I now knew that birch and fir were connected and communicated, but it didn’t make sense that birch always gave more carbon to fir than it received in return. If this were always so, fir might eventually drain the life out of birch. Were there times in its life when fir might give to birch more than it received? Perhaps when the forest was older and fir had naturally outgrown birch there was a net transfer of carbon from fir to birch.
