Effects of Defoliation, Decapitation, and Partial Girdling on Root and Shoot Growth of Pine and Spruce Seedlings : Insects Affecting Reforestation. Biology and Damage

1989

S. 89-100

3 Abb., 2 Tab., 19 Lit. Ang.

Unselbständiges Werk

200069377

One-year-old seedlings of Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) were defoliated, decapitated, or girdled partially in order to simulate different types of insect damage. Immediate growth effects were evaluated in a growth chamber. Another set of seedlings treated in a similar way were planted in a nursery and were followed for four growing seasons. Seedling survival was high, except for the partially girdled spruce seedlings. For both species, total defoliation or partial girdling drastically reduced root growth during the first weeks after the treatment. This effect was also seen after the first field season. After four field seasons, decapitated pines were still smaller than the controls whereas all spruces and the other pines had recovered. The results were interpreted in terms of growth patterns and carbohydrate availability, and the impact of different types of insect damage on planting success and stand establishment was discussed.