I'm working on improving our seedling search protocol, using perhaps photography, a physical grid, or some combination of things. Here's a couple photos I took to test out a locating device: toothpick plus coffee stirrer plus thumbtack. The first photo is in easier short foliage conditions and has two red markers and a blue marker somewhere in the 1m diameter circle marked by the meter sticks. The second photo is in more difficult high foliage and has two red, a blue, and a white. All are visible in both pictures, but perhaps not immediately apparent. Happy hunting!
Ben, Those are really difficult to find! I wonder if bigger markers would help--maybe something the size of a return address label. Would black text on a white background stand out?
Here's the paper that I recommended:
Booth D.T., Cox S.E., Louhaichi M. & Johnson D.E. (2004). Technical Note: Lightweight Camera Stand for Close-to-Earth Remote Sensing. Rangeland Ecology and Management. 57: 675-678.
SW
I wonder if a red-eye algorithm would find the red markers? I think so. But would anybody care?
I care.
Ben is trying to develop techniques and protocols to make refinding tiny seedlings faster and easier. Currently we make paper maps, which are time-consuming and not always accurate.
Digital photos might help and using or developing an algorithm that will find the pixel coordinates of the red markers in a digital image might be a huge benefit to the project.