Sustainable Food Production
Developing the Principles
There are several related principles of sustainable food production, but probably the most central, is not to use resources faster than they renew. A common example I´ve used is that if you want to cut one 50-year-old tree a year, you need to have 50 trees growing of that kind, from seedling to 49 years old. As long as you have all these trees growing, you can cut one 50-year-old tree a year indefinitely, and sustain the forest in its present size.
That might seem more important for forestry than food production, but when we look at the problems of maintaining fertile soil in many areas of the world, trees become a logical source of food, as they produce fruit, nuts, and fodder for animals. The plant nutrients of soil are a resource, than can easily be used faster than they will renew under the plow. Perennial plants like trees can help to solve this problem, as well as reducing needed energy use to pull cultivating tools. Which is once more, following the principle of not using resources faster than they renew, to avoid using too much energy, whether from fossil fuel, or anything else.
Many other factors come into play as we consider trees. Many other things will kill trees, animals like deer, goats, beavers, and diseases and insects and fire and weather events. The animals represent valuable resources themselves, and even if they are not directly valuable to us, they often are indirectly valuable in that they are vital parts of the ecosystem in which they live. For the ecosystem to sustain itself, we can´t use them faster than they replace themselves.
Fortunately, trees will usually produce very large numbers of seeds, and if a seedling gets established and grows beyond the reach of browsing animals, it is not so vulnerable to being killed by them. Mature trees are also usually less vulnerable to wind and fire. Too many animals will prevent any seedlings from growing up, and the forest will soon have an uneven generational pattern: too many older trees, no seedlings or saplings. Yet if too few mature trees are killed, the forest floor may not get enough light to grow vegetation to support many browsing animals at all.
Very often, we can find a tree that is dying or dead from these other factors, and still get good use from it. This looks good, we might think to just be scavengers, but we want to remember, though, that other animals are also scavengers of dying and dead wood, and that they can be valuable to the overall health of the forest. Woodpeckers dig holes in dead trees, looking for insects burrowing in the wood, these holes can be nesting sites for birds that keep insects in check. Whatever we do needs to be considered, all activities need to be kept in balance. The tops of dead trees provide nesting sites, as well as perches for birds of prey.
Trees tend to follow secessions, where one sort of tree grows best in a certain set of circumstances, and when it dies or is killed, the circumstances are changed and a different variety will do better.
How can we possibly keep track of all these factors? It isn´t impossible. We have needs, too, and we belong. Ideally, we can take our share of what grows, and we can watch for things that are getting out of balance and work to restore that balance.
It is possible, in many woodland situations, that we might cut a whole section of trees in long paths each year. Each year, we cut away more trees on one edge of this long narrow clearing, and leave the other side alone. Grass will grow in this clearing, followed naturally by low growing bushes and trees, of which we encourage the fruit bearers. As we go farther in distance and time from each year´s cut, finally the forest trees are growing among the fruit trees, and get taller and more numerous as we get further away, and bearing nuts of various kinds, eventually shading out the shorter varieties. Our cutting goes like a long wave through the forest, on a 50 or 100 year or longer cycle. The cutting is easier for us than to cut selectively in a standing forest, this practice is very difficult, trees get hung up, it can be a very dangerous situation for us, and can do a lot of damage to surrounding trees that we don´t want to hurt. The long path gives us a way to move the wood, the grassland supports the grazing animals that can pull the wood. We have a rotation of many kinds of plants, bushes and trees, and support a large variety of animals.
Nature often does this, but usually in more haphazard fashion. A storm or fire takes out a section of trees, and you have a natural clearing for a few years. In countries that have elephants, these will kill big trees, and they create many openings in forest. Where elephants are in balance with the environment, there are often many islands of trees and bushes in a shifting mosaic with grass. People can take the place of elephants in more northern climates, and help to manage elephants, where they live. By cutting in lines like this, we should control fires more easily, each cut is a potential fire stop. While fire is a natural and needed force in many places, letting it rage out of control seldom seems like a good idea. Left alone, fire is it´s own control, burning frequently enough that fuel seldom builds up to high levels. We can let this happen, or we might also use fallen dead wood as fuel for our own needs. Where fire is needed to open seeds, we have to be aware of the need, and either let fires burn, or open seeds artificially and plant them.
Where steep hills are involved, the way we cut has to take into account possible erosion of soil, we don´t want paths running up and down, even if the location of the path is shifting every year, we need to be careful about this. Even in flat land, there may be good reasons to make our cuts in curves, and sometimes we might not want to cut a section of trees, want to give them more time to grow, and end the cut and start it again further on. A long straight cut can give the wind a place to get going fast, this might be an asset to work with, if done carefully. Simple windmills could cut wood, and sails might help move it, but it is also something to be wary of, since the wind can also be destructive, knocking down young growth, breaking off branches.
Obviously, these kinds of practices are impossible with a social system of private property. We are looking at ecosystems that work over large areas, we cannot break it up into tiny plots and have everyone acting on their own plot to satisfy their personal wants and needs. This is a principle of sustainability, that we treat nature as it is, and not as every individual wants it to be. The latter can only work briefly, with unsustainable soil and energy practices.
Other parts of the world are grassland, or flood plains that may be grass or trees. We also have large areas of water on the planet that are important sources of food. In each case, we will find a web of connections between soil, plants, and animals. Even with bodies of water, soil is a very important part of food production, even though the minerals may be suspended in the water, instead of at the bottom.
With large bodies of water, we have a more difficult time counting fish and other organisms than we have counting trees or animals. But if we use energy in a sustainable way, I think we should find that we easily fall within sustainable limits of harvest. We would not be making huge steel fishing boats powered by fossil fuel, dragging huge nets made with machinery forged and run with fossil fuel. Our impact on the food sources of the ocean would be greatly reduced, and far more likely to be in the sustainable range, with this simple step of using fuel at a sustainable rate.
With the land resources that we can use sustainably, we will get water resources, and the combination of land and water food resources gives us the population that can be sustained.
Looking at this from more long term perspectives, we understand that the world changes dramatically at times, and we shouldn´t run our own population at the limits of food production, but maintain a factor of safety. This gives a cushion of resources, in case of climate change either warmer or colder, drier or wetter, and all that might go with this.
So we have three principles here so far. 1) Use resources no faster than they renew. 2) Treat ecosystems as ecosystems, and don´t break them up. And, 3) maintain a factor of safety in population, below that of the maximum theoretical. What that factor of safety is, is something to talk about in the future. Right now, just getting people to talk about these things is challenge enough. One last principle of sustainable food production, though, is that if we don´t figure right, and maintain the best level of population, nature will figure it for us, and carry it out for us. Those who refuse to think logically about the matter, aren´t likely to make the best choices for sustaining their lives.