Date: Tue, 21 Jan 97 13:52 EST From: "Michael.Chamberland" <23274MJC@MSU.EDU> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg299$foo@default> Subject: Re: "CLODS"
> But fields full of plants are not the norm everywhere, if indeed a norm exis
> My Pinguicula hunts have led me to discover sites where the entire populatio
> numbers maybe as much as 20 plants. Say, for example, that I can remove one
> seed pod (with permission!!!) containing a small number of seeds (let's say
> seed, about normal for a cross pollination). Although I have a "small" numb
> (35) of seeds, I actually have more potential plants than the entire populat
> of plants growing in the source location! As to biodiversity, in such a
> situation, it is probable that there will be more biodiversity in the 20 wil
> plants than in the resulting 35 cultivated seedlings but this is neither cer
> nor is it necessarily significant as, with such small numbers in the wild, a
> new seedlings will in themselves increase the biodiversity significantly (as
> long as they are not all replanted back in the wild whereby their limited
> biodiversity might smother the wild original). Further, by placing some of
> these cultivated plants back in the wild, I can gain an opportunity to colle
> seed from a different plant. I can also take every opportunity to "lend a h
> and cross pollinate any flowers I can find in the wild. Work it out. For
> species where the original population is small, this results in a near
> exponential growth in biodiversity assuming seed is collected and grown
> successfully from successive generations. Therefore it is not only one of v
> few ways (if not the only way) to conserve a plant under dire threat, it is
> both viable and pragmatic and even an improvement on what natural processes
> might be expected to achieve.
I wonder if a wild population consisting of only 20 individuals might already
be well on its way to extinction in the wild? How would its pollinators be
fairing? I doubt that a mere 20 individuals of a plant species constitutes
a viable long-term population. What if a tree falls on the site?
> But back to the Sarracenia field (I wish!). Suppose over a period of 20 yea
> lots of people visit the field, some taking plants (surely not), others taki
> seeds (and some taking only memories). If they all kept decent provenance
> records or if the tagged the location name to the plant name, then potential
> even a field full of thousands of plants may be able to be matched by the sh
> weight of material collected over the years. Using such well documented
> plants, a breeding p[rogramme could be set up to ensure the maximum biodiver
> was gained by multiple cross pollination of different partners. Effectively
> this is identical to the procedure now adopted for rescuing threatened anima
> species, it's just that I've never heard of its application to plants. But
> not? Surely another project a world wide CP conservation body could conduct
> (remember, you heard it first here!). Either a geneticist or a mathematicia
> could work out how many crosses of which plants would be needed to replace a
> wild population lost to a catastrophe (e.g. a plough).
I think you've touched on an important point here. If they ALL kept decent
locality records, and maintianed both these records as well as the plants,
and if this sheer weight of material could be brought together into a
breeding program, then this may have a chance. But it is quixotic to
imagine that hobby collectors will be able to do this. Hobby collecting is
a leisure activity. There is no accountability for data lost, labels
confused, plants killed, flowers left unpollinated, propagules given
away to those who can't maintain the data, etc... If hobby collectors were
responsible for all that, there would be little fun in plant collecting!
Collectors are free to do what they like! (within the law). This is what
makes collecting enjoyable, but it ensures there is none of the organization
necessary for uniting the disparate plants in a multitude of collections.
Why count on some agency to bring together plants from private collectors?
It would be easier to start a conservation program from scratch, and
build it from material collected (with permission!) from the wild.
Consistent record keeping is more likely acheived through organiztion.
Hobby collecting is usually a solitary activity. If hard times befall
you, it's the leisure budget that gets cut off. If collections were
maintained by a community rather than an individual, the chances of riding
through hard times are greater. Those community collections are botanical
gardens. (But not all botanical gardens have a conservation program).
> There is some more maths that could be done on this.
> Perhaps a mathematician amoungst us might like to look at the issue of very
> small populations from a purely mathematical point of view. In the wild: as
> 20 plants; assume about 5% germination success with an average of 35 seeds p
> seed pod, assume 4 - 5 flowers per plant per year, assume 50% of the plants
> flower each year; assume seedlings take 2 years to flower in the wild. In
> cultivation, assume 90% germination success; assume seedlings take 1 year to
> flower; assume other factors equal. How many seedpods would need to be ta
> into cultivation to significantly increase the biodiversity after 1 year, 2
> years, 5 years. If a single seed is taken from the wild and if the resultan
I believe that the "biodiversity" of concern here is the allelic diversity,
which is increased only through mutations. Those mutations which are
benefical or harmless are maintained in the population. This process of
building biodiversity takes thousands of years. With conservation we can
only hope to maintain this biodiversity, not increase it.
Michael Chamberland
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