Articles containing the keyword 'canopy layer'

The effect of growth rate on wood basic density in even-age Norway spruce (Picea abies (L.) H. Karst.) plantations was studied on the basis of samples collected from 53 stands; 30 trees were sampled in each stand. The prediction of basic density with the help of growth rate and some other tree characteristics could be improved if the social status of the tree was taken into account. Within a stand, the smaller trees had a lower density, while taller trees had a higher density than they should have had on the basis of growth rate alone.

The PDF includes a summary in Finnish.

• Kärkkäinen, E-mail: mk@mm.unknown

The proportions of needle and wood in current-year shoots in crown systems of young Scots pine (Pinus sylvestris L.) trees was studied. The proportion of needles out of the total shoot biomass increased according to the increasing number of the whorl counted from the apex. In the lower part of the crown system the needle biomass of newly-formed shoots was 50–60 fold compared to that of wood and bark biomass. In the upper part of the crown system the same ratio was 1–2. The variation in ratio between needle and wood biomass was whorl-specific and independent of tree class. The magnitude of the ratio was not related to the position of the tree in the stand nor to the prevailing light conditions within the state.

The PDF includes a summary in Finnish.

• Mäkelä, E-mail: am@mm.unknown
• Hari, E-mail: ph@mm.unknown
• Kellomäki, E-mail: sk@mm.unknown

The study is based on observations in a Scots pine (Pinus sylvestris L.) stand on a dry upland forest site in Karhumäki, where a 10-15-year old seedling stand grew under a hold-overs of larger trees that had been left in the site in a previous felling. The root systems of 80-120 cm tall seedlings growing around single mother trees were unearthed. Root maps were drawn of the root systems of 120 seedlings.

No seedlings grew around old, large hold-overs. It seems that seedlings could not compete with their root system. If the hold-overs were stunted in their growth, seedlings grew also under the canopy of the mother tree. 90% of the seedlings had a tap root. Rest of the roots grew horisontally in the topsoil. Around a vigorous mother tree, the seedlings grew their roots away from the mother tree. Hold-overs that had belonged originally to the lower canopy layer of the old forest did not have similar effect on the root orientation of the seedlings. Their roots had been previously affected by trees of higher canopy layer, later removed in the felling.

The PDF includes a summary in German.

• Kalela, E-mail: ek@mm.unknown

Crown class is useful tool both in forest management and forest mensuration. The study presents a detailed crown classification for Scots pine (Pinus sylvestris L.). It was used to classify the sample trees prior detailed measurements of the crown and stem form. The stem form of a tree was dependent on which canopy layer it belonged. This relation was detected on both Vaccinium and Calluna site type forests. In addition, the stem tapers faster in poorer forest site types compared to better sites. The shorter the self-pruned part of the stem is, the faster the stem tapers. According to the study, the stems of stunted trees taper faster than trees of other crown classes. Also the age group affects stem form.

The PDF includes a summary in German.

• Lakari, E-mail: ol@mm.unknown

• Meen, Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, P.O. Box 5003, NO-1432 Ås, Norway E-mail: eivind.meen@umb.no
• Nielsen, Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, P.O. Box 5003, NO-1432 Ås, Norway E-mail: an@nn.no
• Ohlson, Norwegian University of Life Sciences, Department of Ecology and Natural Resource Management, P.O. Box 5003, NO-1432 Ås, Norway E-mail: mo@nn.no

• Hotanen, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: juha-pekka.hotanen@metla.fi
• Maltamo, University of Joensuu, Faculty of Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: mm@nn.fi
• Reinikainen, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: ar@nn.fi