Elm | ||||||
---|---|---|---|---|---|---|

Nursery planting depth^{z} | Root remediation at planting | % trunk circled at planting^{xy} | % trunk circled 5 years after planting^{x} | Root depth–north (cm) | Depth of straight^{w}roots–north (cm) | Depth of descending^{v}roots–north (cm) |

Shallow | Yes | 36 b^{u} | 3 b | 14 b | 10 b | 17 b |

No | 36 b | 22 b | 26 a | 22 a | 30 a | |

Deep | Yes | 68 a | 1 b | 20 ab | 21 a | 22 ab |

No | 68 a | 55 a | 20 ab | 20 a | 22 ab | |

Maple | ||||||

Nursery planting depth^{z} | Root remediation at planting | % trunk circled at planting^{xy} | % trunk circled 5 years after planting^{x} | CSA largest circling root–north^{t} (cm^{2}) | Depth of straight^{w} roots (cm) | |

Shallow | Yes | 41 b^{s} | 9 c | 5 b | 13 b | |

No | 41 b | 66 b | 11 ab | 16 b | ||

Deep | Yes | 77 a | 22 c | 15 a | 14 b | |

No | 77 a | 85 a | 8 ab | 22 a |

↵

^{z}Shallow = topmost root 13 mm deep into 11.4 L (#3) and even with substrate surface into 57 L (#15) and 170 L (#45) container; deep = topmost root 64 mm deep into 11.4 and 57 L containers (128 mm deep total), and even into 170 L container.↵

^{y}Data presented in Gilman et al. 2010b; means for root pruning yes and no are identical because roots were not pruned in that study.↵

^{x}Percentage of trunk circumference circled with roots > 5 mm diameter.↵

^{w}Straight = root segment just beyond the root ball was oriented < 60 degrees in either compass direction compared to azimuth of parent root inside root ball; depth measured 10 cm outside root ball.↵

^{v}Descending = growing down < 45 degrees in relation to landscape soil surface on north side of tree.↵

^{u}Means for elm followed by a different letter within columns are statistically different at*P*= 0.05, 0.01, 0.006, 0.003, and 0.02, left to right; n = 10, averaged over mulch treatment due to insignificant interaction (*P*> 0.05).↵

^{t}Diameter of largest root circling the north half of the tree at the position of the 170 L root ball; there was no effect on circling roots on south side.↵

^{s}Means for maple followed by a different letter within columns are statistically different at*P*= 0.01, 0.001, 0.008, and 0.04, left to right; n = 10, averaged over mulch treatment because of insignificant interaction (*P*> 0.05).