Constructed Climates

Although many people presently support planting trees in the name of carbon sequestration and sustainability,  city natural spaces also involve economics, ecology, social aspects,  and air and water quality.
This book summarizes my study of urban environments, the role vegetation and trees play, and costs and benefits humans experience from urban open space.

There are a number of goods, but what resonates most with me concerns the issues of emotional health.
Near the end of the book I show that low-income areas with rental housing have less vegetation, and it may be that by enhancing low-income citizens’ lives through the planting of trees and shrubs, an active demonstration of a long-term investment in people’s lives, a city can promote positive social interactions right where they’re needed most.
Of course, it’s hard to believe that a lack of trees drives the conditions faced by low-income residents, but  some evidence suggests that urban vegetation alleviates social ills.
It makes sense.
I truly enjoy gardening and love seeing plants regenerate every spring, a love probably instilled in me from growing up on a farm, watching my parents plant things for their future (and mine).
As people of the cities become more accustomed to instant access and communication, and more detached from the delayed gratification needed to spend time planting something now with a payoff months or years off in the future, we face a greater challenge in making sure the cities we live in will have 50-year-old trees 60 years from now.

Another important function involves stormwater runoff, a topic I’ve only barely touched upon here.
In my part of the country, rain falls on impervious surfaces and washes off pollutants.
This stormwater runoff brings those substances with it into streams where organisms live and into reservoirs that serve people with drinking water:  cleaner runoff, cleaner city water.
Urban open space can play a role in purifying that water.

A few quick words about the book’s approach and structure:
When approaching any research question, one faces balancing depth and breadth.
Each brief topic I examine warranted independent theses and books, evidenced by the cited primary literature, and the breadth covered here sacrifices discussing many known details.
The plots and results I show often reflect just one small part of a greater whole, leaving out the various nuances about a particular topic that an entire publication or research discipline considers.
I bring in just enough material to fill a several hundred page book that, I believe, introduces the many topics concerning this synthetic area of urban environments.
Nevertheless, I hope my summary accurately reflects  the author’s relevant conclusions, or at least some small part of their study.

Graphs and plots provide the best summary of scientific results, and I use them liberally.
Each of the plots I show comes from one or more peer-reviewed or agency-published publication [In many cases I used a wonderful little open-source JAVA program, Plot Digitizer, freely available from plotdigitizer.sourceforge.net, to extract data from published graphs and replot them here.], and, on occasion, new and unpublished data.
I’ve also shown a clear preference for the underlying data rather than statistical analyses.
Some important studies present the results of formal and complicated statistics without showing a single plot of underlying data.
It is certainly correct that scientists must perform statistical analyses, but I find the data even more appealing, with the statistical measures backing up and supplementing the data, not replacing them.
Although that’s my preference, showing only data is not a rule, and  situations exist when data plots become unworkable.

Probably the most apparent structural feature I’ve introduced and used throughout is the “two-page” format, with plots, tables, and diagrams on left-hand, even-numbered pages, and the relevant explanatory text on the facing right-hand pages. [You won't see that on the website.]
As I stated above, my goal is covering the breadth of urban environment topics in a limited space.
This format constrains how deeply I examine each topic, though to relax this constraint I use endnotes extremely liberally for citations, comments, and further details.
In some ways the format puts concepts on an equal footing:  some topics have many studies, and others have very few, a variation that  reflects differences between ease of study, commercial relevance, environmental importance, or human-health motivations.
Those differences might not truly represent relative levels of importance to urban environments, and my hope was to cover more equally what I believe are important aspects of urban environments.
Further, I think of the rigidly enforced two-page constraint as demanding a prioritization of information rather than expanding sections here and there as more content becomes available.

The format also reflects my visual nature, or my preference for data plots because the data speak for themselves much of the time.
Why use squishy words to talk about a concept when the data show it more clearly?
Granted, not everyone has such an inclination.
For readers uncomfortable with reading graphs I’ve added an Appendix covering the basic concepts and ideas contained within.

In addition to plots, I provide various calculations throughout the book,  many of them rough ones  called order-of-magnitude calculations, designed primarily to see if something makes sense, an approach that checks whether different numbers from different concepts generally agree or disagree.
This approach originates with my physics training and serves scientists well under many situations.
Furthermore, I have struggled with the very odd combinations of measurement units, for example, the volume of stormwater from inches of precipitation per square meter.
I’ve tried to make the units work with our U.S. system, so no matter what one does, that attempt becomes awkward.