ABSTRACT
This chapter deals with the occurrence and characteristics of undergrowth on different peatland sites and, in comparison, on upland sites as well. It focuses on analyses of the stem diameter distribution of sample plots provided by national forest inventories. The undergrowth present in peatland stands is especially abundant. There is an abundance of small trees, and the number of stems diminishes fairly regularly as tree diameter increases. The abundance of undergrowth in Finnish forests is supported by a study concerning so-called natural normal forests. Peatland sites were divided into spruce mires, pine mires, and drained peatlands. A noticeable proportion of the growth increase in peatland stands is attributable to drainage for forestry. A typical feature of peatland forest stands was their close spacing. The regeneration potential of peatland forests in the early 1950s was very high.
