Norway spruce litterfall and forest floor in the IUFRO thinning experiment CZ 13 - Vítkov

Abstract

The effect of thinning on litterfall and decomposition of biomass was investigated in Norway spruce IUFRO thinning experiment (CZ-13), Czech Republic. The experiment was established in 1971 in an 8-year-old spruce stand on former farmland. Quantity and quality of litterfall and biomass from humus horizons were analysed in two treatments (1C – no thinning, 2T – heavy thinning at the young age). Forest floor was investigated in 2002, 2004, 2005 and 2009 and litterfall was observed in the period 2002–2009. Accumulated dry mass in forest floor after 39 years of existence of spruce stands continually decreased until the age of 46 years (from 80–100 to 30–50 Mg·ha<sup>–1</sup>). Under thinned stand, a lower amount of dry mass was observed compared to the control. Although mean total annual litterfall was the same in both treatments (5.3 Mg·ha<sup>–1</sup>), the observed trend indicates a possible effect of thinning on the higher rate of decomposition. With the exception of calcium (2002–2005 samples) we found the forest floor lower in nutrients and litterfall higher in nutrients in thinned plot compared to the control. Our results supported the theory that early thinning is an appropriate silvicultural strategy helping spruce to cope with growth conditions on sites naturally dominated by broadleaves.