During the warmer months, tree leaves inhabit the world above our heads, giving us shade and a pleasant rustle as they soak up sunlight and convert it to food. But as they swirl to the ground on these November days, the leaves reveal their hidden lives, if we care to look.
Pick up a leaf. If the surface has started to wear away, you’ll discover a jumble of tiny veins twisting and merging that may remind you of a map of lower Manhattan. This is the inner skeleton of the leaf. It provides both structural support for the leaf and is also part of the hydraulic system that transports water and nutrients from the tree roots to the leaves, and sugars from the leaves back down to the rest of the tree.
These gossamer remains of the leaf are the handiwork of myriad decomposers, large and small. For example, while photographing these leaves, a tiny transparent worm smaller than one letter on my newspaper crawled out, and I could see the contents of the leaf it had been chewing inside its body.
This little worm, along with slugs, snails, millipedes and miles of fungal roots are the workhorses that clear our forest floors of fallen leaves, and recycle the nutrients from the leaves back into the soil. That is one reason gardeners should consider mulching their leaves instead of relying on gas blowers to take them away. The mulched leaves provide premium free fertilizer! Instead of having your tax money used to pay composters to process the leaves, and then sell them back to you as mulch, you can ask your gardener to mulch mow your leaves, and make your own for free. Extra leaves can be blown or raked into a compost pile for the future.
The fallen leaves reveal not only their beautiful inner structure, but also how important they are to sustaining forest life. Pick up a leaf and you are bound to see signs of it having provided room and board.
Oak leaves, such as the one pictured above, support more life forms than any other native trees. They host hundreds of species of insect, supplying many birds with an important food source.
The bumps on these leaves are galls made by the eggs of a small midge which lives inside. When the insects hatch, the leaf that hosted them becomes their food and in turn, they become food for birds and their squalling babies. These galls cause no harm to the tree, and are quite beautiful in spring when they are plump and pink.
Next time you are outside take a moment to pick up a few leaves. Look for signs that they have nurtured insects. Admire the remaining latticework, not only highly functional but hauntingly beautiful as well.