indicator species

[Regis Courtecuisse]

John Trueman wrote:
> =

> John Landolt asked for good examples of an"indicator species".  He also=
 wrote:
>         "Am I correct in my assumption that an "indicator species" is o=
ne
>         closely tied to a fairly narrow ecological setting?  Is not an
>         "indicator species" one that supposedly can be used to monitor =
the
>         "health" of that ecological setting?"
> =

> It seems to me there are two very different concepts of indicator speci=
es
> out there in the conservation literature.  One is a species the presenc=
e or
> absence of which indicates some environmental condition: metals,
> pesticides,  acidity, overclearing, compaction, temperature-shock, wint=
er
> frosts, etc.  There are plenty of that type of indicator, both positive=
 and
> negative. =



        This is the historical meaning of the indicator species concept. Lots
of specific example could be cited for plenty of different environmental
parameters.

> The other is a species which indicates *biodiversity* per se:
> ie, the presence of this species is correlated with the presence of (i)=

> lots of other, unrelated species or (ii) other species somehow judged t=
o be
> valuable, or endangered, or otherwise in need of some management.
> =

> I cannot think of any examples of the latter type of indicator, but it
> seems that often indicators of the first type are mistaken for the seco=
nd.
> =

> John Trueman.
>

        This second category of indicators confines to bio-indication, as
currently understood.
        I trust that many field botanists, lichenologists, zoologists and
mycologists (I am one of those) are currently working in this topic.
        If I may give some example from my field (mycology), I can tell that I
am working on the bio-indicative value of [higher] fungi with special
regard to the patrimonial value of special habitats, given areas and
even large territories. Some species or [taxonomically related] groups
of species [for example taxa like subsections or sections] seem to
behave in the same manner in my area. I studied the distributionnal
evolution of some fungal species and found that some patterns were
seriously shrinking in Northern France, in a comparable way (same
initial occurence places and same present sanctuaries) [Namely, among
others, Subsection Foetentinae of Russula]. Such results (and other
data) made possible the preparation of a red data list for threatened
Fungi in northern France (the first one for Fungi in France).
        The occurence of such species [like Russula fragrantissima or R.
laurocerasi, to stick to my Russula example] in a relev=E9 will be
indicative of a patrimonially valuable place, to be considered in
conservation projects, and even sometimes will be significant for the
integrity of the global area (depending on the historical management for
example).
        Here is again the connection between [bio]indicative species and
natural sites conservation.

        Further studies are currently processed to elaborate new indices,
useful in the evaluation of the patrimonial value and functionnal
"health" of natural sites (two more or less related concepts).
        This is related to the bio-indicative value of "communities" of species
[not only species on their own] (even if the word "community" can't be
taken in its phyto/myco - coenological meaning), considered as
functionnal ensembles [for example, ectomycorrhizal species are highly
valuable in evaluating the patrimonial value and functionnal health of
forest stands]. This research topic also relates to Robert Fogel's
comment on this thread, stressing the crucial (but often neglected) role
of Fungi in ecosystems :

> Fungi for example determine the structure and function of many
> terrestrial ecosystems.

        This research seems very important to me, to deal efficiently with
nature conservation (ecosystems in their functionnal complexity should
be taklen into to account for a better understanding and conservation).
        It is part of my own research plans but also runs within national
(French, under a Program I initiated and coordonate) and European
programs : in Europe, the ECCF (European Council for the Conservation of
Fungi) tries to develop a common thinking and strategy about fungal
conservation, in relation with the biotopes conservation.

        As to the initial idea in this thread (phylogeny and conservation), I
am not sure it is the more accurate way to come in and deal with the
extreme emergency of conserving the more valuable natural sites and
their specific elements... Anyway, the alternative ideas sent were
stimulating and interesting.

        Best regards to all !

        R=E9gis


-- =

R=E9gis Courtecuisse
D=E9partement de Botanique
Facult=E9 des Sciences Pharmaceutiques et Biologiques
B.P. 83. ; F-59006 Lille Cedex (France)
T=E9l. : (33).03.20.96.40.40
Fax. : (33).03.20.95.90.09
e-mail : rcourtec at phare.univ-lille2.fr