Search

The Internet of Trees


It's 4 AM in the morning again, and its time to contemplate what I'm going to say on the weekly live stream, again. I have an idea, and it is centered around a set of data that i swiped from the internet and re-packaged .. it is not my own data, obviously, and I am only presenting it under the fair-use clauses of copyright law. The source that I got it from did not even make any requests for attribution, which is perfectly understandable, since it is a cumulation of any number of scholarly works, none of which was being attributed in this particular collection. Rooting out the original sources and providing adequate references for the book project is an ongoing slog through the mud, and I really get the sense that %99 of the readers are not going to check the bibliography at all. This is discouraging, because not all, but many of the papers that need to be read and cited require a pay out to peruse, and few will really fact check the work.


A few years ago, I came across a TED Talk video where a forestry researcher named Suzanne Simard was describing an experiment that she had conducted, 25 years previously. In brief, she had planted an area with a mix of Birch, Fir, and Cedar - 80 specimens in all, and covered some of the trees with shade cloth to limit their photosynthesis. She placed plastic bags over the trees to isolate them, and injected radioactively tagged carbon dioxide into some of the bags. Coming back to the site some time later, she found that the trees that had been 'tagged' had taken up the radioactive isotopes of carbon dioxide .. no great shock there, but when she uncovered the bagged and shaded trees and tested those, she found that the radioactive isotopes had been taken up by some of THOSE trees, as well. Here is a link to that video .. she starts talking about the experiment at 4:52.




I had been aware of mycorrhizal fungi already, I knew that there were these types of fungus, most of whom don't produce a visible fruiting body - well, at least not one that WE can see - and these fungi could form a sort of symbiotic relationship with plants, where they would spread out their hyphae to 'mine' for mineral resources that the plant needed, and trade them at the root tips with the plant in exchange for sugars that the plant had produced through photosynthesis. By participating in this relationship, the plant was gaining access to resources far beyond what it could attain through its own root system. That knowledge was in what I would call the "kind of neat" category, but nothing that would give Archimedes cause to leap out of his bath and go streaking down the streets of Syracuse.


I was also aware of this growing trend of 'food forests' .. these properties where people would plant lots of trees and bushes, sometimes overplanting them, and then talking about how they were going to be able to eat the produce from their trees. It seemed a bit silly to me, many of these projects .. there were a lot of fruit trees, but no protein to speak of. How many jars of home-canned peaches would a person have to eat, I wondered, before they would just give up, and go buy a nice, juicy steak? I found the concept of layers intriguing - who wouldn't like to be getting six different crops out of the same square foot of space? The problem inherent in those layers of course is the competition for sunlight. For each subsequent layer down into the forest, one has to find plant species that like more, and more shade, and since some of the best plants that can be grown for food come shipped from the nursery with the advice "plant in full sun" this limits our options to less appetizing foodstuffs.



I don't like bologna. This seems an odd way to commence a paragraph, but permit me a moment to expound upon my deep seated and utter loathing for that most dismal of lunch meats. Growing up, money was scarce, and to compound matters, my mother was not an able cook - she was, in fact a teacher, which explains both the deficiency in culinary skills as well as the empty pocketbook. Evening meals generally consisted of whatever could be made from hamburger meat and the contents of a box, with the contents of a can heated up as an afterthought. For other meals, a slice of the least expensive bologna and some mustard sandwiched between what might at a distance be mistaken for bread was the general fare. I learned to forage out of necessity.


Most of the Ozarks had been clear cut from 1880 to 1920, by which time the lack of any trees worth harvesting for timber caused the timber industry to shut down. Efforts had been made to control erosion in the clear cut areas, with many trees planted from 1920 on up into the 1950's .. mostly junipers that were being referred to as 'cedars', but all over Southwest Missouri in the hills one can still find a mix of other species, those trees having been either seed or seedling during the days of heavy timber harvesting. The region that I spent most of my time foraging was an East-facing slope over lake Taney Como, just a few miles away from the Mark Twain national forest. There were black walnut there, persimmons, plums, and a few cherry trees, lots of blackberry patches could be found along the slope .. but those junipers were everywhere. A lot of talk is made about the edges of ecosystems being the most productive .. after 60 to 80 years since the cutting, everywhere in the Ozarks was edge. The best places to forage were receiving sunlight for at least half of the day, but it was not uncommon to find small trees or bushes growing almost completely in the shade, still bearing fruit.


Hearing Doctor Simard talk about plants within a region forming mutual mycorrhizal associations to pass sugars, among other things UP from the fungi to trees that had a need for them triggered a recollection of having seen wild blueberries growing in a portion of the woods where they couldn't be getting more than 2 hours worth of sunlight in a day. Commercial growers put their fields of berries out in the open, spaced about 12 feet away from each other, and the common wisdom is, these plants require a lot of sunlight. OK, now I am intrigued. I had to learn more about these mycorrhizal fungi, and what they could do. Water, Nitrogen, Phosphorous, now Sugars, too .. what else is getting passed along through this underground mutual network, and how can I use this to my advantage in designing a system?

I learned that there are two main classifications of mycorrhizal fungi: Endo or arbuscular mycorrhizae, and ecto mycorrhizae, with hundreds of known species of each, and probably thousands as of yet unknown - There is not a lot of funding available for pure research in mycology, especially when that research produces results that challenge the old Darwinian view of botany, where all of the species of plants are there in competition with each other for limited resources. Progress is slow, and one researcher might spend their entire career studying a handful of species within one genus just to produce a few crumbs of new information. I see my own role in this intellectual ecosystem as being someone who comes along and gathers these crumbs together, hopefully finding a way to put the information to work in a practical manner - science for the sake of science is wonderful, and I wish we had more of it, but practical applications pay the bills.


Speaking of crumbs, here are a few more: The plants in the family Ericaceae are almost exclusively arbuscular, but with a limited range of species that normally do not form associations with any other family that we know of, as of this time .. some notable specimens from this family include the blueberry and the cranberry .. and that makes the shade growing berries of the natural forest a bit of a puzzle. We'll come back to that in a minute, because our other 'crumb' is also somewhat bizarre: Members of the family Orchidaceae also form associations with a limited range of mycorrhizae, seemingly with arbuscular habits, and an extra little twist - their seeds have no sugars, starches, or any sort of biological 'fuel' to help get the seedling started; they are completely dependent on their fungal associations in order to get even their very first supply of energy.

I began thinking about those blueberries in the woods, growing in the shade more and more. There had to be some sort of 'bridge' between the species, enabling a mutual network to feed the ericaceous plants. After some searching, digging deep into the page lists for information, I found a list of mycorrhizal associations that looked promising .. and sure enough, on that list along with the Heather, Crowberry, Leucothoe, Cranberry, Pieris, Azaleas and Blueberries were the Mountain Laurels and Gaultherias .. Ericoid and Ecto Mycorrhizal. A search of the plants for a future database informed me that the mountain laurels are toxic, VERY toxic, potentially lethal to humans if consumed by accident, so I decided that that idea was out .. what about Gaultheria?

This time, the database rewarded me with a positive result: Gaultheria is the genus to which the wintergreens belong .. that source of aromatic oils that have been used to flavor sweets and toothpastes, and combined in ointments to relieve sore muscles and joints. Of further note, Gaultherias have been found to grow in close associations with evergreen trees - though unspecified, I must assume that those evergreens are ectomycorrhizal - members of the family Pinaceae: Fir, Larch, Spruce, Pine, Hemlock, and True Cedars (Junipers are also commonly called 'cedars', but they belong to the family Cupressaceae, which includes Cypress, Redwoods including also the Giant Redwoods, and the members of the Thuja genus, the Eastern and Western Red Cedars)

Now I had the beginnings of a plan: I would plant members of the Corylus genus (hazelnuts) in association with the Pecan trees that I had started out with, Plant Blueberries, and plant Gaultheria as a bridge between them .. but since the property that I was working on had never had these specific specimens growing together, there was little chance that the right kind of fungi would be found in the soil .. furthermore, as most nurseries grow their stock in pots, each one kept separated from any other plants, there was little chance that those fungi would be found there, either. Fortunately, I was able to find inoculum of ectomycorrhizal fungi and ericoid mycorrhizae as well .. with any luck at least some of these species will be capable of forming a mutual network. Will I need to add members of the Pinaceae family as well? That is an experiment that has yet to be completed at the time of this writing.


Returning to Doctor Simard's experiment, Birch and Fir trees were found to be in communication with each other, but not with the Cedar. In subsequent experiments, Doctor Simard was able to verify mutualism between Cedars and Maples, and if the Cedars in question were Western Red Cedars, this would make sense: Both those members of the Thuja genus and all of the Maples are endomycorrhizal. In a healthy forest ecosystem, we might expect a mutual network to develop between even the Maples and Birches .. but this would require another 'bridge' species. If you look at the tables, you will find them: The plants that form both ectomycorrhizal and arbuscular mycorrhizal associations are listed in blue: Alnus (Alder trees). Acacia and Salicaceae (Poplars and Willows). To connect my nut bearing trees with my fruit yielding trees, I have included Alders and Willows in my own garden plan.

Universities receive their endowments from industry, who pay for research that they believe might help them in some way, and from private sources, who desire research results that support whatever their particular agendas of the moment might be. At this moment, if a person is going to receive university funding for research into mycorrhizal associations, the only people out there willing to donate funding seem to be the ones that are trying to prove anthropogenic climate change. In order for us to get good quality research without the politically driven rhetoric, we have to become the industry that invests in the research .. and that means not just backyard garden experimentation, but full scale agroforestry farming: farming for profit.


Investors in an agricultural venture are not likely to want to put out the funding to try an experimental method .. they want to see working prototypes before going all in. That is where small operations like Green Country Agroforestry, and individual citizen scientists play a role: by attempting to build functioning mutual networks on the smaller scale, we have the opportunity to demonstrate that it CAN be done .. and if it can be done profitably on a small scale, then it can be done profitably on a large scale. The model for agriculture can change, and the looming crisis of 'too many people, not enough resources' can be averted. I thank you, once again, for your kind attention.




49 views0 comments

Recent Posts

See All