Placeholder Image

Subtitles section Play video

  • The substance of things unseen.

  • Cities, past and future.

  • In Oxford, perhaps we can use Lewis Carroll

  • and look in the looking glass that is New York City

  • to try and see our true selves,

  • or perhaps pass through to another world.

  • Or, in the words of F. Scott Fitzgerald,

  • "As the moon rose higher,

  • the inessential houses began to melt away

  • until gradually I became aware of the old island

  • here that once flowered for Dutch sailors' eyes,

  • a fresh green breast of the new world."

  • My colleagues and I have been working for 10 years

  • to rediscover this lost world

  • in a project we call The Mannahatta Project.

  • We're trying to discover what Henry Hudson would have seen

  • on the afternoon of September 12th, 1609,

  • when he sailed into New York harbor.

  • And I'd like to tell you the story in three acts,

  • and if I have time still, an epilogue.

  • So, Act I: A Map Found.

  • So, I didn't grow up in New York.

  • I grew up out west in the Sierra Nevada Mountains, like you see here,

  • in the Red Rock Canyon.

  • And from these early experiences as a child

  • I learned to love landscapes.

  • And so when it became time for me to do my graduate studies,

  • I studied this emerging field of landscape ecology.

  • Landscape ecology concerns itself

  • with how the stream and the meadow and the forest and the cliffs

  • make habitats for plants and animals.

  • This experience and this training

  • lead me to get a wonderful job with the Wildlife Conservation Society,

  • which works to save wildlife and wild places all over the world.

  • And over the last decade,

  • I traveled to over 40 countries

  • to see jaguars and bears and elephants

  • and tigers and rhinos.

  • But every time I would return from my trips I'd return back to New York City.

  • And on my weekends I would go up, just like all the other tourists,

  • to the top of the Empire State Building,

  • and I'd look down on this landscape, on these ecosystems,

  • and I'd wonder, "How does this landscape

  • work to make habitat for plants and animals?

  • How does it work to make habitat for animals like me?"

  • I'd go to Times Square and I'd look at the amazing ladies on the wall,

  • and wonder why nobody is looking at the historical figures just behind them.

  • I'd go to Central Park and see the rolling topography of Central Park

  • come up against the abrupt and sheer

  • topography of midtown Manhattan.

  • I started reading about the history and the geography in New York City.

  • I read that New York City was the first mega-city,

  • a city of 10 million people or more, in 1950.

  • I started seeing paintings like this.

  • For those of you who are from New York,

  • this is 125th street under the West Side Highway.

  • (Laughter)

  • It was once a beach. And this painting

  • has John James Audubon, the painter, sitting on the rock.

  • And it's looking up on the wooded heights of Washington Heights

  • to Jeffrey's Hook, where the George Washington Bridge goes across today.

  • Or this painting, from the 1740s, from Greenwich Village.

  • Those are two students at King's College -- later Columbia University --

  • sitting on a hill, overlooking a valley.

  • And so I'd go down to Greenwich Village and I'd look for this hill,

  • and I couldn't find it. And I couldn't find that palm tree.

  • What's that palm tree doing there?

  • (Laughter)

  • So, it was in the course of these investigations that I ran into a map.

  • And it's this map you see here.

  • It's held in a geographic information system

  • which allows me to zoom in.

  • This map isn't from Hudson's time, but from the American Revolution,

  • 170 years later, made by British military cartographers

  • during the occupation of New York City.

  • And it's a remarkable map. It's in the National Archives here in Kew.

  • And it's 10 feet long and three and a half feet wide.

  • And if I zoom in to lower Manhattan

  • you can see the extent of New York City as it was,

  • right at the end of the American Revolution.

  • Here's Bowling Green. And here's Broadway.

  • And this is City Hall Park.

  • So the city basically extended to City Hall Park.

  • And just beyond it you can see features

  • that have vanished, things that have disappeared.

  • This is the Collect Pond, which was the fresh water source for New York City

  • for its first 200 years,

  • and for the Native Americans for thousands of years before that.

  • You can see the Lispenard Meadows

  • draining down through here, through what is TriBeCa now,

  • and the beaches that come up from the Battery,

  • all the way to 42nd St.

  • This map was made for military reasons.

  • They're mapping the roads, the buildings, these fortifications

  • that they built.

  • But they're also mapping things of ecological interest,

  • also military interest: the hills,

  • the marshes, the streams.

  • This is Richmond Hill, and Minetta Water,

  • which used to run its way through Greenwich Village.

  • Or the swamp at Gramercy Park, right here.

  • Or Murray Hill. And this is the Murrays' house

  • on Murray Hill, 200 years ago.

  • Here is Times Square,

  • the two streams that came together to make a wetland

  • in Times Square, as it was at the end of the American Revolution.

  • So I saw this remarkable map in a book.

  • And I thought to myself, "You know, if I could georeference this map,

  • if I could place this map in the grid of the city today,

  • I could find these lost features

  • of the city,

  • in the block-by-block geography that people know,

  • the geography of where people go to work, and where they go to live,

  • and where they like to eat."

  • So, after some work we were able to georeference it,

  • which allows us to put the modern streets on the city,

  • and the buildings, and the open spaces,

  • so that we can zoom in to where the Collect Pond is.

  • We can digitize the Collect Pond and the streams,

  • and see where they actually are in the geography of the city today.

  • So this is fun for finding where things are

  • relative to the old topography.

  • But I had another idea about this map.

  • If we take away the streets, and if we take away the buildings,

  • and if we take away the open spaces,

  • then we could take this map.

  • If we pull off the 18th century features

  • we could drive it back in time.

  • We could drive it back to its ecological fundamentals:

  • to the hills, to the streams,

  • to the basic hydrology and shoreline, to the beaches,

  • the basic aspects that make the ecological landscape.

  • Then, if we added maps like the geology, the bedrock geology,

  • and the surface geology, what the glaciers leave,

  • if we make the soil map,

  • with the 17 soil classes,

  • that are defined by the National Conservation Service,

  • if we make a digital elevation model

  • of the topography that tells us how high the hills were,

  • then we can calculate the slopes.

  • We can calculate the aspect.

  • We can calculate the winter wind exposure --

  • so, which way the winter winds blow across the landscape.

  • The white areas on this map are the places protected from the winter winds.

  • We compiled all the information about where the Native Americans were, the Lenape.

  • And we built a probability map of where they might have been.

  • So, the red areas on this map indicate the places

  • that are best for human sustainability on Manhattan,

  • places that are close to water,

  • places that are near the harbor to fish,

  • places protected from the winter winds.

  • We know that there was a Lenape settlement

  • down here by the Collect Pond.

  • And we knew that they planted a kind of horticulture,

  • that they grew these beautiful gardens of corn, beans, and squash,

  • the "Three Sisters" garden.

  • So, we built a model that explains where those fields might have been.

  • And the old fields, the successional fields that go.

  • And we might think of these as abandoned.

  • But, in fact, they're grassland habitats

  • for grassland birds and plants.

  • And they have become successional shrub lands,

  • and these then mix in to a map of all the ecological communities.

  • And it turns out that Manhattan had 55 different ecosystem types.

  • You can think of these as neighborhoods,

  • as distinctive as TriBeCa and the Upper East Side and Inwood --

  • that these are the forest and the wetlands

  • and the marine communities, the beaches.

  • And 55 is a lot. On a per-area basis,

  • Manhattan had more ecological communities

  • per acre than Yosemite does,

  • than Yellowstone, than Amboseli.

  • It was really an extraordinary landscape

  • that was capable of supporting an extraordinary biodiversity.

  • So, Act II: A Home Reconstructed.

  • So, we studied the fish and the frogs and the birds and the bees,

  • the 85 different kinds of fish that were on Manhattan,

  • the Heath hens, the species that aren't there anymore,

  • the beavers on all the streams, the black bears,

  • and the Native Americans, to study how they used

  • and thought about their landscape.

  • We wanted to try and map these. And to do that what we did

  • was we mapped their habitat needs.

  • Where do they get their food?

  • Where do they get their water? Where do they get their shelter?

  • Where do they get their reproductive resources?

  • To an ecologist, the intersection of these is habitat,

  • but to most people, the intersection of these is their home.

  • So, we would read in field guides, the standard field guides

  • that maybe you have on your shelves,

  • you know, what beavers need is, "A slowly meandering stream

  • with aspen trees and alders and willows,

  • near the water." That's the best thing for a beaver.

  • So we just started making a list.

  • Here is the beaver. And here is the stream,

  • and the aspen and the alder and the willow.

  • As if these were the maps that we would need

  • to predict where you would find the beaver.

  • Or the bog turtle, needing wet meadows and insects and sunny places.

  • Or the bobcat, needing rabbits and beavers and den sites.

  • And rapidly we started to realize that beavers can be

  • something that a bobcat needs.

  • But a beaver also needs things. And that having it

  • on either side means that we can link it together,

  • that we can create the network

  • of the habitat relationships for these species.

  • Moreover, we realized that you can start out

  • as being a beaver specialist,

  • but you can look up what an aspen needs.

  • An aspen needs fire and dry soils.

  • And you can look at what a wet meadow needs.

  • And it need beavers to create the wetlands,

  • and maybe some other things.

  • But you can also talk about sunny places.

  • So, what does a sunny place need? Not habitat per se.

  • But what are the conditions that make it possible?

  • Or fire. Or dry soils.

  • And that you can put these on a grid that's 1,000 columns long

  • across the top and 1,000 rows down the other way.

  • And then we can visualize this data like a network,

  • like a social network.

  • And this is the network of all the habitat relationships

  • of all the plants and animals on Manhattan,

  • and everything they needed,

  • going back to the geology,

  • going back to time and space at the very core of the web.

  • We call this the Muir Web. And if you zoom in on it it looks like this.

  • Each point is a different species

  • or a different stream or a different soil type.

  • And those little gray lines are the connections that connect them together.

  • They are the connections that actually make nature resilient.

  • And the structure of this is what makes nature work,

  • seen with all its parts.

  • We call these Muir Webs after the Scottish-American naturalist

  • John Muir, who said, "When we try to pick out anything by itself,

  • we find that it's bound fast by a thousand invisible cords

  • that cannot be broken, to everything in the universe."

  • So then we took the Muir webs and we took them back to the maps.

  • So if we wanted to go between 85th and 86th,

  • and Lex and Third,

  • maybe there was a stream in that block.

  • And these would be the kind of trees that might have been there,

  • and the flowers and the lichens and the mosses,

  • the butterflies, the fish in the stream,

  • the birds in the trees.

  • Maybe a timber rattlesnake lived there.

  • And perhaps a black bear walked by. And maybe Native Americans were there.

  • And then we took this data.

  • You can see this for yourself on our website.

  • You can zoom into any block on Manhattan,