Time spent in the natural world benefits human health

Below Article appeared originally in The American Scientist.
July-August 2011Volume 99, Number 4 Page: 301

A Walk in the Woods » American Scientist.

A Walk in the Woods

Evidence builds that time spent in the natural world benefits human health

Anna Lena Phillips

For the month of April, I decided to visit the Haw River, which flows near where I live, every day. I wouldn’t hold myself strictly to this, but I would try, and I would observe—not impartially, of course, but closely—how I felt. Some days I took leisurely walks with friends, leaning over the railing of the pedestrian bridge to watch the river, high from recent rains, and to smell the distinctive, muddy smell of the water mingled with that of the banks overrun with invasive honeysuckle. On others, coming home late at night, I drove straight down to the bridge and walked out to stare down at the dark water, a move that felt a bit like the natural-world equivalent of visiting a drive-through restaurant.

I did this because I hadn’t been spending much time at the river, even though it’s only a short walk from home, and even though I like doing it. The results of my informal experiment? I did, in fact, feel better—calmer, more relaxed, clearer-headed. I suspect that many people have similar feelings about the effects of spending time in the wilder places near where they live. Perhaps that’s why Richard Louv’s 2005 book Last Child in the Woods, which explores the relation between the natural world and children’s development, became a bestseller in the United States.

2011-07SciObsPhillipsFA.jpgClick to Enlarge ImageBut to know empirically that these experiences are beneficial—and to know exactly how they might help us—requires more than personal experience. A growing and varied body of research attempts to quantify how and why spending time in the natural world might have beneficial effects on humans’ physical and psychological health. One of the first and most well-known studies, published in Science by Richard S. Ulrich in 1984, found that patients recovering from surgery in rooms with a window facing a natural setting had shorter hospital stays and took less pain medicine than did patients whose window faced a brick wall. Since then, researchers have asked whether the presence of trees influences people’s sense of safety in inner-city neighborhoods; explored how gardening might improve quality of life for people with disabilities; and used physiolgical measures to test for restorative effects of natural environments. If some of these studies seem too specific to be useful in answering the broader question, their results in sum suggest that time spent in nature improves human health. The more difficult questions are how, and in what ways, these effects arise. These questions are not the kind that can be answered by a single, groundbreaking paper; rather, like so many of the subtle and complex problems science explores, the evidence is being deposited, small study by small study, like layers of sediment on a river bed.

One such body of work is accumulating in Japan, where researchers are investigating the physiological effects of shinrin-yoku—“forest bathing,” or, to put it plainly, taking walks in the woods. Qing Li, a professor in the Department of Hygiene and Public Health at Nippon Medical School, Tokyo, has been involved with several such studies. He and his colleagues recently measured specific physiological markers before and after study subjects took walks in a forest and in an urban control environment. The study’s sample size is small—16 male subjects—and the timescale short—effects were measured after one day trip to the forest and one to the city—but the results suggest that the forest trip had positive effects on health. Subjects’ blood pressure measured in the forest was significantly lower when compared to measurements taken in the city. Levels of the stress hormone noradrenaline, measured in urine, were also significantly lower after the forest walk than after the urban walk. And blood levels of the adrenal hormone dehydroepiandrosterone sulfate (DHEA-S) and of adiponectin, a hormone secreted by fat tissue, were higher after the forest walk but not the urban walk. The authors note that DHEA-S may contribute to heart health, among other benefits, and that lower levels of adiponectin are associated with obesity and type 2 diabetes.

Li and his coauthors, whose study appeared in the European Journal of Applied Physiology in March, speculate that the forest trip’s effects on blood pressure may be related to phytoncides, volatile organic compounds (VOCs) that plants produce and release as protection from fungi and bacteria. In a separate study for which Li was also lead author, researchers unsurprisingly found higher concentrations of several phytoncides in a forest than in an urban area of Tokyo.

Another recent study, by Juyoung Lee, a researcher at the Center for Environment, Health and Field Sciences at Chiba University, Japan, and others, offers similar results. In this three-day field experiment, 12 young male subjects visited forest and urban environments. The study, published in February in Public Health, found that in the forest, subjects’ parasympathetic nervous-system activity was heightened and their sympathetic nervous-system activity suppressed. Pulse rates were lower, as were salivary levels of the adrenal hormone cortisol, which is associated with stress. Participants reported that their positive feelings increased, and negative feelings decreased, in the forest. Blood-pressure measurements, however, did not differ significantly between the forest and urban locations. The authors also measured phytoncide levels in the forest study area and found 10 different compounds, ranging in concentration from 0.3 micrograms per cubic meter to 1,336 micrograms per cubic meter.

In support of the idea that phytoncides may be responsible for some of the health effects seen in Li’s study, he and his coauthors cite a 2003 paper that found that inhalation of cedar-wood oil lowered blood pressure. A review article of forest-bathing studies, published in Environmental Health and Preventive Medicine in 2009 by Yuko Tsunetsugu and others, notes several laboratory studies that tested human responses to inhalation of plant VOCs. The results included such positive effects as lowered blood pressure and improved task performance. But to find a correlation between the mixture of phytoncides in forest air and physiological changes in humans would require experiments of more complex design. So although the idea that the very scent of the forest might improve health is appealing, determining whether it’s true and the extent of any effects will need more study.

This is just one of many avenues of inquiry that forest-bathing research opens. Can the physiological effects of studies like Li’s be replicated in larger studies, and in women and children? Do effects differ across gender and age? Do forests in varied bioregions, with different microclimates and compositions of tree species, vary in their effects on health? Do people who have grown up in one region experience different health effects in forests in their home bioregion than in other forests?

Policy questions abound as well. Carol Colfer, a cultural anthropologist and senior associate with the Center for International Forestry Research in Bogor, Indonesia, studies human use of forests in developing countries. “I suppose the logical result would be developing more or at least maintaining existing parks in cities, and expanding protected areas—but with much more serious attention to the human rights of people living in these areas,” she says of Li’s study. “Even better would be encouraging in situ conservation on people’s own lands.” Li is interested in exploring how his results could be used in medicine. “I am planning to develop forest bathing to be a preventive measure for some diseases such as depression, hypertension and cancers,” he says.

 

What’s clear is that trying to quantify a seemingly intuitive claim—humans benefit from spending time in the natural world—is turning up more complex answers, and more resulting questions, than a fir tree has needles. If policymakers take note of this work as it emerges, they might be better equipped to improve public health. For my part, I’ve extended my efforts to visit the river each day into the month of May. The weather’s better for swimming now, and the air smells as good as ever.

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Eastern Screech Owls -an Album

In early June momma Screech brought two little fluffy Owlets around to show.  They were barely flying – more like bombing around … and they were very needy with their calls for food!    Here is mom below, with one of her fledgling chicks.  I have a long relationship with the screech owls around our neighborhood and every year we get to see them as they perch and hunt in and around our half acre for insects here in Lehigh.  
The tree below is over our Labyrinth and I was sitting under it when she brought them by.  Yes, I try to always have a camera on hand in the Backyard Universe just in case!  
Mom and Owlet

Mom and Owlet

Above and below a fluffly barely fledgling Screech closer up, sitting in the tree above with mom.  Mom had left them up in the tree overhead while she went off to hunt in daylight.  The only issue is, during daylight hours they can be attacked by other birds that find them and this was an open area.  I helped mom out and kept the mocking birds and jays away while the little ones sat up in the tree calling for mom to bring them yummy beetles from nearby backyards.  They were not that far from their nest in a clump of Sabal Palms behind our lot.  (We let our native yard grow tall and wild in the back for cover and hunting areas for the little ones.)  
Fluffly chick

Fluffly chick

In the below images they are much older but still sporting some pin feathers.  The don’t need mom to watch after or protect them from attacking birds.  They know to hide in the shadows during daylight hours until nightfall.

Fledgling1_01

Hiding in among the Bombax tree leaves… a wide eyed fledgling Screech.  300mm Nikon lens

Other Fledgling

I am outside, after dinner looking for the screeches.  Sometimes after a rain I hear them or late at night calling with their soft whinny call…  Eventually they will move out to other areas of the neighborhood to hunt over the Summer.  I hope they are greeted with as much awe, enjoyment and safe haven as they are met with here on the half acre.  Owls like this hunt insects, small bats, mice and snakes.  In yards sprayed with pesticides, they may suffer through their food sources that are impacted by the pesticide applications.  
I have found that when our rodent or snake numbers go up here at the Backyard Universe that we often see an influx of hawks and owls to feed on them.  It’s an intricate, connected age old cycle that will balance itself  out if we allow it to and don’t interrupt it via artificial and deadly means.  If you would like to build Screech Owl Nest Boxes for your yard, go to this link  in my prior article and read down it for the link to the nesting box instructions.
 

Screech Owls New Diggs, up in the Bombax Tree.

Screech Owls New Diggs

The Backyard Universe is truly a hub of activity lately…   every evening the mockingbirds are giving the little Screech Owls a difficult time when they make their appearance known.  You can’t miss the disturbed calls of the mockingbirds and the hisses of the Screech owls.  It was at this latest activity that I decided to read online about Screech Owl Boxes.  They had a nest last year in an old palm snag however that snag fell over this year.  After doing some research I ran across a website for the Treasure Coast Wildlife Center located in Palm City Florida.  They actually had a .PDF file with information about Screech owls AND how to build nesting boxes for them.  It just happens that the boxes for the Screech Owls can also be used by the American Kestrel.  Click here for the Download .PDF link to make your own Screech Owl Nesting Box.

We placed our box up onto a Bombax  (African Floss) Tree, part of a stand of them that is along the back of our half acre.  Now we watch and wait to see if the box is noticed and who takes interest!  The box took only a couple hours to make and cost us $13.00 in pine.  It will weather over time.  Please be sure to follow the directions of the .PDF, don’t paint the box.  Now when I go outside I have yet another possible source of activity to keep an eye on.   We have raised other clusters of Screech Owls here, watched them grown up…  I hope you will consider placing a box in your neighborhood backyard.   A big thank you to the Treasure Coast Wildlife Center for making the easy to follow directions available.  Check out their website!     AND be sure to visit my new Photo Blog called Metta Nature Photography  Click on the images there for full page views of everything else *outside* of my  BackyardUniverse coverage.    

Eastern Screech Owl

Image of an Eastern Screech Owl sitting on a stump in the BackyardUniverse.   

Something Fishy in aBackyard Universe this morning..

I had just mentioned to someone last night, “Pay attention to birds because THEY will tell you what’s going on in the neighborhood or on the trail”   And it’s true, IF you do choose listen to Nature, she will share important things with you.  Like this morning as I was walking out onto the lanai to let the Chihuahuas out I heard this very distinctive call to my left…  

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The neighborhood Osprey was a lot closer to me than the last time I blogged about him – when he was 200′ distant in another neighbors yard…  So I quietly stood and fired off images until the Mockingbird chased him away.  That was a very narrow window I had to enjoy his presence in and I’m grateful for it!  I do hope someone else had the enjoyment of watching him with his meal, that everyone was not glued to the TV and missed an opportunity.

Seeing an Osprey close in like this is a rarity for me.  I’m not near a large body of water such as a beach or lake, so the Ospreys I see occasionally here have travelled to and from larger water sources, or perhaps fished the deep canal that runs along behind (to the East of)  Lehigh Acres Middle School, which isn’t far from me.  I do hope YOU had a chance to get outside this weekend and soak up some wonderful Vitamin N – the Nature Vitamin, and I hope you enjoy the photos.    

The Backyard Universe is all a Buzzzzz!

I spent most of my day, once it warmed up and the grass dried off, outside working on the half acre.  I watered the little garden, checked the plants for “pests” to re-locate, watered around the labyrinth then decided to clean out and re-fill the Hummingbird feeders.  On walking past our next-to-last declining citrus tree in the yard, a Citrus Greening victim, I noticed pollinators busy at their jobs.  There were the usual bees and various wasps, and then I saw a beautiful little Red Banded Hairstreak butterfly.  (I knew by the shape  it was some kind of a little Hairstreak.)  Hairstreaks are a common butterfly in South West Florida but they are rather small (compare to the bee) and easily missed if you don’t really take the time to LOOK for them on your flowering plants or trees:

02-03-13 Red Banded Hairstreak Bee3Best

Look at the beautiful orange on the wings.. the eye spots and what looks like an M on the hind wing.  If you’ve never watched a Hairstreak before,  try it!   You’ll notice they do some interesting things with their back hind wings.  For one thing, they are usually in motion, being rubbed together much like we’d rub our hands together.  GO ahead, try it!   Now take a much closer look at the picture and you’ll see the hind wings have little “tufts” looking outgrowths on them that stick up.  These will also wiggle around.  Now combine the wiggling tufts on the wings and the wings rubbing together with that big black eye spot and a predator just might think it’s looking at the front end of the butterfly instead of the back end!   Allot of times Hairstreaks will be missing part of their lower wings because this worked so well.  Hairstreaks don’t move around so fast when they have a good source of nectar.  I’ve noticed they like to hang around the area and take it easy usually resting on the blooms like this.

If you have a yard with some citrus in it consider watching and exploring there for Hairstreaks as well as other cool insects like this beautiful  Paper Wasp.

 

 

02-03-131 PaperWasp

Look at his coloration what does it tell you?  There’s lots of hot colors there red, oranges, yellows and black in bold arrangements of color.  The colors say “Keep Back”  “Stay Away” “Leave me alone” or I might hurt you to protect myself.  That’s a fair warning!   So just stand back and watch him in the tree or bush and see what he does.  Why is he on the leaf?  Is he getting pollen or hunting for worms?  If we take time to explore and listen, and question – and do a little research later, there’s allot we can learn. 

Insects truly do receive a bad rap for “intruding” upon “our lifestyles” when  in fact, they are just minding their own business!  Outside even!  Whether it is an ant patrolling a counter or a wasp outside in a tree, or a spider in a web a most common thought is Ewwww!   followed by trying to figure out the best way to dispose of it and that is really a shame for we are all part of this same living, macro organism called Earth.  The outdoors are an amazing place to explore with your family or by yourself so go outside and see what you can find.  There are beautiful creatures and plants to see and explore right outside your home.  

     

 

 

    

Weekly Photo Challenge: Green

This post is in response to the Word Press Weekly Photo Challenge  of the color GREEN.  I  also want to apologize for a month of non postings.  Scheduling issues, as well as health things got in the way of creativity.  But I should be back on track now to pick up the blogging so I hope you’ll stay with me and explore the richness of your backyard and community.  There really is allot to see out there and the first step to exploring it, is to go outside.  

To see the individual images larger, please click on them.

My choices for Green include a selection of small green insects, birds and amphibians you are likely to encounter either in your Florida backyard, or on a boardwalk at your local Nature Center or Preserve.  All of these green critters are quite small and can easily be missed if you’re hurried.  The Green Tree Frogs are found during the day resting up or hidden in leaves or along board walks.  The Green fly pictured on the big leaf is out in our yards daily, hanging around foliage, feeding off of rotted plant material.  The beautiful Iridescent Sweat Bees are normally found close to your grasses.. they move fairly slow so they are easy to follow around and study although I have seen them hovering high over trails at almost eye level when you step into their territory – last Friday I was able to hang around a good while watching their antics over the CREW Land and Water Trust trails.  

The Florida Green Anole can be a bit harder to find.  They have been replaced in many areas by invasive lizards (like the brown ones on your porches and lanais)  and loss of habitat.  This Anole is from Corkscrew Swamp Sanctuary, there you can find them along the boardwalks and on Alligator Flag leaves enjoying the sun, and looking for insects.  The beautiful, delicate Juvenile (he does not have his red throat yet) Ruby Throated Hummingbird is attracted to red flowers like Native Firebush, Red Shrimp Plants.  Vines, trees, and shrubs that attract hummers include honeysuckle, morning glory, trumpet creeper, albelia, butterfly bush, flowering quince, rose of sharon, weigela, flowering currant, rosemary, buckeye and horsechestnut, black locust, flowering crabs, hawthorns, mimosa, and tulip poplar.  I’ve also seen them feeding on the orchid like flowers of Bombax trees.  I hope you have enjoyed my selection of  “Green” and that it inspires you look around your local habitat for more of… the little things…         all photography by Linda S. Jacobson.

To see the individual images larger, please click on them.

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