Introducing effects of temperature and CO 2 elevation on tree growth into a statistical growth and yield model

• Published in: Ecological modelling Vol. 181; no. 2; pp. 173 - 190
• Main Authors: Matala, J., Ojansuu, R., Peltola, H., Sievänen, R., Kellomäki, S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 20.01.2005
• Subjects: Boreal forests; Climate change; Growth; Model linking; Physiological model; Statistical model; Model linking; Climate change; Growth; Statistical model; Boreal forests; Physiological model
• ISSN: 0304-3800; 1872-7026
• DOI: 10.1016/j.ecolmodel.2004.06.030

Impacts of elevated temperature and CO 2 on tree growth were introduced into a statistical growth and yield model for Finnish conditions based on corresponding predictions obtained from a physiological growth model. This one-way link between models was made by means of species-specific transfer functions describing the increase in stem volume growth of trees as a function of elevated temperature and CO 2, stand density and the tree's competition status in a stand of Scots pine ( Pinus sylvestris), silver birch ( Betula pendula) and Norway spruce ( Picea abies). This method allows the inner dynamics of the statistical model to be followed when the impacts of temperature and CO 2 elevation on tree growth are introduced into the calculation of volume growth and further allocated between diameter and height growth. In this way compatibility with previous predictions of tree growth by means of statistical models and related model systems under current climatic conditions could be retained. The performance of the statistical model with species-specific transfer functions was evaluated by comparing its predictions with corresponding predictions given by a physiological model under conditions of elevated temperature and CO 2. These calculations revealed that the growth response of individual trees to elevated temperature and CO 2 can be introduced into the statistical model from a physiological growth model with an outcome that results in fairly satisfactory growth responses at the stand level as well.