Transects

Line transect distance sampling is a commonly used method in field ecology, designed to provide estimates of organism or feature abundance in an ecosystem. In ecological studies, statistically robust transect sampling involves laying out a measured transect that is either predetermined or randomly chosen, walking along this straight line, and recording the presence of organisms, objects, environmental features, and their distance relationship to the transect either in toto or at predetermined distances along the transect. This method assumes that the sampling method is unbiased by the observer’s presence along the transect or the way in which the observer records the data. 

For this project, however, I was interested in directly incorporating observer bias into this stalwart ecological sampling method, while simultaneously maintaining a measure of scientific rigor. Very few ecosystems remain untouched by humans, and the majority of the environments we traverse either demonstrate evidence of human intervention; in fact, many “natural” experiences are more or less engineered for our consumption by other humans, through the design of trail networks, interpretive centers, safety features, signage, and etcetera. In addition, differential movement through an area will determine how the environmental features are perceived; a quick and efficient walk over a trail on the way to a distinguished feature will render the user’s experience different than that of a group moving along with pets or small children, picking up sticks and leaves as they travel. 

In this project, I used the basic method of sampling along line transects through different ecosystems while simultaneously incorporating the human elements of differential time use, movement velocity, and the prerogative to shift direction in the face of interesting diversions. A transect was originally chosen by the existence of defined trail or pathway. As such paths were engineered and built by human hands, they were by definition not random transects and very rarely had geometrically straight sections traversing an ecosystem.

However, in the interest of controlling for several aspects of human subjectivity, I also incorporated some rigorous sampling methods into each transect walk. I used a random number generator to form lists of numbers from 1 through 4, corresponding to the four cardinal directions: 1 for north; 2 for east; 3 for south; and 4 for west. At four or five minute intervals (predetermined, and rigorously adhered to for the duration of a transect), I stopped wherever I was located along the transect, consulted the number chart for the direction to be sampled, and took four photographs in that direction: one of the ground immediately underfoot; the second of the nearest plant life in that direction; the third of the middle ground view; and the fourth of the entire view using a large depth of field. I combined the four images for a location into a transect sample, labeled using the initials of the overall location, the date (mm-dd-yy), transect number at that location, and cardinal direction.

For each transect walk, I then combined all individual transect samplings into a single “landscape” image, creating a composite view of each environment. These final landscapes therefore merge scientifically collected visual data about each ecosystem with the imprints of the human-architected environment, the traveler’s subjective gaze, and the time signature of the individual traversal, with expansion and contraction of velocity dependent upon personal use of the environment. What results is a novel landscape dictated by the unique interactions between human and environment at one point in time.