Logging impacts on the biogeochemistry of boreal forest soils and nutrient export to aquatic systems: A review

Abstract

Logging disturbances in boreal forest watersheds can alter biogeochemical processes in soils by changing forest composition, plant uptake rates, soil conditions, moisture and temperature regimes, soil microbial activity, and water fluxes. In general, these changes have often led to short-term increases in soil nutrient availability followed by increased mobility and losses by leaching to receiving waters. Among the studies we reviewed, dissolved organic carbon (DOC) exports usually increased after logging, and nitrogen (N) mineralization and nitrification often increased with resulting increased N availability and exports to receiving waters. Similar processes and responses occurred for phosphorus (P), but to a lesser extent than for N. In most cases, base cations were released and exported to receiving waters after logging. Several studies demonstrated that stem-only or partial-harvest logging reduced the impacts on nutrient release and exports in comparison to whole-tree clear-cutting. Despite these logging-induced increases in soil nutrient availability and movement to receiving waters, most studies reported little or no change in soil chemical properties. However, responses to logging were highly variable and often site specific. The likelihood, extent and magnitude of logging impacts on soil nutrient cycling and exports in boreal forest watersheds will be dependent on soil types, stand and site conditions, hydrological connectivity, post-logging weather patterns, and type and timing of harvest activities. Additionally, logging impacts can interact with, and be confounded by, atmospheric pollutant deposition and climate change. Further watershed-level empirical studies and modeling efforts are required to elucidate these interactions, to improve predictive capabilities, and to advance forest management guidelines for sustaining forest soil productivity and limiting nutrient exports.Résumé : Les perturbations causées par la récolte du bois dans les bassins versants de la forêt boréale peuvent affecter les processus biochimiques des sols en modifiant la composition de la forêt, les taux d'absorption par les plantes, les conditions du sol, les régimes de température et d'humidité, l'activité des microorganismes du sol, et les mouvements de l'eau. En général, ces modifications engendrent souvent des augmentations de courte durée de la disponibilité des nutriments du sol, suivi par une augmentation de la mobilité et des pertes par lessivage vers les eaux réceptrices. Les études analysées font état d'une augmentation des exportations de carbone organique dissout (DOC) après la coupe, et d'une minéralisation de l'azote (N) avec une augmentation fréquente de la nitrification conduisant à une augmentation de la disponibilité de N et son exportation vers les eaux réceptrices. On observe des processus et réactions similaires pour le phosphore (P), mais à un moindre degré que pour le N. Dans la plupart des cas, il y a relâchement des cations basiques et exportation vers les eaux réceptrices après la coupe. Plusieurs étud...

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

“…Possibly clear-cutting increase stream water nutrient concentrations less in northern than in southern Fennoscandia due to slower mineralization rates and lower deposition fluxes (Akselsson et al 2004;Kortelainen et al 2006;Futter et al 2010;Palviainen et al 2014), and in the northern catchments the observed rise in nutrient loading is largely due to the increased runoff (Ahtiainen and Huttunen 1999;Palviainen et al 2014). 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).…”

“…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). Also the properties of buffer zones may affect responses (Gundersen et al 2010).…”

“…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).…”

“…They increase nutrient concentrations and loads in receiving waters (Ahtiainen and Huttunen 1999;Kreutzweiser et al 2008;Nieminen et al 2010) which may result in degradation of water quality, eutrophication, and formation of harmful algal blooms (Conley et al 2009). In Fennoscandia, several hundred thousand hectares of forests are clearcut annually and the majority of clear-cut areas are prepared mechanically before regeneration operations (Swedish Forest Agency 2013;Ylitalo 2013).…”

“…Nitrogen (N) and phosphorus (P) concentrations and loads increase in receiving waters after clear-cutting because the removal of trees decreases water and nutrient uptake and increases runoff (Vitousek et al 1979;Stednick 1996;Kreutzweiser et al 2008). In addition, increased soil temperatures following clear-cutting accelerate mineralization and nitrification in the soil (Paavolainen and Smolander 1998;Smolander et al 2001) and nutrients are released from decomposing logging residues (Palviainen et al 2004).…”