Acta Univ Latv (2008) 745: 131–144

Effect of burial by sand on Scots pine (Pinus sylvestris L.) radial growth on seacoast wooded dunes at Cape Kolka, Latvia

Abstract

Scots pine is a widely distributed species in Latvia, stress tolerant and able to grow in poor habitats. It is the dominating species of seacoast wooded dunes. Dunes in the Cape Kolka area are characterized with moving sand, resulting in stem burial of pines growing close to the beach. Main burial events are thought to occur during major storms, particularly as in 1967 – 1969. The aim of the study was to evaluate the effect of burial and climatic factors on radial growth. Samples from pines growing along the seaside under different levels of sand burial were collected. Tree-ring width series were crossdated and detrended chronologies were established. To evaluate growth relationships with climate correlation analysis was performed. Release/suppression analysis was performed to evaluate burial effect. Burial affected radial growth both in unburied and buried parts of stem. Under deep burial (more than 0.6 m) the occurrence of missing tree-rings increased. Radial growth since storms of 1967 – 1969 declined in pines blown over with sand. No major release periods were observed. Unburied pines also showed growth suppression dominating over release, especially during the last forty years, which might be related with erosion of the Kolka coast, changing the abiotic factors. Late winter and early spring temperatures were the main climatic factors affecting Scots pine growth of unburied trees, but buried trees (parts of stems) showed weaker reaction to extreme temperatures. Precipitation had an insignificant influence, presumable due to a well-drained soil and sufficient available moisture.