Fascinating - it all does help someone like me a lot.
Looked at the Ecad thing and this struck me:
"It is an ecological form rather than a genetic form."
I take that to mean that a plant that was transplanted to the "normal"
environment would adopt the standard characteristics - as its genetics is
the same ?
(And probably very controversially - I am a physical scientist really so
that's my excuse - does loss of an ecad really matter ?)
I can't remember now if it was the same forum but someone reported earlier
this year interesting observations on the occurrence of variant Bee (?)
Orchids which suggested similarly that they might just be standard ones
reacting to environmental differences...
Reply / forward from John Crellin
www.FloralWIKI.co.uk
=3D5020/stime=3D1187769833/nc1=3D4507179/nc2=3D3848571/nc3=3D4763760>
Du Rietz regards subspecies as regional fancies and by that definition it
would be taken that subspecies are largely allopatric. In practice subspeci=
es
can usually be separated from each other by a mean character value (ie ssp =
1
has mean leaf length of 2mm whereas ssp 2 has a mean leaf length of 4mm).
Hedren (2003) also states that subspecies should "be genetically coherent i=
n
neutral characters and relatively differentiated from other subspecies." On
the whole I would agree but it does present me with a problem.
Carex lepidocarpa subspecies jemtlandica is an endemic or near endemic to
Scandinavia. There are plants growing in Ireland that cannot be separated o=
n
grounds of morphology from Scandinavian material (even using derived charac=
ter
sets within a multivariate analysis) but these plants are genetically
distinct. Should the Irish material be classified as a new subspecies or, a=
s it
can't be separated from the Scandinavian material by how it looks, should i=
t be
classified as Carex lepidocarpa subspecies jemtlandica?
Cheers
Nige
My interpretation also.
> does loss of an ecad really matter ?)
In isolation, presumably not. But if you lose the ecad it almost certainly
means you've lost the whole rare habitat which produced it and this would
have had lots of other rare or unique species as well. Especially in this
case where it is shallow sheltered seawater of varying salinity in
Strangford Lough - an absolutely exceptional site, but with all the usual
threats.
http://www.jncc.gov.uk/ProtectedSites/SACSelection/n2kforms/UK0016618.pdf
There was an article in British Wildlife on it:
Reserve Focus, Strangford Lough, Northern Ireland, 7:98-109
This situation isn't unique - in my view the only scientific justification
for concentrating so much of the conservation money and effort on higher
plants, mammals and birds, is that they provide such good hosts for the far
more interesting symbionts, parasites, pathogens and things that recycle
them when they're dead, plus the ensuing food chains. These comprise by far
the greatest part of total biodiversity.
Malcolm
(Now back to the tax!)
> -----Original Message-----
> From: UKBotany@yahoogroups.com
:UKBotany@yahoogroups.com
r
946/msg
> But if you lose the ecad it almost certainly
means you've lost the whole rare habitat which produced it and this would
have had lots of other rare or unique species as well.
Point taken - I was really only trying to reinforce my question and can
quite see Stangford Loch deserves all conservation measures possible.
> (Now back to the tax!)
I've done mine !
Reply / forward from John Crellin
www.FloralWIKI.co.uk
_____
=3D5023/stime=3D1187773849/nc1=3D4507179/nc2=3D3848567/nc3=3D4776364>
> Du Rietz regards subspecies as regional fancies ...
Assume you typed
> Du Rietz regards subspecies as regional facies ...
(B...dy Microsoft autocorrupt feature!!)
Allopatric means arising in geographical isolation.
Facies means ? can't find a formal definition that isn't geological. I take
it to mean the totality of an organism's appearance - ie phenotype?
> In practice subspecies
> can usually be separated from each other by a mean character value
Isn't this more to do with what the author found publishable as a subspecie=
s
but didn't feel he could justify as a species?
This is an example of the clash between different concepts of "species":
morphological, DNA, genetic, inter-breeding, ecological, biochemical,
serological and so on. As I'm sure you're well aware,
species/subspecies/variety are manmade concepts which we try to match to
reality as a few-sizes-fit-all. Personally I'd suggest you decide which typ=
e
of taxonomy you're doing (ie who your audience is) - suspect it's morpholog=
y
- and stick to that. Then you can always add the rider "Irish race" or
"Scandinavian race" when it's significant to further distinguish.
There are countless examples of concealed species in our flora: look at
chromosome nos in CTW - more than a single value for a species means that
number of genetically distinct populations - eg Ladysmock (varies from 16 t=
o
96! - with accompanying morphological trends - didn't there used to be a
Cardamine uliginosus?), Creeping Buttercup (16,24,32). [If you haven't done
so already, you should probably check chromosome nos on your material - or
perhaps that's what you meant by genetically different?]
Then there are the self-fertilising species (eg Ladysmock). What does the
concept of species mean if there is no out-breeding? It's no more than a
handy hook for us to hang information on.
At Uni I was taught that you were justified in dividing an animal species
into subspecies if 90% of one group could be distinguished from 70% of the
other, but have never heard that since. (It stuck in my mind cos it was bot=
h
arbitrary and asymmetrical.)
Just found this:
Current Practice in the Use of Subspecies, Variety, and Forma in the
Classification of Wild Plants
Clement W. Hamilton, Sarah H. Reichard
Taxon, Vol. 41, No. 3 (Aug., 1992), pp. 485-498
doi:10.2307/1222819
The URL's too long but Google for "subspecies regional facies"
The gist seems to be that since subspecific taxomony is outside the
Botanical Rules, there are no rules, so you're free to do whatever works in
that particular case, but always state your philosophy.
HTH
Malcolm
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:UKBotany@yahoogroups.com
