One of the topics addressed in Chapter 4 is Margaret Davis’ pollen work (pages 80-82 in the hardcopy edition). We people who study trees are familiar with the ideas of how different species came back from their refugia during glaciation, and how different assemblages of species have occurred through time. Many different groups of plants and animals have existed in different combinations on any particular piece of land through time. Changes can be due to changes in soil (e.g., Mt. St. Helens), changes in human activities (e.g., Appalachian “market-induced succession”) or invasive species (e.g., Chestnut blight) and changes are always going on (e.g., climate, development, etc.).
When I worked for the Forest Service, people would talk about how “ecosystems have evolved” and I would ask “what is the mechanism for an “ecosystem” to evolve?” If I had one critique with the ideas in Dan’s book, it is that he did not go far enough in talking about the Emperor’s missing clothes. Just reifying an “ecosystem” places natural phenomena within a human idea context and makes it possible to say all kinds of fuzzy things about an “ecosystem”. I think people use it as shorthand for more complex ideas, but the problem is that it lacks specificity and clarity.
I just ran across one this morning, that policies need to address “fire’s role in forest ecosystems.” My first question would be “fire’s role as to what aspect of plants, animals, water, soil and air?” Fire’s role, like climate or anything else, is not a constant. I like this quote from the book:
P 85. ..
we find that nature undisturbed is not constant in form, structure or proportion but change at every scale of time and space. The old idea of a static landscape, like a single musical chord sounded foresver, must be abandoned, for such a landscape never existed except in our imagination. Nature undisturbed by human influence seems more like a symphony whose harmonies arise from variation and change over many scales of time and space, changing with individual births and deaths, local disruptions and recoveries, larger-scale responses to climate from one glacial age to another, and to the slower alterations of soils and yet larger variations between glacial ages.
If you have been a reader and writer of Forest Service regulations lately, the “form, structure or proportion” will call back to your memory perhaps “ecosystem composition, structure and function”:
2012 Planning Rule: Alternative A would require plan components to provide for the maintenance or restoration of the structure, function, composition, and connectivity of healthy and resilient aquatic ecosystems and watersheds in the plan area.
2001 and Colorado Roadless Rule: Tree cutting, sale, or removal is needed to maintain or restore the characteristics of ecosystem composition, structure and processes.
These statements, in regulation, imply that certain characteristics should be “maintained or restored”; that is, maintained as they are today, or restored to what they used to be (yes, I realize that some in the FS is talking that “restoration” doesn’t mean that, it really means “resilience to change”, but English is English, and if you mean that you should put in in regulation, IMHO.)
Now, scientists reviewed all these regulations and did not say “hey, that doesn’t take into account current scientific thought, because there is no one unchanging way that composition structure and function is “supposed to be” and that “needs to be” maintained or restored.” I think in Dan’s book, he is again asking the question “if science tells us that everything is changing, why do scientists (including ecologists, I assume) review and accept regulations and other policies that seem to say the opposite?
I have three hypotheses. One is that the ecosystem idea has fuzzed everyone’s thinking. The second is that so much science is based on these ideas that scientists can’t imagine a world without them. Third is that scientists don’t study the “appeal to nature” idea in philosophy nor the history of its use (see Wikipedia here), so they don’t see that using it has conceptual problems way beyond the scientific community.