Preserving Natural Resources During Landscape Construction – Part 1

In “Green” building, the main emphasis is usually on creating energy-efficient design and using sustainable materials. Other than typical erosion control measures, often not much thought is given to site preservation.
 Natural resources are the existing resources within a landscape, supplied by nature. Plants, animals, soils, water, even microbes are some of the natural resources on any given site before disturbance. The quality of the resources can vary widely from site to site, or even within a site, but don’t discount the value of the resources without investigating what is there. While what looks like a thicket of scrub or a weed patch to the uninformed may be just that,  many times there are a variety of wonderful plants there that can be kept and managed to benefit the site. Often many of the plants on a site are well suited to it, already established, and already adding value to it. Existing soils are usually stable, and nearly always better for plants than disturbed soils, due to fertility, porosity, and fungal and microbial activity. Of course, building projects by their nature have to disturb or destroy some of those resources; trees must be felled, soil must be moved, water must be diverted. This is unavoidable; but it can and should be done in a way to minimize the damage and integrate the project into the landscape.
  The most basic tenet of natural resource preservation is minimization of disturbance. Sites can be cleaned up and somewhat rehabilitated after construction, but even site rehabilitation involves more disturbance. The goal is creating a stable and sustainable environment around buildings, one conducive to human use. Whenever it is feasible, not disturbing parts of a site puts us well on our way to that, and can often make new construction more attractive, seem more established, reduce erosion, and provide habitat and other environmental benefits.

Some of the benefits of trees and natural resources:

Social– Trees and nature create a pleasing environment for us to inhabit. Vegetation can cool surrounding air in the summer, and trees can provide privacy, shade, and shelter. It’s even been shown that patients recover from surgery more quickly in rooms with views of trees.
Aesthetics – At times, the existing plants, trees and water are beautiful. Mature trees can add many aesthetic benefits to a place, and give the landscape a sense of permanence. Sometimes, things may look poor, but consider that it may just require a little work to make it attractive, and it can be possible to have established landscape in those areas immediately, as well as intact soils.
Intact soils – If the soil matrix is intact, soil likely has fertility and horizons— that is, the strata that develop in mature soils. Undisturbed soil absorbs more runoff, and is much less likely to erode. Roots of plants and trees in undisturbed soil hold the soil in place, absorb moisture, and cool temperatures in summer. Some plants can even absorb heavy metals in soils.
Property values – time and again studies have shown that landscaped properties and those with mature trees are more valuable than ones without.
Environmental – the environmental benefits of trees are manifold. They provide shade, habitat, shelter from the elements, improve air quality, moderate temperatures, and on and on. Soil, especially undisturbed forest soil, is not just dirt, it’s a complex interweaving of ecosystems, a balance between fungal, microbial, biotic and abiotic entities.

Often, taking a look at what plants are growing on a site can give clues as to which plants will thrive in the landscape. Next week, we’ll look at some of the ways to minimize site disturbance.

– Michael Davie

Master Arborist
Natural Resource Manager