[APWG] Performance standards to get weed-free and 100% native

[Craig Dremann - Redwood City Seed Company]

Dear Wayne and All,

I want to start my reply, to wax poetically about how nice walking through
a restored, a weed-free North American native ecosystem can be.

It is like visiting the Promised Land, a fairy tale land that people talk
about at annual wildland weed meetings--what would an area look like, that
they have been weeding for years or decades, if it was not only weed free,
but was 100% covered with the original pre-Columbian native ecosystem
understory?

The Shaw property is like a flawless 74-acre diamond, currently set in an
unending ocean of almost a 100% solid exotic understory of over 1,000
species of weeds, going 250 miles to the North, 200 miles to the East and
600 miles to the South, to the Mexican border.

===============

Wayne wrote:
Mowing before seed-set is a reasonably good practice in some contexts, it
may not always be practical (e.g., 2:1 slopes, etc.).

Reply:  99% of lower elevation California is gentle slopes to fairly flat,
so the level to gently sloping wildlands should be converted first, while
there are still viable native seeds in the soil seedbank.

If the native seeds in the soil seed bank are already 35-100 years old, my
big concern is we will not get started in this conversion back to 100%
native cover process, in time to take advantage of the viable native seeds
that are lying dormant underneath the exotics, before they lose their
viability.

The clock is ticking for these native seeds lying dormant in the soil
seedbanks, waiting for us to pay attention to them within our and their
lifetimes, otherwise their lives will be lost forever.

===============

Wayne wrote:  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.

Reply:  Mowing absolutely must to get the standing crop of weed seeds
before they ripen, for that year, and contrary to popular belief, you do
not have to be concerned about the dormant weed seeds in the soil.

What has been happening over the last decades or hundred years, is that
the percentage cover of the weeds tipped the balance, where the weed
densities were able to use allelopathic chemicals to suppress the
germination of the dormant native seeds in the soil.

See Journal of Chemical Ecology, especially Dr. Liu’s 1994 and 1995 papers
on a method to study plant-produced allelopathic chemicals  as an
independent plant suppression system, separate from competition for water,
nutrients, sunlight, etc..

Where the concern should be focused, instead of the weed seed bank, is
managing and resurrecting the native seeds in the soil seedbank, and once
you cross a percentage native cover threshold, the natives will start
permanently suppressing the weeds still viable in the soil.

Those weed seeds will remain alive underneath the natives for a long, long
time, but once you get the right densities or the right local natives in
place, the natives will suppress the weed seeds from every germinating
again, the weed seeds will eventually die in the soil.  Weeds Rest in
Peace.

=================

Wayne wrote:

Then there's the issue of the thatch/chaff, post-mowing regrowth, and
other specifics that raise questions.

Reply:  Thatch is not a problem. Fortunately most of the weeds that cover
California are annuals, but for the perennials that might regrow,  is
where a little brushing of the cut surfaces with Roundup might be
necessary, like Pampas grass, Harding grass, etc.

=================

Wayne wrote:

Not only that, but the vital importance that such treated sites must
self-sustain rather than be continuously treated for eternity.

Reply: That is why for the Performance Standards that I am recommending
for restoration of California perennial native grassland habitats, on my
web page at http://www.ecoseeds.com/standards.html is that you need to
make the conversion from exotic cover, back to at least 95% native cover,
within 90 days or less, with no future maintenance.

If you have to weed after the 90th day, you need to do your small scale
test plots over, until you get the right native cover that stops the weeds
cold.  It is like a poker game, you have to lay down your Royal Flush of
local natives, to beat the local weeds.  You do not want to have to keep
playing hand after hand of weeding-poker to eternity.

The only maintenance that might have to be done after the 90th day, is to
add more local native species to increase the diversity, and to fill in
gaps where native plant understory families have been catastrophically
exterminated, like California and the West.

Sincerely,  Craig Dremann (650) 325-7333