AS MY WIFE AND I WATCHED THE LATE-AUTUMN LEAVES FLOAT to the ground from the tall trees lining our lot, I got to thinking. Every fall those leaves turn beautiful colors and then gradually accumulate in our yard — particularly gradually this year, it seems, with leaves on the trees past Thanksgiving. Then it’s time for rakes, huge paper bags, and many trips to the town dump. Every fall, the same routine; every year, I’m taken by surprise. Why is that?

Because my high school biology teacher omitted at least half the story. Despite all his admirable qualities — such as earning a reputation as a pioneer in the protection of wetlands in the United States — Erwin Ernst suggested the “miracle of photosynthesis” was one of the most wonderful things in nature. Maybe it feels that way if you are only looking at the trees through a classroom window. Or if you have 10 children and make them do all the yardwork (as he did). But the inconvenient truth, I now realize, is that photosynthesis does not look so wonderful when you’re raking 200 bags of leaves. It looks like a nightmare.