(Continued from Part 2.)
2.3 – Finding Edible Cambium Locally And Harvesting It
If we live in an area with a sufficient number of trees, the next step would be to find out which ones have edible cambium. To accomplish this I recommend two sources. First, you would need to buy the National Audubon Society’s book titled Trees of North America or something equivalent. Here are two free sources that just have tree maps: Tree Map Link 1 and Tree Map Link 2. I am referring to the 2021 edition of Trees of North America in my following statements. This book has great maps that show which trees populate particular areas in North America. Each page has information on one tree. It also has great photos and descriptions to help identify the trees.
The second source is the Plants for a Future (PFAF) website. This is a free site that has great information on which trees and plants have edible portions and the sources for this information. Here is how I used these two sources together. In the Trees of North America book I went from page to page and found trees on the maps that are common in a 50-100 mile radius from where I live. Then I would take the scientific tree name and type it into the PFAF website search bar. Then I checked if it has an edible cambium layer and any other edible parts. For example, pine nuts from most pine trees. I wrote what I found in my Trees of North America book for trees with and without edible parts. If it was not listed as edible I mark it as poisonous to be safe. I added my notes to both the tree page and in the index for easy reference. I also saved the PFAF page as a PDF and printed it to have a hard copy.
Once this was done, I created a summary document of the trees in my area that have edible parts. This will be part of a packet I will preprint and can use to help gather and train recruits if I ever need to setup an emergency tree harvesting co-op. Common trees with edible cambium include, most pines, maples, cottonwoods, box elder, most spruce, most fir, quaking aspen, and most birch. If you are still with me do your homework and find the tree resources in your area.
Now that you have identified the local tree cambium sources in our area it is time to go and practice the skill of harvesting cambium. There are tons of great videos and articles on the Internet so just start searching cambium harvesting. If possible, try harvesting cambium from a tree that you are cutting down for wood or from a tree with larger branches you are trimming. To do this we will shave off the outer bark layer first on the tree trunk or branch. We can use a small hatchet, machete, a bark removal tool, or just a longer knife. After the outer bark layer is removed then separate the cambium layer from the sap wood. Try to do this in large strips to make it easier to collect. Some cambium will be stuck very tightly to the sap wood layer and others will almost peel off. This will depend on the type of tree and even the time of year. If we are cutting a tree down for firewood we do not need to harvest the cambium layer immediately. We can wait for one to two weeks if necessary and the cambium will still retain its calories.
[JWR Adds: It is important to not let cambium heavily ferment, because by hydrolysis it could create methanol (a.k.a. wood alcohol.) Unlike ethanol (a.k.a. grain alcohol), it ican be toxic in small quantities. In the beer and spirits distilling industry, methanol threshold levels and legal limits have been set in various jurisdictions.]
If we are going to remove cambium from a live tree for practice, we should limit the number of trees we practice on. We don’t want to accidentally kill a tree and destroy a future resource and/or create a future hazard from a standing dead tree. Here are a few recommendations for live trees. First, never girdle a live tree, which is removing the bark in a ring around the whole tree trunk. This will cut off the flow of nutrients and some water to the whole tree and will kill it. Instead, try and cut a window on just one side of the tree and limit this to no more than one-fourth of the tree trunk’s surface area. Second, pick a larger tree that can more easily shrug off this damage and recover. Third, we should only practice on trees on our own property or on public lands. I also recommend doing our practice in private to avoid drama with people who love trees more than they love people, tree-hugging Karens.
Next, you will need to do some scouting for trees with edible cambium that are within walking or biking distance from where we live.
Focus on public parks, trees along roads, trees along waterways, and national and state public lands. Note trees that are on private property but remember that these are someone else’s property and should be respected. In the event of an emergency, or even before, the owners could be approached and offered trade for access to their cambium like a portion of the cambium in exchange for the labor to collect it and/or process it into firewood for the owner. Mark the resources on a map and rank them according to value and ease of access. This information can be used in setting up a harvesting operation if the need arises.
Finally, here are a few thoughts on harvesting cambium if we are doing it in an actual T2E. First, if the tree with the edible cambium has any other food value, like pine nuts in pine trees, don’t cut these trees down unless we have to for firewood or to prevent starvation. Harvest only up to a third of the trunk’s surface area and/or just remover larger branches and process those. Don’t kill a proverbial Golden Goose unless you have no other option.
Second, try and kill as many birds with one stone as possible using this process. People will be more motivated to cooperate if they will gain multiple things from their efforts. For example, plan out the groups needs for fire wood and use this dual purpose to collect the wood and food at the same time. Prioritize cutting down trees that would offer fire breaks for important structures nearby. This is a win-win-win. We get to collect a food source, fire wood and help an area become more resistant to fires. Consider the other uses for the trees being processed; road barriers for security, log walls for security, long poles for vertical gardening, poles for building greenhouses, poles for garden fencing, poles for livestock pens, and on and on. We should use our imagination and maximize our precious time and energy in a post-T2E situation.
Third, set up an assembly line process. Have a group of no-kill cambium harvesters with the right tools like ladders and limb saws. Have a group of tree fellers for safely downing trees. Have a group of cambium harvesters to work on large limbs and on downed trees. Have assignments for logistical support, security, and first-aid to maintain a small camp and perimeter security. Have a group of runners that can transport processed cambium and equipment back and forth from other locations. Have a group that can forage for other food resources in the area. Have a group making charcoal for soil improvement to grow food, see more details later in this article. These specializations will allow for efficiency, and efficiency equals more calories collected per day for fewer calories expended. Also, don’t forget to cross-train so people gain more skills and allowing the process to become more resilient.
Fourth, if the trees with edible cambium are far enough away we might need to plan for overnight camping on site and using the most efficient and abundant forms of transportation we have. This will become more of an issue if we have already used up our walking distance resources. Depending on the type of emergency we may or may not have working vehicles and even if we do, fuel is likely now a scarce resource. Human-powered wheeled objects will become a go-to resource. Bikes with trailers, hand-pulled or pushed carts, wheelbarrows, game carts, and hand trucks will all be huge force multipliers to move people and supplies two and from work sites.
If the site is far enough away it may make for sense to have people camping onsite we should prepare a work camp. For this effort we would need to gather tents, sleeping bags, pads, food, water, and hygiene supplies for the workers and other gear to have a smooth operation. How far we should travel will depend mainly on the area’s security risks, our ability to provide security at the camp and our ability to have security and other necessities at the homes people are leaving behind for a time. This becomes easier if we have a large enough group of people that are pulling together and if local law enforcement and leadership is supportive of these efforts.
Another advantage is that most people don’t know that the cambium layer in trees is a food source and may be uninterested in bothering people in a tree harvesting operation. I would recommend that groups only expand to this level if security is a possibility and if prior harvesting operations have started to net a calorie surplus for our group.
2.4 – Eating Cambium
Once we have successfully collected cambium how do we use it feed people? On the internet people talk about eating it raw or frying it in oil or boiling it as a noodle. Having tried all of these except the noodle idea. I don’t recommend these. It doesn’t taste great and after chewing it we are left with big wad of tree pulp in our mouths. The go to method for native groups for this food source was to dry it out near a fire or in the sun and then turn it into a flour. This flour was often mixed with other things like grains, bean flours, or ground nuts and used to make a bread or porridge.
Cambium flour can be used on its own but I recommend using it as an ingredient and not a solo act for nutritional and taste reasons. The extra fiber will also help people feel full for longer, helping to reduce the new normal of feeling hungry more often during a type two emergency.
One final reason to go the flour route is that people will absorb more calories per serving if the food source has a larger surface area to be digested. In our current world, obesity is a way larger problem than starvation. If a T2E strikes these problems will flip. A real health risk in our world today is excessive consumption of highly processed foods that contributing to obesity. We should translate highly processed in our minds to high surface area foods. Foods that come from ground powders have large exposed surface areas and this makes their calories very easy to absorb and easy to digest. The highest surface area calories are liquid calories like sodas or other sugary drinks. Lower surface area foods are raw foods or lightly processed foods. These foods are both harder to absorb and take more calories from our bodies to digest. That is why eating them is useful for losing weight. These less processed foods are great current health food choices but in a calorie-starved world we should over-process every food source we can to maximize the calories we absorb and to minimize the calories we need to digest them. Here are links for two pine bread recipes to use with our cambium flour. Bark Bread Link 1 and Bark Bread Link 2.
A final comment on making flour from cambium. It needs to be dried very well to make it easier to process. This could be done with low heat, over time in an oven, sun drying, or in a dehydrator. Once it is dry break it up into very small crumbles. Then it can be used in a grain mill. If it is not dried up and broken up well enough it can plug up a grain mill. This happened to me a couple of times as I was learning how to make it into flour and I wasted a lot of time taking my mill apart, cleaning out the compressed cambium chunks, and putting it back together. It also seemed to process better if it is combined with other grains like rice or wheat berries. I hope this will shorten your learning curve on making cambium flour. Another must is a hand-cranked grain mill if part of our emergency plan is produce cambium flour — or any flour for that matter. We could try using the historical mortar and pestle method, but this just adds another layer of laboriousness in an emergency. Let’s save our shoulders, forearms, and time and buy a grain mill now.
(To be continued tomorrow, in Part 4.)
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