Is it just chance that people are about two meters tall, or is it a result of laws of nature?

Life comes in many sizes. The smallest creatures are bacteria. The smallest of these are about one millionth of a meter long and half that wide, and weigh less than a billionth of a billionth of a kilogram. The longest and widest creature is a surprise — not an elephant, not a whale, not a giant sequoia tree. It is a huge fungus that lives in soils in western North America, just under the ground. Some of these individuals stretch across two kilometers! If one of these giants were merely 10 cm thick, it would weight about 314,000 kilograms. These fungi live by digesting decaying vegetation in the soil, a vital role in the eternal cycling of life’s chemicals. Thank goodness, however, they have no sharp teeth or legs to walk on, or an interest in feeding on living flesh.

The heaviest organism is probably the largest of the giant Sequoia trees of California, known as the “Del Norte Titan” sequoia. It stands 94 meters high and is more than 7 meters in diameter, and weighs more than one million kilograms. [Read more...]

Restoration of nature and sustainability of natural resources have become popular terms these days. They sound straightforward enough, but they come with their own loaded meanings. If you restore a painting, you make it look exactly as it did when it was first painted – you put it back into its original state. So it is with restoring houses, gardens, antique cars. Restoration has always meant to bring back to a single original condition.

The idea that nature can be restored – and will restore itself – to a single, best, perfect state is ancient. It forms the basis of the great myth of the Balance of Nature – stated and believed by the ancient Greeks and part of Western civilization ever since. According to this belief, nature exists in a perfect balance that will persist forever, and, if disturbed by human action but then released from that disturbance, will return to that single perfect state.

The idea that nature can be restored to a single best condition is also part of a modern nature-myth, the belief in nature as a machine. According to this belief, developed in the nineteenth century, nature was like a watch or steam engine. It could be operated to run steadily. Not only was nature in a balance like a well-crafted watch, but it could be operated to provide a constant output or any constant, desired condition – maximum number of trees, for example.

So by analogy with a painting – and following the ideas of the Balance of Nature and the machine-nature myth – if we restore nature, we bring it back to its original single natural state. Right? Wrong. What environmental scientists have learned in the past 30 years is that nature has no single “natural” state. Instead, we have learned that nature is truly dynamic, it is always changing, and that species have evolved and adapted to those changes. If we actually succeeded in restoring nature in the same way that we restore the Sistine Chapel, many species would go extinct – they depend on, require change.

Case in point: the Kirtland’s warbler, a pretty warbler that nests in Michigan on coarse sandy soils and only in jack pine trees. The species has long been of interest and concern among conservationists, ornithologists, and people who just enjoy the outdoors. In 1951 a survey was made of the Kirtland’s warbler, making it the first songbird in the United States to have a complete census. About 400 nesting males were found. In 1971 only 201 nesting males were found.1 The numbers were falling abruptly. What was happening? Would this warbler go extinct? The answer lay in the then current ideas about conserving, restoring, and sustaining nature. The warbler and its habitat were managed by people who believed in the Balance of Nature and the nature-machine myth, and as a result believed that any disturbance to nature was bad. In 1926 one expert on the warbler wrote in Audubon magazine that “fire might be the worst enemy of the bird.”2 Their solution: suppress forest fires so that nature could keep itself in its perfect balance – restore it like a painting back to its single best state. In this case, the perfect state was an old-growth forest – maples and other hardwoods along with some huge white pines.

This ideas of restoration and sustainability were wrong for the warbler because the jack pine woodlands it nests in occur only after fire. Kirtland’s warblers nest only in jack pine woodlands that are 6 to 21 years old, ages when the trees are 5 to 20 feet tall. Since the jack pine is a “fire species,” sustaining itself only where there are periodic forest fires, the Kirtland’s warbler thus requires change at a rather short interval – forest fires approximately every 20 to 30 years, which was about the frequency of fires in jack pine woods in presettlement times.

So two ancient myths not only failed to save the warbler, they were doing him in. Another ancient myth provided an possible answer – the myth of mother nature that the Greeks and Romans also wrote about. This is the idea that nature – the Earth and the entire system that contains and supports life – is like or is a fellow creature. And like all creatures, it has had a birth, a youth, and a maturity, and is destined to have an old age. Mother Nature was once like a young woman, beautiful, perfect in form and symmetry, and fertile. Our unfortunate fate was to be born when nature had become old and, like an aged creature, was wrinkled (Earth’s mountains), covered with warts (Earth’s volcanoes), and had lost her fertility.

Could the Mother Nature myth help? Probably not. Believing that, one would shrug and say, well, too bad for the warblers alive today, they were just born too late. Their habitat is no longer fertile; Mother Nature is just plain old.

So how do we restore the warbler’s habitat and sustain it? Modern environmental sciences provide the answer: by aiding or creating change. This was done on 38,000 acres set aside in Michigan for the birds. Prescribed burning was introduced, based on planning done by the Audubon Society, the U. S. Fish and Wildlife Service, and the State of Michigan Department of Natural Resources. Success! The warbler is thriving again, in its periodically changing environment.

There is more to the story – the warblers also suffered from cowbirds who lay their eggs in other birds’ nests. The unsuspecting nesters raise cowbird chicks along with their own chicks. When cowbird parasitism is common, birds like the Kirtland’s warbler suffer. Many of their own chicks die. Controlling cowbirds was also part of the solution. But without a changing environment, allowing jack pine stands to regrow, the warbler would have gone extinct, cowbirds or not.

Many species require change, and the required changes can occur at many scales of time and space. Think about restoring the salmon of the Pacific Northwest, for which billions of dollars have been spent. Salmon are fish of cold waters not far south of high-latitude glaciers. Over the time scale of glacial ages, salmon have to move among streams. The old belief that salmon always return to their natal stream except when they make a “mistake” fits in with the belief that restoring their habitat is like restoring a painting. But that “mistake” has been essential for their survival. If they could not shift among streams, by occasionally going up the “wrong” stream, they would have gone extinct when water became too cold or warm, or when other factors altered their habitats – landslides filling streams with debris; water erosion removing gravel required for the eggs. Salmon are sustainable and restorable only if changes at many time scales occur – from seasonal changes in water flow to variations in ocean El Nino events and periodic forest fires that allow alders to grow along the salmon’s stream, to the glacial-age changes already mentioned.
How then do we restore and sustain species in an ever-changing environment, to which the species are adapted?

• Allow changes to occur at natural rates and of natural kinds. This means we have to study species and their habitats from a new perspective – what kinds of changes do species need?
• Therefore, promote the scientific understanding of the kinds and rates of change required by species. The idea that change is natural is gradually altering ecological sciences, but the acceptance needs to proceed faster, before the species that depend on change go extinct.
• Avoid novel changes – like the introduction of artificial chemicals never encountered before by any life form. Just because some kinds of changes and rates of change are natural does not mean that any kind of change is acceptable. Let nature and its dynamics be our guide.
• Rethink management policies, so that the harvest of living resources is done within the world view of natural change. The world’s fisheries have been traditionally managed in the twentieth century with the goal of maintaining a single maximum sustainable yield, the same yield every year, year after year. But when fish habitats changes, and a fish species’s prey and predator also change, abundance of that fish species has to vary as well.
• Therefore, rather than seeking a constant yield from a living resource, harvest within a range determined by natural variations. The scientific way to do this has been developed and is on the shelf waiting to be applied. Push for that application.
• Change the way you think about restoring and sustaining nature. Instead of likening restoration of nature to restoring a Van Gogh or a ‘57 Chevy, think about restoring the wild and always changing Missouri River, with its frequent and sometimes abrupt changes in flow, direction, location of backwaters, meanders, and everything else.

Written for the Nature Conservancy
Copyright © 2002 Daniel B. Botkin
Originally published in TNC magazine

Augusta, Maine: The taking down of Edwards Dam — the first intentional removal of a major hydropower dam in United States history, was scheduled for 9:00 am on a beautiful spring morning in 1999. We arrived early to find a parking place and watch preparations. As a crowd gathered along the east bluff, a great blue heron flew low above the Kennebec River, traveling downstream from where water still flowed smoothly over the 161 year-old structure. Soon out of view, the heron had been disturbed from its usual stalking territory, perhaps by the big diesel shovel digging bucketfuls of soil from a temporary dam across the river, or the large crowd on the opposite shore, a unique mass of white and bright colors in the heron’s habitat. Or perhaps it was the noise of a helicopter and a float-plane circling overhead carrying television crews.The dam was being removed to save migrating fish, restore the river’s habitat, and improve fishing and boating. If fish increased in the river, it might be a boon for the heron. Built in 1837, the dam was operating when Henry David Thoreau canoed Maine’s rivers in the 1840s. [Read more...]