Pinhook Bog nutrient-poor. The outstanding feature of Pinhook Bog is the tree-covered mat of sphagnum moss. Sphagnum moss is a stringy, delicate moss of a light-green color. The mat floats on top of the water and can become thick, yet it can have a pocket only a few inches thick in the middle. As the mat thickens, larger and larger plants take root and grow. Under the mat a peat bed develops. The acidic water slows the decay of the sphagnum moss and other plants. With time, the peat may fill the bog from the mat to the bottom. As the moisture
Portlethen Moss saturated organic layers could actually rupture, spilling large volumes of mud and organic debris to surrounding fields, thus enabling a bed for further spatial expansion of the entire bog. Ultimately the colour of the moss waters became blood red in colour, from the successive organic decay and stagnation. Only in times associated with cattle grazing and significant human presence (probably the late Iron Age), would this process reverse and the bog reduce in size. A wide variety of sphagnum, sedges, rushes and other characteristic bog species inhabit Portlethen Moss. Sometimes insectivorous plants reside in mosses, since the soils are generally