LEARN: What is Sustainability?

Heron Rookery

Photo by Terril Shorb

Altitude, Aspect, Latitude, Attitude

by Terril Shorb

To help understand some of the ways of the Earth, it is useful to think about the ups and downs of a place. Added to these physical features is a look at the relationship of human attitudes toward the particular place, which has affects just as real as the sunlight that falls upon a given patch of ground.

Altitude is measured by how high up (or down) a place is relative to the levels of the seas. I live in a place that is one mile above sea level. And the plants and animals who live here are tolerant of life at this altitude. Generally speaking, the higher the altitude, the lower are average temperatures. The exception to this is that lands in the Earth’s polar regions are also much cooler, even at low elevations. We’ll talk about latitude in a moment. Plants and animals have a range of tolerance for high and low temperatures, and thus altitude can be a limiting factor on whether they can survive in a certain place. At a sufficiently high altitude, sometimes called “tree line,” biological life is typically not found. When someone tells you that we have millions of acres of preserved land, ask them how much of those acres are above tree line and thus not capable of supporting life. Purple mountain majesties are inspiring for our view, but they do not inspire life to make homes there.

When you gaze out over your local landscape, look for the ups and downs and ask yourself what the differences are in temperatures, and who can live at the various altitudes. Another physical feature to look for is “aspect” of the various slopes of the hills or mountains. A north-facing “aspect” or slope will host different conditions than a south-facing aspect. In my region of central Arizona, for example, south-facing slopes tend to support more sun-tolerant plant species, less densely clustered. On the north slopes, where snow lingers longer in the winter and the surface is shrouded in share longer during the day, cooler tolerant plants are found, along with the animals that need those conditions to make their living.

Latitude is another way nature’s design determines where certain can live. With the exception of the polar regions, as I said, the father north of the Earth’s equator one goes, the cooler the temperatures. In contrast, the farther south one goes, the warmer, generally, the temperatures. So when you combine altitude, aspect, and latitude, the combination of microclimates—the conditions in a smaller patch of Earth—vary greatly and help to determine both the habitat of living beings, which is the place they call home, and their niche in that place, sometimes popularly known as the way they make their living.

A fourth very significant factor that describes a particular ecosystem is what I think of as the “attitude” of humans who dwell and do business in that place. Human behavior has immediate impacts on the local environment and if we look around us in an urban sphere, for example, we can see all sorts of examples of how human houses, roads, power lines, mining sites, dams, and other features of the built environment have changed the original characteristics of that place. The collective behaviors and thoughts about the relationship with local nature thus frequently produce more immediate and extensive impacts on what plants and animals can live in a place than do altitude, aspect, and latitude.

For example, suppose that in planning future developments, the decision-makers in my city first looked at a site and determined its richness in species of plants and animals based on the site’s altitude (down in the valley floor; up on a nearby mountain), its aspect (a south or north facing slope), and its latitude (probably less of a factor because the latitude of the development is the same as the existing settlement, or only a mile or so north or south). If the proposed development site is in a lower elevation area on a north-facing, moist foothill where local life forms have found favorable conditions for growth, this site might be regarded as more crucial to conserving local life forms than a rocky, sun-baked, south-facing hillside just a half-mile away. But to influence the decision on what site to disturb for human gain, there would need to be in place an “attitude” of stewardship toward the other-than-human residents who also dwell in that place. That would be, in my humble opinion, the root of authentically sustainable community planning.

Life Lesson: Plants and animals live where they live because the altitude, aspect, and latitude serve their life needs. It is much more difficult to change the elevation, the way a hillside faces, or the latitude of a particular place. What we can change is human attitudes, and thus conserve the physical features necessary for life forms that call a place home.

Life practice:
Whenever a proposal comes before a local decision-making body to disturb a place where nature yet flourishes, I offer testimony that the particular site has certain characteristics that make it especially rich in local natural life. I point out alternative sites that either have already been disturbed or that host fewer species of life. Lot or land trades, then, came perhaps come into the discussion to conserve a particularly rich natural site.


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