[APWG] What caused surprise results in Poppy Project?

[craig at astreet.com]

Dear Wayne, Robert and All,
I am very surprised about the two
comments warning against ex situ test pots and their use?  
I
have been using them with great success since the mid-1990s and was the
main reason we were able to beat the cheatgrass north of Reno on the 600
acres for the gas pipeline right of way, that you can see at
http://www.ecoseeds.com/greatbasin.html.
Using the ex situ pots a
few years ago, I was able to test the use of native straw on germinating
weed seedlings, that has helped me get close to 100% weed-free cover here
in weedy California.  The biggest advantage of the ex situ pots, is
you can take snippets of the ecosystem you are working with, home with
you, and keep a closer eye on the results.  
You can also set
up dozens to hundreds of different treatments at the lowest cost possible,
to test out ideas that you can use the successful ones on a larger scale
on the restoration site.  
Usually NO  test plots are done
for any large native plant mitigation projects, and at least the ex situ
pots could show that your plan may be successful on a larger scale. I
have watched project after project in California grasslands and the Great
Basin using natives fail year after year, for many decades now.  At
least small scale ex situ boxes or pots, could provide some proof of
concept.
You can look at the ex situ test pots like mini common
garden plots, where you have made uniform conditions in terms of heat,
light, water, soil--then all of those environmental factors are uniform.
 You are just doing different treatments in each pot, to see if you
can produce a different response from the native seeds or the weed seeds
that are in the soil.    
In regards to the current
question---what caused the seedlings to survive in one pot, and die in the
second pot--what caused that result was measured by other means, and the
living and dying seedlings just confirmed what was measured by other
methods.  
Any other guesses?
Sincerely,  Craig
Dremann (650) 325-7333
 
> I have nothing against pots
but they do not accurately represent what

> physically happens in field or forest soils when it rains. Any
container

> will adversely affect the drainage of a field soil, resulting in
very

> different soil moisture levels at different depths within the
container

> compared to the real world. This is true whether the pot is 12 inches
or

> 2 inches deep, six inches or 6 feet wide. This is called a
"perched"

> water table. The drainage holes at the bottom of pot channel the
water

> above them to the holes, resulting in wetter soil for a longer time
then

> if the water drained naturally through the field soil. Pathogens
that

> cause the complex known as "damping off" thrive at higher
moisture levels.

> Pots tend to keep those pathogens in the immediate vicinity of the

> seedlings where they may or may not kill them. These fungal pathogens
are

> widespread in all soils. I don't know how you can rule out damping
off.

> Did you have them tested by a pathologist?

>

> ________________________________

>

From: APWG [apwg-bounces at lists.plantconservation.org] on behalf of

> craig at astreet.com [craig at astreet.com]

> Sent: Friday, September 13, 2013 9:50 PM

> To: apwg at lists.plantconservation.org; craig at ecoseeds.com

> Subject: [APWG] What caused surprise results in Poppy Project?

>

>

> Dear Robert and All,

>

> Sorry you don't like pots? How about a one foot by two foot flat that
is

> four inches deep, as an ex situ test pot?

>

> You can see that same result in two flats at

> http://www.ecoseeds.com/good.example.html.

>

> Not damping off, in either case.

>

> Sincerely, Craig Dremann (650) 325-7333

>

>

>

>

>

>

>

>> Hi Craig

>>

>> Putting soil in pots changes the entire ecology of the
experiment. I

>> hate

>> it when people do pot studies on plants that are growing in
natural

>> settings and try to extrapolate that data into the real world.
Your

>> plants

>> most likely died from damping off, a common complex of fungal
pathogens

>> that is most virulent in containers and much less so in the real
world.

>>

>> Bob

>>

>> ________________________________

>>

>

From: APWG [apwg-bounces at lists.plantconservation.org] on behalf of

>> craig at astreet.com [craig at astreet.com]

>> Sent: Wednesday, September 11, 2013 1:41 PM

>> To: apwg at lists.plantconservation.org; craig at ecoseeds.com

>> Subject: [APWG] What caused surprise results in Poppy Project,
where

>> seedlings all died?

>>

>>

>> Dear All,

>>

>>

>>

>

>From my Poppy Project in Palo Alto, California, (Google = Poppy

>> Project+Arastradero) I took soil samples from under the poppies
where

>> they had been shedding seeds this summer from locations 10 feet
apart,

>> and

>> put the soil into 4 inch plastic pots.

>>

>> I watered the pots and within a few weeks, had a lush growth of
poppy

>> seedlings in both pots. Both pots were side-by-side evenly
watered and

>> neither were fertilized.

>>

>> However, within a month, every single poppy seedling in one pot
died,

>> and

>> you can see a picture of both pots at

>> http://www.ecoseeds.com/what-difference.jpg.

>>

>> These pot-tests of checking soil samples from the future
revegetation

>> sites have become the standard for Caltrans for their projects,
ever

>> since

>> I taught them classes on the use of native plants 13 years ago,
to

>> discover and correct this problem.

>>

>> This is the second time I have encountered this very important
issue in

>> such a dramatic way that is often overlooked, when trying to get
native

>> plants established here in the West---so any guesses of what
the

>> difference was?

>>

>> Sincerely, Craig Dremann (650) 325-7333

>>

>
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