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Forest soils in Northern Europe are generally trafficked by forest machinery on several occasions during a forest rotation. This may create ruts (wheel tracks), which could increase sediment transport to nearby surface water, reduce recreational value, and affect tree growth. It is therefore important to reduce soil disturbance during off-road forest transportation. In this study, rut depth was measured following forwarder traffic on study plots located along four harvested till hillslopes in Northern Sweden with drier soil conditions uphill and wet conditions downhill. The treatments included driving 1) using no ground protection, 2) on logging residue (on average, 38–50 kg m–2) and 3) on logging mats measuring 5×1×0.2 m. The hillslopes contain areas with a high content of boulders, stones, and gravel as well as areas with a significant content of silt. Six passes with a laden forwarder with four bogie tracks were performed. On the plots with ground protection, the application of logging residue and the application and removal of logging mats necessitated additional passes. Rut depth was measured using two methods: 1) as the difference in elevation between the interpolated original soil surface and the surface of the rut using GNSS positioning (Global Navigation Satellite Systems), and 2) manually with a folding rule from an aluminium profile, placed across the rut, to the bottom of the rut. The two methods generally gave similar results. Driving without ground protection in the upper part of the hillslopes generated ruts with depths <0.2 m. Here, the rut depth was probably modified by the high content of boulders and stones in the upper soil and drier soil conditions. In the lower part of the hillslopes, the mean rut depth ranged from 0.21 to 0.34 m. With a few exceptions, driving on logging residue or logging mats prevented exposure of mineral soil along the entire hillslope. Soil disturbance can thus be reduced by acknowledging the onsite variability in ground conditions and considering the need for ground protection when planning forest operations.
Eva Ring; Mikael Andersson; Linnea Hansson; Gunnar Jansson; Lars Högbom. Logging Mats and Logging Residue as Ground Protection during Forwarder Traffic along Till Hillslopes. Croatian journal of forest engineering 2021, 42, 445 -462.
AMA StyleEva Ring, Mikael Andersson, Linnea Hansson, Gunnar Jansson, Lars Högbom. Logging Mats and Logging Residue as Ground Protection during Forwarder Traffic along Till Hillslopes. Croatian journal of forest engineering. 2021; 42 (3):445-462.
Chicago/Turabian StyleEva Ring; Mikael Andersson; Linnea Hansson; Gunnar Jansson; Lars Högbom. 2021. "Logging Mats and Logging Residue as Ground Protection during Forwarder Traffic along Till Hillslopes." Croatian journal of forest engineering 42, no. 3: 445-462.
Forests are the dominant land cover in Nordic–Baltic countries, and forestry, the management of forests for improved ecosystem-service (ES) delivery, is an important contributor to sustainability. Forests and forestry support multiple United Nations Sustainability Goals (UN SDGs) and a number of EU policies, and can address conflicting environmental goals. Forests provide multiple ecosystem services and natural solutions, including wood and fibre production, food, clear and clean water and air, animal and plant habitats, soil formation, aesthetics, and cultural and social services. Carbon sequestered by growing trees is a key factor in the envisaged transition from a fossil-based to a biobased economy. Here, we highlight the possibilities of forest-based solutions to mitigate current and emerging societal challenges. We discuss forestry effects on forest ecosystems, focusing on the optimisation of ES delivery and the fulfilment of UN SDGs while counteracting unwanted effects. In particular, we highlight the trilemma of (i) increasing wood production to substitute raw fossil materials, (ii) increasing forest carbon storage capacity, and (iii) improving forest biodiversity and other ES delivery.
Lars Högbom; Dalia Abbas; Kęstutis Armolaitis; Endijs Baders; Martyn Futter; Aris Jansons; Kalev Jõgiste; Andis Lazdins; Diana Lukminė; Mika Mustonen; Knut Øistad; Anneli Poska; Pasi Rautio; Johan Svensson; Floor Vodde; Iveta Varnagirytė-Kabašinskienė; Jan Weslien; Lars Wilhelmsson; Daiga Zute. Trilemma of Nordic–Baltic Forestry—How to Implement UN Sustainable Development Goals. Sustainability 2021, 13, 5643 .
AMA StyleLars Högbom, Dalia Abbas, Kęstutis Armolaitis, Endijs Baders, Martyn Futter, Aris Jansons, Kalev Jõgiste, Andis Lazdins, Diana Lukminė, Mika Mustonen, Knut Øistad, Anneli Poska, Pasi Rautio, Johan Svensson, Floor Vodde, Iveta Varnagirytė-Kabašinskienė, Jan Weslien, Lars Wilhelmsson, Daiga Zute. Trilemma of Nordic–Baltic Forestry—How to Implement UN Sustainable Development Goals. Sustainability. 2021; 13 (10):5643.
Chicago/Turabian StyleLars Högbom; Dalia Abbas; Kęstutis Armolaitis; Endijs Baders; Martyn Futter; Aris Jansons; Kalev Jõgiste; Andis Lazdins; Diana Lukminė; Mika Mustonen; Knut Øistad; Anneli Poska; Pasi Rautio; Johan Svensson; Floor Vodde; Iveta Varnagirytė-Kabašinskienė; Jan Weslien; Lars Wilhelmsson; Daiga Zute. 2021. "Trilemma of Nordic–Baltic Forestry—How to Implement UN Sustainable Development Goals." Sustainability 13, no. 10: 5643.
Wood-ash application to forest land has been proposed as a means to compensate for increased nutrient removal at high harvest intensity. A study-plot experiment was established on a mineral soil site in Sweden to study how this measure affects soil-water chemistry. In 1995, ten treatments were applied. Here we present results from years nine to seventeen after application for eight of the treatments: control, 3×103, 6×103 and 9×103 kg ha-1 of self-hardened and crushed wood ash (WA), 150 kg N ha-1 supplied as ammonium nitrate, 3×103 kg WA and 150 kg N ha-1 applied simultaneously, 3×103 kg WA with 150 kg N ha-1 applied one month before the ash, and 3×103 kg ha-1 of pelleted ash. Soil-water samples were collected from a depth of 50 cm. Treatment effects (p+, Mg2+, Ca2+, Al, SO42--S and B. Elevation of K+ and SO42--S concentrations tended to cease towards the end of the study period. Effects were generally more pronounced with increasing ash dosage. No difference between the treatment 150 kg N ha-1 and control was detected. Despite the high solubility of the ash, effects on the soil-water chemistry could still be detected nine to seventeen years after application.
Eva Ring; Gunnar Jansson; Lars Hogbom; Staffan Jacobson. Long-term effects on soil-water chemistry of wood-ash and nitrogen application in a conifer forest. Canadian Journal of Forest Research 2020, 1 .
AMA StyleEva Ring, Gunnar Jansson, Lars Hogbom, Staffan Jacobson. Long-term effects on soil-water chemistry of wood-ash and nitrogen application in a conifer forest. Canadian Journal of Forest Research. 2020; ():1.
Chicago/Turabian StyleEva Ring; Gunnar Jansson; Lars Hogbom; Staffan Jacobson. 2020. "Long-term effects on soil-water chemistry of wood-ash and nitrogen application in a conifer forest." Canadian Journal of Forest Research , no. : 1.
Nitrogen (N) fertilization is a routine practice in boreal forests but its effects on fungal functional guilds in Pinus sylvestris forests are still incompletely understood. Sampling is often restricted to the upper organic horizons and based on DNA extracted from mixtures of soil and roots without explicitly analysing different spatial niches. Fungal community structure in soil and roots of an 85-y-old Pinus sylvestris forest was investigated using high throughput sequencing. Fertilized plots had been treated with a single dose of N fertilizer, 15 months prior to sampling. Species richness of fungi colonizing roots was reduced in all horizons by N fertilization. In contrast, species richness of soil fungi in the organic horizon was increased by N fertilization, but unaffected in the mineral horizons. Community composition of fungi colonizing roots differed from that of soil fungi, and both communities were significantly influenced by soil horizon and N. The ectomycorrhizal community composition in both roots and soil was significantly affected by N fertilization but no significant effect was found on saprotrophic fungi. The results highlight the importance of analysing the rhizosphere soil and root compartments separately since the fungal communities in these two niches appear to respond differently to environmental perturbations involving the addition of nitrogen.
Srisailam Marupakula; Shahid Mahmood; Karina E. Clemmensen; Staffan Jacobson; Lars Högbom; Roger D. Finlay. Root associated fungi respond more strongly than rhizosphere soil fungi to N fertilization in a boreal forest. Science of The Total Environment 2020, 766, 142597 .
AMA StyleSrisailam Marupakula, Shahid Mahmood, Karina E. Clemmensen, Staffan Jacobson, Lars Högbom, Roger D. Finlay. Root associated fungi respond more strongly than rhizosphere soil fungi to N fertilization in a boreal forest. Science of The Total Environment. 2020; 766 ():142597.
Chicago/Turabian StyleSrisailam Marupakula; Shahid Mahmood; Karina E. Clemmensen; Staffan Jacobson; Lars Högbom; Roger D. Finlay. 2020. "Root associated fungi respond more strongly than rhizosphere soil fungi to N fertilization in a boreal forest." Science of The Total Environment 766, no. : 142597.
We present a framework for evaluating and communicating effects of human activity on water quality in managed forests. The framework is based on the following processes: atmospheric deposition, weathering, accumulation, recirculation and flux. Impairments to water quality are characterized in terms of their extent, longevity and frequency. Impacts are communicated using a “traffic lights” metaphor for characterizing severity of water quality impairments arising from forestry and other anthropogenic pressures. The most serious impairments to water quality in managed boreal forests include (i) forestry activities causing excessive sediment mobilization and extirpation of aquatic species and (ii) other anthropogenic pressures caused by long-range transport of mercury and acidifying pollutants. The framework and tool presented here can help evaluate, summarize and communicate the most important issues in circumstances where land management and other anthropogenic pressures combine to impair water quality and may also assist in implementing the “polluter pays” principle.
Martyn N. Futter; Lars Högbom; Salar Valinia; Ryan A. Sponseller; Hjalmar Laudon. Conceptualizing and communicating management effects on forest water quality. Ambio 2016, 45, 188 -202.
AMA StyleMartyn N. Futter, Lars Högbom, Salar Valinia, Ryan A. Sponseller, Hjalmar Laudon. Conceptualizing and communicating management effects on forest water quality. Ambio. 2016; 45 (2):188-202.
Chicago/Turabian StyleMartyn N. Futter; Lars Högbom; Salar Valinia; Ryan A. Sponseller; Hjalmar Laudon. 2016. "Conceptualizing and communicating management effects on forest water quality." Ambio 45, no. 2: 188-202.
Boreal streams are under pressure from large scale disturbance by forestry. Recent scenarios predict an increase in forest production in Scandinavia to meet market demands and to mitigate higher anthropogenic CO2 emissions. Increased fertilization and shorter forest rotations are anticipated which will likely enhance the pressure on boreal streams in the near future. Among the major environmental impacts of forest harvesting is the increased mobilization of inorganic nitrogen (N), primarily as nitrate (NO3-) into surface waters. But whereas NO3- inputs to first-order streams have been previously described, their downstream fate and impact is not well understood. We evaluated the downstream fate of N inputs in a boreal landscape that has been altered by forest harvests over a 10 year period to estimate the effects of multiple clear-cuts on aquatic N export in a boreal stream network. Small streams showed substantial leaching of NO3- in response to harvests with concentrations increasing by ~ 15 fold. NO3- concentrations at two sampling stations further downstream in the network were strongly seasonal and increased significantly in response to harvesting at the medium size, but not at the larger stream. Nitrate removal efficiency, Er, calculated as the percentage of "forestry derived" NO3- that was retained within the landscape using a mass balance model was highest during the snow melt season followed by the growing season, but declined continuously throughout the dormant season. In contrast, export of organic N from the landscape indicated little removal and was essentially conservative. Overall, net removal of NO3- between 2008 and 2011 accounted for ~ 70 % of the total NO3- mass exported from harvested patches distributed across the landscape. These results highlight the capacity and limitation of N-limited terrestrial and aquatic ecosystems to buffer inorganic N mobilization that arises from multiple clear-cuts within meso-scale boreal watersheds.
J. Schelker; Ryan A Sponseller; E F Ring; Lars Hogbom; S. Löfgren; Hjalmar Laudon. Nitrogen export from a boreal stream network following forest harvesting: seasonal nitrate removal and conservative export of organic forms. Biogeosciences Discussions 2015, 1 .
AMA StyleJ. Schelker, Ryan A Sponseller, E F Ring, Lars Hogbom, S. Löfgren, Hjalmar Laudon. Nitrogen export from a boreal stream network following forest harvesting: seasonal nitrate removal and conservative export of organic forms. Biogeosciences Discussions. 2015; ():1.
Chicago/Turabian StyleJ. Schelker; Ryan A Sponseller; E F Ring; Lars Hogbom; S. Löfgren; Hjalmar Laudon. 2015. "Nitrogen export from a boreal stream network following forest harvesting: seasonal nitrate removal and conservative export of organic forms." Biogeosciences Discussions , no. : 1.
Large-scale forestry operations, like clear-cutting, may impair surface water quality if not done with environmental considerations in mind. Catchment and country level estimates of nutrient loads from forestry are generally based on specific export values, i.e., changes in annual exports due to the implemented forestry operations expressed in kg ha(-1). We introduce here a specific concentration approach as a method to estimate the impact of clear-cutting on nutrient concentrations and export in headwater streams. This new method is potentially a more dynamic and flexible tool to estimate nutrient loads caused by forestry, because variation in annual runoff can be taken into account in load assessments. We combined water quality data from eight boreal headwater catchment pairs located in Finland and Sweden, where the effect of clear-cutting on stream water quality has been studied experimentally. Statistically significant specific concentration values could be produced for total nitrogen, nitrate, ammonium, and phosphate. The significant increases in the concentrations of these nutrients occurred between 2 and 6 years after clear-cutting. Significant specific concentration values could not be produced for total phosphorus and total organic carbon with the whole dataset, although in some single studies significant increases in their concentrations after clear-cutting were observed. The presented method enables taking into account variation in runoff, temporal dynamics of effects, and the proportional size of the treated area in load calculations. The number of existing studies considering large site-specific variation in responses to clear-cutting is small, and therefore further empirical studies are needed to improve predictive capabilities of the specific concentration values.
Marjo Palviainen; Leena Finér; Ari Laurén; Tuija Mattsson; Lars Högbom. A method to estimate the impact of clear-cutting on nutrient concentrations in boreal headwater streams. Ambio 2015, 44, 521 -531.
AMA StyleMarjo Palviainen, Leena Finér, Ari Laurén, Tuija Mattsson, Lars Högbom. A method to estimate the impact of clear-cutting on nutrient concentrations in boreal headwater streams. Ambio. 2015; 44 (6):521-531.
Chicago/Turabian StyleMarjo Palviainen; Leena Finér; Ari Laurén; Tuija Mattsson; Lars Högbom. 2015. "A method to estimate the impact of clear-cutting on nutrient concentrations in boreal headwater streams." Ambio 44, no. 6: 521-531.
Eva Ring; Lars Högbom; Hans-Örjan Nohrstedt; Staffan Jacobson. Soil and soil-water chemistry below different amounts of logging residues at two harvested forest sites in Sweden. Silva Fennica 2015, 49, 1 .
AMA StyleEva Ring, Lars Högbom, Hans-Örjan Nohrstedt, Staffan Jacobson. Soil and soil-water chemistry below different amounts of logging residues at two harvested forest sites in Sweden. Silva Fennica. 2015; 49 (4):1.
Chicago/Turabian StyleEva Ring; Lars Högbom; Hans-Örjan Nohrstedt; Staffan Jacobson. 2015. "Soil and soil-water chemistry below different amounts of logging residues at two harvested forest sites in Sweden." Silva Fennica 49, no. 4: 1.
The water footprint by the Water Footprint Network (WF) is an ambitious tool for measuring human appropriation and promoting sustainable use of fresh water. Using recent case studies and examples from water-abundant Fennoscandia, we consider whether it is an appropriate tool for evaluating the water use of forestry and forest-based products. We show that aggregating catchment level water consumption over a product life cycle does not consider fresh water as a renewable resource and is inconsistent with the principles of the hydrologic cycle. Currently, the WF assumes that all evapotranspiration (ET) from forests is a human appropriation of water although ET from managed forests in Fennoscandia is indistinguishable from that of unmanaged forests. We suggest that ET should not be included in the water footprint of rain-fed forestry and forest-based products. Tools for sustainable water management should always contextualize water use and water impacts with local water availability and environmental sensitivity.
Samuli Launiainen; Martyn N. Futter; David Ellison; Nicholas Clarke; Leena Finér; Lars Högbom; Ari Laurén; Eva Ring. Is the Water Footprint an Appropriate Tool for Forestry and Forest Products: The Fennoscandian Case. Ambio 2013, 43, 244 -256.
AMA StyleSamuli Launiainen, Martyn N. Futter, David Ellison, Nicholas Clarke, Leena Finér, Lars Högbom, Ari Laurén, Eva Ring. Is the Water Footprint an Appropriate Tool for Forestry and Forest Products: The Fennoscandian Case. Ambio. 2013; 43 (2):244-256.
Chicago/Turabian StyleSamuli Launiainen; Martyn N. Futter; David Ellison; Nicholas Clarke; Leena Finér; Lars Högbom; Ari Laurén; Eva Ring. 2013. "Is the Water Footprint an Appropriate Tool for Forestry and Forest Products: The Fennoscandian Case." Ambio 43, no. 2: 244-256.
Karin Johansson; Eva Ring; Lars Högbom. Effects of pre-harvest fertilization and subsequent soil scarification on the growth of planted Pinus sylvestris seedlings and ground vegetation after clear-felling. Silva Fennica 2013, 47, 1 .
AMA StyleKarin Johansson, Eva Ring, Lars Högbom. Effects of pre-harvest fertilization and subsequent soil scarification on the growth of planted Pinus sylvestris seedlings and ground vegetation after clear-felling. Silva Fennica. 2013; 47 (4):1.
Chicago/Turabian StyleKarin Johansson; Eva Ring; Lars Högbom. 2013. "Effects of pre-harvest fertilization and subsequent soil scarification on the growth of planted Pinus sylvestris seedlings and ground vegetation after clear-felling." Silva Fennica 47, no. 4: 1.
Short-term increases in soil solution nitrate (NO3−) concentration are often observed after forest harvest, even in N-limited systems. We model NO3− leaching below the rooting zone as a function of site productivity. Using national forest inventories and published estimates of N attenuation in rivers and the riparian zone, we estimate effects of stem-only harvesting on NO3− leaching to groundwater, surface waters and the marine environment. Stem-only harvesting is a minor contributor to NO3− pollution of Swedish waters. Effects in surface waters are rapidly diluted downstream, but can be locally important for shallow well-waters as well as for the total amount of N reaching the sea. Harvesting adds approximately 8 Gg NO3–N to soil waters in Sweden, with local concentrations up to 7 mg NO3–N l−1. Of that, ∼3.3 Gg reaches the marine environment. This is ∼3% of the overall Swedish N load to the Baltic.
M.N. Futter; E. Ring; L. Högbom; S. Entenmann; K.H. Bishop. Consequences of nitrate leaching following stem-only harvesting of Swedish forests are dependent on spatial scale. Environmental Pollution 2010, 158, 3552 -3559.
AMA StyleM.N. Futter, E. Ring, L. Högbom, S. Entenmann, K.H. Bishop. Consequences of nitrate leaching following stem-only harvesting of Swedish forests are dependent on spatial scale. Environmental Pollution. 2010; 158 (12):3552-3559.
Chicago/Turabian StyleM.N. Futter; E. Ring; L. Högbom; S. Entenmann; K.H. Bishop. 2010. "Consequences of nitrate leaching following stem-only harvesting of Swedish forests are dependent on spatial scale." Environmental Pollution 158, no. 12: 3552-3559.
In the future it may become common practice to return wood-ash to forest ecosystems in order to replenish nutrients removed when brash has been extracted as a source of bioenergy. Wood-ash contains most of the nutrients that are present in the brash before its removal and burning, with the important exception of nitrogen (N). In the present paper we report measurements of CO2 emissions and net N mineralisation in the humus layer and the upper 5 cm of mineral soil 12 years after the application of wood-ash to two study sites, representing different tree species, climatic conditions and N deposition histories. We hypothesized that application of wood-ash would increase both carbon (C) and net N mineralisation rates at Torup, an N-rich site with Norway spruce (Picea abies (L.) Karst.) in the south, whereas the net N mineralisation rates would not be affected at Vindeln, an N-poor site with Scots pine (Pinus sylvestris L.) in the north, where a possible N-limitation would restrict any N mineralisation. The treatments, comprising additions of 0, 1, 3 or 6 Mg of granulated wood-ash ha−1, were applied in a randomised block design, replicated three times. Wood-ash from the same batch was used for all treatments at both sites. All factors were measured under laboratory conditions with controlled temperature and moisture levels. The potential CO2 emissions (kg ha−1 year−1 of CO2–C) at Torup were significantly higher in the 3 and 6 Mg ha−1 treatments than in the control treatment, and the highest application resulted in an extra loss of 0.5 Mg ha−1 of soil C annually as compared to the control. No such differences were detected at Vindeln. The results suggest that wood-ash application can deplete soil organic C at locations with similar characteristics (N-rich soil, spruce dominated, warm climate) as at Torup in this study.
O. Rosenberg; T. Persson; L. Högbom; S. Jacobson. Effects of wood-ash application on potential carbon and nitrogen mineralisation at two forest sites with different tree species, climate and N status. Forest Ecology and Management 2010, 260, 511 -518.
AMA StyleO. Rosenberg, T. Persson, L. Högbom, S. Jacobson. Effects of wood-ash application on potential carbon and nitrogen mineralisation at two forest sites with different tree species, climate and N status. Forest Ecology and Management. 2010; 260 (4):511-518.
Chicago/Turabian StyleO. Rosenberg; T. Persson; L. Högbom; S. Jacobson. 2010. "Effects of wood-ash application on potential carbon and nitrogen mineralisation at two forest sites with different tree species, climate and N status." Forest Ecology and Management 260, no. 4: 511-518.
Riparian forests (RF) growing along streams, rivers and lakes comprise more than 2% of the forest area in the Nordic countries (considering a 10 m wide zone from the water body). They have special ecological functions in the landscape. They receive water and nutrients from the upslope areas, are important habitats for biodiversity, have large soil carbon stores, but may emit more greenhouse gases (GHG) than the uplands. In this article, we present a review of the environmental services related to water protection, terrestrial biodiversity, carbon storage and greenhouse gas dynamics provided by RF in the Nordic countries. We discuss the benefits and trade-offs when leaving the RF as a buffer against the impacts from upland forest management, in particular the impacts of clear cutting. Forest buffers are effective in protecting water quality and aquatic life, and have positive effects on terrestrial biodiversity, particularly when broader than 40 m, whereas the effect on the greenhouse gas exchange is unclear.
Per Gundersen; Ari Laurén; Leena Finér; Eva Ring; Harri Koivusalo; Magne Saetersdal; Jan-Olov Weslien; Bjarni D. Sigurdsson; Lars Högbom; Jukka Laine; Karin Hansen. Environmental Services Provided from Riparian Forests in the Nordic Countries. AMBIO 2010, 39, 555 -566.
AMA StylePer Gundersen, Ari Laurén, Leena Finér, Eva Ring, Harri Koivusalo, Magne Saetersdal, Jan-Olov Weslien, Bjarni D. Sigurdsson, Lars Högbom, Jukka Laine, Karin Hansen. Environmental Services Provided from Riparian Forests in the Nordic Countries. AMBIO. 2010; 39 (8):555-566.
Chicago/Turabian StylePer Gundersen; Ari Laurén; Leena Finér; Eva Ring; Harri Koivusalo; Magne Saetersdal; Jan-Olov Weslien; Bjarni D. Sigurdsson; Lars Högbom; Jukka Laine; Karin Hansen. 2010. "Environmental Services Provided from Riparian Forests in the Nordic Countries." AMBIO 39, no. 8: 555-566.
Mercury (Hg) levels are alarmingly high in fish from lakes across Fennoscandia and northern North America. The few published studies on the ways in which silviculture practices influence this problem indicate that forest operations increase Hg in downstream aquatic ecosystems. From these studies, we estimate that between one-tenth and one-quarter of the Hg in the fish of high-latitude, managed forest landscapes can be attributed to harvesting. Forestry, however, did not create the elevated Hg levels in the soils, and waterborne Hg/MeHg concentrations downstream from harvested areas are similar to those from wetlands. Given the current understanding of the way in which silviculture impacts Hg cycling, most of the recommendations for good forest practice in Sweden appear to be appropriate for high-latitude regions, e.g., leaving riparian buffer zones, as well as reducing disturbance at stream crossings and in moist areas. The recommendation to restore wetlands and reduce drainage, however, will likely increase Hg/MeHg loadings to aquatic ecosystems.
Kevin Bishop; Craig Allan; Lage Bringmark; Edenise Garcia; Sofie Hellsten; Lars Högbom; Kjell Johansson; Anja Lomander; Markus Meili; John Munthe; Mats Nilsson; Petri Porvari; Ulf Skyllberg; Rasmus Sorensen; Therese Zetterberg; Staffan Akerblom. The effects of forestry on Hg bioaccumulation in nemoral/boreal waters and recommendations for good silvicultural practice. Ambio 2009, 38, 373 -380.
AMA StyleKevin Bishop, Craig Allan, Lage Bringmark, Edenise Garcia, Sofie Hellsten, Lars Högbom, Kjell Johansson, Anja Lomander, Markus Meili, John Munthe, Mats Nilsson, Petri Porvari, Ulf Skyllberg, Rasmus Sorensen, Therese Zetterberg, Staffan Akerblom. The effects of forestry on Hg bioaccumulation in nemoral/boreal waters and recommendations for good silvicultural practice. Ambio. 2009; 38 (7):373-380.
Chicago/Turabian StyleKevin Bishop; Craig Allan; Lage Bringmark; Edenise Garcia; Sofie Hellsten; Lars Högbom; Kjell Johansson; Anja Lomander; Markus Meili; John Munthe; Mats Nilsson; Petri Porvari; Ulf Skyllberg; Rasmus Sorensen; Therese Zetterberg; Staffan Akerblom. 2009. "The effects of forestry on Hg bioaccumulation in nemoral/boreal waters and recommendations for good silvicultural practice." Ambio 38, no. 7: 373-380.
In the future, it may become common practice in Swedish forestry to recycle wood-ash, a waste product of the combustion of bio-fuel. As a consequence of the Chernobyl radioactive fallout in 1986, large areas of central Sweden were contaminated. Application of recycled wood-ash, originating from contaminated areas, to a previously uncontaminated forest, risks an increase in the concentration of radioactive 137Cs. We measured 137Cs radioactivity in different parts of coniferous forests in seven field experiments. Measurements of radioactivity were made 5-8 years after an application of wood-ash equivalent to 3000 kg ha(-1). The sites, in a north-south transect across Sweden, have a background radioactivity ranging from 0 to 40 kBq m(-2), the higher levels are mainly a result of the Chernobyl fall-out. Depending on its origin, the radioactivity of the applied wood-ash ranged from 0.0 to 4.8 kBq kg(-1), corresponding to 0.0-1.44 kBq m(-2). In autumn 1999, samples were taken from the soil, field vegetation, needles and twigs and the levels of 137Cs determined. In addition, soil samples were analysed for extractable K. The highest 137Cs concentration was found in the soil. At six of the seven sites there were no statistically significant effects of wood-ash application on 137Cs activity. This was despite the fact that the wood-ash had, in one case, added the same amount of radioactivity as the background. However, at one site with intermediate 137Cs deposition (10-20 kBq m(-2)), there was a statistically significant decrease in 137Cs radioactivity in the soil, needles and twigs from the plots treated with wood-ash. The decrease in radioactivity was partly due to the fact that one of the main constituents of wood-ash is K, which is antagonistic to 137Cs. Based on our results, it appears that application of wood-ash containing 137Cs does not necessarily increase the 137Cs radioactivity in plants and soil. However, some of the observed effects could be a result of the low number of replicates used in this study.
Lars Högbom; Hans-Örjan Nohrstedt. The fate of 137Cs in coniferous forests following the application of wood-ash. Science of The Total Environment 2001, 280, 133 -141.
AMA StyleLars Högbom, Hans-Örjan Nohrstedt. The fate of 137Cs in coniferous forests following the application of wood-ash. Science of The Total Environment. 2001; 280 (1):133-141.
Chicago/Turabian StyleLars Högbom; Hans-Örjan Nohrstedt. 2001. "The fate of 137Cs in coniferous forests following the application of wood-ash." Science of The Total Environment 280, no. 1: 133-141.
High transition metal concentrations were previously unexpectedly observed in soil water extracted by suction lysimeters following forest N fertilization. This observation called for additional measurements to investigate if the finding is a general phenomenon and, if so, whether stream water concentrations of transition metals could increase as a result of N fertilization. The measured levels of Cd in the preliminary findings were well above health limits for drinking water. Hence, the problem could be of major concern. Here we report on soil water and stream water concentrations at two partly fertilized watersheds. All sites were situated in the central part of Sweden. The N application (150 kg N ha(-1) in the form of calcium ammonium nitrate) resulted in increased concentrations of nitrate, and a pulse of acidity through the soil profile, which increased the solubility of transition metals (mainly Cd and Zn) and Al. Stream water concentrations of transition metals, on the other hand, were not affected during the studied period by the increased solubility of transition metals in the soil. The data imply that the solubilized transition metals probably insolubilize further down the soil profile, and that there is no risk from forest N fertilization (at normal soil pH levels) of transition metal levels increasing in nearby surface waters. To our knowledge, this is the first time this side effect of N fertilization has been considered.
Lars Högbom; Hans-Örjan Nohrstedt; Sten Nordlund. Nitrogen Fertilization Effects on Stream Water Cadmium Concentration. Journal of Environmental Quality 2001, 30, 189 -193.
AMA StyleLars Högbom, Hans-Örjan Nohrstedt, Sten Nordlund. Nitrogen Fertilization Effects on Stream Water Cadmium Concentration. Journal of Environmental Quality. 2001; 30 (1):189-193.
Chicago/Turabian StyleLars Högbom; Hans-Örjan Nohrstedt; Sten Nordlund. 2001. "Nitrogen Fertilization Effects on Stream Water Cadmium Concentration." Journal of Environmental Quality 30, no. 1: 189-193.