How Trees Calm Us Down

I looked up prices as I was initially in doubt if this was a good cost-benefit. This article claims that New York Cty trees have a lifetime cost of ~3,500 USD (in gardening). I was under the impression of a much higher annual cost, so I was way off in my initial reasoning.

This report puts annual gardening costs of Portland trees at around 40usd [1]

These numbers do not include added road, curb and sidewalk maintenance incurred by the tree, as far as I can tell.

[0]http://scienceline.org/2013/10/the-high-cost-of-carbon-in-ci... [1] https://www.portlandoregon.gov/parks/article/514095

My main point however, is a call for some prudence especially with the relatively recent focus on bad statistics in psychology and the neurosciences. A caution against accepting a paper's conclusions because of the correlation of a few variables, and the omission of some obvious other ones. Here's just one link from 2013 [1]. fMRIs are a tool, and like any other, can be used incorrectly, which is also part of the problem. I am not negating Marc Berman's paper or this article based on it; I am just a bit wary of papers or articles with big claims (remember the article cites a 1% improvement after all of the buoying of the affects).

A variable not mentioned is that if you are walking outside, or facing a bunch of trees in a yard from your hospital room, you are getting daylight. Window panes block UVb, but not UVa (some are treated to block UVa too). Sunlight/daylight help you to produce vitamin D, which is linked to depression and the immunity system. This could be the cause of the 1% improvement the article states, and possibly not the trees. Treatment for clinical depression figures are 60-80% successful depending on the study. An order of magnitude greater than 1% [2].

Aside from the few people who have replied to this thread about allergies and other maladies, how many people do you think are going to associate pain, depression or other negatives with an image of trees in their head when responding to a survey?

All that being said. My neighborhood was poor, and crime-ridden, yet my tree-lined block provided me with many peaceful moments of just staring at the trees, or simply listening to the wind in the leaves. I do believe they are beneficial, at least to me (except during a hurricane in NJ, where I thought the 60 foot tall, old oak tree just by my house was going to fall on my roof!).

[0] https://en.wikipedia.org/wiki/Correlation_does_not_imply_cau...

[1] http://www.wired.com/2013/04/brain-stats/

[2] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908269/

We are mostly not human. Our bodies contain a vast assortment of usually symbiotic species so it is appropriate to think ecologically, more co-evolution.

It seems reasonable that flora and fauna responses to environmental factors that in of themselves may not be directly relevant to a human, but that we benefit from the interaction as a side effect e.g. useful compounds being produced naturally, partially synthesized from plant life even though the direct plant product may show no sign of helping us because we cannot yet process it artificially. Hope that makes sense.

Having said that, the Japanese researcher I mentioned above does say some kinds of hinoki oil produce comparable effects to traveling in forests.

Now seems like a good time to plug my favorite anime on tiny invisible life forms:

Mushishi http://www.imdb.com/title/tt0807832/

Let me ask you: why do people play digital soccer games when real soccer is so much better?