[APWG] What caused surprise results in Poppy Project?

[Robert Layton Beyfuss]

Pot studies are very useful for determining the way things happen in pots. That information may or may not apply to the real world. I would not bet the farm that what happens in pots will actually happen in the field.

Your question of why the seedlings all died is most likely answered by the complex called "damping off". The only other reasons I can think of might be not watering enough, in which case drought is the answer, heat stress that cooked them, cold that froze them, or watering too much, in which damping off is still  the "actual" cause.

If your previous pot studies have accurately predicted that way things will happen in the field, good for you!



________________________________
From: APWG [apwg-bounces at lists.plantconservation.org] on behalf of craig at astreet.com [craig at astreet.com]
Sent: Monday, September 16, 2013 1:00 PM
To: apwg at lists.plantconservation.org; craig at ecoseeds.com
Subject: [APWG] What caused surprise results in Poppy Project?


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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