Siikakankaan mäntytaimistojen tuhoista
Regeneration of large open areas in dry mineral soil forest sites that usually grow Scots pine (Pinus sylvestris L.) have several problems. For instance, soil frost, snow, ground vegetation and dryness can prevent germination and growth of seedlings. The damages caused by insects and fungi in seedlings of a large burned area in Siikakangas in Southern Finland was studied. A forest fire burned the area nearly completely in 1909, and 310 hectares have been sowed or planted with mostly Scots pine during the following years. Minor areas have been regenerated with Pinus montana Noll, Pinus excelsa Lamb., Pinus murrayana Balf. and Larix sibirica Ledeb.
No completely healthy pine seedling stands could be found in the area. About 41% of the seedlings in the sample plots were damaged. The most common causes for damage were Evetria resinella (now Retinia resinella L.), Luperus pinicola (now Calomicrus pinicola (Duft.)), Pissodes notatus (now Pissodes castaneus Degeer), Evetria turionana Hb. and Hylobious abietis L. The most usual fungal disease was Lophodermium sp. Evetria resinella caused damages in all the area. Evetria turionana, Pissodes notatus and Hylobius abietina were found in the older seedling stands. Other damages were more localized. The slacks in the terrain seemed to have most damages, the original cause being probably soil frost. Some damages, as Lophodermium, were related to the density of the seedlings, especially in the sown areas. Cleaning of seedling stands could decrease these damages. Planting seems to have succeeded better than patch sowing.
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Published in 1931