January 11, 2015
A typical Oak Savannah on Windward's property.
Oregon White Oak, Garry Oak (Quercus garryana)
Garry Oaks are one of the three over-story trees in Windward's native forests. Depending on the soil and moisture conditions, they can be found growing in a variety of densities, from a open structured Savannah, to dense thickets.
Garry Oaks form single species stands in areas of shallow soil where bedrock is near to the surface. In these conditions moisture from snow melt fills the soil profile and pools in depression, making it uninhabitable by the Ponderosa Pine and Douglas fir.
Oak clump ~60-80 years old.
Garry oaks in Windward's cold arid conditions are very slow growing. Growth ring counts from Oaks of similar diameter (6-8 inches) as those shown in the image above turned out to be ~60-80 years old. That means roughly an inch of diameter growth per decade.
Garry Oaks naturally coppice,and are adapted to re-sprout from root crown buds after top death of the main trunk(s).
The Oaks have a thick bark which protects them from light fires, but due experience top death during severe (high temperature, long duration) fires, or when fires climb into the canopy. Garry Oaks also experience top death due to other causes such as severe ice storm damage.
To our knowledge, Windward's acreage was logged approximately 80 years ago. We suspect that the small diameter clumps of oaks which are most prevalent in in the forest is the re-sprouting of the Garry oaks after that systematic disturbance. You can see the typical clumping of 2-5 trunks from a single root mass.
A coppiced oak wherein the right trunk has died and is re-sprouting, and the left side is still alive. These are the same tree.
A fairy-ring of trunks which sprouted from the roots of a very large tree which once stood in the center of the stand.
Stewarding Native Garry Oaks as Coppice and Pollard
In 2009-2010 we undertook the thinning and limbing of the conifers and oaks on 20 acres of the property. The management practices we follows were taken from the local Department of Natural Resources forester. They included two basic practices and objectives:
- Thinning of trees to 10ft between drip lines to improve timber stand health by decreasing competition for scarce water resources for healthy well formed mature trees,
- Limbing all remaining trees to 20ft to reduce ladder fuels in the event of a forest fire. The "natural" (i.e. pre-pioneer logging) forest stand featured mixed aged trees of forming a more open woodland of somewhere between 50-70% canopy cover.
The forestry practices are more of less intended to return the forest to this state. It just so happens that these specifications also create a reasonably good condition for the re-growth of the Oaks.
Dormant cuts were made in mid-late winter, and we have been monitoring the regrowth of the oaks in the intervening years.
Oaks cut in the winter of 2009-2010. This oak has been regrowing in a, ~50 percent shade canopy gap, receiving little to no morning or afternoon light, but getting a few hours of full sun in the afternoon. This has resulted in relatively slow re-growth.
Oak cut just 12 months ago in January 2014. This Oak has received significantly more light and water (it is literally inside of a swale that is under construction).
You can see the density and length of the growth in one season has nearly matched the growth of the more shade grown oak coppice that is several years older. This provide evidence for the more-or-less obvious reality that light dramatically effects re-growth performance.
A close up on the root crown sprouts from the Oak in the image above.
We also cut some oaks as a pollard to see how they would respond.
Oak pollarded in January 2011.
Oaks pollarded in January 2014 which did not sprout from the trunk at all this year.
While we have a lot more to understand about the effects of pollarding on the Oaks, we have had mixed results.
Some oaks sprout from the base and well as from latent buds on the trunk. Some oaks sprout only from the base, and others only from buds on the trunk. We have endeavored to cut the oaks in the same time frame each year to minimize the variables in the tree. Despite this, the appear to respond in an unpredictable manner.
One final side note: The Oaks do not form long whips of young growth like other coppice species. They tend to form rather scraggly looking bushes for many years (maybe 10-15) before dominant leaders begin growing more vertically. As the top growth fills out, it shades and retards the bottom growth. Eventually the bottom growth dies. It may be that naturally fire would kill the bottom growth more quickly.
Coppice and Pollard in Silvopasture and Living-Fences
Black Locust (Robinia Psuedoacacia) and Honey Locust (Gleditsia triacanthos)
We are in the process of mass propagating Honey and Black Locusts from seed to select for genetics that are most adapted to our conditions.
The seeds have been gathered from diverse sources throughout our County. They are being planted/seeded at 6 feet intervals along keyline or contour depending on relation to the swale. (Those along the swale on contour, below and above the swale on keyline).
Newly planted locusts along the uphill side of the freshly cut swale.
The seedlings are being left alone to live or die in the field. This way, we are ensuring the hardiest genetics make it through. In the first year we experienced about 15% survival rate of both the honey and black locusts.
Black locust seedling, less than one year old at the tail end of the summer drought before the first fall rains in mid October this year. This little guy made it through the harsh summer sun.
Naturally, as the seedlings die gaps will form sporadically in the plantings enabling more planting each year until the system is more or less filled out.
In this process a more diverse management system and species composition with arise. Similar to the "coppice with standards" systems of Europe we intend to integrate several management practices simultaneously into the swale-lining tree rows as well as in the keyline tree, including:
- 1. Long term single-boled trees to provide nectar, mast and shade. Placed at intervals throughout the system.
- 2. Long term single-boled trees, limbed up as they develop, with the intention to provide quality sawn timber logs in 50-60 years and beyond.
- 3. Medium term rotation coppice for fence post and pole wood. (creating patch disturbances which we can utilize to grow more light demanding short rotation forage species species.
- 4. Short term rotation pollard to provide cut forage to the animals in the system.
Diagrams of the evolution of the Silvopasture System
Specifically, along the swale from the pioneer plantings into a more mature silvopature/coppice-with-standards/contour-food-forest type system.
Diagram of how the inital pioneer planting is being implemented.
Diagram of how the mature system will, hopefully, be structured.
Upland Willow, Scouler Willow (Salix scouleriana)
Native to most of western North America , Scouler willow is a relatively drought tolerant tall shrub. In our area it grows in the light filled Ponderosa Pine / Oregon White Oak /Douglas Fir forests, usually after substantial forest fire of heavy logging. In our dry conditions the tall shrubs topping out at ~25ft but in moister regions is documented at 35ft.
Like most Salix spp. it is easy to propagate from live stake cuttings. It the primary species we are working with to establish multi-functional hedgerows/living fences as part of this silvopasture system, as well as throughout the rest of the property.
Live stake cutting made in winter 2013, at the end of it's first dry-season in mid October 2014.
Scouler willow has a good natural growth form for coppicing, producing long, nearly branchless stems even without coppicing.
Trunks reach their maximum height in 3-5 years (faster in full sun) and tend to grow to about 3-4 inches in diameter within the first 10 years. This fast growth (for our dryland forests) makes them a good candidate for fuelwood, replacing the non-coppicing ponderosa pines.
Scouler willow is also a significant source of food for deer and elk in the winter months (bark and buds) and we are having good success with it as a source of cut forage for our sheep and goats.
It promises to be a reasonably good source of additional drymatter forage in the "summer slump”", especially when paired with higher protein legumes. We also anticipate it being a decent cut storage fodder, as the leaves tend to stay well attached to the stems.
Other Species planned for experimentation in the silvopasture and living fences.
As the system develops, other trees will be incorporated into the system for similar purposes as shade and forage trees, as well as producing wood products.
Species we are either already looking at currently are:
- White Mulberry (Morus alba) - cut forage, mid-late summer nectary
- Douglas Maple (Acer glabrum var. douglasii) - for foliage, furniture wood, early spring nectary, potentially long term timber. Appears to easily coppice and pollard.
- Grey Alder (A. incana subsp. tenuifolia) - foliage, N fixation, fire wood, smoking wood.
- Blue Elderberry (Sambucus Cerulea) - native dryland elder, mid-summer nectary, medicinal berry.
- Quaking Aspen (Populus tremuloides) - cut forage, firewood.
- Osage Orange (Maclura_pomifera) - hedging plant, early summer nectary, wood suitable for posts, outdoor furniture and tool handles.
- Korean Nut pine (Pinus koreanensis) - tall windbreak elements in certain hedgerows, and long term nut yield.
- Pea Shrubs (Caragana spp.) - hedging plant, N. fixation, spring nectary, some potential as cut forage.
- Sea-Buckthorn (Hippophae rhamnoides) - hedging plant, N. fixation, spring nectary, berry.
- Goumi (Elaeagnus ). - hedging plant, N. fixation, spring nectary, berry, potential cut forage
Diagram of potential living fence/windbreak planting configuration.
Some Other Notes:
The silvopasture already has some re-growth of Ponderosa pine and we have several uses for them in the system. Pines that are close to keyline plantings will be left to provide shade and wind buffering in the system.
There are also some dense thickets of re-growth which are going to be left as a form of "natural barn" for animals to take shelter in during inclimate weather. These areas are up on the high-ground where the keyline plowing will not effectively under-irrigate. Hence the native conifers stand the best chance of growing well.The planting pattern is planned similarly to the New Forest Farm system, trees planted on keyline with alleyways between. We're looking to keep ~20ft alleyways between rows of trees to enable our 8ft seed drill to make a double pass, and also to incorporate keyline plowing into the system.
The large roadway/swale running through the center diverts a seasonal creek across the landscape to irrigate the ex-closure forage and productive trees such as cider apples and mulberry which we anticipate will be most productive with the greatest potential soil moisture.
More information on this system and it's development is recorded in an article I wrote in Spring 2014 available at this web address:http://windward.org/2.0/notes/2014/2014andrew06.htm
Other Coppice Species We're Working With
Choke Cherry (Prunus virginiana)
Choke Cherry is a mid-succession light loving small tree adapted to fire disturbance - sprouting from the root crown after top death. Choke cherry coppices readily when cut, and also sends out root suckers outside of the drip line of the main tree.
A mature choke cherry with a multitude of suckers, amidst deerbrush, hazel, oak, pine, rose and raspberry regrowth. This area was leveled about 15 years after a severe forest fire, and the subsequent natural pattern of succession is typical for similar forest in the region. Our silvopasture and living fence systems are being designed to mimic this resource partitioning regrowth community.
We are just starting to work with Prunus virginiana as a coppice species in living fences, particularly to keep out deer. Since the foliage is quite toxic in the height of summer, we are not planning on incorporating it into living fences within livestock systems.
Another experimental use we are exploring is the utilization of choke cherry as a site-adapted root stock for grafting cultivated varieties of cherries and plums. We have cut a few native specimens back and are allowing the sprouts to grow to a suitable size for grafting. We anticipate making our first grafts this upcoming spring.
I anticipate the young shoots to be suitable for larger basketry projects. Other uses we have found for the wood include smoking (early spring cut wood imparts a sweet and tangy flavor to meat), and furniture and handle wood species (dense wood and straight growth).
Deerbrush (Ceanothus integerrimus)
A medium sized, nitrogen fixing, pyrophylus bush. Coppices readily from root buds. Produces long straight whips, shorter than willow, but of a similar quality. Generally thinner than willow, but more numerous. Very tolerant of drought and fire.
Cutting back in late fall and early winter results in a flush of whips which, when cut green in late summer, are long, flexible and good for basketry. If left to grow for more than one year, they send out branches from the whips making them less suitable for basketry.
Deerbrush cut in December 2012 and the 2nd year of regrowth.
Deerbrush is a an excellent forage crop for browsers, with a hi protein, calcium and potassium content in the leaves. Like many fire dependent species, it accumulates potassium which is readily available in ash resulting from fires.
The Whips are also easily harvested for forage in late fall before the leaves drop, and can be stored overwinter.
Beaked Hazel (Corylus cornuta)
A native shrub form hazel to the northwest. Like most hazels, it coppices readily and grows as a multi-stemmed shrub. Wood is suitable for furniture and some forms of natural building such as wattle and daub.
Beaked hazel produces small, thick shelled nuts and are less prolific than cultivated forms. However, wide tolerance to our native conditions make it a useful hazel for use on site where nut production is not the primary goal – such as in living fences, fuel and craft wood coppice, and as a cut forage for livestock.
We have not yet begun managing any of our native hazels yet, but are planning on encorporated it into many of our systems as they develop further.