jameslee1

Once upon a time, the study of nature was a low-tech affair; pack a compass, a pencil, and a sturdy pair of shoes and you were pretty much good to go. No longer. Modern naturalists are -- must be -- seriously plugged in. They orient themselves precisely with GPS and GIS. They plumb Internet databases, download remote-satellite imagery, use advanced computers (or sometimes mere laptops) to mine data, detect patterns, and model large-scale, long-term trends. Just recently a team of scientists found the imprint of a giant, ancient meteor impact simply by using that most ubiquitous of digital tools, Google Earth.

It isn’t just geology, or biology, or ecology anymore, it’s Earth-system science. That’s a good thing; never have we understood so well our species’ impact on the natural world. But it also presents a paradox: the more sophisticated our means of studying nature, the fuzzier the nature of this thing called "nature" has become.

Consider a map of the world’s biomes created three years ago by Erle Ellis and Navin Ramankutty, geographers at (respectively) the University of Maryland, Baltimore County, and McGill University. Biomes are classic categories established by naturalists decades ago that define the world’s ecosystems according to a handful of natural factors like local climate, leaf type, and plant structure. Ecologists officially recognize a dozen biomes or more -- tundra, deserts, tropical grasslands, temperate forests -- and rely on them to situate their own field studies and view their findings in a global context.

Ellis and Ramankutty reexamined these traditional biomes through a modern lens, combining satellite data, agricultural statistics, and a population model developed by the USGS. As it turns out, only about 20 percent of earth’s ice-free land is in pristine condition; the rest is influenced, directly or indirectly, by human activity. (As much as 40 percent of the world’s land is used just for growing food or grazing animals.) The deserts, tundra, and forests are still there; it’s just that these classic biomes are now so fragmented, Ellis and Ramankutty found, that they’re no longer the defining feature of most landscapes. As ecological tools, they’re all but useless.

So the two geographers drew up a new set of "anthropogenic biomes," or anthromes, to better characterize where most of the world’s nature actually resides. They divided earth’s land into to 21 categories of usage, from sparse trees and wild forest to residential rangelands, remote croplands, irrigated villages, and dense settlements. Most of these areas aren’t traditionally considered ecological habitats, yet inasmuch as they comprise 80 percent of dry land, that’s precisely what they are -- and exactly the point the map aims to make.

Indeed, by design, the map raises a provocative question: if 80 percent of the terrestrial world, including a wealth of nature, is anthropogenic, why do naturalists largely ignore it? When we study "nature," what exactly are we studying?

With Ellis’s help, Laura Martin, a doctoral student in ecology at Cornell University, recently sought to find out. She combed through five years of ecology journals and analyzed 2,573 terrestrial studies. She crunched so much data that at one point the school cut off her online access, convinced she was illegally redistributing journal documents. "I learned that you should always tell your library before doing a meta-analysis," Martin jokes.

According to the authors’ own descriptions, at least two-thirds of the studies aimed to study nature in places devoid of human influence, including "protected areas" like national or state parks. But when Martin pulled back the camera slightly, she saw something different. Using each study’s geographic coordinates, she plotted the field sites against Ellis’s database, to see where on the scale of anthropogenic usage each site actually sat. To her surprise, she found that at least half the studies were conducted within regions that, on a six-by-six-mile scale, would be considered densely settled. In other words, more than half the ecologists were focusing on the least-trafficked parts of the most human-modified regions -- and treating them as pristine.

Since the aim of ecology is to reveal how natural processes work, one has to ask: Are these areas natural or not? The answer might well be yes, but the point, Martin says, is that ecologists can’t say for sure. "There’s an assumption that ecosystems behave differently in areas that have been modified by people. But we don’t know, because we’re studying only the uninhabited areas and assuming that the inhabited areas are somehow different." Ellis underscores the notion. "We live on a used planet," he says. Ecologists, by averting their gaze from the anthropogenic world -- i.e., most of it -- "have isolated themselves, and they don’t have a good idea of how the biosphere functions today."

What Ellis, and Martin, and other scientists of their viewpoint aren’t suggesting is that truly pristine wilderness should be studied any less than it already is. Rather, they contend, the less-than-pristine world -- our dominant and expanding backyard -- deserves more credit and attention as wildlife habitat.

Call it a coming of age. Increasingly, scientists contend that we’ve entered a new geological epoch, the Anthropocene, marked by humanity’s tremendous, irrevocable impact on the natural world. That’s an echo of Bill McKibben’s argument from the 1980s (itself an echo going back to the 1700s) that nature has ended -- that the realm of wilderness separate from mankind has ceased to exist. Personally I’m not convinced that nature and humankind were ever so categorically distinct. But let’s say they once were and no longer are -- that nature and we are now inseparably entwined. How long can we go on studying nature as if it’s something that’s found only where we aren’t? At the very least, we owe it to the flora and fauna that have managed to thrive in our shadow. If the Anthropocene is truly here, let’s do more than give it a name: let’s get to know it.

"We need to get beyond the idea that people are a disturbance or an impact," Ellis says. "We’re permanent, we’re stewards, we’re here."