Day 11: Trees And Their Energy Transactions
Dear Student,
Trees are immense contributors to the biosphere but are sometimes the forgotten heroes in the self-sufficiency and sustainable agriculture movements.
Among their multitude of functions, they:
- Create rainfall. Trees can return 75% of their water to the air from transpiration.
- Prevent erosion. By holding the soil together and preventing rainfall from hitting the ground directly, they physically hold land together.
- Recharge the water table. If you cut any of your property’s trees and don’t replant, water will run off the land quicker, causing erosion and runoff, hindering the water table’s recharge, and making the land more prone to drought.
- Are energy-capture systems. They mine nutrients from deep within the ground through their roots. A large tree may have a leaf surface area of up to and beyond 40 acres, through which they capture massive amounts of solar energy and pump water back out at night.
- Provide food and animal fodder.
- Provide shade and shelter for animals.
- Prevent evaporation of soil moisture and create condensation on leaves at night.
- Provide lumber and firewood.
- Are the natural habitat for other flora and fauna.
Mycorrhizal Fungi
Beneficial fungi are an essential synergistic partner to trees. Fungal threads up to a mile long connect to tree root systems and create a more efficient connection to the soil in a relationship called mycorrhiza.
Mycorrhizal fungi help trees absorb water and nutrients in mineral deposits, soil aggregates, and organic matter that have pores too small for “naked” roots to reach alone, improving plant growth and increasing the chance of survival during drought.
And because these trees are so nutrient-rich, they have high levels of phosphorus, which increases their ability to fight pests and disease. Some fungi even protect trees from soil-borne disease and pests by producing antibiotic compounds, stimulating other beneficial microorganisms, activating plant defense genes, out-competing harmful fungi, and acting as armor around fragile roots.
“Without trees, we cannot inhabit the Earth.”
–Bill Mollison co-founder of the permaculture movement
Trees With Superpowers (Nitrogen-Fixing Trees)
Nitrogen is essential for growth of any plant life, and it happens to be the most lacking nutrient in soil today.
Luckily, the symbiotic relationship between leguminous trees or plants and rhizobium bacteria helps to provide more essential, life-giving nitrogen to the environment…
Found naturally occurring in soil, rhizobium bacteria can infect the roots of trees and other plants, producing nodules where they fix nitrogen gas from the atmosphere. They turn it into a more useful form of nitrogen (nitrates), which is then used by the tree or plant to grow. When the host plant dies, the nodule breaks down and the rhizobia are released back into the soil where they can live alone or reinfect a new plant host.
This symbiotic relationship is one of the main drivers of life on Earth.
Nurse Trees (Support Trees)
But the usefulness of nitrogen-fixing trees doesn’t end with themselves… as nurse trees, they can even help the non-nitrogen-fixing trees and plants around them, providing free nitrogen for their neighbors—and meaning you don’t have to fertilize.
Nitrogen can be released by cutting/pruning a few branches from the nitrogen-fixing tree just before the rainy season. Just let them fall to the ground. As they rot, nitrogen is released into the soil for the benefit of other plants in the area. Plus, cutting the branches causes some root mass to die back, further releasing nitrogen into the soil.
For example, if you were to plant leguminous plants or trees in between your orchard’s rows of fruit trees, they will benefit hugely from the nitrogen boost, growing faster and stronger, and when the fruit trees are fully mature, they can be removed (or not).
Recommended Support Trees:
- Short-term (1 to 3 years): cowpeas, lupins
- Medium-term (3 to 15 years): leucena, gliricidia, Siberian pea shrub
- Long-term (infinite): tipuana tipu, ice cream bean, black locust, grey alder
Trees: The Building Blocks Of Life
Modern agriculture has taught generations of farmers to remove trees from their pastures to the great detriment of their soils, herds, and their own livelihoods.
In fact, many of the great threats to modern nature could be mitigated or prevented by the sensible planting of trees throughout pastures and crop-growing fields.
A full 20% to 30% of your pasture land can be planted with trees with no decrease in grass production per acre while adding to your output—you’d have another yield (fruit, nuts, or animal forage) as a second crop for free.
Timber trees are just as valuable, and you’d do well to plant some of this variety, too, so that you’ve got a free supply of lumber to build and do repairs on your homestead in the future.
“The best time to plant a tree was 20 years ago. The second best time is now.”
–Chinese Proverb
The Magic Of Self-Sufficient Food Forests
Food forests are the most sustainable way of providing food security using 100% natural systems. Using integrated design and system-stacking, you can build yourself a nearly zero-maintenance, all-natural food production factory.
While food forests provide fruit, nuts, and lumber, they are also great pasture land for running poultry or pigs. These animals will eat fallen fruit and pests, upcycling these nutrients back into the system as they fertilize for you. Chickens can maintain the system once it is implemented, though pigs might do damage to certain layers once you’ve fully planted out all your stories.
I’ll talk food forests in detail in a later class…
Sustainable Milpa Farming
Maya farming systems called milpas have gotten a bad reputation these days for using unsustainable slash-and-burn methods. But historically, at the height of the Maya civilization, slash-and-burn wasn’t commonly used.
Uneven farming areas were cut out of the jungle and the biggest they got was about a quarter-acre. This size was small enough and the edge effect big enough to allow yearly farming on the same land, with nutrients replenished by the surrounding support trees in the forest.
We can copy this system today and never have to buy fertilizer or even carry manure to the trees to get the maximum production.
Pollarding And Coppicing
Some trees can be pollarded by cutting the tree off at head height and letting the tree regrow bushy branches at the top. Coppicing uses the same principle, but you cut at ground height.
Trees suitable for pollarding or coppicing grow faster and stay healthier when maintained this way. It can be done every few years and the tree then left to regrow for future pollarding. Willow trees, for example, are pollarded to encourage rapid regrowth of weaving branches.
This is a great way to get a big load of firewood or building lumber when you need it, while allowing the tree to reap equal benefits.
Day 11 Assignment:
- Research the trees, lumber, nut, fruit, and nitrogen-fixing support trees that grow well in your area.
- If you only have a small space, research what dwarf varieties grow in your climate.
- Calculate how much fruit and/or nuts you and your family would eat in a year. Using information available from your nursery or online, work out how many trees you’d need to supply your own needs.
- Find sources from which to purchase some of the trees you’ve decided will work well for your homestead.
Happy homesteading,
Con Murphy
Your Total Independence Coach, Live and Invest Overseas