Table 1. The number assigned to each Sitka spruce clone planted in the experiment, numbered 1–8. Four clones (1, 3, 5, 8) had common parents, another clone (clone 7) shared a parent with these four clones and clone 2. The remaining two clones (clones 4 and 6) were unrelated to any other clones in this experiment. Clones were propagated using somatic embryogenesis with seeds from controlled crosses of elite parents used in the Irish tree improvement programme. | |

Clone Number | Cross |

1, 3, 5, 8 | 230 × 519 |

2 | 377 × 574 |

4 | 286 × 542 |

6 | 27 × 306 |

7 | 377 × 519 |

Table 2. ANOVA summary for sources of variation and P-values with significant differences in 2013, 2014 and 2015. NS = > 0.05, * = < 0.05, ** = < 0.01 and *** = < 0.001. CV = coefficient of variation. | |||

P-value | |||

Source of variation | Clone (C) | Deployment (D) | C × D |

Year – 2013 | |||

Absolute stem height, May | * | NS | NS |

Absolute stem diameter, May | NS | NS | NS |

Absolute stem height (CV), May | NS | * | NS |

Absolute stem diameter (CV), May | NS | * | NS |

Relative stem height, July | * | NS | NS |

Relative height, mid-July | * | NS | NS |

Relative height, August | ** | NS | NS |

Relative stem height, September | NS | * | NS |

Relative stem diameter, December | NS | ** | NS |

Year – 2014 | |||

Relative stem height, May | *** | NS | NS |

Relative stem height, mid-May | *** | *** | NS |

Relative stem height, June | ** | *** | NS |

Relative stem height, mid-June | ** | *** | NS |

Relative stem height, July | NS | ** | NS |

Relative stem height, mid-July | NS | * | NS |

Year – 2015 | |||

Absolute stem height, August | * | * | * |

Absolute stem diameter, May | * | * | * |

Absolute stem height (CV), August | NS | * | NS |

Absolute stem diameter (CV), May | NS | * | NS |

Branch biomass | * | NS | NS |

Total above-ground biomass | * | NS | NS |

Relative stem height, June | NS | NS | * |

Table 3. Absolute stem height (May 2013 and August 2015) and diameter at base (May 2013 and 2015) for eight juvenile Sitka spruce clones planted in monoclonal and mixed plots (n = 5) and mean values for all ramets in each deployment-type (n = 10). Data shown are mean values and corresponding coefficient of variation (CV). Values showing the same letter are not statistically significant (P ≤ 0.05). | |||||

Clone | Deployment Type | Diameter ’13 (mm) | Diameter ’15 (mm) | Height ’13 (cm) | Height ’15 (cm) |

1 | Monoclonal | 3.0b (14a) | 6.1ab (15a) | 19.9a (12a) | 56.5a (15a) |

Mixed | 2.7bc (13a) | 5.9b (18a) | 20.8a (16a) | 55.3ab (19a) | |

2 | Monoclonal | 3.3ab (9a) | 6.5ab (9a) | 20.4a (11a) | 57.2a (9a) |

Mixed | 3.6a (13a) | 7.1a (12a) | 20.1a (17a) | 51.6abc (13a) | |

3 | Monoclonal | 3.2ab (18a) | 6.4ab (9a) | 20.6a (17a) | 55.0ab (9a) |

Mixed | 3.0b (18a) | 6.4ab (9a) | 18.8a (15a) | 50.9abc (9a) | |

4 | Monoclonal | 3.2ab (16a) | 5.8b (11a) | 20.8a (17a) | 47.1bc (11a) |

Mixed | 2.8bc (16a) | 6.3ab (18a) | 20.6a (18a) | 49.8abc (18a) | |

5 | Monoclonal | 2.6c (16a) | 7.0a (10a) | 21.1a (17a) | 51.8ab (16a) |

Mixed | 2.8c (17a) | 5.9b (11a) | 18.8a (18a) | 43.8c (18a) | |

6 | Monoclonal | 3.3ab (15a) | 6.3ab (6a) | 23.0a (12a) | 47.9bc (7a) |

Mixed | 3.0b (12a) | 6.0ab (12a) | 21.8a (18a) | 49.8abc (16a) | |

7 | Monoclonal | 3.1b (14a) | 5.9b (7a) | 19.1a (12a) | 43.1c (7a) |

Mixed | 2.8bc (17a) | 6.4ab (16a) | 17.6a (17a) | 50.2abc (16a) | |

8 | Monoclonal | 2.6c (15a) | 5.7b (11a) | 18.9a (15a) | 49.6abc (12a) |

Mixed | 2.5c (14a) | 5.8b (11a) | 17.7a (14a) | 45.2bc (11a) | |

Mean monoclonal values | 3.1a (15b) | 20.5a (15b) | 6.1a (10b) | 50.5a (11b) | |

Mean mixed values | 2.9a (22a) | 19.7a (19a) | 6.1a (20a) | 49.1a (18a) |

Table 4. Biomass partitioning of eight juvenile Sitka spruce clones in January 2015. Data shown are mean values ± 1 SE (standard error). Means showing the same letter are not statistically significant (P ≤ 0.05). n = 10. | |||

Biomass Partitioning | |||

Year | Clone | Branch (g) | Total above-ground biomass (g) |

2015 | 1 | 1.23 ± 0.2ab | 12.89 ± 1.5b |

2 | 1.88 ± 0.3a | 17.26 ± 1.0a | |

3 | 1.27 ± 0.3ab | 12.98 ± 1.4b | |

4 | 1.33 ± 0.3ab | 12.24 ± 0.6b | |

5 | 1.71 ± 0.4ab | 11.77 ± 2.0b | |

6 | 1.50 ± 0.3ab | 12.83 ± 1.6b | |

7 | 1.11 ± 0.3b | 11.22 ± 1.9b | |

8 | 1.16 ± 0.3b | 12.08 ± 1.7b |