[tdwg-content] Proposed new Darwin Core terms - abundance, abundanceAsPercent

[Donald Hobern [GBIF]]

Thanks - I think I too have missed something.  If we want to make these
terms usable, there needs to be a simple way to get numbers out of records
that can be compared with one another where sampling methods allow such
comparisons.  The suggested plain text examples for Abundance don't make
this possible.  Forcing normalisation into percentages seems an unnecessary
hurdle and risks encouraging the impression that number of ducks on a
reservoir is somehow comparable with percentage dry mass, proportional
expression of CO1 for a particular species in an ecogenomics sample, or
whatever.

I would much rather we ensured we had a standard, preferred field which the
data publisher can populate directly with whatever number is the most
appropriate expression of the relative abundance in the sample.  That gives
consumers a clear expectation of how to interpret and handle it. 

Donald

----------------------------------------------------------------------
Donald Hobern - GBIF Director - dhobern at gbif.org 
Global Biodiversity Information Facility http://www.gbif.org/ 
GBIF Secretariat, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark
Tel: +45 3532 1471  Mob: +45 2875 1471  Fax: +45 2875 1480
----------------------------------------------------------------------


-----Original Message-----
From: tdwg-content-bounces at lists.tdwg.org
[mailto:tdwg-content-bounces at lists.tdwg.org] On Behalf Of Aaike De Wever
Sent: Thursday, September 26, 2013 8:44 AM
To: tuco at berkeley.edu; TDWG Content Mailing List
Subject: Re: [tdwg-content] Proposed new Darwin Core terms - abundance,
abundanceAsPercent

Dear all,

As somewhat of an outsider I have another question with regards to the
proposed terms abundance and abundanceAsPercent.

Is there a specific reason for not adopting:
* the abundance field as a field to store only the value and
* a field abundanceUnit/abundanceType to specify whether the value is in %
of species, % of biovolume, % of biomass, individuals/l, ind./m^2, ind/m^3,
ind./sampling effort,...(instead of having a field specific for %)?

Maybe this has been discussed during the hackathon and I missed it in the
report?

Thanks for considering this question.

With best regards,
Aaike

John Wieczorek wrote:
> Dear all,
>
> GBIF has just published "Meeting Report: GBIF hackathon-workshop on 
> Darwin Core and sample data (22-24 May 2013)" at 
> http://www.gbif.org/orc/?doc_id=5424. Now that this document is 
> available for public reference, I would like to formally open the 
> minimum 30-day comment period on two related new terms proposed during 
> the workshop and defined in the referenced document.
>
> The formal proposal would add the following new terms:
>
> Term Name: abundance
> Identifier: http://rs.tdwg.org/dwc/terms/abundance
> Namespace: http:/rs.tdwg.org/dwc/terms/
> Label: Abundance
> Definition: The number of individuals of a taxon found in a sample.
> This is typically expressed as number per unit of area or volume. In 
> the case of vegetation and colonial/encrusting species, percent cover 
> can be used.
> Comment: Examples: "4 per square meter", "0.32 per cubic meter", 
> "24%". For discussion see 
> http://code.google.com/p/darwincore/wiki/Occurrence (there will be no 
> further documentation here until the term is ratified) Type of Term: 
> http://www.w3.org/1999/02/22-rdf-syntax-ns#Property
> Refines:
> Status: proposed
> Date Issued: 2012-03-01
> Date Modified: 2013-09-25
> Has Domain:
> Has Range:
> Refines:
> Version: abundance-2013-09-25
> Replaces:
> IsReplaceBy:
> Class: http://rs.tdwg.org/dwc/terms/Occurrence
> ABCD 2.0.6: not in ABCD (someone please confirm or deny this)
>
> Term Name: abundanceAsPercent
> Identifier: http://rs.tdwg.org/dwc/terms/abundanceAsPercent
> Namespace: http:/rs.tdwg.org/dwc/terms/
> Label: Abundance as Percent
> Definition: 100 times the number of individuals of a taxon found in a 
> sample divided by the total number of individuals of all taxa in the 
> sample.
> Comment: Examples: "2.4%". For discussion see 
> http://code.google.com/p/darwincore/wiki/Occurrence (there will be no 
> further documentation here until the term is ratified) Type of Term: 
> http://www.w3.org/1999/02/22-rdf-syntax-ns#Property
> Refines:
> Status: proposed
> Date Issued: 2012-08-01
> Date Modified: 2013-09-25
> Has Domain:
> Has Range:
> Refines:
> Version: abundanceAsPercent-2013-09-25
> Replaces:
> IsReplaceBy:
> Class: http://rs.tdwg.org/dwc/terms/Occurrence
> ABCD 2.0.6: not in ABCD (someone please confirm or deny this)
>
> The related issues in the Darwin Core issue tracker are
> https://code.google.com/p/darwincore/issues/detail?id=142
> and
> https://code.google.com/p/darwincore/issues/detail?id=187
>
> If there are any objections to the changes proposed for these new 
> terms, or comments about their definitions, please respond to this 
> message. If there are no objections or if consensus can be reached on 
> any amendments put forward, the proposal will go before the Executive 
> Committee for authorization to put these additions into effect after 
> the public commentary period.
>
> Cheers,
>
> John
> _______________________________________________
> tdwg-content mailing list
> tdwg-content at lists.tdwg.org
> http://lists.tdwg.org/mailman/listinfo/tdwg-content

--
Aaike De Wever
BioFresh Science Officer
Freshwater Laboratory, Royal Belgian Institute of Natural Sciences
Vautierstraat 29, 1000 Brussels Belgium
tel.: +32(0)2 627 43 90
mobile.: +32(0)486 28 05 93
email: <aaike.dewever at naturalsciences.be>
skype: aaikew
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BioFresh: <http://www.freshwaterbiodiversity.eu/> and
<http://data.freshwaterbiodiversity.eu/>
Belgian Biodiversity Platform: <http://www.biodiversity.be>
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