Big crew goes to work on leaves
Posted By DAVID HAWKE
Posted 2 months ago
What to do with all those fallen leaves? You can rake them, blow them, bag them, mulch them or even burn them (last option not recommended). You can pile them, jump in them (this option highly recommended), ignore them or even utilize them as garden mulch. But, do we ever stop to just appreciate them?
Dead leaves are the end product of a fabulous season of growth, a season that witnessed each leaf performing the magic of carbon and oxygen separation, the provision of sunlight-based energy to growing cells, and, of course, shade to countless cool seeking humans.
But that was then and this now, the leaves are kaput and on the ground. What good are they now? Well, actually, this is when the leaves provide the link to all things living. Not bad for a second act.
To understand this process, let's first look at some impressive numbers. Every acre of mature hardwood forest produces about 10 million leaves. The bigger the trees, the more leaves they have, which explains why my maple-lined backyard seems to take longer each year to clean up.
In addition to the fallen leaves, the forest floor also contains dead branches, nuts and seeds, as well as other organic debris. If you were to weigh all this stuff (and don't worry, somebody did) the result is in the neighbourhood of two tonnes per acre. It really doesn't matter whether you understand imperial or metric measurements, the weight is about the same as a small car.
So, if a forest is 100 years old, and all these leaves have been falling every year, why aren't there a billion leaves weighing 200 tonnes on every acre? The answer is found within a special, yet very thin, layer of activity just beneath the new fallen leaves. It's where the shredders and decomposers live.
Billions of organisms reside here, each with a specific role in this massive recycling operation. First, the leaves have to be softened, a job done by various fungi and bacteria. The moist and fairly stable environment under the protective layer of new leaves allows these agents to work uninterrupted, secreting enzymes that makes the debris soft and spongy.
Next come the shredders, the sow bugs, millipedes, snails, slugs, mites and springtails. This army attacks the weakened leaf material and cuts it to ribbons, and as a result they leave a trail of digested and nutrient-rich poop in their wake. Carbon, nitrogen and a long list of other minerals, vitamins and elements are starting to be released for uptake by nearby rootlets.
How big of crew does it take to render the old leaves into reusable materials? About 2,000 springtails per square foot, and seven-fold that number in soil mites. In a recent survey I conducted as to job satisfaction, all these individuals seemed to be content with their current working conditions, although a few springtails wanted shorter winters and longer daylight hours.
OK, the leaf hits the ground, is damped by rain and slimed by slugs, softened by bacteria and shredded by millipedes. What next? In a way these steps are repeated until the once-crisp leaf is an unidentifiable mass of organic particles, something we can now call soil.
The shredders have become fodder for predatory mites and pseudoscorpions (now there's a horror movie in the making) as well as spiders, ants and ground beetles. The food chain becomes a food web as more players are added.
The mites, spiders et al are sought by moles, shrews, salamanders and small birds. These, in turn, are prey to weasels, owls, hawks and snakes. How do you feed an owl? Put a dead leaf on a forest floor.
How do you feed a brook trout? Put a dead leaf in the water. The same process occurs within our local streams as does on the forest floor, albeit with aquatic organisms.
Research has shown that almost all the nutritional energy found in an aquatic system comes from land-based organics. From bacteria to stonefly nymphs, and from dragonfly nymphs to turtles and trout, the cycle completes itself.
Now if I can just train some of these critters to carry the leaves off my lawn and into the forest, my work here would be done. As it is, another couple hours of raking awaits me.
