[APWG] What caused surprise results in Poppy Project?--Got it!

[craig at astreet.com]

Dear Tony and All,
You got it.!
All land plants have at
least two soil nutrient thresholds. (1.) The threshold for seedling
survival (2.) The threshold that larger plants can survive in.
 
So if you are the  manager of 200+ million acres like
BLM and you have allowed exotic animal grazing for a period of time, then
you may still have mature native grasses on your lands, but if you do an
age-pyramid survey by measuring the basal diameters of 100 plants, you
might not see any young plants or seedlings in the population.
That
was the case in the 600 acre Great Basin project, where you see the
seedlings die in the flat at http://www.ecoseeds.com/good.example.html.
 
Grazing had mined the soil nutrients and surface organic
matter below the threshold needed for seedling survival.  So we had a
population of old native grass plants on the 600 acres, and they were
producing viable seeds each year, but no seedlings were surviving in the
soil next to the mature plants.
We found that each native grass
species in the Great Basin had a different seedling survival threshold, in
that some species'  seedlings could survive at very low thresholds
where other species required very high thresholds to keep
growing.
That goes for weeds here in the West also, like cheatgrass,
medusa head, Saharan mustard, Italian thistle, etc., where their seedlings
can survive in soils where the nutrients have been drawn down by grazing,
below the threshold required by the local native plant seedlings.
I
call those soil-nutrient depleted weeds, the default weeds, and by
fertilizing and bringing the soil nutrient threshold back up to where the
local native seedlings need to survive, may be the easiest way to
eradicate these weeds and restore the original ecosystem.
 
Once we start doing local soil nutrient native and weed
seedling survival threshold measurements across the county, I think we
will be very surprised on how many of our weed problems are caused by the
lack of nutrients, and how far we need to restore the native threshold
that existed before our grazing animals walked away with them.
I put
details of this problem in comments to BLM in 2007, that you can read at
http://www.ecoseeds.com/blmprotest.html.
Sincerely,  Craig
Dremann (650)
325-7333
 
 
 
>

> Craig - something to do with soil chemistry?

>

> Tony

>

>

> P.S. And thanks for keeping this important conversation going.

> Clearly your methods have led to some very important successes and

> certainly shouldn't be simply ignored (and especially when the

> alternatives are what exactly?); and you were obviously most
certainly

> aware of some of the negatives surrounding using pots in this
fashion;

> quite clearly they can also be useful as well within those known

> limitations.

>

>

>

>

>

> Quoting craig at astreet.com:

>

>>

>>

>>

>> Dear Robert and All,

>> Thanks for your latest guess, but the mulch

>> content was the same in both pots. However, what made the

>> difference between the two pots, is a major key to the success
or

>> failure

>> of getting natives established, especially here in the arid
West.

>>

>> And the difference in the two pots is a common problem which

>> helps create infestations of weeds covering tens of millions of
acres

>> here

>> in California and the Great Basin. The acres here in the West

>> currently covered with cheatgrass, star thistle, or medusa head
grass

>> will

>> be covered for eons, and you will not be able to get any
native

>> established in their place, until you correct what killed the
seedlings

>> in

>> the first pot.

>> Any more guesses?

>> Sincerely, Craig

>> Dremann (650) 325-7333

>>

>

>

>
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