Seasonal stakeout
Site assessment for busy people Story and photos by Michelle Sutton
LEFT: Wispy pale purple coneflower (Echinacea pallida), the favorite snack of the author’s resident woodchuck, had to be rescued by a friend RIGHT: A Scotch broom (Cytisus scoparius) cultivar proved insufficiently hardy for the author’s garden but did give a number of years’ enjoyment before a particularly cold cold snap did it in INSET: The sole surviving box-store wildflower, a lovely, forgiving toad trillium (Trillium sessile) 8 | MARCH-APRIL 2021
O
ne of my most important mentors, Dr. Nina Bassuk, taught a fabulous urban forestry course that I got to take while in graduate school. Bassuk gave us the opportunity to try out the most professional site assessment tools, protocols, and applications. For instance, to measure soil compaction, we got to use a device called a soil penetrometer that tests the resistance of the soil to pressure, giving you a result in PSI (pounds per square inch). Bassuk showed us to how to take soil core samples, dry them out in the lab, and then calculate the bulk density of the soil, which is the weight of soil in a given volume. (Bulk density is another indication of compaction and therefore how rootfriendly or unfriendly a soil environment is.) She taught
us how to systematically take soil samples across a given site and then how to interpret the lab’s findings as to pH, soil texture, and soil nutritional makeup. In her course, we looked at and quantified every possible facet of site assessment. That level of testing and documentation is especially important for large-scale projects, like the one that Bassuk and her colleagues Barb Neal, Bryan Denig, and Yoshiki Harada did, at nothing less than … the National Mall. The team was commissioned to analyze the site and the ailing American elm (Ulmus americana) trees and come up with recommendations. You can bet that for something this high profile, they were busting out the penetrometer and all the other gadgetry. Their site findings and their ultimate recommendations are extensively documented
