Dr Hooker first started off with a talk about Biomes, as discussed in the last lecture. He showed an illustration of the worlds biomes that I found really interesting. It was a little different than this one from the USDA but the information is essentially the same.
I found it really interesting to see how the same biomes are repeated around the world. I think it's a good tool to think about as we plan our garden designs to think about the foods and plants that are grown in the similar biomes to our own in the different parts of the world. Because of these differences between the various biomes, Dr hooker makes the very valid point of saying wherever you are, or end up starting your garden, take a permaculture class in that region as it will have the most pertinent information for you. This biome difference got me thinking about trees that I could plant on my own land that I could use for food, fuel and soil enrichment.
Trees are like the lungs of the earth. As they respire, they add oxygen to the atmosphere, but even more they transpire water that has been pulled up from the deep soil. That water adds to the atmosphere as well and has a measurable influence on the hydrologic (precipitation) cycle as well. In addition to this, Trees in our garden, create predictable and stable micro climates by shading the soil, breaking the wind and, depending on the type of species (Leguminous), can add fertility as well. Also, as I mentioned in passing earlier, they can obviously provide food in a completely different vertical arena than our low growing annual vegetables and can provide renewable fuel as well.
"Trees are,for the earth, the ultimate translators and moderators or incoming energy." ~Bill Mollison
Trees can create edgse in our gardens. As they capture energy (Sunlight, wind) they provide safe places for different species to take hold. Capturing wind driven seed, providing a place where both sunlight and shade meet allow for greater bio-diversity than monoculture areas. As the leaves drop and decay over time, trees also help build soil by creating a thick blanket of mulch below them.
Not only do trees provide benefits for our gardens, but for our homesteads as well. By having trees around our homes we can help keep our home temperatures more moderated from the outside temperatures. The shade and evapo-transfer of water through the trees leaves dissipate heat in the heat of the day. Conversely, In the winter months, trees can help to hold heat closer to the house by capturing it under it's branches and holding it close to the soil.
This was not a hugely information dense lecture, but one I know I will keep in mind as I move forward with my farm plan. I look forward to the next lecture on design and site analysis. Assignments for Next week... (Lecture 7/8) is Gaia's garden chapter 3.
And I leave you with these words from Rosemary Morrow, _Earth Users Guide to Permaculture 2nd Edit_~ A forest cannot be precisely measured or costed. Neither can its destruction. However, we do know that removing forests results in water loss, nutrient loss, soil loss, salinity problems, river flooding, local drought, habitat loss and destabilizing the climate. How do we cost these?