Work Package 2d “Establishing shelter in advance” plots
This trial investigated the impact of providing shelter in advance of planting a broadleaf crop species. Therefore the trial was designed for the medium-term (10 – 15 years) to the point at which the shelter species is removed. The spacing configuration for oak/conifer mixtures used, was alternate lines 2 m apart of broadleaf crop at 0.75 m within the line and shelter species 2 m within the line. At least two trial sites, distributed throughout the country, were established by WP2d. Species that were investigated were informed by WP2a. A Randomised Complete Block Design was used with four treatments and three replicates. Each trial site (see Figure 4) was approximately 0.75 ha, allowing for open space for access.
Treatments were:
- Pure broadleaf crop;
- Broadleaf crop and shelter planted at the same time;
- Shelter planted three years in advance of broadleaf crop;
- Shelter planted four years in advance of broadleaf crop.
The pure broadleaf crop treatment plots were planted at a distance from the other treatments in an attempt to minimise any sheltering effect from neighbouring plots. At time of establishment of pure broadleaf crop and broadleaf/shelter alternate lines, the shelter lines of the remaining two treatments were also planted. The crop species were subsequently planted within these two remaining treatments three years and four years later respectively.
Figure 7. Experimental design of "Establishing shelter in advance" plots.
Individual plots (Figure 8) are 24 m x 20 m (approximately 0.05 ha). The 8 m x 10 m “Measurement area”, surrounded by a buffer zone, contains 28 broadleaf crop measurement trees as per Table 3.
Figure 8. Plot design of "Establishing shelter in advance" plots
| Table 3. Number of stems measured per treatment type of the "Establishing shelter in advance" plots. | ||
|---|---|---|
| Treatment type | Stems per measurement area | Stems to be measured per measurement area |
| Pure broadleaf crop | 70 broadleaf crop | 28* broadleaf crop |
| Broadleaf crop with shelter | 28 broadleaf crop 33 shelter |
28 broadleaf crop 33 shelter |
| * Only broadleaf crop stems located on lines also available in the shelter treatments were measured | ||
One shelter-in-advance trial has been established near Charlestown, Co. Mayo, using oak (Quercus robur) and Scots pine (Pinus sylvestris), both of native origin. There are three replicates of four treatments. The treatments were:
- pure oak control, planted 2010-11 planting season;
- alternate lines, Scot’s pine and oak both planted 2010-11 planting season;
- alternate lines, Scot’s pine planted 2010-11 planting season, oak planted 2012-13 planting season;
- alternate lines, Scot’s pine planted 2010-11 planting season, oak planted 2014-15 planting season.