I recently had a conversation with a colleague about what in the heck a transect is. In ecology, it’s just an experimental tool, to help orient you to the landscape. Literally, it’s a line with known geographical coordinates. Gradients of various types are often revealed along a transect, through repeated sampling or experimental plots.

Urbanists like to talk about transects, especially in the context of the typology of the city. The transect articulates transitions between zones, with the idea that there are concentric circles of economic activities as you move out from the central city, from dense urban core, to sparse rural farmhouses.

Anyway, at Big Marsh, we are using the transect on Mars to look at how vegetation and soil characteristics vary along this transect, and over time. Part of our slow science research.

But what does this actually look like? It’s trivial for me to imagine, but not so for others. Here’s a collection of images I found that may help to visualize it.

The transect goes from northish to southish on the east side of Big Marsh Park, across what’s affectionately called Mars, because of the unearthly iron-red slag. The transect is about 600m.

We set up a plot every 25m and record plant species and coverage twice a year. At the paired plots every 50m, there’s an additional plot on the opposite site of the marker, that was cleared of all plant material when plots were set up in 2020.

What’s the point of clearing plots? We want to see if there is a trend in the species that are able to persist on “bare ground,” and if there is a predictable order in which species make themselves at home in the plot, or a process called “ecological succession.”

By surveying the plants every year, we will see how community composition changes over time. We’ve collected six years of data, so stay tuned for a publication in the next decade!