The human footprint falls most heavily on cities where high human population density and significant infrastructure development combine to dramatically alter ecological patterns and processes. As a result, some in the public and even some ecologists, treat cities as places outside of nature, rather than seeing the urban environment in its ecological, albeit highly constrained, context.  But what is that context and how can it be used to shape development of the city in the future?  Here I explore a thorough geographic reconstruction of the pre-European ecology of Manhattan Island (“Mannahatta”) as it existed on the afternoon of September 12, 1609.  We based our reconstruction on a highly detailed, large scale map of the landscape in the eighteenth century, when most of the original hills, streams, beaches and wetlands of the island were extant.  We combined geographic layers derived from historical maps with other information on the geology, topography, and climate of the island to suggest the original extent of ecological communities.  We modeled the landscape-level impacts of Native American use through settlements, horticulture and fire, and described the networked habitat relationships of the likely species of the island and surrounding waters, after analysis of historical records relating to species composition for plants and vertebrate animals.  We combined these different information sources on the original ecology to generate hypothetical, probabilistic maps of species distribution, which, when combined with modern geographic descriptions of the city, allow us to hypothesize about the block-by-block community compositions of the original island.  These compositions were then used to create historical views of the landscape exactly matched to aerial photographs of the city today.   

Results/Conclusions

We found that Mannahatta once had fifty-five different ecological communities which provided habitat for at least 1000 species, including people.  These communities and species varied widely in their distributions and probabilities across the landscape.  Human-induced fire influenced 80-100% of the island over two-hundred year simulation runs, and horticulture led to significant forest clearings and provided up to 30% of human caloric intake for the approximately 300 – 600 people that made Mannahatta home.  The network of habitat relationships, the “Muir web,” showed high levels of linkage redundancy, which may have stabilized ecosystem structure and function through disturbance.  The Mannahatta Project highlights the ecological legacies and patterns that still shape an island which now provides habitat to over 1.6 million people and an unknown number of other species.