Changes in radiative forcing due to clear-cutting in Sweden

Land cover conversion affects climate by imposing perturbations in the surface properties and greenhouse gas fluxes. Forest management systems often disregard that modification in surface albedo influences the exchange of energy and greenhouse gases. In this study, we examine the net climatic effect of clear-cutting in high-latitude regions by comparing the importance of biogeophysical (albedo) and biogeochemical (carbon dioxide release) changes in Sweden. The hypothesis is that the albedo effect of high-latitude clear-cutting can reduce climate warming.Data on incoming and reflected shortwave radiation was obtained from four-component net radiometers installed in the forest and neighbouring clear-cut sites, in southern (56&#176;N), central (60&#176;N) and northern (64&#176;N) Sweden. The study site pairs along a latitudinal gradient were chosen to account for different climatic conditions. Data at these station pairs covered a continuous period of three (2016-2018), five (2014-2018) and one year (2014), respectively. Due to lack of clear-cut measurement stations in close vicinity to the northernmost forest site, the shortwave radiation data was retrieved from an open mire, where albedo and its temporal dynamics are similar to a clear-cut. All the forest stations and the mire station are part of ICOS Sweden network. Data on carbon dioxide release from clear-cutting was estimated as a difference in the aboveground carbon stock of the standing biomass between forest and clear-cut sites. The estimated carbon dioxide release was translated into an equivalent change in absorbed shortwave radiation and compared to the radiative forcing by albedo difference between forest and clear-cut sites.Our results underline results from previous studies showing that the magnitude of the net radiative forcing by clear-cutting varies considerably depending on the latitudinal position of the examined sites. Based on available data, clear-cutting in southern and central Sweden had a warming effect on the climate while in northern Sweden clear-cutting had a net cooling effect. However, large inter-annual variability (central Sweden) and lack of available continuous data (northern Sweden) resulted in high uncertainty of the climatic effects of changes in net radiative forcing due to clear-cutting. Our study indicates that the albedo effect has an essential role in the estimation of the climatic effect of clear-cutting and should thus be incorporated in future forest management strategies.

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Impacts of Clear-Cutting of a Boreal Forest on Carbon Dioxide, Methane and Nitrous Oxide Fluxes

Forests ◽

10.3390/f11090961 ◽

2020 ◽

Vol 11 (9) ◽

pp. 961

Author(s):

Patrik Vestin ◽

Meelis Mölder ◽

Natascha Kljun ◽

Zhanzhang Cai ◽

Abdulghani Hasan ◽

...

Keyword(s):

Carbon Dioxide ◽

Nitrous Oxide ◽

Forest Management ◽

Boreal Forest ◽

Total Carbon ◽

Clear Cut ◽

Clear Cutting ◽

N2o Fluxes ◽

Ch4 And N2o ◽

Ghg Fluxes

The 2015 Paris Agreement encourages stakeholders to implement sustainable forest management policies to mitigate anthropogenic emissions of greenhouse gases (GHG). The net effects of forest management on the climate and the environment are, however, still not completely understood, partially as a result of a lack of long-term measurements of GHG fluxes in managed forests. During the period 2010–2013, we simultaneously measured carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes using the flux-gradient technique at two clear-cut plots of different degrees of wetness, located in central Sweden. The measurements started approx. one year after clear-cutting, directly following soil scarification and planting. The study focused on robust inter-plot comparisons, spatial and temporal dynamics of GHG fluxes, and the determination of the global warming potential of a clear-cut boreal forest. The clear-cutting resulted in significant emissions of GHGs at both the wet and the dry plot. The degree of wetness determined, directly or indirectly, the relative contribution of each GHG to the total budgets. Faster establishment of vegetation on the wet plot reduced total emissions of CO2 as compared to the dry plot but this was partially offset by higher CH4 emissions. Waterlogging following clear-cutting likely caused both plots to switch from sinks to sources of CH4. In addition, there were periods with N2O uptake at the wet plot, although both plots were net sources of N2O on an annual basis. We observed clear diel patters in CO2, CH4 and N2O fluxes during the growing season at both plots, with the exception of CH4 at the dry plot. The total three-year carbon budgets were 4107 gCO2-equivalent m−2 and 5274 gCO2-equivalent m−2 at the wet and the dry plots, respectively. CO2 contributed 91.8% to the total carbon budget at the wet plot and 98.2% at the dry plot. For the only full year with N2O measurements, the total GHG budgets were 1069.9 gCO2-eqvivalents m−2 and 1695.7 gCO2-eqvivalents m−2 at the wet and dry plot, respectively. At the wet plot, CH4 contributed 3.7%, while N2O contributed 7.3%. At the dry plot, CH4 and N2O contributed 1.5% and 7.6%, respectively. Our results emphasize the importance of considering the effects of the three GHGs on the climate for any forest management policy aiming at enhancing the mitigation potential of forests.

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Group selection harvesting supports diversity of forest specialist carabids

ARPHA Conference Abstracts ◽

10.3897/aca.2.e38499 ◽

2019 ◽

Vol 2 ◽

Author(s):

Bela Tóthmérész ◽

Tibor Magura ◽

Szabolcs Mizser ◽

David D. Nagy

Keyword(s):

Forest Management ◽

Group Selection ◽

Environmental Changes ◽

Control Area ◽

Oak Forests ◽

Pitfall Traps ◽

Clear Cut ◽

Clear Cutting ◽

Specialist Species ◽

Selection Harvesting

Increased fragmentation and considerable environmental changes in native forests caused by the timber-oriented forest managements are threatening the biodiversity of forests. As a remediation, uneven-aged approach is recommended during forest management, because this is less intensive and could be less harmful than even-aged practices. We tested the effects of clear-cutting (as even-aged method) and group selection harvesting (as uneven-aged method) on carabids in lowland oak forests. Pitfall traps and litter sifting were used during the study. We found that the total number of species was significantly higher in the gaps harvested by group selection and in the clear-cut than in the mature forests (control area). The species richness of forest specialist species was significantly lower in the clear-cuts than in the other area. Our findings demonstrated that the conventional clear-cutting caused a decrease in the number of forest specialist species. Therefore, group selection method should be favoured during forest management to maintain diversity.

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Continuous-cover management and attractiveness of managed Scots pine forests

Canadian Journal of Forest Research ◽

10.1139/cjfr-2019-0431 ◽

2020 ◽

Vol 50 (8) ◽

pp. 819-828

Author(s):

Matti Koivula ◽

Harri Silvennoinen ◽

Hanna Koivula ◽

Jukka Tikkanen ◽

Liisa Tyrväinen

Keyword(s):

Forest Management ◽

Scots Pine ◽

Boreal Forests ◽

Negative Attitude ◽

Living Environment ◽

Forest Ownership ◽

Clear Cut ◽

Clear Cutting ◽

Gap Cutting ◽

Intensively Managed

Forest management, characterized in many northern countries by the predominance of clear cutting and growing even-aged and -sized trees, has simplified the structure of boreal forests. Consequences include alterations in cultural ecosystem services such as forest attractiveness, i.e., combined aesthetic and recreational values. Continuous-cover forestry might mitigate these effects through the use of selection and gap cutting, but these methods have been little studied, particularly from the attractiveness viewpoint. We used photo surveys to assess Finnish citizens’ perceptions of attractiveness of in-stand scenery of Scots pine (Pinus sylvestris L.) forests logged using different methods. (i) The attractiveness scores, given by respondents, declined steadily from unharvested forest through continuous-cover methods to seed-tree and clear-cut methods. (ii) Respondents with a negative attitude to forest management gave lower scores than respondents with a positive attitude, but the declining slopes of attractiveness against logging intensity were similar. (iii) In unharvested and less intensively managed stands, summer photos received higher scores than corresponding winter photos. (iv) Background variables (gender, education, living environment, memberships in recreational or nature NGOs, forestry profession, and forest ownership) had negligible effects on the scores. We recommend the use of continuous-cover logging methods in settlement and recreational areas.

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An alternative to clear-cutting in the boreal forest of Alaska: a 27-year study of regeneration after shelterwood harvesting

Canadian Journal of Forest Research ◽

10.1139/x01-014 ◽

2001 ◽

Vol 31 (6) ◽

pp. 999-1011 ◽

Cited By ~ 23

Author(s):

T L Wurtz ◽

J C Zasada

Keyword(s):

Forest Management ◽

Boreal Forest ◽

Picea Glauca ◽

Management Practices ◽

White Spruce ◽

Seed Crop ◽

Clear Cut ◽

Calamagrostis Canadensis ◽

Clear Cutting ◽

All Treatment

We present 27-year results from a comparison of clear-cutting and shelterwood harvesting in the boreal forest of Alaska. Three patch clear-cut and three shelterwood units were harvested in 1972; about 100 dispersed white spruce (Picea glauca (Moench) Voss) leave trees per hectare were retained in the shelterwoods. Units were mechanically scarified and an exceptionally large seed-crop was dispersed that year. Shelterwood trees were removed after 15 years. After 27 years, overstory treatment had no effect on the density or growth of the species we studied, while scarification had highly significant effects. In 1999, scarified areas were densely populated with white spruce seedlings and saplings (118 000 129 000 stems/ha, with spruce in 100% of plots). Unscarified areas had far fewer spruce stems but were nevertheless well stocked (11 000 15 000 stems/ha, with 87% frequency). Initially, spruce grew best on scarified surfaces, but by 27 years, growth of the tallest spruce saplings was significantly greater on unscarified than scarified surfaces. By 27 years, cover of the grass Calamagrostis canadensis (Michx.) Nutt. had returned to preharvest levels in all treatment types. Because criteria for evaluating forest management practices have changed since this study was begun, partial overstory retention systems for the management of Alaska's boreal forest deserve further study.

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Habitat selection of Ortolan Buntings Emberiza hortulana on forest clear-cuts in northern Sweden

Ornis Svecica ◽

10.34080/os.v26.22527 ◽

2016 ◽

Vol 26 (2) ◽

pp. 89-103

Author(s):

Julianna Anne Percival ◽

Svein Dale

Keyword(s):

Forest Management ◽

Habitat Selection ◽

Bare Soil ◽

Positive Influence ◽

Northern Sweden ◽

Clear Cut ◽

Management Policies ◽

Emberiza Hortulana ◽

Ortolan Bunting ◽

Selection Of

Ortolan Buntings Emberiza hortulana in Sweden used to occur mainly in farmland. Nowadays, a large proportion of the remaining population is found on forest clear-cuts in northern Sweden. Few studies have identified the types of clear-cuts that Ortolan Buntings prefer and whether these habitats are used for both breeding and foraging. We recorded presence and abundance of ortolan buntings on clear-cuts in Västerbotten County, northern Sweden. We sampled 123 clear-cuts (present N = 48, absent N = 75; total of 93–100 territories) and our results showed that clear-cut size, the number of remaining trees, bare soil percentage (≥10%) and narrow-leaved grass vegetation had a positive influence on ortolan bunting occupancy. The number of territories on clear-cuts was positively related to clear-cut size and number of remaining trees. Proximity to nearby farmland did not influence occupancy on clear-cuts. Behavioural observations indicated that the forest clear-cuts were used for both nesting and feeding. We discuss these results in relation to forest management policies and conservation of the ortolan bunting.

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Continuity forest or second-generation forest? Historic aerial photos provide evidence of early clear-cutting in northern Sweden

Silva Fennica ◽

10.14214/sf.10460 ◽

2021 ◽

Vol 55 (1) ◽

Author(s):

Hanna Lundmark ◽

Lars Östlund ◽

Torbjörn Josefsson

Keyword(s):

Boreal Forests ◽

Second Generation ◽

Common Knowledge ◽

Time Frame ◽

Aerial Photographs ◽

Northern Sweden ◽

Forest Land ◽

Clear Cut ◽

Clear Cutting ◽

The 1950S

Modern forestry, which mainly consists of clear-cutting, is one of the most important factors influencing todayâs boreal forests. In Sweden, the breaking point for modern forestry is generally considered to be around 1950. Recently, our common knowledge of the implementation of clear-cutting in Sweden has increased, and new research indicates that clear-cutting systems were already applied before the 1950s. In this case study, we used aerial photographs from the 1940s to analyze the extent of contemporaneous clear-cuts and even-aged young forests in an area in northern Sweden. Our results show that almost 40% of the study area had already been clear-cut by the end of the 1940s, but also that clear-cutting had been applied to 10% of the forest land in the early 1900s. This implies that the historical development of forestry in northern Sweden is more complex than previously thought, and that certain proportions of the forest land were already second-generation forests in the 1950s. Our results have implications for the use of concepts such as âcontinuity forestâ, suggesting that this concept should employ a time frame of at least 100 years.

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Microbial efficiency in a meromictic reservoir

Oceanological and Hydrobiological Studies ◽

10.2478/v10009-007-0047-9 ◽

2008 ◽

Vol 37 (2) ◽

Cited By ~ 2

Author(s):

Grażyna Mazurkiewicz-Boroń ◽

Teresa Bednarz ◽

Elżbieta Wilk-Woźniak

Keyword(s):

Carbon Dioxide ◽

Oxygen Consumption ◽

Release Rate ◽

Oxygen Consumption Rate ◽

Consumption Rate ◽

Metabolic Efficiency ◽

Sulphur Compounds ◽

Carbon Dioxide Release ◽

Microbial Efficiency ◽

Ion Contents

Microbial efficiency in a meromictic reservoirIndices of microbial efficiency (expressed as oxygen consumption and carbon dioxide release) were determined in the water column of the meromictic Piaseczno Reservoir (in an opencast sulphur mine), which is rich in sulphur compounds. Phytoplankton abundances were low in both the mixolimnion (up to 15 m depth) and monimolimnion (below 15 m depth). In summer and winter, carbon dioxide release was 3-fold and 5-fold higher, respectively, in the monimolimnion than in the mixolimnion. Laboratory enrichments of the sulphur substrate of the water resulted in a decrease in oxygen consumption rate of by about 42% in mixolimnion samples, and in the carbon dioxide release rate by about 69% in monimolimnion samples. Water temperature, pH and bivalent ion contents were of major importance in shaping the microbial metabolic efficiency in the mixolimnion, whilst in the monimolimnion these relationships were not evident.

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Role of sea surface temperature responses in simulation of the climatic effect of mineral dust aerosol

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-6049-2011 ◽

2011 ◽

Vol 11 (12) ◽

pp. 6049-6062 ◽

Cited By ~ 30

Author(s):

X. Yue ◽

H. Liao ◽

H. J. Wang ◽

S. L. Li ◽

J. P. Tang

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Radiative Forcing ◽

Mineral Dust ◽

Dust Aerosol ◽

Sea Surface ◽

Climatic Effect ◽

Radiative Effects ◽

Climate Simulations

Abstract. Mineral dust aerosol can be transported over the nearby oceans and influence the energy balance at the sea surface. The role of dust-induced sea surface temperature (SST) responses in simulations of the climatic effect of dust is examined by using a general circulation model with online simulation of mineral dust and a coupled mixed-layer ocean model. Both the longwave and shortwave radiative effects of mineral dust aerosol are considered in climate simulations. The SST responses are found to be very influential on simulated dust-induced climate change, especially when climate simulations consider the two-way dust-climate coupling to account for the feedbacks. With prescribed SSTs and dust concentrations, we obtain an increase of 0.02 K in the global and annual mean surface air temperature (SAT) in response to dust radiative effects. In contrast, when SSTs are allowed to respond to radiative forcing of dust in the presence of the dust cycle-climate interactions, we obtain a global and annual mean cooling of 0.09 K in SAT by dust. The extra cooling simulated with the SST responses can be attributed to the following two factors: (1) The negative net (shortwave plus longwave) radiative forcing of dust at the surface reduces SST, which decreases latent heat fluxes and upward transport of water vapor, resulting in less warming in the atmosphere; (2) The positive feedback between SST responses and dust cycle. The dust-induced reductions in SST lead to reductions in precipitation (or wet deposition of dust) and hence increase the global burden of small dust particles. These small particles have strong scattering effects, which enhance the dust cooling at the surface and further reduce SSTs.

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Relationship between cloud radiative forcing, cloud fraction and cloud albedo, and new surface-based approach for determining cloud albedo

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-7155-2011 ◽

2011 ◽

Vol 11 (14) ◽

pp. 7155-7170 ◽

Cited By ~ 26

Author(s):

Y. Liu ◽

W. Wu ◽

M. P. Jensen ◽

T. Toto

Keyword(s):

Radiative Forcing ◽

Climate Models ◽

Cloud Fraction ◽

Shortwave Radiation ◽

Cloud Radiative Forcing ◽

Analytical Expression ◽

Cloud Albedo ◽

Annual Variations ◽

Hourly Data ◽

Radiation Parameterizations

Abstract. This paper focuses on three interconnected topics: (1) quantitative relationship between surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo; (2) surface-based approach for measuring cloud albedo; (3) multiscale (diurnal, annual and inter-annual) variations and covariations of surface shortwave cloud radiative forcing, cloud fraction, and cloud albedo. An analytical expression is first derived to quantify the relationship between cloud radiative forcing, cloud fraction, and cloud albedo. The analytical expression is then used to deduce a new approach for inferring cloud albedo from concurrent surface-based measurements of downwelling surface shortwave radiation and cloud fraction. High-resolution decade-long data on cloud albedos are obtained by use of this surface-based approach over the US Department of Energy's Atmospheric Radiaton Measurement (ARM) Program at the Great Southern Plains (SGP) site. The surface-based cloud albedos are further compared against those derived from the coincident GOES satellite measurements. The three long-term (1997–2009) sets of hourly data on shortwave cloud radiative forcing, cloud fraction and cloud albedo collected over the SGP site are analyzed to explore the multiscale (diurnal, annual and inter-annual) variations and covariations. The analytical formulation is useful for diagnosing deficiencies of cloud-radiation parameterizations in climate models.

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