National Geographic : 2009 Sep
Sanderson called this network a Muir web, a er American naturalist John Muir, who once noted that "when we try to pick out anything by itself we nd that it is bound fast by a thousand invis- ible cords that cannot be broken, to everything in the universe." Sanderson and his team, in a sense, were trying to make those thousands of cords visible. Consider a beaver that lived at Times Square in 1609. If you grabbed him by the scru of his neck and li ed him out of the web, you d nd lines connecting him to a slowly meandering stream, to the aspen trees he ate, and to the mud and twigs he used to build a lodge. Not only that, you d also nd lines to the bobcats, bears, and wolves that depended on him as prey and to the frogs, sh, and aquatic plants that lived in the pond he helped to create. " e beaver, it turns out, is a landscape architect, just like people," Sanderson said. "You need him to ood the forest, which kills the trees that attract the woodpeckers that knock out cavities that wood ducks use for shelter." Li ing a beaver out of the web disrupts scores of other residents, which demonstrates how important it can be to think about an ecosystem as a network. By the time Sanderson and his team had nished compiling their database, they d put together one of the most detailed scientific reconstructions of a landscape ever attempted, identifying 1,300 or so species and at least 8,000 relationships linking them to one another and their habitats. is was somewhat ironic, San- derson admitted, since it described a place that didn t exist anymore. But the same methods that created a portrait of Mannahatta could be applied to wild places today, such as the Greater Yellowstone region, the Congo forest, or the eastern steppes of Mongolia. If scientists have a model of how a landscape and species interact, they can better predict the impact of climate change, hunting, or other disruptive factors. For the Mannahatta Project, the next step was to turn all of these data into realistic 3-D scenes, like the one you see at the top of page 122. Sanderson s goal, from the start, had been to show what any spot in today s city---say, the taxi stand on Seventh Avenue in front of Madi- son Square Garden---looked like 400 years ago. (It was a marsh at the edge of a forest.) To make that happen, Markley Boyer, a visualization spe- cialist, used 3-D modeling so ware to populate each digitally created scene, block by block, with the right mix of oaks, hickories, streams, ponds, and marshes according to the Muir web database. "We re basically using the same kind of 3-D so ware they use in Hollywood to create digital armies marching across a plain," Boyer said, "only we re generating tens of thousands of trees in appropriate proportions for each for- est type." Visitors to themannahattaproject.org can give the time machine a try by entering any address in Manhattan to see what that block looked like way back when. As New Yorkers this month mark the 400th anniversary of Hudson s visit, Sanderson hopes his project, which has grown to include more than 50 historians, archaeologists, geographers, botanists, zoologists, illustrators, and conserva- tionists from the WCS and other institutions, will stimulate a new curiosity about what existed on Manhattan before the explorer arrived. "I d like every New Yorker to know that they live in a place that had this fabulous ecology," he said. " at New York isn t just a place of fabulous art, music, culture, and communications, but also a place of amazing natural potential---even if you have to look a little harder here." j Herald Square W. 125th Street Columbus Circle Times Square George Washington Bridge Canal Street (Interstate 95) Today 1609 100 0 200 ft NGM MAPS BULLDOZING BROADWAY A cross section of the island along the avenue shows how much of the landscape was leveled to build the city.