Six miles from my home is a 1,000 acre wildlife refuge that is slowly being converted from its previous use (row crops &
dairy farming) to wildlife habitat. It is situated along the Columbia river in SW Washington state (the area south of the highway:
http://www.google.com/maps?hl=en&q=&ie=UTF8&t=h&om=1&ll=45.563403,-122.294912&spn=0.048013,0.08523&z=14). It has some decent sized wetlands and open
water, but the majority of the
land is open fields. Some of these fields have become dominated by an aggressive non-native grass called reed canarygrass. There are also patches of the ever-present Himalayan blackberry, canada thistle, etc. here and there. The agency managing the refuge battles the blackberries through mowing, spraying, etc. They do not do anything with the canarygrass. They are fairly "old school" in their management, i.e. if it is invasive and you want to get rid of it, some combination of mowing and herbicide is
the answer. They also work with a cooperator to
hay most of the fields in the summer, so that there are tender grass shoots in the winter for geese to eat. In the past they have worked with a cooperator to have cows graze the fields (vs. mowing) however maintaining fencing is not high on the agency's priority list and is counter to "habitat restoration" so the cooperator got nervous after some of his cows wandered off the refuge near the highway.
In total there are about 300 acres that will be planted with
native shrubs and
trees, mostly using volunteers (which instills a sense of ownership of the refuge in the
local community). I lead many of these
volunteer plantings, and I am involved with the planning of restoration projects (as a volunteer). There is only 1 agency staff member for this and two other nearby refuges so most of the work is done by volunteers. There is another agency office 25 miles away which provides some consulting (e.g. a biologist) and management.
The general approach we have been taking with the planting projects is:
1. Consult the
Conservation Plan to see what type of habitat is planned for the area in question.
2. Inspect the site, note what is growing there, what is the soil like, terrain, etc.
3. Work together with the biologist and others to come up with a list of plants to plant at that site. This includes everything from grasses all the way up to large trees. All species must be native to the site and must conform to the Conservation Plan. No exceptions.
4. Decide what to do about the existing vegetation. It is unusual to have many native species present, so the usual decision is to mow, then spray (sometimes more than once), and perhaps disk the site.
5. If the site has been disked, we plant native grass seed in the fall.
6. Once the grass begins to grow, we bring out volunteers to plant native shrubs & trees from 1 & 2 gallon pots. We usually plant in rows spaced 10' apart so that the area can be mowed. Once the plants get large
enough to compete with the grass, we stop mowing and fill in between the rows. We plant between November and April when the weather is cool and wet. Note that we do not disk every site, so sometimes we are planting in dead grass. We place a protective planting tube around each plant which is removed once the plant reaches the top of the tube. A typical
project uses somewhere between 300 and 6000 potted plants.
7. On some projects we have set up a temporary water line and done hand watering for the first 2 summers, but we have decided that is too much work. Also we did not realize that our temporary water line (white PVC) was not UV-resistant and after the 4th year it has begun to break down.
8. The agency mows between the rows to reduce competition from the grass, blackberry, thistle, etc. We have found that the canarygrass returns in a year or two, even after being sprayed. If you are not familiar with reed canarygrass, it grows to about 6 feet tall and thus shades out shorter plants.
Overall this is working fairly well, but many of the plants are growing slower than expected, and the survival rate is not as high as we would like. We (including the biologists) have studied the situation and the primary causes (of mortality and sluggish growth) suggested are:
-
deer browsing
- insufficient water due to competition from canarygrass
- mole activity around the plant
roots, allowing the roots to dry out
-
voles girdling the plants near the ground (which personally I disagree with)
I would like to apply some
permaculture principles here. Has anyone done any projects like this?
Most of the people involved have heard the term
permaculture, but none of us have put it into practice, though I am doing so in my backyard. It is a completely foreign concept to the refuge manager, and fairly foreign to the biologist (though I'm working on that
). It is a bit more familiar to me and my fellow volunteers, though I am by far the most knowledgeable, i.e. I have attended
Toby Hemenway's 1-day
class, and have his book "Gaia's Garden" (and I hang out on this forum
).
I have found a supportive tree care service who will deliver
wood chips to the refuge for free. I have spearheaded some mulching projects (i.e. put 2" of wood chips around the outside of the planting tube) to see if that slows the growth of the grass and also hold some moisture. However the biologist (who is fairly new) has decided that "mulch attracts voles which are chewing the bark of the plants, so we
should not mulch". In reality there are few plants with bark damage, and there are already many voles living on the sites, mulch or no mulch.
We still have hundreds of acres to plant, so we need to figure out some best practices that can be done by volunteers and which are not too demanding in terms of labor and money.
I am going to propose that we design some experimental plots into our next project, and have posted my brainstorm list below.
Finally, my question:
Using permaculture principles, can you think of any other experiments that I should include in the list below? Thanks for any insights or suggestions you may have!
Here are the experiments I was thinking of. I would only do this on plants that we expect to thrive in a certain location but have not been thriving. No need to do it for plants that are doing well or that are obviously not in their element (and which should never have been planted there). The "control" for each would be to do the opposite.
1. Mowing grass around plants. I am fairly certain that mowing is attracting deer to the site. It may be slowing the growth of the canarygrass somewhat. And it was certainly helpful when we were watering.
2. Spraying grass around plants. The big disadvantage of this is if the shrub has sent up any suckers and the suckers get sprayed, you have killed the plant.
3. Mulching:
3.1. Sheet (i.e. wetted newspaper with a layer of mulch on top. The mulch could be hay which was cut on the site)
3.2. Straw:
3.2.1. loose
3.2.2. mat ("flakes" from a bale)
3.3. Wood chips:
3.3.1. fresh
3.3.2. aged
4. Hugelkultur:
4.1. Place decomposing wood chips in bottom of hole
4.2. Place decomposing log/branch vertically in hole next to plant
5. Protective tubes:
5.1. solid vs. mesh
5.2. various colors (blue seems to be in vogue)
5.3. various diameters
5.4. various lengths:
5.4.1. 1 foot
5.4.2. 2 foot
6. Companion planting. In nature, it is very rare for a native shrub to sprout up in the middle of a grassy field all by itself. The idea is to plant not just the shrub, but some companion plants as well. These could be in the same pot (e.g. via seed), in seed balls dropped around the shrub when it is planted, or in potted plants planted very near the shrub.
6.1. Permanent:
6.1.1. Perennial forbs that encourage the growth of the shrub and/or discourage the growth of canarygrass by growing aggressively, fixing nitrogen, accumulating nutrients, etc. Examples are vetches, flowering bulbs, yarrow, clovers.
6.2. Temporary:
6.2.1. Annuals that encourage the growth of the shrub and/or discourage the growth of canarygrass by growing aggressively, fixing nitrogen, accumulating nutrients, etc., and which do not aggressively reseed. Examples are (TBD)
6.2.2. Fast-growing trees that encourage the growth of the shrub and/or discourage the growth of canarygrass, and which are easily killed after they have served their purpose (e.g. by girdling or cutting). Examples are alder, cottonwood, fir? The shrub could be encouraged and the grass discouraged by cutting off the branches only on the shrub side of the tree. Other habitat restorers do this sort of thing by interplanting with firs which are then girdled, but the refuge manager has resisted planting firs thus far. This would also probably protect the shrub from deer damage since they would browse/scrape the tree instead of the shrub.
Some photos:
Volunteers doing a plant survival survey (this is the same site as the photo above, in September). The tall grass is reed canarygrass, about half its mature size.
The same site, in January 2009, removing planting tubes. The grass had been mowed in the summer.
Volunteers planting at another site.
Watering in August.
Planting in November 2006.
"You planted these for me, right?"
January of this year. We planted this site in the winter of 2006/2007 but many of the shrubs are still pretty stunted & scrawny.
Typical wildlife (Great Blue Heron, Cackling Geese)
Looking out from a remnant Quercus garryana (Oregon White Oak AKA Garry Oak) stand into a recent planting of more Oregon White Oak. We have learned that the best way to plant these is to just plant the acorns. We planted the grass in the foreground which is native, of course - though the refuge manager forgot to see how tall it got - it shaded all the wildflowers we planted. The area under the oaks was originally solid blackberries 10 feet thick.
The same oak stand, showing the planted grass & shrubs.
Quercus garryana, looking good.
Pacific chorus frog. These guys love the planting tubes. So do paper wasps.
We plant wildflowers too.
Awesome scenery from the refuge - Mt. Hood & Crown Point in Oregon.
Looking up the Columbia gorge from the refuge during a March rain storm.