#13 Examine the soil here; you'll find it's very sandy. The large particle size of sand means that rain drains through it quickly, and therefore this soil is dry (xeric) in nature. There is also very little organic material in this soil, except in the topmost inch or so. These two factors explain why the most common ground covers are lichens, mosses and fungi. These simple, non-vascular plants (and related kinds of organisms) can grow reasonably well in such harsh conditions, but they are frequently out-competed by grasses and herbs in richer soils. Sandy soil is not common on most of the UMBC campus and in Catonsville to the north. However, to the south and east, sandy soil is much more common. UMBC's CERA is atop the junction of two of Maryland's physiographic zones, the Piedmont and the Coastal Plain. Piedmont soils are complex, fairly rich in nutrients, and feature much clay and many stones. Coastal Plain soils are much coarser and sandier, descended from alluvial runoff from the uplands to the west and north.