Re: Allelochemicals, roots and competition

> From: Charley Bay <charleyb at hpgrla_gr.hp.com>
> [during thinning] some vegetation may go 
> through some form of shock.  After this recovery, the plant is 
> *best* able to grow at that one point in time than ever again.  
> Foresters term this "release".  
> Young vegetation *always* grows better than 
> old, and no plants ever get younger.  The longer the plant waits 
> for release, the more difficult the individual has in adapting 
> (reacting) to favorable release conditions.
> Also, many plants seem to be morphologically ready to "seize the 
> day" at the first disturbance that lends one individual the upper 
> hand [snip]
> Getting back to the "first day", some individuals *can* release, 
> while others (if they exist at a very low NPP for a significant 
> portion of their lives) will never release even though an 
> infinite amount of space, light, water, and nutrients are 
> available.

Sounds like A. mad.

> However, most plants are "capitalists", and perform the current 
> year's mitosis and cell expansion completely dependant on the current
> year's nutrient availability.  They can best take advantage of
> (capitalize on) nutrient availability, but can be very stressed if 
> a "false start" on nutrient supply for the year falls short of the 
> plant's later needs for completion of the cell expansion process.

Upon first putting a new bulb into a tank, it grows like crazy
putting out big new leaves. I think these leaves are the ones
that the plant needs to have functioning for its photosynthesis
factory to produce and store food reserves, or to continue growing.
If at this stage, you practice pruning and there is a sufficient
supply of nutrients, I think it would keep on sending up new leaves.

If, however, you move it (as I have done) I think you disrupt
the roots too much and the plant just doesn't recover. It just
doesn't have that second wind that even in a new environment
with plenty of nutrients and light, it doesn't seem to "release".

It could be that it would release, if there wasn't allelochemicals
or root competition preventing that. From what you say, however,
I suspect it's just that the plant is one of those which does not
recover well from a change in the environment which might allow
it to continue new rapid growth.

When you talked about root competition, you didn't mention any
chemical mechanisms (aside from pH) such as allelochemicals
in the soil or substrate and I was curious if that might be a
factor. In other words, some plants may inhibit their less
competive neighbours to different degrees chemically. We could
assume that there is probably no shortage of nutrients that
are being competed for or space (at least in my situation)
and I think those were the other two factors you mentioned in
root competition.

That might mean that certain plants would be better neighbours
for the lace plants than others. My big tank currently has a
lot of these fast growing, competitive plants which probably
had to evolve ways to compete successfully in the optimal
growing locations. I used these initially to try to create an
algae free environment for the Lace plants; maybe that was a
wrong strategy. A better strategy might be to start out with
a new tank and plant it with several A. mad bulbs along with
several Cryptocorynes and other Aponogetons. Start out slow
with a low fish population, less intense light and perhaps
a shorter photo period (going against conventional wisdom that
you want a 12 hr. photo period to kickstart the Aponogeton
seasonal cycle). The substrate probably needs to contain
laterite, peat, vermiculite and/or humus and should probably
be supplemented by fertilizer tablets to provide the nutrients
for that burst of growth and the sustained growing period
afterwards assuming ONLY root feeding.

This is of course all only happy conjecture and anybody who
knows the real secret of growing A. mad. should please set us
straight! ;-)