The Reliability of Historical Data

I've been writing up my research on presettlement forests in western New York, and one of the most frustrating things about this work is that there is a huge gap in the data and--obviously--no way to go back and correct it.

The land surveys I work with were done in 1811. Three out of four surveyors used the same sampling methods. But one of them--was he confused? too innovative?--did not collect one of two types of data. Specifically, what surveyors were expected to do was to find the corner of the property lots and then locate the closest tree to that corner. They would write down the species of that tree, its diameter, and where it stood in relation to the corner (distance and compass direction). Then they would also blaze the tree with the lot numbers (carve the numbers into the bark). This information was collected so that whoever bought the property could then go out and identify the boundaries of their land. Unless the tree was struck by lightning and went up in a blaze, this was a fairly reliable way of keeping track of property corners for at least a couple of decades. And it helps forest scientists 200 years later.

But in the surveys I'm using, one surveyor did not record this information at all. Instead he had his team cut posts and set them in the ground at the lot corners. This sounds like a LOT more work than blazing a tree and taking down some notes. Moreover, the posts that he set were of ironwood--a small tree that is hard to cut but rots quickly. Those posts probably didn't stand for even a decade.

This is a common type of problem with historical data. It's full of gaps. It's not entirely reliable. It can't be checked! Or, in the case of historical records, it may have been gathered in a way that is difficult to reconcile with contemporary measures.

I read of an interesting example of using historical records which was recently published in the Journal of Geophysical Research. Woodworth (et al) made use of tidal gauge measurements in the Falkland Islands collected in the mid-19th century by the explorer James Clark Ross. They correlate these with other historical measurements of sea level and with contemporary measures based on satellite altimetry in order to construct a more long-term record of change in sea level.

What this historical data accomplishes is to show that the rate of sea level rise has been accelerating. In historical ecology, too, what the vegetation data show clearly is that there has been rapid change in the last 200 years but only slow changes in forest composition before that.

Historical data is gappy, but it's often good enough to demonstrate a key point.

Motivating Concern for Natural Places

A post that I wrote a few weeks ago on a project to restore an urban old-growth forest in my neighborhood continues to receive some hits and comments, so I think I'll give an update.

Margaret just asked if I could say more about nature and vulnerability to decline.

My sense is that there are several ways of looking at nature--both here, in this Grove, and elsewhere. In one story, nature is a magnificent force who looks after herself. Although we humans can do things to harm natural settings, in time they eventually recover. Damage is not permanent. And at the same time, if we try to tame nature, she will reassert herself. In the case of this very old and very tall piece of forest, the forces of nature seem strong and our influence seems weak. The trees are tall and old. When they fall, that's just nature's development. The vegetation is at times dense and healthy. There are many chipmunks and squirrels and insects and birds. In this story, as long as there is no asphalt, there is nature, and she is looking after herself.

But another way of looking at this same forest pays attention to some details: the young trees are mostly escapees from garden plantings, as are many of the shrubs and herbs. Besides the mature trees, the plants that looks so vigorous and dense are Norway maples and black swallowwort and English ivy. The trillium are gone, the mayapples are mostly gone. In this story, there is greenery, and in one sense it is natural--and vigorous! But in another sense, it is the result of human culture, and these are the same plants that grow everywhere else--in my yard and in the drainage ditches. And we see that even things that seem permanent--the dirt we walk on--winds up in the storm sewers as erosion takes over when the roots of growing things are not holding it stable.

Margaret, I like your idea about focusing on wildflowers. I've seen that be a successful strategy both where I grew up, in Texas, and also where I now work in western New York. In the 1980's a campus group planted trillium and some other spring ephemerals and now they are naturalized.

In the last few weeks the city foresters have proposed a plan to run a trial of removing the invasive Norway maple saplings in some constrained areas. This sounds like a good plan to me. It proceeds decisively but also slowly enough to find out if the intervention will have the desired effect in terms of achieving some control but also not impacting the aesthetics of the grove. My concern is just that the saplings are ID'd properly since there is a mix of the native sugar maples and the invasive Norway maples. These two kinds of trees can be hard to distinguish even though they aren't closely related--especially in early spring.

Nature, Culture, and Gardening

I've been participating in a community-based restoration project in my neighborhood. The agreed upon objective is to restore and maintain a mature (probably old-growth)oak-hickory woodland. The woodland is part of a city park, and the city has had a hands-off management approach. About once a year, paths are cut through the largest deadfalls blocking trails, and the city will take down dead trees that threaten structures on the neighboring properties. The park has dense networks of trails, and it is heavily used in all seasons.

It's also ecologically distinctive. It contains a number of mature butternut trees, which have become rare in the northeast, and some other rare tree specimens. Its majestic red, black, scarlet, and white oaks are close to 200 years old. There are also large tulip trees, hickories, and black cherries, as well as two glacial kettles. Archival photographs and maps indicate that it was never logged.

And, not surprisingly, it contains many, many Norway maples. Lots of autumn olive. Banks of black swallowwort. And garlic mustard looms on the edges. Invasive species are a real problem. Knocking out all the Norway maples, though, would quite possibly cause a noticeable impact in the understory. Members of the project are passionate and, in many ways, knowledgeable about natural history. The project itself, though, is not data-driven.

One of the things that has interested me about the public response to the project has been frequent opposition on the grounds that any form of maintenance or intervention is akin to gardening and therefore "unnatural."

I've heard several people say that they do not mind the idea that the oaks would be overcome by Norway maples fifty years from now. One said that one tree is as good as another--as long as the woodland is green, it's essentially the same. But others have said that they wouldn't mind the transformation because they see that change as part of the natural order. Things change, and as long as the change is "natural," it can be welcomed. Keeping Norway maples out of this grove is viewed as manipulation, and the specific kind of manipulation as driven by nostalgia, a desire to treat this woodland as though it is a museum piece.

What are the politics behind these views? I sense a kind of anti-intellectualism that identifies science with elitism. The concept of "invasive species" is a scientific concept, not a folk category. Moreover, perhaps there is the feeling that a negative judgment against this grove that they have always enjoyed and perceived as perfectly healthy is a judgment against them for not being as attuned as others have been to its ecological fragility. There is resistance to the idea that this grove--or any part of nature--is or could be fragile.

There seems to be an identification of these 50 or so acres as wilderness, despite their location inside the city limits of a large city. Since they're perceived as wilderness, the legitimate response is seen as neglect, not management. Perhaps more trust is put in nature as manager than humans as managers.

Trees, We Love Them

A friend called my attention to the NYT's profile of Diana Beresford-Kroeger, a medical researcher who has written books about trees, including Arboretum America: A Philosophy of the Forest.

Her ideas range from the common-sensical to the visionary (and perhaps beyond, to the wishful).

She tries to bring together aboriginal healing, Western medicine and botany to advocate an unusual role for trees. She favors what she terms a bioplan, reforesting cities and rural areas with trees according to the medicinal, environmental, nutritional, pesticidal and herbicidal properties she claims for them, which she calls ecofunctions. Wafer ash, for example, could be used in organic farming, she said, planted in hedgerows to attract butterflies away from crops. Black walnut and honey locusts could be planted along roads to absorb pollutants.

One thing the article's author focuses on is the speculative nature of some of her proposed uses for trees. Many are based on folk medicinal lore, some of which has been confirmed by science and some of which are certainly far-fetched.

© Scot MacLean

But the real challenge of her ideas seems to me to be something different--it is a radical idea that we should look to the particular uses of trees and plan which trees grow where based on their uses rather than their appearance. For one thing, most forests aren't planned, they just grow. Urban forests are partly planned, as when city foresters pick street trees to create an aesthetic and disease-resistant mixed forest. (This is a top concern ever since our monoculture street trees were devastated by Dutch elm disease.) But urban forests are mostly unplanned. Norway maples, at least in my New York neighborhood, grow wherever they find soil and aren't pulled up or mowed down. And people make aesthetic decisions about planting trees which are based on fashion and availability.

Planning a forest, outside of the context of plantation planting or restoration projects, is a novel idea. I think that some might jump on this idea and worry that too much planning undermines the agency of nature. That is not my worry. The agency of nature is already working against a great burden. Apathy is the real force that would work against it. For instance, some would not see the point in growing medicinal or food trees when we are living in such a time of plenty. A half dozen times last month, neighbors saw me and my kid grazing on mulberries and asked "You really eat those?"

Conservation Biology and Intervention

Ecological restoration is usually thought of as preserving or recreating previous conditions that were changed as a result of human activity. An important part of this is being true to both time and space. Preserving Himalayan pines in a Rochester, NY arboretum is the vegetative equivalent of a zoo; it’s not restoration. But restoring tallgrass prairie in Illinois to its presettlement condition after most of our American prairies were converted to agriculture is considered restoration.

What is not usually considered either restoration or preservation is assembling species in new configurations. This week a policy article in Science proposes, though, that such new assemblages will be required in order to preserve the existence of certain species in the face of rapid climate change. The authors call the proposed policy action “assisted colonization.” The idea is that climate may be shifting too rapidly (due to human activity) for many species to migrate on their own. In addition, human development has fragmented habitats in ways that prevent migration.

What and how should we (environmental philosophers) think of this proposal? Is it still a means of preservation? Is it preservation in a robust sense, as opposed to the sort of last-ditch, pathetic rescue that zoos attempt for the last remaining exemplars of species? What considerations should be taken into account?

While there may be some essentialist objection to the intense intervention that assisted colonization would allow, I can only see it resting on contested understandings of the natural. Migration itself is natural. For example, in the west, pinyon pine is migrating northward, and in the east, white oak is slowly migrating northward following the last ice age, 15,000 years ago. On the other hand, this particular climate change and much habitat fragmentation is human-caused. And the consequences of the current mass extinction of species are dire.

Rather, appropriate objections revolve around gaps in our knowledge. When should we act, and how much risk can we take on, especially given humanity’s past mistakes? When weighing these questions, though, we should consider that many of those mistakes happened in pursuit of other goals—political and economic advantage.

Conservation biologists and environmentalists care about preserving species, and we care about natural associations. But if climate change predictions are correct, then we can’t have it both ways. One requirement, as we proceed, is to carefully collect and analyze information, including the success and failure of restoration projects. Habitat destruction remains the greatest single threat to biodiversity, over and above climate change, and will be the first priority for decades to come. But considering these questions is wise, while we still have the luxury of thinking about them.

CFP: An interdisciplinary conference on ecology and philosophy

Call for Papers

Recreate, Replace, Restore:
Exploring the Intersections between Meanings and Environments

A Conference at
Ohio Northern University

17-19 April 2009

Sponsored by the ONU Working Group on Religion, Ethics, and Nature

The natural world has been “humanized”—even areas thought to be wilderness bear the marks of human impact. Given the long reach of human influence, environmental thought in the humanities and the sciences have sought to understand how we can limit, change, or reverse the more disastrous effects that humans have had on the environment. Preservation is not the sole or primary strategy; restoration, sustainable design, and other creative responses to place have become part of the debate. Further, both the sciences and the humanities have increasingly realized the interconnection between human accounts of meaning and the more-than-human world. Thus, reflections on the proper approaches to natural and built environments increasingly include investigations into contested religious, philosophical, and ethical meanings of the
environments that surround us.

Possible themes include (though are not limited to):
• The philosophical, ethical, religious or spiritual dimensions of restoration in all its aspects
• Scientific assessments of restoration, the reintroduction of species, or the preservation of locales
• Built environments, nature, and the meaning of place
• Theological and philosophical reflections on human alterations of environments
• Architecture and green building as recreating places

More info here(pdf).

This is a call for papers (20 minutes reading time) and for poster presentations.
Deadline for proposals is Oct. 31, 2008.

Ecology and History

Here's a New York Times article about new ideas in stream restoration. It does a great job of making presettlement environmental history seem at least a teensy-weensy bit sexy!

In the embedded video, Dorothy Merritts says that when we are considering the reasons for environmental problems, such as heavy silt loads deposited into the Cheasapeake Bay, "we can't just look around at modern land use and say 'We see agriculture—that's the problem. We see new suburbs—that's the problem.' Instead, go in and look at the history of that location."

Two good points here:
1. Land use history is not just interesting--it's an essential piece of knowledge to have in order to understand causes.
2. Over a billion dollars of private and public money is being spent on environmental restoration, but many projects are not based on evidence. The practice is advancing faster than the academic study of failures and successes.

Trees

When I'm not teaching philosophy, one of the things I do is study presettlement-era forests in western New York. During the coming quarter I expect to be doing more of that, so in anticipation I've collected a few items on trees:

For one, I keep up with the policy debate over the Bush Administrations "Healthy Forests Initiative" which pays lip service to selective logging. If done right selective logging could decrease the frequency, intensity, and extent of wildfires. But the initiative has been used as an excuse to log (lucrative) areas which would otherwise be off-limits. For instance, since it gives priority to logging in national forests at the "wildland/urban interface," huge remote areas have received that designation. (Read more here.) In December, though, the Ninth Circuit Court of Appeals suspended the policy that has allowed logging in national forests without environmental review on the basis that the policy violated the 1969 National Environmental Policy Act. (NEPA is the legislation that requires that management of public land include public input.)

There is a blog carnival, Festival of the Trees, and the March edition celebrates orchards.

My favorite tree blogs are:
Tree Species: Exploring the world of trees
Arboreality: About trees, forests, and wood
The Forest Protection Blog

And here are some more general plant and ecology blogs:
Talking Plants, on NPR
Invasive Species