1、May 2013 Translation by DIN-Sprachendienst.English price group 11No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 13
2、.060.99!%#k“2008872www.din.deDDIN EN 16164Water quality Guidance standard for designing and selecting taxonomic keys;English version EN 16164:2013,English translation of DIN EN 16164:2013-05Wasserbeschaffenheit Anleitung zur Gestaltung und Auswahl von taxonomischen Bestimmungsschlsseln;Englische Fas
3、sung EN 16164:2013,Englische bersetzung von DIN EN 16164:2013-05Qualit de leau Guide pour la conception et le choix des cls taxonomiques;Version anglaise EN 16164:2013,Traduction anglaise de DIN EN 16164:2013-05www.beuth.deDocument comprises 16 pagesIn case of doubt, the German-language original sha
4、ll be considered authoritative.04.13DIN EN 16164:2013-05 2 A comma is used as the decimal marker. National foreword This document (EN 16164:2013) has been prepared by Technical Committee CEN/TC 230 “Water analysis” (Secretariat: DIN, Germany). The responsible German body involved in its preparation
5、was the Normenausschuss Wasserwesen (Water Practice Standards Committee), Working Committee NA 119-01-03-05-06 AK Biologisch-kologische Gewsseruntersuchung of NA 119-01-03 AA Wasseruntersuchung. This standard has been published to implement the Water Framework Directive (WFD), Directive 2000/60/EC o
6、f the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy*). Designation of the method: Guidance standard for designing and selecting taxonomic keys (M 46): Method DIN EN 16164 M 46 *) Registered in the DITR database of
7、 DIN Software GmbH, obtainable from: Beuth Verlag GmbH, 10772 Berlin. DIN EN 16164:2013-05 3 Expert assistance and specialized laboratories will be required to perform the analyses described in this standard. Existing safety requirements are to be observed. Depending on the objective of the analysis
8、, a check shall be made on a case-by-case basis as to whether and to what extent additional conditions will have to be specified. This standard has been prepared by the Normenausschuss Wasserwesen (Water Practice Standards Committee) in collaboration with the Wasserchemische Gesellschaft Fachgruppe
9、in der Gesellschaft Deutscher Chemiker (Water Chemistry Society Division of the German Chemical Society). It is part of the series Deutsche Einheitsverfahren zur Wasser-, Abwasser- und Schlammuntersuchung (German standard methods for the examination of water, waste water and sludge): Guidance standa
10、rd for designing and selecting taxonomic keys (M 46). Standard methods published as DIN Standards are obtainable from Beuth Verlag GmbH, either individually or grouped in volumes. The standard methods included in the loose-leaf publication entitled Deutsche Einheitsverfahren zur Wasser-, Abwasser- u
11、nd Schlammuntersuchung will continue to be published by Wiley-VCH Verlag GmbH appropriate taxonomic level for the analysis in question; all known taxa from the region; written in a language familiar to the analyst. The key itself should provide: a clearly defined title and scope (completeness of tax
12、onomic group); robust characters; clear layout; clear language; complete glossary. The points mentioned above are especially relevant since academic taxonomists often write from the perspective of an expert and do not always empathise with the skills of those performing the analyses. These points ar
13、e described in more detail below. 4.2 Title and scope An identification guide should be clear about the taxonomic groups and life stages covered, and the geographical scope of the guide. These should be reflected both in the title and, in more detail, in the introduction. EXAMPLE 1 Titles like “Chir
14、onomidae larvae of the Lowlands of Northwesttern Europe”, “Oligochaeta of North-West Europe” and “Chironomidae exuviae of the West Palaearctic Region” suggest a defined overview of the content. However, a number of terms within each title would need amplification in the introduction. Terms such as l
15、owlands would need to be explained in more detail, whilst maps and text showing the limits of the authors understanding of North-West Europe and West Palaearctic would also be useful. On the other hand, it is often inappropriate to define the geographical scope too precisely; firstly, because the ge
16、ographical ranges of many species are themselves known only imprecisely and secondly, because the ranges of many species are changing. EXAMPLE 2 Two species of the Trichopertan genus Drusus have been recorded from the Netherlands: D. trifidus and D. annulatus. A third species, D. biguttatus is simil
17、ar to D. annulatus and has been recorded from sites close to the Dutch border, though not yet from within the Netherlands. A Dutch Trichopteran key which made no reference at all to D. biguttatus runs the risk of users shoehorning specimens into D. annulatus. A similar situation exists for the Mollu
18、sc genus Corbicula in Britain and Ireland. C. fluminea is described in “Freshwater Bivalves of Britain and Ireland”; however, C. fluminalis has not yet been recorded from Britain and Ireland and is omitted. Users may not realise that C. fluminalis is spreading throughout Europe and may, in time, als
19、o spread to Britain and Ireland. DIN EN 16164:2013-05 EN 16164:2013 (E) 7 For this reason, authors should always produce an accurate description of the geographical region primarily covered by the key and illustrate it by a detailed map. In addition, all species recorded from the region should be me
20、ntioned in the key. Relevant species known from adjacent regions should be explicitly listed. If data are absent this should also be clearly mentioned. 4.3 Characters Choosing the best characters: How easy are they to describe? Are they appropriate for the potential users? Are they very fragile or e
21、asily damaged? Are they sex specific? Are they restricted or limited to particular regions? Are they restricted to particular seasons? Are they adult or juvenile? Use obvious characters even if they do not differentiate all specimens or do not define the taxon (e.g. habitat, markings, size). The use
22、 of characters requiring very high magnification or special preparations should be avoided where possible, and included only as a last resort. If such characters are essential then this should be mentioned as part of the description. 4.4 Layout The layout of the key should guarantee easy routing thr
23、ough the identification couplets enabling accurate identification in the minimum time. Layout comprises both typography and graphics. 4.5 Description of Morphology 4.5.1 Couplets 4.5.1.1 As far as possible, couplets in a dichotomous key (or choices in a multi-access key) should be discrete and categ
24、orical in nature. Common and obvious taxa should be differentiated early in the key. Couplets should be simple and focus on those aspects of a taxons morphology that best distinguish it from similar taxa. The number of features which are not relevant should be limited. Avoid geographical and ecologi
25、cal characters within the body of the key itself as far as possible (although such information may, occasionally, be useful: for example, if all the taxa in one couplet are all endo-parasites and those in the other are free living). As far as possible, each choice within a couplet should be based on
26、 positive attributes of the taxa in question and it is especially important to give clear guidance when the absence of a character is used to differentiate between taxa. The presence of an adipose fin, for example, is a useful means of recognising a Salmonid fish. However, the absence of an adipose
27、fin is only a useful taxonomic character of a non-Salmonid fish if the key contains a clear description (ideally alongside the couplet) showing what an adipose looks like and where, on the fish, it can be found, so that the user can be sure that s/he has recorded a genuine absence. It is useful to h
28、ave illustrations of critical characteristics. DIN EN 16164:2013-05 EN 16164:2013 (E) 8 The step-wise routing through a key should be easily traced back to the origin. This can be accomplished by indicating the number of the last couplet especially when a step involves more than one couplet. At the
29、end of each key, reference should be made to a complete description of the identified taxon for final confirmation of the identification. All descriptions within a guide should be structured in the same way, to make it easy for users to find the information they require. Descriptions vary in format,
30、 but always start by giving the correct latin name of the taxon, along with the authority and year of publication, and consist of three further sections: 4.5.1.2 Morphological characteristics of the taxon, including dimensions. Where continuous variables are used in keys (e.g. dimensions), then eith
31、er the ranges chosen should not overlap, or each range should be accompanied by a discrete variable that can be used to differentiate taxa in the zone where continuous characteristics overlap. Two other types of information that are useful to include are: the most useful diagnostic characters for a
32、particular organism; taxa that are likely to be confused with the organism (include cross-references). 4.5.1.3 Essential taxonomic information, including synonyms. It is recommended that, for identification guides, which are not intended as the standard taxonomic work for a group of organisms in a p
33、articular region, the synonyms should be limited to those that are used in the works that are widely available, and that users are likely to consult during the course of their work. If there have been nomenclatural changes or taxonomic revisions in recent years, it is useful to include justification
34、 for the approach adopted. This is particularly important for groups of organisms where there have been significant recent changes or there is an ongoing debate about taxonomic concepts. Where authors decide to amalgamate taxa (as “agg.” or “ag.”, they should explain which taxa are included, reasons
35、 that may prevent routine separation of these (e.g. lack of sexual organs) and provide references to more detailed literature. Whilst it is not necessary to provide a reference to the holotype (original description) in a practically oriented identification guide, it is essential to provide enough in
36、formation to provide a traceable link with this. 4.5.1.4 Ecological and distribution notes. These should be based, as far as possible, on the direct experience of the authors in the region where the guide is to be used and include information on the type of habitat along with seasonal preferences an
37、d phonological information. Vague qualitative terms, such as “oligotrophic“ and “mesosaprobic“, should be avoided as far as possible. Use of quantitative information is preferred but if qualitative terms are unavoidable the range of chemical variables embraced by such terms should be specified. User
38、s also need to know if the application of such a term is based on actual measurements or on the association of the taxon in question with other taxa with known preferences for those conditions. Bar charts and scatter plots, relating the distribution of organisms to key environmental variables are ge
39、nerally more useful than such phrases. Distribution maps are useful if there are sufficient data to allow meaningful geographic comparisons, otherwise the maps reflect sampling activity, rather than the true distribution. 4.5.2 Illustrations Illustrations opposite couplets make keys easy to use. Gro
40、uped illustrations allow rapid comparisons between similar taxa. Depending on exact circumstances, either approach may be appropriate. However, grouping illustrations together purely for ease of printing should be avoided. A key should adopt a consistent format for images. If a series of illustratio
41、ns are to be compared, then all should be presented at the same magnification to enable rapid visual comparisons of size. Relevant characters should be clearly marked. An indication of scale (ideally a scale bar) is essential on all illustrations. Each taxon should be illustrated with examples of th
42、at taxon from the region covered by the guide. Several images per taxon are often necessary, in order to show the range of morphological variation likely to be DIN EN 16164:2013-05 EN 16164:2013 (E) 9 encountered. These should show the organism as seen by an observer. Whilst photographs give the opp
43、ortunity to show the organism as seen by the observer, there are still situations where illustrations may be more appropriate. Where high magnifications are necessary, for example, it is often difficult to obtain sufficient depth-of-field in photomicrographs and a three-dimensional shape may be bett
44、er conveyed by a drawing. Colour illustrations are only necessary if colour is an important diagnostic property of the group in question. If used, colour illustrations should show the full range of colour variability within the taxa in the region covered by the guide. However, caution is required as
45、 the perceived colour can be influenced by the surroundings. It is also important to note that inconsistencies can occur in the printing of colours in the final publication (or in their display by computer monitors, in the case of electronic identification guides). 4.5.3 Binding Identification guide
46、s are subject to large amounts of wear and tear, and a strong, appropriate binding is essential. The choice of binding will depend, to some extent, on where the guide is to be used. A guide that is designed for field use should have waterproof covers, at the very least. Such covers are also useful i
47、n laboratories, particularly for analysing aquatic organisms, where work surfaces often get wet. A binding that allows the guide to lie open, rather than springing shut, allows the user to focus on the identification without distraction. It is also useful to have the title on the spine (but this may
48、 not be possible if the document is spiral bound, for example). 4.6 Linguistics Where taxonomy forms an integral part of ecological assessments to underpin legislation such as the Water Framework Directive, the identification guide chosen for a specific monitoring task should be written in a languag
49、e with which all analysts are familiar. This is important if nuances in the text are not to be lost. Straightforward language should be used throughout: “Crab with more or less than three teeth” is a confusing form of “Never crab with three teeth”. Analysts working with freshwater organisms frequently work with a wide variety of taxonomic groups. For this reason, guides should use non-group-specific terms in the native language of the readers as far as possible. A common complaint of published keys is the use of ambiguous and
