A calamity in a swamp of calamity. Ozone.
Forest Service Summary Report [pdf]:
Tropospheric O3 is toxic to humans beings, plants, and many other life forms. Before the industrial age, the lower atmosphere was relatively free of O3. Today, this toxic contaminant is found across all geographic and political boundaries and in areas previously believed to be pristine. Plant scientists consider ground-level O3 the most pervasive air pollutant worldwide and a threat to world food, fiber, and timber
Once inside the leaf, Ozone immediately forms toxic derivatives that react with many components of the leaf cells. The first reaction to injury by oxidants is loss of chlorophyll, increased fluorescence, and changes in energy levels.
The cell membranes suffer changes in permeability and leakiness to important ions such as potassium…
As injury progresses and antioxidants come into play, carbon fixation is reduced, foliar and root respiration is increased, and there is a shift in the partitioning of carbon into different chemical forms and allocation patterns. At the most basic cellular level, a plant injured by O3 is not the same as a plant without injury.
Gail is cataloging findings at Wit’s End. “A cursory inventory of foliage will disclose that it is virtually impossible to find a leaf or coniferous needle that doesn’t have symptoms of poisoning from ozone.”
Carrying capacity —when a population’s consumption exceeds the carrying capacity of its environment— is a stunning challenge. Let’s all strive mightily.