Decomposition and element concentrations of Norway spruce needle litter with differing B, N, or P status

Abstract

Adequate boron (B) nutrition may decrease concentrations of phenolic compounds and enhance structural integrity and lignification in plants, compared with suboptimal B. This could affect decomposition in areas where B deficiencies are common. The mass loss and changes in element concentrations in Norway spruce needle litter were studied with combinations of litter from high-B and low-B trees, incubated for 29 months, in either B fertilised or control plots without B addition. The litter originated from the same Norway spruce field experiments. Additionally, the field experiments included longterm N and P treatments. Initially, lowest lignin concentrations were found in Norway spruce litter from the treatment P and particularly in the combination B+P, and highest in the B+N fertilised plots. The mass loss of Norway spruce litter was not affected by the treatments. However, B litter increased Cu accumulation. The litter from the B + P fertilised plots accumulated considerably more Al, Ca, S and Zn than the other treatments, whereas B together with N reduced the remaining amounts of these elements. Reduced nutrient release from litter may have farreaching consequences on nutrient cycles in forests.

Decomposition of harvest residue needles on peatlands drained for forestry – Implications for nutrient and heavy metal dynamics

“…The mass losses of the needles in the present study were comparable to those reported for Norway spruce and Scots pine needles in earlier studies on mineral soil sites (Lundmark-Thelin and Johansson, 1997;Hyvönen et al, 2000;Palviainen et al, 2004b;Lehto et al, 2010). No significant differences in the mass loss, nutrient or metal dynamics of the harvest residue needles were found between the clear-cut and control sites.…”

“…The net accumulation in the spruce needles was approximately 333 % after 3 years, and the net release from the pine needles was approximately 19%. On mineral soils accumulation of Al into Norway spruce needles (Lehto et al, 2010) and some other conifer litter types (Rustad and Cronan, 1988;Rustad, 1994) has been confirmed earlier. The release of Al from pine needles is consistent with a study by Palviainen et al (2004a), where the net release from pine harvest residue needles over 3 years was approximately 26%.…”

“…There are no earlier studies on boron dynamics in harvest residue needles on drained peatlands, but it has been shown that B was released rapidly from spruce needle litter on mineral soils (Lehto et al, 2010). However, with B-poor litter material, also accumulation of B may occur, probably due to transportation of B by fungi into the litter (Lehto et al, 2010).…”

“…There are a number of nutrient release studies on conifer needle litter (e.g. Nilsson, 1972;Berg and Staaf, 1980;Rustad and Cronan, 1988;Laskowski and Berg, 1993;Rustad, 1994;Laskowski et al, 1995;Vesterdal, 1999;Lehto et al, 2010) and harvest residues (e.g. Lundmark-Thelin and Johansson, 1997;Palviainen et al, 2004a,b) from mineral soil forests, whereas the knowledge on the element release dynamics from litter and especially from harvest residues on drained peatlands is scarce.…”

Boron in forest trees and forest ecosystems

“…Boron level during growth slightly increased the initial mass loss in silver birch leaf litter (Lehto et al, 2010a), however, Norway spruce litter was not affected (Lehto et al, 2010b). Lignin concentrations in Norway spruce needle litter were decreased as a result of B fertilisation, but only if P was also applied.…”