Metla Project 3301

Short term variation of tree growth

[  Suomeksi  |  Objectives  |  Results  |  Project leader  |  Researchers  |  Publications  |  Metla Research  ]

Duration: 2000-2003   Keywords: Diameter growth, girth band, modeling

Objectives

First objective of the study is to analyse the variation of tree circumference by dividing the variation into its components: actual growth caused by cell division and enlargening, changes in the water content of the tree stem that causes reversible diameter changes and changes that are connected to winter dormancy. This knowledge is utilized by analysing girth band measurements for determining the lenght of growing season, for quick estimation of annual growth indices and for analysing differences between tree provenances in beginning and cessation of growth. An additional objective is to further develop the accuracy and reliabbility of the girth bands that have been used.

Results

A method for monitoring the daily radial growth of trees was developed. The method is based on taking mini-cores from tree stems at regular intervals during the growing season. From the minicores one can accurately determine the number of new cell layers that had accumulated by the time the sample was taken. By repeating the sampling sufficiently often, one can monitore radial growth rate during the growing season.

Also a prototype of a new girth band was developed. The new girth band uses a GMS-connection for transmitting the measurement data directly into office. Thus a data logger, which collects and stores the measurement results in the forest, becomes unnecessary.

The daily radial growth of Pinus silvestris L. and Picea abies (Karst.) for 2001-2003 was monitored in different parts of Finland using both girth bands and the mini-coring technique. Examples of the results were presented in the internet (www.metla.fi/metinfo/kasvu/paivittainen). In the application, results of girth band measurements were transmitted into the internet on daily basis. Thus the reader was provided with fresh observations on radial growth of trees throughout the growing season. The techniques for monitoring the daily radial growth of trees were also applied for analyzing growth differences between different Norway spruce provenances as well as growth periodicity of Pinus patula in Tanzania.

Project leader: Nöjd, Pekka
The Finnish Forest Research Institute, Vantaa Unit, PL 18, 01301 Vantaa
Phone: +358 10 211 2331 Telefax: +358 10 211 2203
E-mail: pekka.nojd@metla.fi

Other researchers: Mäkinen, Harri, VA (2001-03), Pesonen, Erkki, VA (2000-03)


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Updated 30.12.2006
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