Effect of thinning on the foliar nutrient status of Scots pine stands on drained boreal peatlands

• Published in: Canadian Journal of Forest Research
• Main Authors: Hökkä, Hannu, Penttilä, Timo, Hånell, Björn
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1996
• Subjects: Ecology; Forestry; Global and Planetary Change; The Needle; Northern Finland
• Online Access: http://dx.doi.org/10.1139/x26-177; http://www.nrcresearchpress.com/doi/pdf/10.1139/x26-177

Foliar responses to thinning in midrotation stands of Scots pine (Pinussylvestris L.) were studied in six thinning experiments (0–50% of basal area removed) established on drained peatlands in northern Finland and southern Sweden. The trophic level of the sites varied from ombrotrophic to meso-eutrophic. Needle sampling and analyses were carried out on individual trees of dominant and suppressed canopy layers. The variation in the needle dry mass and in the element concentrations and contents, calculated as plot means, was explained by thinning treatment, blocking by site groups and randoming blocking within the site. Thinning increased foliar concentrations of P, needle size, and contents of N, P, and K in all the canopy layers. It was concluded that thinning improved the foliar nutrient status by reducing the competition for nutrients.