I've been working with mushroom cultivation as a crucial part of my survival solution set for over a year now. In many ways they are bedrock for a permaculture solution (pre or post shift). There is no photosynthesis involved with mushroom growth and in fact the only thing they use light for is to let the fruitbody know when it is time to release spores for propagation. The amount of light necessary to trigger this is very, very minimal. There is a lot to all of this but some other basic information. They are wonderful sources of proteins and amino acids and many species have medicinal properties. In a wooded environment you can use materials on hand (fallen trees, etc) to propagate several 'runs' of fruitbodies (mushrooms) during various stages of decomposition of the material (mushrooms are decomposers). At the end of these processes what you are left with is very rich soil that you can then use to grow other crops. Another use for certain species is detoxification of soil and water. If you want more information on the subject please feel free to write.
Offered by Andy.