I have 3 side-by-side compost bins. The newest one is added to every day--garbage and leaves, last fall's dead mums, dead pine needles and pine cones. Another pile was topped off last fall with a layer of manure from the local farm. Now it sits there, gestating, lost under an accumulation of last fall's leaves. The third pile is the one i dig into almost every day--using its rich black humus to transplant plants or to pot up extra plants i find volunteering in places i don't want them.
This third pile--the one that's being subtracted from--has collected a winter's cap of leaves to keep itself warm, but now i rake it clean and toss the leaves into the neighboring bin. Having removed the skim of leaves, i finally see the half-used heap--dead leaves, dead mums, dead flowers and garbage all miraculous digested and transformed into living soil.