Letting Nature Do Its Work

Many New Hampshire residents enjoy living in a heavily forested landscape where they can live close to the natural environment. Suburban house lots often contain manicured lawns surrounded by woodland, or are adjacent to large tracts of forestland.

Despite this closeness to the natural world, we often try to tame and domesticate nature around us. I am reminded of this tendency when I see piles of brush and limbs stacked on the roadside after each spring cleanup, or rows of bagged leaves in the fall, all bound for municipal composting facilities.

New Hampshire prohibited the disposal of leaf and yard waste in landfills or incinerators in 1993, and many towns created municipal composting facilities to comply with that law. As a result, many residents bag leaves and stack brush for recycling at the municipal facility. Yet it seems foolish to spend tax dollars to haul away these valuable natural resources from our land.

Since the last glacier receded some 12,000 years ago, the soils in New Hampshire are being constantly replenished. The slow, ongoing natural processes that build soil will continue as long as we don’t interfere.

Pennsylvania State University Professor Richard Yahner has estimated that as much as two tons of leaf litter per acre can accumulate in a mature forest during a single season. Fortunately, naturally occurring bacteria and fungi, along with a large number of other organisms, decompose the material and return nutrients to the soil.

Someone walking through a deciduous forest for the first time and observing the deep carpet of fall leaves might think the forest would eventually be buried under the accumulation. From experience, we know the mass of leaves will have mostly disappeared by mid-summer. Nature’s recyclers will have finished their work and returned to the soil the nutrients vital to the growth of all plants in the forest.

But it isn’t only falling leaves that return nutrients and energy to the forest. Falling limbs, branches, twigs, and even whole trees add to the process. In his book, The Trees in My Forest, Bernd Heinrich summed up this whole dynamic process by writing: “The tree’s decaying body releases the resources collected throughout its life, passing them back into the forest.” All living things in the forest, not just plants, benefit from the recycled energy.

Leaf litter is important to many species of wildlife that inhabit the forest floor. Shrews and rufous-sided towhees search the leaf litter for invertebrates that are one of their primary food sources. Hollow logs on the forest floor are favorite den sites for up to seventeen species of mammals in New Hampshire. The coarse, woody debris is used as habitat by 30 percent of the state’s mammal species, 45 percent of the amphibians, and 50 percent of the reptiles.

One of the amphibians, the Eastern Newt in its “red eft” (terrestrial) stage, lives in woodlands under rocks and logs on the forest floor for up to seven years before returning to water and transforming into an aquatic adult.

Downed logs and woody debris also provide habitat for insects and other invertebrates, as well as mosses, fungi, and lichens. The larger the log, the more value it offers to a wider range of species, but all woody debris on the forest floor has value to some species.

When we recognize the value of these natural resources, we might change how we view woodlands. We have become conditioned to looking at woodland around our homes as an extension of the lawn, to be kept neat and manicured. But nature is not tidy,

If the woods in and around your home landscape seem messy and you cannot let nature take its course, then go ahead and clean things up: break fallen branches into smaller pieces and spread them on the forest floor, limb fallen trees so they lie on the ground, and create brush piles in a hidden corner of the woods. The piles provide tunneling space and cover for wildlife and are easy to build. On their Web site, the National Wildlife Federation offers detailed instructions for constructing a brush pile.

Consider raking your leaves from lawns and spreading them directly into adjacent woodland, which is much less labor intensive than bagging them. If you don’t have woods nearby, create a compost pile, simple or elaborate to match your ambition.

Reduce the size of your lawn by allowing surrounding woodland to expand into the yard and by using the fallen leaves to define the new border. Instead of a lawn that may require a significant addition of nutrients, pest controls and irrigation water, the natural woodland will maintain its own health, returning nutrients to the soil through natural processes.

Live with nature, don’t fight it.

by Larry E. Ely, UNH Cooperative Extension Wildlife Coverts Cooperator