Every year the tell-tale signs that fall is imminent, along with pumpkin spice and football, are the vibrant and beautiful colors that deciduous trees bring. But why does this happen?
It all starts with sunlight, trees use chlorophyll to capture energy from the sun and turn it into sugars that the trees can use for food. As the days shorten and temperatures cool down, it simply becomes inefficient for the trees to keep trying to use chlorophyll to produce energy. This is when carotenoids and flavonoids kick in, these are the pigments that give the classic yellows to Hickorys and Poplars, and amber reds to Maples. Deciduous trees go dormant in the wintertime to preserve energy, which is why it is important to plant trees during this time of year.
But why is this important? First, across deciduous forests falling leaf matter breaks down to help produce richer soils than in pine forests. Secondly the leaf matter provides home and shelter to an abundance of species of insects, reptiles, and amphibians. Riparian forests shed their leaves into creeks, rivers, and lakes which provide nutrients and biomass for macroinvertebrates which fuel the food chain in aquatic environments.
What can I do? Simply the answer is nothing, instead of spending hours blowing leaves this fall, maybe reconsider leaving small natural areas in your yard. The leaf litter can help reduce erosion and runoff, as well as provide habitat for all manner of small creatures. So this fall consider working less to help more.