Wednesday, November 11, 2009
For the acorn flour I used bur oak acorns we collected locally and kept fridged (most of them I plan to plan and grow next spring). I cracked the acorns and extracted the nut fruit last night. Yes, it took a while. This is Minnesota and "bur oak acorns" means 1) tiny nut, 2) thick shell, 3) not a lot of nut meat. It would be a different story with the Titleist size acorns down South.
At this point most environmentalists/urban homesteaders would lie and say that the process of cracking the acorns is "meditative" or "contemplative." Both are euphemisms for "mind-numbingly dull." But I got it done.
This morning I ground the nut meat to the approximate consistency of corn meal. I spread it on a cookie sheet and put it in a warm oven to dry - about 1 hour or so. It was by no means bone dry in that time, but more importantly: I was hungry! I used a coffee grinder to further grind the meal to a fine flour.
Here's the recipe:
1/2 cup butter (always a good start)
1/2 cup real maple syrup
1/2 tsp vanilla extract
1/4 tsp almod extract
1/2 cup acorn flour
1-1/2 cup all purpose flour
1 tsp baking powder
Melt the butter, combine with syrup (at this point I discovered that melted butter + syrup = yummy. Who knew?) Add the rest of the wet ingredients. Mix dry ingredients separately. Add dry to wet, mix.
The dough was looking a little wet & sticky at that point (possibly because I didn't get the acorn flour completely dry) so I ad-libbed another tablespoon of flour.
350 degree oven for 15 minutes. (A trademark feature of a Chris Siems recipe is telling you the pre-heat info in the last line.)
After a suitable level of shock was expressed that, "Papa actually baked something without burning down the kitchen," the verdict was unanimous: Awesome. Loved by one and all - Alice, Katrina & Ethan. The shock was genuine. I once mistakenly used baking soda instead of baking powder to make pancakes (Katrina's birthday pancakes no less). They had that metallic flavor that is highly prized by... no one I can possibly imagine.
Excuse me - I need to go grab another cookie.
I took advantage of a nice evening yesterday to sit outside and crack some acorns in anticipation of doing some baking. (Those of you who know me therefore know the absurdity of that last sentence - you can stop laughing now; I'm serious enough about the importance of RE-learning how to eat acorns that I'm willing to undergo the torture of spending time in the kitchen to show how easy, good and healthy it is!). Here are my tools of the trade. The rustier the better, that's my motto. I found that the needle nosed pliers didn't work. By the time it cracked the hull it damaged the nut fruit. The standard pliers was better. In the end I reverted to the most time-tested acorn-cracking tool of them all: my teeth.
Monday, November 2, 2009
Frequent hybridisation among oaks has consequences for oak populations around the world; most notably, hybridization has produced large populations of hybrids with copious amounts of introgression, and the evolution of new species. Frequent hybridisation and high levels of introgression have caused different species in the same populations to share up to 50% of their genetic information. The high rates of hybridisation and introgression, produces genetic data that often does not differentiate between two clearly morphologically distinct species, but instead differentiates populations. Numerous hypotheses have been proposed to explain how oak species are able to remain morphologically and ecologically distinct with such high levels of gene flow, but the problem is still largely a mystery to botanists.
The Fagaceae, or oak family, is a very slowly evolving clade compared to other angiosperms, and the hybridisation patterns in Quercus pose a great challenge to the concept of a species. A species is often defined as a group of “actually or potentially interbreeding populations which are reproductively isolated from other such groups.” By this definition, many species of Quercus would be lumped together according to their geographic and ecological habitat, despite clear distinctions in morphology and, to a large extent, genetic data. Thus, although it may be difficult to place a definition on a species within a genus like Quercus, it is trivial and uninformative to apply the biological species concept to all forms of life.
The natural tendency of oaks to hybridize (and the ease with which artificial hybridization can be achieved) is probably - no, is without question - the most underexploited area of plant improvement in the world. If oaks had received 1/1,000,000th the attention from plant breeders that corn and wheat have received we'd have oak trees capable of growing 6ft per year and producing acorns in year 3. And I'm not joking.
I came across this cool story in an old article. H. Ness of the Texas Experiment Station (a man who loved his given name so much that he always went by the initial H; I'm guessing Herman) wrote an article for the Journal of Heredity in 1927 entitled "Possibilities of Hybrid Oaks: Further Observations on Hybrid Oaks at College Station, Texas." Ness wrote that the Texas A&M campus in Brazos Cty TX was situated in an area with very little forest species diversity. post oak (Q. minor), black-jack oak (Q. marilandica) and water oak (Q. nigra) in the river bottoms. (Of course in northern Minnesota that level of oak diversity looks positively rainforest-like!)
In 1891 a few live oak (Q. virginiana) trees were planted on campus. More live oaks were subsequently planted on campus, all of them descendents of the first ones. Many of these young trees were planted at great distances from the nearest live oaks, and in places where wind direction and obstructions from buildings etc, "greatly reduce the chances of any pollen reaching them from the trees of the first planting." Live oak trees produce female flowers at about 5 years of age, but do not product male flowers until several years later.
According to my old friend "Herman" Ness: "Yet, the female flowers on these young trees, apparently beyond the reach of pollen from their own species, fail but rarely to produce an ample crop of well developed acorns." So... only female flowers, no live oak pollen. How then are the female flowers fertilized? Well, let's just say that the offspring look suspiciously like post oaks (insert your own "mail man" joke here). More accurately, the offspring display a range - a continuum - of characteristics from (nearly) pure live oak to (nearly) pure post oak, and everything in between.
Hybrid oaks - the offspring of these natural of artifical inter "species" fertilization - often exhibit faster growth and earlier maturity than either of the parent species.
Oaks definitely challenge our conception of species. It's more of a continuum with millons of variations and tremendous genetic elasticity. And within that elasticity lies the potential to feed the world. This will be the focus of future "Oaks: One Species?" posts.
Wednesday, September 30, 2009
Steve Kunde was a pioneer in the area of oak wilt prevention and eradication. He was also, and I'll never forget this, an early supporter of a little non-profit organization called Lasting Woodlands that I started as an urban forestry student back in 1988. A few years ago Kunde Company was acquired by S&S Tree Specialists, but remained essentially intact. I saw Steve about 18 months ago and he was really happy about the arrangement, which allows him to focus on the forestry side of things while the larger S&S organization can handle more of the business matters.
Glen Olson is a highly experienced forester with Kunde Consultants. Rather than driving 45 minutes south to Northfield to visit the site in person he brilliantly saved time & gas... and visited the site via satellite. Glen called say he was looking at my neighbor's home via an aerial image on Google Maps. He could see the line of oaks, and the location of the various walkways, sidewalks and driveways that I have always worried would make trenching to sever root grafts difficult if not impossible. He could tell from the imagery which trees were oaks and which were not. Amazing.
The bad news: Trenching is impossible.
The good news: The adjacent trees can be injected with fungicide to prevent infection. This will need to be done now and again in 2 years. The fungicide is called Propiconazole.
I was happy to provide some "ground truth" (as we say in the remote imaging game) by taking diameter measurements of the trees so that Glen could complete his quote quickly.
The 2 threatened oaks immediately to the north of the infected tree are 28 and 27 inches in diameter. The 2 oaks to the south are even bigger - 29 and 31 inches.
But of course the tree that died was the biggest of the group: 35.5 inches in diameter - 111.5 inches in circumference!
It's been a weird summer... arriving home from work in May 22 to learn that some hacks had pruned my neighbor's red oak trees smack dab in the middle of the danger zone for oak wilt spread... watching those trees all summer, first hoping against hope that they'd be all right, and then hoping against hope that the die back I was seeing was caused by something else, something less deadly... getting the diagnosis of oak wilt... then reconnecting with a great company like Kunde Consultants to do things right and protect the surrounding trees.
Every time I get discouraged that there are guys out there calling themselves tree care professionals who are wantonly (or accidentally through ignorance, which is just as bad) harming trees, I remember that there are people like Steve Kunde and Glen Olson out there who are committed to doing things right. And, who now have technology available to them that allows them to "visit" a site 35 miles away in a matter of minutes so they can do their important work even more efficiently and effectively.
While Cannon River Tree Care doesn't have the equipment required to take on this project, I came away really, really impressed with John's knowledge and integrity. Like me he was appalled that a so-called tree care company would prune those gorgeous red oaks in May, and was sick about the consequences.
If you live in the Northfield / Rice County, MN area I highly recommend Cannon River Tree Care. We're lucky to have such a high-quality tree care company here in the area.
Now comes the task of protecting the adjacent trees from the fungus. Now that one tree got infected via the inefficient means of a picnic beetle carrying fungal spores from a diseased tree to the May 22 pruning wounds made on this tree, oak wilt now becomes a much deadlier threat, spreading at an approximate rate of 30 feet per year through the roots from one tree to the next.
Oak wilt transmission overland via the picnic beetle is a question of "if." Transmission via the root systems is a matter of "when." Oak trees form root grafts with nearby oaks of the same species - northern red oak to northern red oak, bur oak to bur oak, etc. Whether this is an example of aboreal socialism which allows a stand of oaks to share water and nutrient resources, or is a Darwinian means by which stronger oaks draw upon the resources of weaker ones, I don't know.
What I do know is it makes a great highway by which systemic fungal infections can travel from one oak tree to the next... and the next... and the next.
But we have been hard at work getting the right people involved in preventing the spread of the fungus to adjacent trees, and these experts have more tools at their disposal than they did 20 years ago when I was first learning about and giving talks about oak wilt.
Monday, September 14, 2009
Well, it has happened, my fears are (nearly) confirmed. Remember, a soon-to-be named south Twin Cities metro tree "care" company pruned my neighbor's gorgeous red oak trees on May 22 - smack dab in the middle of oak wilt season. When they remained healthy throughout June and part of July, I was hopeful that we had dodged a bullet and that the trees had escaped infection. No such luck. Since showing the first signs of flagging & die back in July, the tree collapsed rapidly in August. Samples have been sent to the Plant Disease Clinic at the University of Minnesota for culture & diagnosis. Results are expected in 1-2 weeks, but the technician was convinced that it is indeed oak wilt, and a tree inspector from a Mpls suburb who was dropping off samples believes it is oak wilt.
So, in all likelihood, these guys killed my neighbor's tree. Actually, trees - since this red oak is part of a row of huge red oaks that spans 5 different front yards. Sidewalks, driveways, the street and buried electrical/cable/phone lines will make it very difficult to effectively trench to severe the root grafts between the trees and prevent the spread of the fungus from this diseased tree to its cohorts.
So we have the cost of removal and the cost of trenching to try to save the remaining trees. We'll be having a "chat" with this particular tree "care" company very soon. Stay tuned.
Tuesday, August 25, 2009
Monday, August 24, 2009
Balanophage is a term coined by restoration ecologist Dr. David Bainbridge meaning, literally, "acorn eater."
It is a term that could solve 99.3% of the world's problems (the exception being the Twins' starting pitching situation).
After gathering, cracking (or, more accurately, bribing my son to crack) and leeching (about 24 hours in water, changing the water every 4 hours or so, to leech out the tannins) bur oak acorns I have put them to use two ways. Yesterday, to the horror of my family, I sprinkled some crushed acorns into my blueberry pancake batter. Until my daughter demonstrated that it was possible, I never realized that the word "nasty" could have 4 syllables. They were delicious, and way more filling than regular pancakes. This morning I sprinkled some in my oatmeal. Just add the 1/4 cup of brown sugar (compressed with the approximate force of a auto crusher) I always need to make oatmeal edible and it was delicious... and kept me full, happy and productive all morning.
Another trip to the woods tonight to gather tomorrow's feast!
(Click on images to enlarge)
We're always told that if you plant an oak you can expect to wait 15 to 20 years before it begins to produce acorns. Somehow this little tree didn't get the memo!
On Friday I visited Knecht's Nursery here in Northfield, MN. Owner Leif Knecht showed me some young - very young, as in perhaps 2-3 years since grafting - hybrid oaks that are already bearing acorns! These trees are white oak / English oak crosses (Q. alba x robur). Notice the diameter of the trunk as compared to the size of the acorns and the diameter of the 5/8" bamboo support stake. Whenever somone mentions oaks as a potential human food or forage crop farmed on a commerical scale, the 15 to 20 year time lag is always mentioned - sometimes by the proponents of the idea themselves who reluctantly mention the time lag probably in an effort to prove that they are not complete head-in-the-clouds nut-jobs (luckily I have not such reservations!) - as a reason why the idea is not practical.
To which I say: Oh, really? True, the half dozen acorns on each of these trees hardly constitute a commerical crop, but given their early maturity and the fast growth we know oaks are capable of, is there any question that these trees will be pumping out significant volumes of acorns within a few years??
Tuesday, August 18, 2009
(Click on image to enlarge)
Barely 2 months after planting English oak (Q. robur) acorns - not seedlings, but acorns - in 1 gallon pots and protecting with 30 inch tree tubes... after the 3rd coldest year in Minnesota history... they are now just 2 inches away from emerging from 30 inch tubes.
Guarantee they will be 5ft to 6ft tall by the end of next summer. So much for slow growing!
Monday, August 10, 2009
This gorgeous bur oak is located just south of my town of Northfield, MN on the future site of a brand new KFC. (Memo to city planners: We need a new KFC like we need a hole in the head. What we need is some good PIZZA. But I digress...)
Click on the image to enlarge. A token effort has been made not to disturb the soil under the tree, but as you can see the heavy equipment has been driving and grading well inside the drip line, and cement culverts are busily compacting the soil.
Obviously somone thought about protecting this tree. How much better it would have been if they had put up a perimeter fence 10 feet outside the drip line. How much better it would have been if they had consulted a qualified arborist to draft a simple tree preservation plan.
Because we know how this story ends. The new KFC will be built, and the tree will look fine. For a while. Then next year or the year after it will start showing signs of stress or die back. Then, 3 to 5 years from now the tree will be dead and someone will spend hundreds - or thousands - of dollars removing it (certainly a helluva lot more than it would have cost to have an arborist draft a protection plan). An no one will make the connection between the damage that happened during construction - the soil compaction, the re-grading - with the tree's death a few year later.
I noticed some flagging about 3/4 of the way up the tree. Today I took this photo today from the middle of the street looking up (click to enlarge). I hope it's nothing but the die back sometimes common to mature oaks. I hope it's not the early warning signs of oak wilt. Red oaks usually succumb very quickly - within a matter of months or even weeks - while white oaks sometimes can survive longer before the fungus finally plugs all of the vascular tissue.
Please remember if a tree care "professional" ever offers to prune your oaks in April, May or June - don't let him anywhere near your trees, oaks or otherwise. He has no idea what he's doing.
Meanwhile, I'll keep crossing my fingers for this tree - especially because it's part of a row of at least eight mature red oaks that...
1. Have interlocking, grafted root systems that will spread oak will from tree to tree
2. Are too close together, and have too many impediments such as sidewalks, driveways and street in the way to allow for successful trenching with a vibratory plow to prevent the spread of the fungus from an infected tree to its neighbors.
Oaks play host to more creatures than nearly any other tree genus. Galls are made by wasps as a home and food source for larvae. They rarely harm the host oak, and a single mature oak is, by midsummer, host to several different types of gall wasp, each producing its own distinctive gall.
Inside each is a labyrinth of safety and all the food the wasp larva(e) needs.
Tuesday, August 4, 2009
So how many of those acorns does the jay find? About 1 in 4. That's a pretty amazing feat of memory on the part of the jay. They are highly skilled at using landmarks to find their caches. But it's an even better deal for the oaks! That means that 3 out of every 4 acorns buried by jays are not found, and while a significant portion of those will be found and eaten by various animals or succumb to infection or rot a much larger portion will germinate and grow (at least until the deer browse them).
What's more, jays make better oak planters than most humans. They don't plant acorns in the deep shade of the woods (where they would never thrive), because they'd also be very difficult to find again. They plant them along forest edges where the jays have landmarks to find them, and the new oaks get full sun but also get some shelter from the wind. They don't plant in compacted or wet soils, because they would be difficult to bury properly. In short, they plant oaks in exactly the places where they have the best chance to thrive.
William Bryant Logan says, "the fact is that the jays are the world's great cultivators of oak and a principal tool in the oak's spread and dominance."
Co-evolution is pretty cool.
Thursday, July 30, 2009
Now I know I definitely want to become a "balanoculturist" when I grow up!
Interestingly, David concluded that oak uplands in California, whose indiginous balanocultures thrived in great numbers, could support villages of one thousand people. Enough acorns could be harvested in 3 weeks to last 2 or 3 years.
This dovetails with William Bryant Logan's statement that "balanocultures were among the most stable and affluent cultures the human world has ever known." It was only as people moved down into the plains from the oak uplands of Europe, Asia, North Africa and North America and began cultivating grains that we actually had to start working hard for our food!
"In Germany and Switzerland, a law survived into the Middle Ages that required a young man contemplating matrimony to plant two young oak trees prior to the nuptials. By the time the couple's children were ready to marry, there would be two more fruit-bearing trees to help sustain them. But since the time from the planting to an oak's first fruiting is between fifteen and thirty years, the cultivation of oaks as a fruit tree has never been practicable."
What a cool law! It's cool that many of our traditions, like planting a tree to commemorate a marriage or the birth of the child, have their roots in both basic human need (planting trees as a future food source) and ancient law.
Here's where I would take issue with Mr. Logan: I don't believe that you have to wait 15 years to begin producing acorns. If 1/1,000,000,000th of the effort that went into breeding crops like corn and soybeans, or even tree crops like apples and almonds, had been spent on selecting and selectively breeding early and annual producing oak trees I believe we could have oaks that would reliably produce acorns at 5 years of age.
I also believe that with better planting and establishment methods we can dramatically compress the time from planting to the first significant acorn crop.
Friday, July 24, 2009
So, as a public service to those who are trying to kill oak trees but only doing a half-hearted job of it, here is a list of fool-proof ways to do away with the offending trees:
1. Prune an oak in April, May and June so as to make it susceptible to oak wilt. This isn't guaranteed to kill the tree - in many ways oak wilt is not a very efficient pathogen - but you get bonus points because if the tree does become infected it will likely infect neighboring oaks through interconnecting root systems.
2. Compact the soil in the root zone (which extends out past the longest branches) with heavy equipment (like your car). This reduces water infiltrations and squeezes the air spaces out of the soil, suffocating the roots.
3. Pile additional soil or fill over the root zone. Don't worry, it doesn't take much. In fact, it takes less fill than you think to prevent oak roots from getting the air and water they need.
4. Sever root systems (the closer to the tree - and therefore the higher the % of the root system lost - the better, but remember the root system extends out past the branches so you can trench pretty far from the tree and still do great harm).
And remember, kids: A combo platter of the above is even more effective. But be patient. You might have to wait months or even years to see the results of your handiwork. Oaks are tough old things. Don't worry, sooner or later your efforts will pay off with dead trees.
Balanophages: acorn eaters.
And if you come from European stock, chances are your acenstors were. Balanophages, that is.
From this awesome book by William Bryant Logan (about which much, much more to come...).
Wednesday, July 22, 2009
That's why it was so disheartening to return home from work one evening to find that a "professional" tree care company had just pruned my elderly neighbor's gorgeous mature red oak trees... on May 22 (oh yeah, and charged her a king's ransom to do it).
I called the owner of the company and asked if he knew about the risks of oak wilt. He proudly stated he's been pruning oaks during April, May and June for nearly 20 years and "hasn't lost a tree yet." Right. He was completely unapologetic, completely arrogant. Another example of chain saw + pick up truck = tree care company.
With so few oaks being planted, and so many being lost to construction damage & natural/accidental oak wilt, we sure as hell don't need so-called tree care experts doing the fungus' work for it.
"The oak tree should sue poets for damages. Poets have used the oak tree as the symbol for slowness - sturdy and strong, yes, but so slow, so slow! The reiterations of poetry may be responsible for the fact that most people think of this tree as impossibly slow when one suggests it as the basis of an agricultural crop. On the contrary the facts about the oak are quite otherwise. I am sure no poet ever grew a grove of the faster growing varieties, for he would have put speed into his oak poetry.
Stereotypes about oaks being slow growing trees have kept people from planting them as often as the should, and nurseries from growing them as much as they should.
It's time to change all that.