Experimental design

A key question in CCF is to determine the most appropriate pathways for transforming forest stands from plantations to CCF. The TranSSFor project is addressing this by comparing conventional thinning in Sitka spruce plantations with two alternative less commonly applied thinning regimes.

Two productive forests, both planted in the early 1990s, were selected for the study (Figure 2). One is based on a poorly-drained gley soil and at a relatively high altitude (>300 m) in Co Laois. The other is on a more sheltered site with a well-drained brown earth soil at a lower altitude (250 m) in Co Wicklow.

In each forest in 2010, experimental blocks were set up to compare the three thinning regimes over a medium- to long-term management period (Figure 3). Each forest is being managed for commercial forestry, so the experiment is designed to be as close as possible to a normal forest operation. The thinning regimes being tested are described here: Details of the thinning regimes.