Current issue: 53(2)

Under compilation: 53(3)

Impact factor 1.683
5-year impact factor 1.950
Silva Fennica 1926-1997
1990-1997
1980-1989
1970-1979
1960-1969
Acta Forestalia Fennica
1953-1968
1933-1952
1913-1932

Articles by Olli Vaartaja

Category: Article

article id 7452, category Article
Olli Vaartaja. (1955). Factors causing mortality of tree seeds and succulent seedlings. Acta Forestalia Fennica vol. 62 no. 3 article id 7452. https://doi.org/10.14214/aff.7452

Germlings and small tree seedlings are exposed to extreme conditions in the forest floor. In this study the influence of climatic factors to seeds and seedlings were studied experimentally, and an attempt was made to estimate the importance of various factors in several sowing experiments in Finland.  

Seeds of Scots pine (Pinus sylvestris L.) were subjected to temperature variations which simulated those of exposed forest sites. The seeds lost some of their germinative capacity during the five-day treatments. Succulent seedlings died when subjected to immersion for 15 minutes at temperatures from 51.5 to 55 ºC. After a hardening pretreatments the seedlings tolerated 2-3 ºC higher temperatures. In artificial humus soil exposed to strong insolation for 15 minutes, temperatures in the range of 54-65 ºC proved to be critical for the seedlings. In natural conditions, also little lower temperatures may prove fatal. Exposure of succulent seedlings of Scots pine and Norway spruce (Picea abies (L.) Karst.) to insolation showed that most damage occurred on humus, quartz sand, and humus-sand mixture, due to rapid evaporation. Seeds of Scots pine, Norway spruce, Betula pendula and Betula pubescens tolerated poorly drought if germination had progressed to a 5–10 mm long radicle. Succulent seedlings tolerated 53-77 days long drought better in humus than in fine silty sand. Seedlings of Pinus sylvestris, Picea abies, Alnus incana and A. glutinosa tolerated cold variably. The developmental stage of the seedling affected cold resistance. Pine seeds sown in furrows germinated well after rain and the survival was high. Frost heaving, snail and insects caused some damages. Germination was lowest at the shallowest furrows. Sowing on natural surfaces gave poor results. Largest damages were caused by birds and ants. 

 The PDF includes a summary in Finnish.  

  • Vaartaja, ORCID ID:E-mail:
article id 7407, category Article
Olli Vaartaja. (1951). Alikasvosasemasta vapautettujen männyn taimistojen toipumisesta ja merkityksestä metsänhoidossa. Acta Forestalia Fennica vol. 59 no. 3 article id 7407. https://doi.org/10.14214/aff.7407
English title: On the recovery of released Scots pine undergrowth and its silvicultural importance.

There are contrary opinions on the ability of Scots pine (Pinus sylvestris L.) seedlings to withstand oppression by hold-overs and recover after their felling. The recovery potential of oppressed pine stands in Southern and Northern Finland was studied using two kinds of material, fully recovered Scots pine stands and stands recently released. The volume and volume increment of the stand were measured, and the health of the sample trees was determined.

The study showed that those released pine stands that had been in oppressed state very long (25-60 years) had recovered after clear-cutting. After the release the stands grew at first slowly, but after recovery at about the same rate as natural normal stands of a similar height. The smaller, younger, and less stunted the seedlings were when they were released, and the better the site, the faster was the recovery. At the base of released pine stands various defects was detected. When the trees were released, the defects decrease their technical value. A heavy partial cutting had generally a disadvantageous effect on the stand. Recovering seedlings were found clearly to hinder the development of younger seedlings nearby. This inhibition seemed to be a result of the rapid spread of the root system of released pine trees.

The PDF includes a summary in English.

  • Vaartaja, ORCID ID:E-mail:
article id 7390, category Article
Onni Pohjakallio, Olli Vaartaja. (1948). Über Vorkommen und Sporenbildung von Coleosporium Melampyri Kleb. auf verschiedenen Standorten und Wirtspflanzen. Acta Forestalia Fennica vol. 55 no. 2 article id 7390. https://doi.org/10.14214/aff.7390
English title: Occurrence and spore production of Coleosporium melanpyri Kleb. (pine needle rust) on different sites and host plants.

Department of plant pathology of University of Helsinki conducted studies in the surrounding forests of Viikki test farm and on the Hyytiälä forest training station to find about occurrence and spore production of pine needle rust.

The damages have been minor. Most often the infection did not cause yellowing of the needles, only individual needles might have dried up. There were no dead young trees.

The spore production was strongest at the more fertile sites, with abundant occurrence of cow-wheat (Melanpyrum spp.). The infection caused more harm on the cow-wheat than on the pines. In many cases the foliage died prematurely. Melanpyrum spp. were more strongly infected on sites with more light. However, there was no difference found with the fertility of the site.

The PDF contains a summary in Finnish. 

  • Pohjakallio, ORCID ID:E-mail:
  • Vaartaja, ORCID ID:E-mail:

Register
Click this link to register for Silva Fennica submission and tracking system.
Log in
If you are a registered user, log in to save your selected articles for later access.
Contents alert
Sign up to receive alerts of new content
Your selected articles

Committee on Publication Ethics A Trusted Community-Governed Archive