I look outside on November 17.
At first I didn't see anything other than lots and lots of black cylinders, tossed everywhere on the green grass in the circle.
Then I saw these three men, working at gathering what turned out to be black pots. It makes sense to plant as much as possible on a slope, in addition to the trees which had been planted days before. Hopefully the roots will soon grab hold of the freshly placed dirt and remove the chance that it will erode during Portland's wet winter. You can see the gray-colored path the men made, walking back and forth from their white trailer parked on SE MLK to the bottom of the slope. It says Valley Growers on the side of the trailer.
They or some other nurserymen returned at some other point and planted even more on the slope which goes up to the westbound bridge ramp, on the right of the photo where the dirt is bare. Notice the puddle beside the pile of rocks near the bottom edge of the fall foliage? There is a pretty-good-size pipe resting on the rocks. Your view of it is blocked by the man stacking black pots together, but you can see it in the photo above this one. I am assuming that is the drain for at least one of the several small-box-culvert-looking drain devices built at intervals into the curb--you can see one at the bottom right corner. I believe that bale of hay helps slow down the flow of water which enters through oval-shaped hole in the curb.