Last week or so ago we went through several days of high winds. I've written about the wind here, as it is fairly constant and can be quite active.
I had just cleared the yard of all the branches brought down over the winter and gad enough to keep a fire going for hours and then wind came and blew down much much more and the yard looks like I never done anything.
Another thing that it blew down were pine cones. Hundreds and hundreds of them.

All around the yard and in the woods there is almost a layer. More so than I can recall.

From a distance they look like a mole or something similar until you realize they aren't moving.
Looking high in the trees there are still plenty up there and who knows when they will join the rest.
I recall when we lived in a house with oak trees that would go through cycles and would dump so many acorns that I used a snow shovel and barrel to clean them up.
I am sure there is a similar cycle for pine trees and cones.