Part of the experience of hiking in the wild is the dramatic flow of changes in light as you move through the forest. To capture part of this experience we created a cap with photo sensors on it to record the changes in light patterns as we walk. The cap was made before we left for the wilderness.

[image of cap]

We created the PhotoSphere with 16 photo-resistors meticulously sewn into the cap. Each photo-resistor needed a 1000 ohm resistor as a voltage divider to be able to extract the voltage changes. A typical Arduino only has 6 analog analog-to-digital converters (ADC). We used an Arduion Mega instead, which has 16 ADCs.

[image of photo resistor circuit diagram]

[image of closeup of conductive thread]

[image of wire with loop]

[image of all loops connecting to wires]

[image of closeup of sewing mega into the

[image of the rtc sd logger shield]

[image of closeup of connector wires]

[image of windows error message for device driver not working]

-Written by Matthew Swarts

The Succession of Trees

The Tennessee/North Carolina Appalachians are renowned for their diverse tree population, and our trek took us from 4470 feet at Unicoi Gap to the Citico Creek Campground #14 elevation of 1720, providing an altitude-inflected arboretum. Different areas were logged off over the years, so at the higher elevations most were younger than in the lower areas, but of course we benefitted from hiking on old logging roads and a rapidly disappearing railroad grade.

There were the constants– rhododendron forming the familiar Appalachian green tunnel and, at least in these forests, a preponderance of maples. Early we hiked amongst those maples, a few poplars, several species of birch, and what looked like a buckeye tree (though I could only find one rotten buckeye on the ground). What stopped everyone in their tracks were the monumental dead hemlocks. The Wooly Adelgid is rapidly decimating the hemlock population in the area, leaving behind standing dead trunks that still loom ghostly over the surrounding forest.

Descending further down were fewer dead hemlocks, along with a number of smaller live ones, the occasional hickory, very large maples, and finally a few oaks (they were noticeably absent higher up). Soon the tulip poplars started to dominate, and around the base camp were the largest in the forest. Turning from the largest to the smallest, there were a variety of club mosses including one which was nearly six inches high, and a lot of stubby Sassafras trees. Located only in our camp was a specimen of the nearly extinct Owl tree (see picture), and just down from the base was another campsite located in a grove of mature beeches–the light, filtered through the leaves, was the greenest of green.

Hugh Crawford

Maybe the mountains imprinted themselves in my dad’s DNA during his childhood in South Korea, and those highland genes are what always draw me to the spectacular sights and sounds of southern Appalachia. While camping in Joyce Kilmer National Forest, I was completely awed by all the life that was around us, and the cool, clear weather during most of our trip allowed us many opportunities to enjoy the incredible array of flora and fauna near our idyllic base camp by Citico Creek.

Hiking in TN mountains

While the 6-foot tall Hugh was contemplating the taller trees in the forest, those of us closer to the ground had our eyes focused on the plants near our feet. The pipsissewa, or striped wintergreen, had white berry-like buds and were just beginning to bloom. Traditionally, the leaves have been used medicinally for ailments ranging from rheumatism to kidney problems. The plant does have antiseptic properties and is still sometimes used as a flavoring for candy. We had just missed the lady slipper orchids and only saw the spent inflorescence, but we were too early for the rattlesnake plantain orchids. There were a few Indian ghost pipes, which are named for their white, nearly ghostly appearance due to the lack of chlorophyll. The wildflowers were growing amongst the groundcover of partridge berries surrounding the trees.

Appalachian azures

Around the edges of the base camp were young sassafrass, which attracted black swallowtail butterflies. There were also a few silver spotted skippers. Both of these species, however, were greatly outnumbered by the Appalachian azures that congregated around our site like a gathering of forest fairies.

Definite tussock moth caterpillar

Our more earth-bound neighbors included a definite tussock moth caterpillar that had yet to earn its wings. On the first day, we had picked up an oil beetle using a stick and managed to avoid the chemical it secretes to cause blisters on menacing predators. Shiva named one of the queen crater snails in our camp “Squickie” and its leopard slug cousin “Slickie.” Andy preferred the colored flatbacked millipedes and the giant North American millipedes, whose defense mechanism is to secrete a chemical containing cyanide, faintly scenting them of almonds. I came to think of a large fishing spider that lived in the dead tree above my head as my pet away from home.

Oil beetle

North American millipede

Although Shiva and I had some perturbed mammalian visitors by our tent on the first night hiking to the campsite, we didn’t spot as many vertebrates near our home base as we expected. We did hear a variety of birds: sapsuckers, a barred owl, red-breasted grosbeaks, cardinals, sparrows, wrens, chickadees, and warblers, including the black-throated green warbler whose mating call sounds like the Teenage Mutant Ninja Turtles theme song – “Heroes in a half shell!” Laura caught a Southern toad on the trail, and Andy and Shiva startled a rattlesnake on their afternoon run. In the water, I managed to catch one of the smallest salamanders in the world, the pygmy salamander. It was so translucent that you could see all its internal organs and its beating heart.

Timber rattlesnake

Southern toad

While wishing for someone with foraging knowledge to prepare us a camp meal, we came across some chanterelles a quarter of a mile from camp. After scaring ourselves with horrific fungus poisoning stories, we left the chanterelles in the forest to decompose the decaying matter around them. The damp conditions were perfect for the toadstools, shelf fungi, and coral fungi. Their fellow decomposers, slime molds, also populated the fallen rotting trees. The log outside my tent became covered in white, marshallow-like poufs almost overnight. Other logs were covered in slime molds of various shapes, colors, and textures.

Coral fungus

Slime mold

The striking thing about the wildlife we saw was that quite a few are threatened or endangered, particularly in certain parts of their habitat ranges, and very few opportunities are left to see these species. Having the chance to see these organisms was certainly a wonderful experience. However, our hiking hack aspired to garner the potential of technology – something that seems to be incompatible with nature – to encourage people to engage with the natural environment and instill a sense of stewardship. Helping to preserve these natural wonders – that is a truly exciting prospect indeed.

~ Angela