A Sand County Almanac

Over the course of the book, Leopold notes the various ways in which human beings have interfered with the functioning of natural systems: through the suppression of natural processes, such as fire; through the disruption of food webs, with the removal of predators and other interventions; and through their own alienation from the land.

In describing the impact of interventions such as fire suppression, Leopold considers the bur oak, “the only tree that can stand up to a prairie fire and live” (29). These oaks were insulated by yearly spring wildfires on the prairie by their thick bark, but the fire, as well as the actions of mice and other animals, ensured the oak never took over and that the prairie remained open. When settlers on the prairie began suppressing fire, however, by turning the prairie into fields, oaks began to take over. Human changes to the landscape can also increase fire risk, as is the case in former marshland on the Wisconsin prairie, which was drained by settlers to make way for farming but which produced poor yields and was prone to wildfires; unlike the prairie, where fires are natural, these fires changed the former marsh for the worse: “great pockmarks were burned into field and meadow, the scars reaching down to the sands of the old lake […]. Rank weeds sprang out of ashes, to be followed after a year or two by aspen scrub” (106). By listing these examples of the consequences of landscape-level changes, Leopold is underscoring how little humans understand about the ecosystems they’re modifying—and how costly that ignorance can be.

The removal of predators also represents an interruption to natural processes. To highlight this dynamic, Leopold draws on his own experience of hunting a wolf in Arizona under the conviction that the removal of wolves was an unmitigated good: “I was young then, and full of trigger-itch; I thought that because fewer wolves meant more deer, that no wolves would mean hunters’ paradise” (138). Nonetheless, the opposite turns out to be true; the extirpation of predators causes deer populations to explode, causing overgrazing in the habitat, which ultimately leads the deer to starvation. While a deer killed by wolves is quickly replaced, ecosystems destroyed by deer are very slow to recover. Moreover, attempts to restore balance, by having hunters take over the role of killing deer, have their own environmental impact because they require roads and other incursions into the wilderness. In the discussion of the elimination of predators—particularly of wolves—which is repeated at several points throughout the book, Leopold demonstrates how human intervention can throw the normally stable food webs that form ecosystems into disarray, and how this imbalance, once introduced, can be very hard to address.

Finally, Leopold notes that humanity’s interruption of natural processes also applies to the connection between people and the land; humans are part of the planetary system, but the way in which modern life has developed has made them forget that fact—most people are ignorant of where the food they eat or the fuel they use comes from, much less how ecosystems function. Restoring the human relationship to the land through the development of a land ethic would not only address human alienation from nature but also restore the other two schisms discussed here—the natural functioning of landscapes and interactions between species—by inculcating an appreciation of their importance.