Subject: Re: Sinner or saint...? (rather long I'm afraid)

From: [email-masked] (Jan Wesenberg)
Date: Mon, 13 Mar 1995 12:37:28 GMT

I think, one generally should approve and support growing plants from the
native flora in gardens. It may be a way of attracting people's attention
to the qualities of the native nature, and it may also help stimulating
the pride about every aspect of the local heritage and environment, which
is so important for keeping an aware public eye on what threats might be
to it. It may also help diminishing the threat from aggressive alien
plants (mention Abies alba, Acer pseudoplatanus, Heracleum mantegazzianum
or Fallopia japonica to a Nordic botanist, and you will see what
antipathy looks like) or from possible genetic pollutants (exotic close
relatives to native species threatening the genetic integrity of the
native species).

At the same time it involves a great responsibility. The attitude "I am
doing what I want to do and I don't bother what would be the consequences
if everybody else did the same thing" is something very different from
"I am doing what I think everybody else should be doing, and I am willing
to help others do it in a way so that it won't do nature any harm". Even
in the Nordic flora, several native orchid species have been threatened
by digging up for gardens and/or sale, not to mention the ruthless
overexploitation of native populations that has been (and is) going on
in parts of the world where there are more numerous attractive species.
I think, the main point should be to help minimize the amount of
collecting from wild populations. Therefore the first question to ask
oneself, should be: has anybody in the neighbourhood been doing the same
thing before me? If sources of seed or cloned plant material from culture
are available, one should not harvest from wild populations once more.
And if one happens to be the first one, one should be prepared to share
material with neighbours, friends and others if the interest should
spread (which of course is what one wants!), and to spread information
about what one is doing so that noone else should have to collect from
the wild just because he or she wasn't aware of the cultivated material
available. If a species should become very popular, some local plant
nursery should be requested to take it into culture and propagate it for
sale along with a certification of the origin from cultivated material.

Which species should be collected and how should this initial collection
take place? First, there is the legal matter applying to protected
species and protected areas. But what about non-protected species growing
in non-protected localities? Well, there is an obvious diference between
commonplace species and more restricted species. For these last ones, I
think, a little knowledge of the different species' biology may help. For
clonal (rhizomatous) perennials, neither seed sampling nor even removal
of ramets will usually do any harm to the population, given it covers
some area. For non-clonal iteroparous perennials seed sampling will
usually do no harm, but digging up plants should be avoided if the
population isn't extremely rich in individuals - such populations usually
have very constant population numbers, the individuals usually being
quite old, and establishment from seed only taking place on rare
occasions. For semelparous perennials or biennials every individual which
has managed achieving mature state and producing seeds, matters to the
population. Therefore, one should only take a fraction of the seeds
produced by any particular individual, and try to sow some of the
remaining around the mother plant. In any case, digging up individuals
of such plants has no sense - they won't survive for long and possibly
they won't manage to produce seeds either. Annual plants usually have an
extensive seed bank, and rely more upon large numbers of small
individuals than on getting some few large individuals to maturity.
Therefore, collecting some of the population's seeds shouldn't do any
harm if the population is large enough. For annuals or biennials growing
in low densities or numbers, no collection should take place. In such
situations, management measures at the locality often may help bringing
the population number up over some years, making it possible with some
collection in a later season. 

The ecological preferences of the species also has some importance: it
is usually much easier to keep plants which are naturally growing in
unstable or transient habitats (scree, rock, forest edge vegetation) than
plants adapted to mature, climax vegetation, where the species'
interactions and adaptations to eachother and to the habitat is much more
intricate. Some plant groups are notoriously difficult to grow in
culture.

Then there is the question of the compatibility of the species and the
place one intends to grow it. If the habitat matches the species's
demands to soil, exposition, hydrology, light regime etc exactly, then
most of the more common "cohabitants" of the species are likely to be
there already, and what you are doing is in fact restoring a piece of
native vegetation or some managed variant of it (which in most cases
would be welcome!). If, on the other hand, the match is less exact, you
will encounter problems of some kind - maybe the seed won't germinate,
the plants (if perennial) won't survive winter or drought periods or
inundation after snow-melting, the plants won't flower properly or won't
produce mature seed, etc. In such circumstances, trying to introduce
plants by seed may be just a waste of native seed material. One should
therefore not try to introduce annual or short-lived species at all to
places where the potential vegetation isn't the same which the species
naturally occurs in. Long-lived perennials, on the other hand, might be
successfull if transplanted vegetatively (by a ramet) or if germinated
in a flowerpot. And if one has luck, one might even be able to propagate
the species in a similar way.

A completely differnt question, I think, is sowing rare native plants in
the wild in localities where they don't grow spontaneously. I think,
noone should do such a thing on his own. It should only be done as an
action on behalf of nature conservation authorities, only as a last
measure when the original populations are in great danger and it should
always be properly published. For one, there is usually not much chance
of long-term survival of the new population, so the action may quite well
turn up to be in vain. But more seriously, unauthorized and unpublished
actions of that sort may obscure the species's distribution pattern and
make biogeographical, population genetical and other studies of it
impossible. And, it may also in fact threaten the species by giving a
false picture of abundancy. The "real", original populations, which by
their existence have proved to have high long-term survival chances, may
then become exterminated without the due attention, and all one then has
left is the newly established populations which (who knows?) may turn up
to have substancially lower chance for long-term survival. These
considerations, I think, apply mostly to rare species of native
vegetation. Rare species of traditionally managed vegetation (hay meadow,
pasture, ancient weed plants) should on the contrary be tried established
in places where such vegetation and management regimes are being
restored. Of course, if relatively local seed material is available and
if there is no danger of genetic pollution to other populations.

In any case, these are extremely interesting and important matters to
discuss.

Best regards, 

Jan Wesenberg
Agricultural University of Norway
Department of Biology and Nature Conservation

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From: [email-masked] (NJH0323)
Date: 25 Mar 1995 16:04:49 -0500

Right on, Jan!  Here in Calif. we are having awful problems with native
plant
destruction, and the misguided attempts on the part of developers to
"transplant" rare plants to new locations when the original site is to be
covered with concrete
and asphalt.  It just doesn't work!  The rare plants may survive for a
season or two, but then die out.
  It's really difficult here to get people to use native plants (bought at
nurseries or at native plant sales) in their gardens, for unlike Norway,
we have a six-month summer drought, and the natives are adapted to NO
WATER in the summer.
Well, as you can imagine, people like to see green, not brown, all year
'round, so they want to water their gardens, thus the natives just drown!
  I am a self-taught botanist and have been studying the native flora of
my No.Cal. county (Sonoma Co.) for about 20 yrs.  We have so much
wonderful vegetation, and so much of it is rapidly being destroyed by
development.  But on the good side, many more people are becoming
concerned with plant conservation.
  I enjoyed your long note very much.  Keep up the good work!  Nancy
Harrison