[APWG] Ecosystem restoration essential to retain alien species at minimal levels Re: Getting 95% weed-free & 95% native cover in 90 days or less

[Wayne Tyson]

Craig, et al:

I'm looking forward to others weighing in on this discussion. While Craig has some very interesting things to say, and he has stimulated me to again think harder on this subject, I hope this doesn't become just a tennis match between the two of us. 

Mowing before seed-set is a reasonably good practice in some contexts, it may not always be practical (e.g., 2:1 slopes, etc.). Once a site has been dominated by weeds for a year or two, not to mention decades or centuries, there is a considerable buildup of dormant seeds in the soil's seed bank. Mowing can't get those, nor can it get all of the standing crop. Then there's the issue of the thatch/chaff, post-mowing regrowth, and other specifics that raise questions. I'm really looking forward to the possibility of seeing at least one project next month, when I will be traveling up the CA coast into Oregon, thence through much of the Intermountain West. 

I am delighted to hear about Craig's and Anita's projects, and hope that others will post information about other ones. Also, I would like to hear from more list subscribers on whether or not they agree with Craig's (and my) claims that weed eradication without restoration is futile. 

Not only that, but the vital importance that such treated sites must self-sustain rather than be continuously treated for eternity. It's kinda like Ben Franklin said when he and the other signers left Independence Hall and a man shouted, "Gentlemen--what have you given us!" Franklin responded, "Liberty--IF you can KEEP it!"* 


Best to you all,
WT

PS: That applies to weed eradication and ecosystem restoration too--semper vigilans may be a requirement, but constant maintenance should not be--if the "constitution" is sound in the first place. Not to say that a little tweaking might not be useful after the emerging vegetation (and perhaps some animal species) has had a chance to become strong enough for the kind of traffic the tweaking (planting, for the most part) might require. 


----- Original Message ----- 
From: "Craig Dremann - Redwood City Seed Company" <Craig at astreet.com>
To: <apwg at lists.plantconservation.org>
Sent: Tuesday, August 11, 2009 10:06 AM
Subject: [APWG] Getting 95% weed-free & 95% native cover in 90 days or less


> Dear Wayne, Anita and All,
> 
> Thanks for your emails.
> 
> Anita asked, how were the exotics eradicated?
> ============
> Reply: Mowing and pulling plus a tiny bit of herbicides.  No burning,
> tilling, grazing, insects.  And no native seed sowing until recently, to
> start putting back the missing species that did not emerge from the soil
> seedbank.  The most important thing about the Shaw property, as Michael
> Shaw says, is to get the weeds cut every year, before they make any more
> seeds.
> ==================
> Wayne writes:
> 
> I do not endorse arbitrary time limits and "cover" criteria, as they are
> irrelevant to ecosystem development. If, for example, "cover" is demanded
> within 90 days, seedling density will be far too high, resulting in the
> more aggressive (even indigenous) species suppressing the more
> slowly-developing ones. Getting the plant density and species proportions
> right is one of the most demanding aspects of ecosystem restoration
> practice.
> ==========
> 
> Reply: With a nearly 100% weed cover in lower-elevation California
> consisting of over 1,000 species of weeds, that reality absolutely
> requires a Performance Standard, that I talk about at
> <http://www.ecoseeds.com/standards.html> with a less-than-90-day
> time-frame attached.
> 
> To achieve that 95% native cover and 95% weed eradication within 90 days
> or less, you have to do numerous small-scale test plots before you do the
> big project, so you can test your ecological restoration technologies and
> see if they are tuned for the site.
> 
> The small scale test plots are where you find the proper sowing rates and
> the correct species mixes, so that your native seedlings come up at just
> the proper densities, to suppress the exotic seeds still in the soil, but
> not so dense that the natives will crowd each other.  You can see some
> photos of some successful small scale test plots at
> http://www.ecoseeds.com/greatbasin.html
> 
> Really, you do not have any choice in central or northern California
> grassland habitats, because it is an absolute necessity to get 95% native
> cover and 95% weed eradication within 90 days or less.  That means if you
> sow your local native seeds in October or November, you should see 95%
> native seedling cover by February 1st.
> 
> If you cannot achieve that Performance Standard, the weeds in California
> will eat your project for breakfast, like what is happening on the public
> lands at Russian Ridge just 10 miles up the hill from me, that you can
> read about at http://www.ecoseeds.com/invent.html
> 
> Sincerely, Craig Dremann (650) 325-7333
> 
> 
> 
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> 
> Disclaimer
> Any requests, advice or opinions posted to this list reflect ONLY the opinion of the individual posting the message.


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