Development of ground vegetation biomass and nutrient pools in a clear-cut disc-plowed boreal forest

Abstract

Nutrient leaching from forest substrate after clear-cutting and subsequent soil preparation is strongly influenced by the capacity of ground vegetation to sequester the released nutrients. We studied the rates and patterns of biomass and nutrient accumulation in ground vegetation growing on ridges, in furrows and on undisturbed surfaces for 2-5 years after disc-plowing in eastern Finland. The biomass of mosses on ridges remained significantly lower than that in furrows and on undisturbed surfaces. Field layer biomass on ridges and in furrows was significantly lower than on undisturbed surfaces throughout the study period. Field layer biomass increased more on ridges than in furrows. Root biomass on ridges and undisturbed surfaces was considerably higher than in furrows. Five years after disc-plowing, total biomass and nutrient pools for ridges (biomass 4,975 kg ha −1 , N 40 kg ha −1 , P 5 kg ha −1 , K 20 kg ha −1 and Ca 18 kg ha −1 ) and undisturbed surfaces (biomass 5,613 kg ha −1 , N 43 kg ha −1 , P 5 kg ha −1 , K 22 kg ha −1 and Ca 18 kg ha −1 ) were similar, but considerably lower for furrows (biomass 1,807 kg ha −1 , N 16 kg ha −1 , P 2 kg ha −1 , K 10 kg ha −1 and Ca 6 kg ha −1 ). Ridges covered 25% of the area, furrows 30 and 45% was undisturbed surfaces. Taking into account the proportion of each type of surface, values for the whole prepared clearcut area were 4,312, 34, 4, 18 and 14 kg ha −1 for biomass, N, P, K and Ca, respectively. Biomass and nutrient pools had not returned to uncut forest levels at the end of the 5-year study period. The results indicate that mosses and field layer vegetation respond differently to soil preparation, that the development of biomass on ridges, in furrows and on undisturbed surfaces proceeds at different rates, and that the biomass and nutrient uptake of ground vegetation remains below pre-site preparation levels for several years. However, ridges, which are known to be the most susceptible to leaching, revegetate rapidly.

A method to estimate the impact of clear-cutting on nutrient concentrations in boreal headwater streams

“…The increase in total N, NO 3 -N, NH 4 -N and PO 4 -P concentrations after clear-cutting is in accordance with the results from other boreal catchments (Grip 1982;Rosén et al 1996;Lamontagne et al 2000;Kreutzweiser et al 2008). The increases in the concentrations of N fractions in stream water could result from higher deposition loads due to the lack of N retention by tree canopy (Piirainen et al 2002), reduced nutrient uptake by trees and understory vegetation (Palviainen et al 2007), and increased nitrification in litter layer and soil (Paavolainen and Smolander 1998). Nitrate is poorly retained in the soil by sorption and can be easily leached to surface waters (Rosén et al 1996;Kreutzweiser et al 2008).…”

“…The increases in NO 3 -N concentrations (maximum 190 lg l -1 for the 100 % clear-cut) were considerable smaller than those reported for temperate streams in high N deposition areas, where mean annual NO 3 -N concentrations have been shown to increase by 500-3800 lg l -1 after clear-cutting (Adamson et al 1987;Wiklander et al 1991;Reynolds et al 1995;Feller 2005;Gundersen et al 2006). The elevated PO 4 -P concentrations may be due to reduced nutrient uptake and mineralization from logging residues and dead ground vegetation (Palviainen et al 2004(Palviainen et al , 2007. Furthermore, elevated ground water levels and more superficial water flow paths after clear-cutting may also have promoted PO 4 -P solubility and transport to the stream Kreutzweiser et al 2008).…”

“…2) and, consequently, 95 % confidence intervals of the specific concentration estimates were rather wide (Table 3). The magnitude and duration of the changes in concentrations depend on several factors such as catchment topography, soil properties, site fertility, atmospheric deposition, vegetation recovery, the timing of management practices and weather conditions after clear-cutting (Ahtiainen and Huttunen 1999;Mattsson et al 2003;Gundersen et al 2006;Palviainen et al 2007;Kreutzweiser et al 2008;Löfgren et al 2009;Futter et al 2010;Palviainen et al 2014). In addition to above-mentioned factors, the location of clear-cut area in relation to the stream may cause variability in treatment effects among studies (Kreutzweiser et al 2008;Abdelnour et al 2011).…”

Impact of Tree Stump Harvesting on Soil Carbon and Nutrients and Second Rotation Tree Growth in Mid-Wales, UK

“…In the absence of vegetation, these potential pollutants can leach from the site, posing a risk to water quality and potentially compromising the growth of following rotations. This will be partly countered by faster rate of re-vegetation on destumped sites, which should shorten the period of nutrient loss as plants take up nutrients (Emmett et al, 1991;Palviainen et al, 2007).…”

Environmental Services Provided from Riparian Forests in the Nordic Countries

“…The most important processes occurring in RF that can decrease the N export are vegetation uptake (Silvan et al 2005;Palviainen et al 2007), retention to soil and assimilation to soil microbes (Silvan et al 2003;Palviainen et al 2004) as well as gaseous N fluxes from soil to the atmosphere (Regina et al 1998;Silvan et al 2002;Maljanen et al 2003). Nitrogen export depends on the mobility of N fractions including ammonium (NH 4 ?…”