Table 1.
The dependent and explanatory variables entered into the analysis of results from each study.
| herbivore | pine life stage | dependent variable modelled | explanatory variables |
|---|---|---|---|
| slugs | less than 3 weeks | seedling mortality (alive = 0, dead = 1) | monoterpenes: α-pinene, β-pinene, δ3-carene, terpinolene, myrcene, total monoterpenes camphene, limonene |
| other chemical traits: needle nitrogen | |||
| morphological traits: stem diameter (mm), stem length (mm), needle length (mm) | |||
| experimental design parameters: family, slug × array row (row) × array column (col) | |||
| voles | three to seven months | seedling mortality (alive = 0 dead = 1) | monoterpenes: α-pinene, camphene, β-pinene, myrcene, δ3-carene, α-terpinene, limonene, γ-terpinene, terpinolene |
| other chemical traits: — | |||
| morphological traits: no. of needles, needle length (mm) | |||
| experimental design parameters: family, plant community (PC) × access to voles (AV) × vegetation cleared (C) | |||
| red deer experiment 1 | 3 years | % height loss of saplings owing to deer browsing | monoterpenes: needle and elongating bud (−) α-pinene, (+) α-pinene, tricyclene, (−) camphene, myrcene and (+) camphene (coeluting), (+) β-pinene and an unidentified monoterpene (coeluting), (−) β-pinene, δ3-carene, (−) limonene, β-ocimene, (+) limonene and β-phellandrene (coeluting), γ-terpinene and terpinolene |
| other chemical traits: needle and elongating bud nitrogen | |||
| morphological traits: total number of new buds, total height of the sapling (cm), length of the leading bud (cm), average length of three lateral buds (cm), stem diameter under the leading bud (mm) and stem diameter at the base of the sapling (mm) | |||
| experimental design parameters: family, day of experiment, deer, deer × day, patch number, location in patch | |||
| red deer experiment 2 | 5 years | proportional length of available leader and laterals eaten | monoterpenes: as for red deer experiment 1, plus bornyl acetate |
| other chemical traits: — | |||
| morphological traits: mean length of five needles (mm), diameter at base of leading shoot (mm), diameter of main stem at ground level (mm), total length of leading + lateral shoots (mm), total height of sapling (cm), number of laterals at uppermost whorl (count), number of laterals below uppermost whorl (count). | |||
| experimental design parameters: — | |||
| capercaillie | mature trees | trees used by capercaillie for foraging (0 = non-caper, 1 = caper) | monoterpenes: as for red deer experiment 1 |
| other chemical traits: needle concentrations of calcium, magnesium, sodium, potassium, nitrogen, condensed tannin, total phenolics | |||
| morphological traits: tree height (m), girth (cm), crown diameter (m), nearest neighbour distance (m), proportion of total height occupied by crown |