MetINFO - Daily growth of trees

The growing season of forest trees is very short in Finland. Radial growth generally starts in late May in the south. In northern Finland radial growth typically starts in early June, but in the harsh conditions of northernmost Finland the start may be delayed to late June. Radial growth of conifers typically ceases in August both in southern and northern Finland.

Height growth accumulates during an even shorter period, beginning in late April- early May and typically ending during the first days of July.
→See a demo on height growth of Scots pine (Pinus sylvestris L.).

The amount of annual growth varies considerably. On favorable summers, such as 2010 and 2011, radial growth can be 20-30% above average in southern Finland. In the north, where the climatic signal in tree rings is especially strong, the year-to-year variation can be even larger. Summer temperatures are strongly correlated with radial growth of conifers. In southern Finland also a clear precipitation signal has been detected in tree rings.

An exceptionally long time series is available on the cubic volume and the annual growth of the forest of Finland. The first systematic National forest inventory took place in 1921-1921. Both volume and annual growth developed fairly steadily from the 1920s to the early 1970s, but have increased rapidly thereafter (see Statistical Yearbook of Forestry).