Its Byte is Worse Than Its Bark: New York’s Tree Census

15 Dec

I am two with nature, professes Woody Allen, and this New Yorker is only too happy to corroborate his math.  I know nothing about the flora that roots itself in the city’s spaces, and with my gaze locked in perceptual auto-filter, I hardly see them at all. The only branch I’ve noticed lately is the one that belongs to my bank.

In other words, I can’t see the trees for the forest, but they’re there – about 623,000 of them, and the New York City Open Data site’s borough-wide arboreal inventory fills me in on each and every one of them, should I at last decide to make the acquaintance. Look here for the data:

https://data.cityofnewyork.us/browse?q=Street%20Tree%20Census&sortBy=relevance&utf8=%E2%9C%93

The census has pretensions to completeness, and given its address-level molecularity I’d guess it comes pretty close. In the interests of cross-county comparisons (borough equals county) I downloaded and copied-and-pasted the records to a consolidating master workbook, thus harvesting all 600,000 or so trees into one Sequoia-large data set, one that at 60 MB would do severe ecological damage to Word Press’s downloading channel. In other words, you’ll need to consolidate the above link’s offerings on your own.  (Note: the Staten Island data originate in DBF, or dBase mode, but follow the standard File> Open check-in with a specification for dBase Files (*.dbf), and the data will effect its proper spreadsheet mien. Note in addition that Staten Island’s Treepit numbers – referencing a field about which I know absolutely nothing – were minted in label format, and I don’t know why; but I’ve yet to work with them, either, so the matter remains moot, though curious.)

And the meaning of the entries in the set’s fields isn’t entirely forthcoming; preeminent among the recalcitrant is Species, whose coded tree names had me searching for a Boy Scout, at least until stepped on this document in the wilderness:

http://www.nycgovparks.org/sub_your_park/trees_greenstreets/treescount/images/species_list.pdf

Courtesy of none other than New York’s tree census.

After saving it all as a text file and pasting it into a new workbook sheet, feeding the names into a text-to-columns grinder and mashing the columnized names via a concatenating ampersand or two (e.g. =B3&” “&C3&” “&D3&” “&E3), I nailed and glued the whole goopy effluvium into a tottering VLOOKUP table that seems to be standing up to New York’s December gusts and showers. After next inundating the sheet’s next available column (which I titled Species Name) with lookup formulas that exchanged the codes for the full species names, and paved the formulas over with a copy Paste Special > Values hard-coded surface, the deed was done.

Now what? Well, note for starters that the folks of the New York design studio Cloudred  have cultivated an interactive chart of the trees and their species/borough distributions, leaving your character-based correspondent here to wonder about such other tree novella in there as might be learned. So how might the tree census tally broken out by the city’s zip (i.e. postal) codes work? Try running this by or through a pivot table:

Slicer (or Report Filter): BOROUGH

Row Labels: ZIPCODE

Values: ZIPCODE (Count)

Then try Slicing Manhattan, for example, and sorting the results Largest to Smallest. I get, in excerpt:

 trees1

Now here is where some New York-percolated smarts would hand-craft your understanding of the numbers should you want to key tree demographics to zip codes and their constituent neighborhoods (and if you’re in need of percolation, look to this zip code/service-area legend:)

https://www.health.ny.gov/statistics/cancer/registry/appendix/neighborhoods.htm

Heading the count is 10021, coding none other than Manhattan’s fabled Upper East Side, among the country’s poshest districts and 50% greener than silver medalist 10025, right across Central Park in the island’s Upper West Side, itself literally just above third-place 10024, somewhere in the middle reaches of the Upper West Side. The sociologists among you will wonder if class, politics, or the politics of class have committed their invidious inputs to the tree populations, or rather if territorial receptivities to the planting enterprise better explain the variance.  And for the curious, Staten Island –  containing far fewer human New Yorkers than any other borough but second only to Queens in the hardwood department  – can market its 10312 as the New York’s most tree-swarmed zip code, reporting 23,156 of those life forms to the authorities. (Note by the way the 24,000 zip-code-less entries in the data set, though, and I see no enumerations of park-resident trees, clearly an enormous and apparently uncounted cohort. It appears as if our data surveys address-bearing trees alone, unless I’ve got it way wrong.)

And you’ve been asking about New York’s tree diameters, and I hear you. They’re recorded here in what must be inches, and we can kick off with something simple:

Row Labels: BOROUGH

Values: DIAMETER (Average, squeezed to two decimal points. I get

The averages diverge notably, though you’ll need a greener thumb than mine pressing these keys to understand and explain why. Perhaps Manhattan’s penumbrous skyline stunts tree girths, but again you’re hearing that supposition from the wrong person – just ask Woody. If, on the other hand, you try this table out:

Row Labels: Species Name

Column Labels: BOROUGH

Values: DIAMETER (Average)

trees2

You’ll find some inter-borough comparisons across the same species that place the Manhattan diameters on the low side.

A few final points: As could be anticipated with a 623,000-record data set, some distinctly outsized numbers appear to have crept into the park. The 148-32 86th Avenue address in Queens’ Jamaica neighborhood boasts a 2100-inch-diametered  tree, and my Google Maps photo just doesn’t capture it. At 175 or so feet in width, I think it would show up.

The last point: the data with which we’ve been working hold up the back end of what New York Open Data showcases in the first instance as a set of borough tree-positioning maps of the census. Here’s the one for Manhattan:

trees3

Maximum coverage – maximized information? That’s called a rhetorical question.

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