sampling begins.In the field, maps can be used in conjunction with a compassand GPS (Global Positioning System) unit to precisely locateand record study areas, lay transect lines, and to define plotareas. Site or point locations obtained
45、with a GPS can berecorded for entry into a GIS (Geographic Information System)for future analysis. Information on the use and limitations ofcompasses and GPS units can be obtained where such devicesare sold. Current United States Geological Survey (USGS) 7.5Minute Topographic Maps are available from
46、 a variety ofsources and contain the appropriate compass declination for thestudy area. Aerial photographs are usually available for severaldifferent dates from government agencies, colleges, and uni-versities near the project area. Most of the continental UnitedStates has been photographed repeated
47、ly since 1938. Althoughthe photographic record is incomplete and sporadic, andtechnical limitations (such as varied camera angle and altitude)are typically great, the photographic records contain valuablequalitative information on vegetation and land use patternsover a time span of 50 or more years.
48、 If a larger area with lessresolution is acceptable, LANDSAT imagery is available formost areas since 1972. Even subjective knowledge of gener-alized trends over five decades can offer important interpretiveperspectives to ecological assessment.7.3 Tape Measures:7.3.1 DistanceA 100-m tape with cm in
49、crements and ametal hook at one end should be used for distance measures,line transects, and quadrat measurements. Tapes should beflexible for ease of use and to avoid the damage caused bybending metal tapes, but strong enough to withstand snaggingon vegetation and rocks. When measuring distances, tapesshould be taut and held at the same height above the ground atboth ends of the tape (usually at breast height), and care shouldbe taken to avoid stretching the tape. In many cases, range-finders can be used for the above measurements, but theirinst
