You're absolutely right, I know. The soil layer is too thin and there's not enough smaller biomass present. But I had to work with the material on the site and it wasn't there at the moment. I'm planning on adding a lot of compost and straw on top of it at the end of the winter and using plants that like acidic soil, like blueberries and cranberries. I'm sure that over the years it will get it to be more balanced. Thanks for your tips!