[APWG] Ecosystem Restoration and Management Re: Native grassland and forest understory weedings needtobe at least 99%
Wayne Tyson
landrest at cox.net
Fri Aug 12 23:58:30 CDT 2011
APWG:
I stand partially corrected. I was thinking of Mediterranean climates, particularly California. I will be the first to give a dollar for a bronze likeness of Dremann if he can make this method work on a grand scale at reasonable (feasible) cost. But what one needs is solid science--in this case or cases like this, one needs pre-project baseline data, description of methods, and post-project data that continues beyond the project (to demonstrate self-sufficiency) and trends toward betterment (indistinguishable from pre-disturbance conditions) after hands-off. I can't quite wrap my head around why, over ten years, that one would settle for 99.99 percent rather than 100. The key here is whether the trend went from 99.99 through, say, 99.991 to 99.995 to 99.999 percent and did not significantly decline when the weeders leave. Just one weed, provided it is fertile, can always seed itself into a vast population in fairly short order.
The Swann Park project's "decline" might be an anomalous blip; one needs at least five years of post-project data to even start to prove much of anything. That is, if the project data advanced and declined but showed a consistent overall improvement in diversity and frequency (I'm unimpressed with "cover") over time, I would consider that a successful project. If, on the other hand, one worked for ten years, then immediately took a picture, I would be less impressed--but hopeful, mind you, that the project, being so wonderful at that time, to get better over time. What matters most is that a functioning, self-sufficient, permanent ecosystem has been the result. Continued "maintenance" is perhaps good gardening, but it is still gardening.
In some habitats (e.g. forest) alien invasives are not so persistent or even present in the first place, and often will succumb to recolonization by indigenous species. California's Mediterranean ecosystems are often plagued by many species of non-indigenous species that seem to be persistent, but a lot of factors come into play. I have seen what I thought were 100 percent alien grasses and forbs that, upon doing a Dremann-type transect proved to contain stands of re-colonizing indigenous species. A lot depends upon the state of the soil. Grassland soils are rather easy for grassland establishment, but chaparral soils are more suited to chaparral--and particular kinds of chaparral at that.
I'm all for Dremann's goals, and if I thought 100 percent removal of all alien species from places where they amounted to dominant infestations was feasible, I would be all for it. But at the moment (and for the last fifty years or so), I prefer a one-time restoration project with zero weeding, irrigation, and maintenance (talk about outlandish claims, eh?), and with "management" consisting primarily of observation (which might lead to some selective planting after the five-year mark in most cases) and surveys by independent, unbiased researchers only to chart the trends. The "end" result should be a dynamically-stable, self-sufficient ecosystem in which indigenous species are clearly dominant, with alien species clearly limited to disturbed niches for the most part. This approach is practical and cheap and provides habitat for the complex species associations that normally occupy such sites. I am always ready to change my mind, however, and look forward to critical remarks and a continued discussion of ecosystem restoration and management objectives and actual performance.
I would not spend a dime on weeding. If the restoration project is properly designed and carried out, there is no need for it. And, while certainly desirable, 99.99 percent weed-free is not a condition that can continue to be met without continued weeding in a wildland full of alien propagules being vectored by every breath of wind and furry or hairy or plumed defecating plant-eating trespasser.
WT
----- Original Message -----
From: Marc Imlay
To: apwg at lists.plantconservation.org
Sent: Thursday, August 11, 2011 4:10 PM
Subject: Re: [APWG] Native grassland and forest understory weedings needtobe at least 99%
I can believe 99% for just 14 acres in a full 10 years of removal. We have an area of Swann park in Maryland that was 99% cleared about 5 years ago. It is now only 95% cleared because we got involved with other sites and no longer do a perfect job.
Marc
-----Original Message-----
From: apwg-bounces at lists.plantconservation.org [mailto:apwg-bounces at lists.plantconservation.org] On Behalf Of Wayne Tyson
Sent: Wednesday, August 10, 2011 9:31 PM
To: apwg at lists.plantconservation.org
Subject: Re: [APWG] Native grassland and forest understory weedings need tobe at least 99%
APWG:
Dremann keeps making this 99.99% claim. I, for one, doubt it. I would like to have that doubt removed, but that would take more information than I have noticed in his previous posts or this one. Successes of this magnitude and quality should be published in a peer-reviewed journal.
WT
----- Original Message -----
From: "Craig Dremann - Redwood City Seed Company" <Craig at astreet.com>
To: <apwg at lists.plantconservation.org>
Sent: Wednesday, August 10, 2011 11:25 AM
Subject: [APWG] Native grassland and forest understory weedings need to be
at least 99%
> Dear All,
>
> I just visited Mark Vande Pol's home in the Santa Cruz Mtns., above the
> city of Santa Cruz, where he has produced by weeding 14 grassland and
> forest acres that are 99.99% pure native plant cover, single handedly, in
> only 10 years.
>
> He view is, if your weeding efforts in native grassland and forest
> understory areas are not producing 99% native plant cover, you are wasting
> your time.
>
> I am suggesting to all of our local public agencies within our county,
> that each agency tries to achieve at least an acre of 99% native cover
> grasslands, within the next 12 months.
>
> In California, native grasslands are where a lot of our endangered species
> of butterflies are trying to survive and we need to improve their habitats
> so they can survive and recover.
>
> Sincerely, Craig Dremann, Redwood City, CA (650) 325-7333
>
>
>
>
>
>
>
>
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