Lab Sheet for Patient Earth

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Planetary Health
Base Line
Indicators and Indexes
Biomass Distribution
Bioregion Health
Environmental Indicators
Indicators for the Humansphere
Basics of Indicators
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Bioregion Health

Our scientists tell us that the earth’s natural bioregions are close to tipping points that may make human habitation quite difficult. Assessing bioregion health and how it is changing is therefore a critical task.

The question of bioregion health is a conceptually difficult one. One might think that pristine conditions, i.e. before humans would be a good starting point. In 1955, Trail Lake, in front of my house in Moose Pass, Alaska, was slate grey in color, heavily laden with fine sediments, and tasted gritty. In contrast, the little stream that ran past our cabin was crystal clear and delicious. The lake was fed by a glacier and while the stream came from snow-melt from the mountains behind the house. Both the stream and Trail Lake were in “pristine” condition, i.e. neither has been much effected by humans.

Hollings and his colleagues have demonstrated that bioregions do not achieve a stable end state, but rather go through cycles of expansion and contraction xxx. For all these reasons, defining bioregion health in terms of either a “pristine” condition or in terms of some natural absolutes does not seem reasonable.

Consider for a moment what the hospital does to monitor a patient. The essential variables that are continuously monitored are these four: heart rate, breathing rate, blood pressure and temperature. These four are adequate even though they do not measure everything that is important. Rather, if anything goes seriously wrong with the patient, one or more of these four will be effected and the doctor will be alerted to see what is wrong. We at EVC have adopted a similar strategy: we selected variables that 1) are themselves important and 2) will be effected if other things go wrong.

EVC focuses on river systems (watersheds) because the watersheds have the most comprehensive data available. And, just like the blood in a human body, the waterways fairly quickly reflect whatever is going on in the areas enervated by these flows.

Essential Variables

Trail Lake, mentioned earlier, is nestled among mountains, and gets perhaps 80% of its water from a glacier and the rest from dozens of small streams fed by snow-melt. The lake and many of the streams feeding it are full of trout and salmon. Bears, moose, mountain goats, and bighorn sheep are abundant in the area, as are a variety of smaller critters. Spruce, birch, and poplars cover the lower elevations. The northern climate and the glacier keep the water temperature in the lake near freezing all summer and the lake is frozen over for seven or eight months each winter. The ice is thick enough to drive on although Ed Estes did manage to lose his big flatbed truck through the ice one spring when he knew the ice was getting soft (i.e., he survived because he drove with the door open and jumped when the ice started breaking behind the truck). The truck is still in the lake, some 60 years later.

The ideal set of essential variables would include measures for animals, fish, land use (e.g., wilderness, agriculture, urban) as well as water quality indicators. However, the available data is mainly for rivers and streams.

Our strategy for defining bioregion health involves what humanity needs from nature. In short, what humans need from nature is a whole range of services including clean air, clean water, oxygen, fertile soil, crop pollination, garbage removal services (e.g. ants and beetles), xxx. Therefore, we define watershed health in terms of the bioregions support for clean air, clean water, oxygen, fertile soil, crop pollination, garbage removal services, etc.

While not perfect, water quality indicators provide good indicators of a watershed’s ability to provide these services.

The essential variables include:

  • Phosphorus concentration
  • Nitrogen concentration
  • Carbon concentration
  • Dissolved oxygen
  • Toxins (e.g. from mine runoff, from manufacturing processes, from discarded medicines)
  • Flow rate (gallons per year)
  • Annual variation in flow rate