The Impact of Controlled Grazing by Clethrionomys rufocanus on Experimental Guilds of Boreal Forest Floor Herbs

Oikos ◽  
1987 ◽  
Vol 50 (3) ◽  
pp. 403 ◽  
Author(s):  
Lars Ericson ◽  
Lauri Oksanen
Keyword(s):  
Boreal Forest ◽  
Forest Floor ◽  
Clethrionomys Rufocanus ◽  
The Impact

The impact of variable predation risk on stress in snowshoe hares over the cycle in North America’s boreal forest: adjusting to change

Oecologia ◽  
2021 ◽  
Author(s):  
Sophia G. Lavergne ◽  
Charles J. Krebs ◽  
Alice J. Kenney ◽  
Stan Boutin ◽  
Dennis Murray ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Predation Risk ◽  
Snowshoe Hares ◽  
The Impact

European beech is a net annual source of methane (CH4)

2021 ◽  
Author(s):  
Katerina Machacova ◽  
Hannes Warlo ◽  
Kateřina Svobodová ◽  
Thomas Agyei ◽  
Tereza Uchytilová ◽  
...  
Keyword(s):  
Greenhouse Gas ◽  
Seasonal Dynamics ◽  
Forest Floor ◽  
Greenhouse Gas Emission ◽  
European Beech ◽  
Individual Variability ◽  
Spatiotemporal Variability ◽  
Vegetation Season ◽  
Dormant Season ◽  
The Impact

<p>Trees are known to be sources of methane (CH<sub>4</sub>), an important greenhouse gas, into the atmosphere. However, still little is known about the seasonality of the tree stem CH<sub>4</sub> fluxes, particularly for the dormant season, and about the impact of environmental parameters on this gas exchange. This makes the estimation of net annual ecosystem CH<sub>4</sub> fluxes difficult.</p><p>We determined seasonal dynamics of CH<sub>4</sub> exchange of mature European beech stems (<em>Fagus sylvatica</em>) and of adjacent forest floor in a temperate montane forest of White Carpathians, Czech Republic, from November 2017 to December 2018. We used static chamber methods and gas chromatographic analyses. We aimed to understand the unknown role in seasonal changes of CH<sub>4</sub> fluxes of these forests, and the spatiotemporal variability of the tree fluxes.</p><p>The beech stems were net annual sources for atmospheric CH<sub>4</sub>, whereas the forest floor was a predominant sink for CH<sub>4</sub>. The stem CH<sub>4</sub> emissions showed high inter-individual variability and clear seasonality following the stem CO<sub>2</sub> efflux. The fluxes of CH<sub>4</sub> peaked during the vegetation season, and remained low but significant to the annual totals during winter dormancy. By contrast, the forest floor CH<sub>4</sub> uptake followed an opposite flux trend with low CH<sub>4</sub> uptake detected in the winter dormant season and elevated CH<sub>4</sub> uptake during the vegetation season. Based on our preliminary analyses, the detected high spatial variability in stem CH<sub>4</sub> emissions can be explained neither by the CH<sub>4</sub> exchange at the forest floor level, nor by soil CH<sub>4</sub> concentrations, soil water content and soil temperature, all measured in vertical soil profiles close to the studied trees.</p><p>European beech trees, native and widely spread species of Central Europe, seem to markedly contribute to the seasonal dynamics of the ecosystem CH<sub>4</sub> exchange, and their CH<sub>4</sub> fluxes should be included into forest greenhouse gas emission inventories.</p><p> </p><p><em>Acknowledgement</em></p><p><em>This research was supported by the Czech Science Foundation (17-18112Y), National Programme for Sustainability I (LO1415), CzeCOS (LM2015061), and SustES - Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797). We thank Libor Borák and Leszek Dariusz Laptaszyński for their technical and field support.</em></p><p> </p>

scholarly journals Microbial Substrate Utilization and Vegetation Shifts in Boreal Forest Floors of Western Canada

2021 ◽  
Vol 4 ◽  
Author(s):  
Emily Lloret ◽  
Sylvie Quideau
Keyword(s):  
Boreal Forest ◽  
Microbial Communities ◽  
Forest Floor ◽  
Microbial Respiration ◽  
Substrate Utilization ◽  
Utilization Efficiency ◽  
Western Canada ◽  
Spruce Forest ◽  
Vegetation Shifts ◽  
Forest Floors

Boreal forest soils are highly susceptible to global warming, and in the next few decades, are expected to face large increases in temperature and transformative vegetation shifts. The entire boreal biome will migrate northward, and within the main boreal forest of Western Canada, deciduous trees will replace conifers. The main objective of our research was to assess how these vegetation shifts will affect functioning of soil microbial communities and ultimately the overall persistence of boreal soil carbon. In this study, aspen and spruce forest floors from the boreal mixedwood forest of Alberta were incubated in the laboratory for 67 days without (control) and with the addition of three distinct 13C labeled substrates (glucose, aspen leaves, and aspen roots). Our first objective was to compare aspen and spruce substrate utilization efficiency (SUE) in the case of a labile C source (13C-glucose). For our second objective, addition of aspen litter to spruce forest floor mimicked future vegetation shifts, and we tested how this would alter substrate use efficiency in the spruce forest floor compared to the aspen. Tracking of carbon utilization by microbial communities was accomplished using 13C-PLFA analysis, and 13C-CO2 measurements allowed quantification of the relative contribution of each added substrate to microbial respiration. Following glucose addition, the aspen community showed a greater 13C-PLFA enrichment than the spruce throughout the 67-day incubation. The spruce community respired a greater amount of 13C glucose, and it also had a much lower glucose utilization efficiency compared to the aspen. Following addition of aspen litter, in particular aspen leaves, the aspen community originally showed greater total 13C-PLFA enrichment, although gram positive phospholipid fatty acids (PLFAs) were significantly more enriched in the spruce community. While the spruce community respired a greater amount of the added 13C-leaves, both forest floor types showed comparable substrate utilization efficiencies by Day 67. These results indicate that a shift from spruce to aspen may lead to a greater loss of the aspen litter through microbial respiration, but that incorporation into microbial biomass and eventually into the more persistent soil carbon pool may not be affected.

scholarly journals Production of peroxy nitrates in boreal biomass burning plumes over Canada during the BORTAS campaign

2016 ◽  
Vol 16 (5) ◽  
pp. 3485-3497 ◽  
Author(s):  
Marcella Busilacchio ◽  
Piero Di Carlo ◽  
Eleonora Aruffo ◽  
Fabio Biancofiore ◽  
Cesare Dari Salisburgo ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Forest Fire ◽  
Biomass Burning ◽  
Forest Fires ◽  
Chemical Mechanism ◽  
Fire Emissions ◽  
Fire Plumes ◽  
Peroxy Nitrates ◽  
In Fire ◽  
The Impact

Abstract. The observations collected during the BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS) campaign in summer 2011 over Canada are analysed to study the impact of forest fire emissions on the formation of ozone (O3) and total peroxy nitrates ∑PNs, ∑ROONO2). The suite of measurements on board the BAe-146 aircraft, deployed in this campaign, allows us to calculate the production of O3 and of  ∑PNs, a long-lived NOx reservoir whose concentration is supposed to be impacted by biomass burning emissions. In fire plumes, profiles of carbon monoxide (CO), which is a well-established tracer of pyrogenic emission, show concentration enhancements that are in strong correspondence with a significant increase of concentrations of ∑PNs, whereas minimal increase of the concentrations of O3 and NO2 is observed. The ∑PN and O3 productions have been calculated using the rate constants of the first- and second-order reactions of volatile organic compound (VOC) oxidation. The ∑PN and O3 productions have also been quantified by 0-D model simulation based on the Master Chemical Mechanism. Both methods show that in fire plumes the average production of ∑PNs and O3 are greater than in the background plumes, but the increase of ∑PN production is more pronounced than the O3 production. The average ∑PN production in fire plumes is from 7 to 12 times greater than in the background, whereas the average O3 production in fire plumes is from 2 to 5 times greater than in the background. These results suggest that, at least for boreal forest fires and for the measurements recorded during the BORTAS campaign, fire emissions impact both the oxidized NOy and O3,  but (1 ∑PN production is amplified significantly more than O3 production and (2) in the forest fire plumes the ratio between the O3 production and the ∑PN production is lower than the ratio evaluated in the background air masses, thus confirming that the role played by the ∑PNs produced during biomass burning is significant in the O3 budget. The implication of these observations is that fire emissions in some cases, for example boreal forest fires and in the conditions reported here, may influence more long-lived precursors of O3 than short-lived pollutants, which in turn can be transported and eventually diluted in a wide area.

Length–biomass and energy relationships of terrestrial gastropods in northern forest ecosystems

1997 ◽  
Vol 75 (3) ◽  
pp. 501-505 ◽  
Author(s):  
J. W. Hawkins ◽  
M. W. Lankester ◽  
R. A. Lautenschlager ◽  
F. W. Bell
Keyword(s):  
Boreal Forest ◽  
Efficient Method ◽  
Forest Floor ◽  
Forest Ecosystems ◽  
Northern Forest ◽  
Terrestrial Gastropods ◽  
Power Equation ◽  
Biomass Models ◽  
Energy Relationships ◽  
Underlying Soil

Length–biomass models are a convenient and time-efficient method of estimating the biomass of invertebrates. Our purpose was to develop such a model for terrestrial gastropods that adequately predicted gastropod dry tissue biomass (Y) on the basis of animal length (X). The power equation Y = 0.172X1.688 (r2 = 0.85) proved to be the best model for this purpose. Gastropod dry tissue biomass was 6.52 ± 1.58 mg (mean ± SE) and, based on gastropod densities ranging from 2 to 38/m2 reported in the literature, snails and slugs active on the surface of the forest floor accounted for 2.5 and 6% of the total animal biomass and energy, respectively, of boreal forest ecosystems. However, because densities of gastropods in both the litter and underlying soil can reach 1607/m2, our results suggest that published values for total animal biomass (4.9 g/m2) and caloric energy (104 cal/m2) in boreal forest ecosystems are underestimated.

Forest floor microarthropod abundance and oribatid mite (Acari: Oribatida) composition following partial and clear-cut harvesting in the mixedwood boreal forest

2004 ◽  
Vol 34 (5) ◽  
pp. 998-1006 ◽  
Author(s):  
Zoë Lindo ◽  
Suzanne Visser
Keyword(s):  
Boreal Forest ◽  
Community Composition ◽  
Relative Abundance ◽  
Forest Floor ◽  
Oribatid Mite ◽  
Diversity Indices ◽  
Mite Species ◽  
Oribatid Mites ◽  
Clear Cut ◽  
Mixedwood Boreal Forest

The effects of partial and clear-cut harvesting on abundance and community composition of forest floor microarthropods and oribatid mites were investigated in conifer and deciduous stands of the mixedwood boreal forest. Soil samples from clearcuts, strip-cut corridors in a partial cut, green-tree retention patches in a partial cut, and uncut control sites were collected 2.5 years after harvest and microarthropods were extracted, enumerated, and identified. Densities of microarthropod suborders were lower in the strip-cut corridors of the deciduous stands and significantly lower in the suborder Oribatida (oribatid mites). Changes in microarthropod community composition, decreased relative abundance of prostigmatid mites, and increased relative abundance of mesostigmatid mites were observed in corridor and clear-cut treatments. Lowered abundances and changes in community composition are likely due to compaction of the forest floor during harvesting. Selected oribatid mite species showed significantly lower abundances in clearcuts than in uncut sites, but diversity indices for oribatid mites were generally not significantly different between uncut sites and clearcuts. Changes in oribatid mite communities following harvesting were thus more quantitative (absolute abundance) than qualitative (diversity, composition), and as a result, use of oribatid mites as biological indicators of disturbance is limited because of the lack of changes in species composition.

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