Growth patterns from different forest generations of Scots pine in Estonia

Abstract

There is strong evidence that climate change alters tree growth in boreal forests. In Estonia, the analysis of ring measurements has been a common method to study growth changes. In this study, annual height growth data from dominant or co-dominant Scots pine (Pinus sylvestris L.) trees were used to develop a growth model for three forest generations. Stem analysis was applied and annual height growth was measured as the distance between whorls, as detected by branch knots of whorls on the split stem surface. Retrospective analysis of height growth produced comparative trends for three different age groups. Statistical analyses were used to estimate the impact of different factors on growth. Annual height growth was considered the best indicator for detecting possible trends in the growth potential of trees. Study results indicate that three generations (separated by time periods of 30–40 years) showed significant differences in growth patterns caused by shifts in climatic factors and management regimes (anthropogenic and natural disturbances).

Keywords:

• Annual growth
• Forest growth change
• Growth modelling
• Stem analysis

Acknowledgments

This study was supported by Järvselja Training and Experimental Forest Centre, Estonian Environmental Investment Centre, State Forest Management Centre, Metsämiesten Säätiö and The Ministry of Education and Research (project SF0170014s08 and grant no ETF8890). We are very grateful to Lee E. Frelich, University of Minnesota, for discussion and language correction.