Changes in soil ammonia oxidizers and potential nitrification after clear-cutting of boreal forests in China

AbstractFew studies have focused on broad scale biogeographic patterns of ammonia oxidizers in coastal systems, yet understanding the processes that govern them is paramount to understanding the mechanisms that drive biodiversity, and ultimately impact ecosystem processes. Here we present a meta-analysis of 16 years of data of ammonia oxidizer abundance, diversity, and activity in New England (NE) salt marshes and 5 years of data from marshes in the Gulf of Mexico (GoM). Potential nitrification rates were more than 80x higher in GoM compared to NE marshes. However, nitrifier abundances varied between regions, with ammonia-oxidizing archaea (AOA) and comammox bacteria significantly greater in GoM, while ammonia-oxidizing bacteria (AOB) were more than 20x higher in NE than GoM. Total bacterial 16S rRNA genes were also significantly greater in GoM marshes. Correlation analyses of rates and abundance suggest that AOA and comammox are more important in GoM marshes, whereas AOB are more important in NE marshes. Furthermore, ratios of nitrifiers to total bacteria in NE were as much as 80x higher than in the GoM, suggesting differences in the relative importance of nitrifiers between these systems. Communities of AOA and AOB were also significantly different between the two regions, based on amoA sequences and DNA fingerprints (terminal restriction fragment length polymorphism). Differences in rates and abundances may be due to differences in salinity, temperature, and N loading between the regions, and suggest significantly different N cycling dynamics in GoM and NE marshes that are likely driven by strong environmental differences between the regions.

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Long-term effects of clear-cutting on epigaeic beetle assemblages in boreal forests

Forest Ecology and Management ◽

10.1016/j.foreco.2015.09.041 ◽

2016 ◽

Vol 359 ◽

pp. 65-73 ◽

Cited By ~ 12

Author(s):

Therese Johansson ◽

Joakim Hjältén ◽

Jörgen Olsson ◽

Mats Dynesius ◽

Jean-Michel Roberge

Keyword(s):

Boreal Forests ◽

Long Term Effects ◽

Clear Cutting ◽

Beetle Assemblages

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The Status of Contaminants in Bald Eagles and Wildland Firefighters in the Teton Ecosystem

The UW National Parks Service Research Station Annual Reports ◽

10.13001/uwnpsrc.2008.3721 ◽

2008 ◽

Vol 31 ◽

pp. 117-124

Author(s):

George Montopoli ◽

Hank Harlow ◽

W. Smith, MD ◽

A. Wheeler, MD ◽

Andy Byerly ◽

...

Keyword(s):

Climate Change ◽

Boreal Forests ◽

Global Climate ◽

Small Sample ◽

Bald Eagle ◽

Bald Eagles ◽

Clear Cutting ◽

Lead Ammunition ◽

The Status ◽

Small Sample Sizes

Advancing global climate change and associated desiccation of temperate and boreal forests, exacerbated by extensive clear-cutting, may increase poisoning of aquatic ecosystems with high levels of contaminants, especially Hg. We report on contaminants identified in nestling bald eagles and wildland firefighters of the Teton Ecosystem (Grand Teton National Park (GTNP) and the Snake River Unit (SRU), Wyoming) during summers of 2006, 2007 and 2008. In bald eagles, we focus primarily on mercury (Hg), lead (Pb), and selenium (Se) because each was detected in all nestlings during all summers at moderate levels. In wildland firefighters, we report primarily on Hg due to potential contamination from Hg when fighting fires and ingesting smoke and particulates produced by those fires. We feel that studying Hg both in the eagles and humans simultaneously is a better indicator of the general health of the environment than studying them separately. Both humans and bald eagles occupy top tiers on the food web, and intricately reflect the status of the environment. Results of the bald eagle analyses showed trends indicating increases in Hg and Pb from 2006 to 2007, and decreases from 2007 to 2008. Selenium essentially remained constant from 2006 to 2007 and increased from 2007 to 2008. In wildland firefighters, Hg appears to be elevated in those firefighters who are exposed to significant levels of smoke and particulates, both in 2007 and 2008. Conjectures about firefighters, however, are not statistically significant due to small sample sizes and logistical problems. Encouraging trends in bald eagle contaminant levels from 2007 to 2008 suggest reduction (or stabilization) of contaminant concentrations in the Teton Ecosystem. We also encourage the continued elimination of Pb attributable to humans (lead ammunition, lead shot, etc.) from the Teton Ecosystem. We encourage periodic monitoring of contaminants in the Teton Ecosystem, minimally at five-year intervals (Harmata 1996), unless unexpected events mandate more immediate monitoring. In wildland firefighters, we suggest a well-designed, comprehensive research study for summer 2009, to immediately address future ecological issues that are emerging due to climate change.

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Drivers of arboreal lichen community structure and diversity on Abies balsamea and Betula alleghaniensis in the Avalon Forest Ecoregion, Newfoundland

Botany ◽

10.1139/cjb-2020-0061 ◽

2021 ◽

Vol 99 (1) ◽

pp. 43-54

Author(s):

Rachel D. Wigle ◽

Yolanda F. Wiersma ◽

André Arsenault ◽

R. Troy McMullin

Keyword(s):

Community Structure ◽

Boreal Forests ◽

Abies Balsamea ◽

Local Environment ◽

Lichen Species ◽

Environmental Data ◽

Betula Alleghaniensis ◽

Diverse Range ◽

Clear Cutting ◽

Lichen Diversity

There is debate about what drives and maintains the structure of arboreal lichen communities and the relative importance of substrate vs. local environment. Here, we examined which lichen species are unique to two tree species [Abies balsamea (L.) Mill. and Betula alleghaniensis Britton] in the boreal forests of the Avalon Peninsula, Newfoundland, and which environmental variables are most important for lichen colonization and community structure. We collected data on lichen diversity from tree boles along with environmental data (tree size, bark pH, canopy cover) for each tree and each site. Multivariate analyses were used to determine the relationship between community structure and environmental data. The results show that a diverse range of tree characteristics are needed to support a diverse range of lichen species. Certain stands, such as old B. alleghaniensis stands, are more suitable to host a unique community of lichens than others. These results can inform land managers on the Avalon, recommending strategies for protected areas and providing forest harvest guidelines that limit clear-cutting of A. balsamea to maintain a diverse community structure and limit harvest of B. alleghaniensis trees in sites less optimal for lichen growth. These baseline data can also be used to monitor changes caused by moose browse and selective harvesting, two locally important threats to lichen diversity.

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Slow recovery of bryophyte assemblages in middle-aged boreal forests regrown after clear-cutting

Biological Conservation ◽

10.1016/j.biocon.2015.06.024 ◽

2015 ◽

Vol 191 ◽

pp. 101-109 ◽

Cited By ~ 10

Author(s):

Mats Dynesius

Keyword(s):

Boreal Forests ◽

Middle Aged ◽

Slow Recovery ◽

Clear Cutting

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Erratum to: Responses of small mammals to clear-cutting in temperate and boreal forests of Europe: a meta-analysis and review

European Journal of Forest Research ◽

10.1007/s10342-013-0761-7 ◽

2013 ◽

Vol 133 (1) ◽

pp. 199-199 ◽

Cited By ~ 28

Author(s):

Michał Bogdziewicz ◽

Rafał Zwolak

Keyword(s):

Small Mammals ◽

Boreal Forests ◽

Meta Analysis ◽

Clear Cutting

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Spruce resins constitute a strong sink for methane (CH4)

10.5194/egusphere-egu2020-2892 ◽

2020 ◽

Author(s):

Katerina Machacova ◽

Thomas Schindler ◽

Ülo Mander ◽

Kaido Soosaar

Keyword(s):

Greenhouse Gas ◽

Norway Spruce ◽

Bark Beetle ◽

Boreal Forests ◽

Large Scale ◽

Temperate Zone ◽

Exchange Potential ◽

Potential Control ◽

Clear Cutting ◽

Roof Experiment

Woody plants are known to emit methane (CH4) as an important greenhouse gas into the atmosphere. Recent studies show that tree stems might be also sinks for CH4; however, the mechanisms of CH4 uptake and its fate are unknown. Norway spruce (Picea abies) is characterised as negligible CH4 source in boreal forests. Even though spruce trees have been widely planted for its wood in large-scale monocultures in European temperate forests, no studies have focused on their CH4 exchange potential in the temperate zone.We determined stems of Norway spruce growing in a temperate zone aiming to find out whether the tree stems exchange CH4 with the atmosphere and how they contribute to the forest trace gas exchange.The measurements were performed at the experimental station of the &#8216;Kranzberg Forest Roof Experiment&#8217; near Freising, Germany, in June 2019. Fluxes of CH4 in mature tree stems were measured using non-steady-state stem chamber systems (n=32) installed in stem vertical profile approx. two weeks prior to measurements using a portable greenhouse gas analyser. Moreover, resins sampled from spruce stems were investigated for their CH4 exchange potential. Control measurements were performed to ensure that the fluxes do not originate from used chamber materials, in particular silicones used for chamber installation.Our preliminary results show that the spruce stems can be a strong sink for CH4 (-0.288 &#177; 0.053 mg CH4 m-2 stem area h-1, mean &#177; s.e.), even if a small amount of resin is present on the bark. The stems exuded resins to different extent (covering 4.8 &#177; 1.3% of the stem surface area in chambers), partly as a result of smoothening of rough surface layers of dead bark for chamber installation. However, even spruce stems without obvious &#8220;injuries&#8221; released small amounts of resins for unknown reasons (response to drought, bark-beetle attack, etc.?). The incubated resin samples consistently consumed CH4 (-12.0 &#177; 1.7 mg CH4 m-2 resin area h-1). Moreover, the detected stem CH4 uptake negatively correlated with the resin occurrence in the stem chambers (R&#178; = 0.884). After re-calculation of the stem fluxes to resin area, the CH4 consumption rates of stems and resin samples were in the same order of magnitude at median level (-13.2 and -12.0 mg CH4 m-2 resin area h-1, resp.).Concluded, the spruce resins appear to be a very strong and until now undiscovered sink for CH4. Even one small droplet of resins on bark can turn the known negligible CH4 exchange of intact spruce stems into strong CH4 sinks, having thus severe impact on the overall forest CH4 balance. This consumption potential of fresh resins should be considered by estimation of forest ecosystem CH4 balance especially in areas, where resin bleeding is widely spread or is to be expected (bark-beetle areas, drought events, tree harvest, clear-cutting).&#160;AcknowledgementThis research was supported by the Czech Science Foundation (17-18112Y) and National Sustainability Program I (LO1415). We thank Prof. Thorsten Grams for all his kind support, and Jan Hrdli&#269;ka and Thomas Feuerbach for their technical support.&#160;&#160;

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An experimental study of how variation in deer density affects vegetation and songbird assemblages of recently harvested boreal forests

Canadian Journal of Zoology ◽

10.1139/z2012-037 ◽

2012 ◽

Vol 90 (6) ◽

pp. 704-713 ◽

Cited By ~ 17

Author(s):

Etienne Cardinal ◽

Jean-Louis Martin ◽

Jean-Pierre Tremblay ◽

Steeve D. Côté

Keyword(s):

Picea Glauca ◽

Boreal Forests ◽

Forest Canopy ◽

Forest Succession ◽

Ecological Integrity ◽

Abies Balsamea ◽

Active Management ◽

Large Herbivores ◽

Clear Cutting ◽

Deer Density

Intense browsing by abundant large herbivores can threaten the ecological integrity of ecosystems by inducing modifications in the structure and composition of vegetation that trigger trophic cascades affecting plant and animal communities. We investigated the relationships between density of white-tailed deer ( Odocoileus virginianus (Zimmermann, 1780)), forest succession after clear-cut, and songbird communities on Anticosti Island, Quebec, Canada. We hypothesized that lower deer densities would alter the trajectory of forest succession after clear-cutting and lead to a rapid recovery of habitat attributes favorable to songbirds associated with a dense complex shrub layer. Six years after establishing a controlled browsing experiment (0, 7.5, 15, and >27 deer·km–2) in recent clearcuts, reducing deer densities ≤7.5 deer·km–2 initiated the restoration of balsam fir ( Abies balsamea (L.) Mill.) forests and increased the regeneration of paper birch ( Betula papyrifera Marshall). Increasing birch ground cover from 10% to 20% increased songbird total abundance, species richness, and diversity by 17%, 39%, and 31%, respectively. Alder Flycatcher (Empidonax alnorum Brewster, 1895) was only present at ≤7.5 deer·km–2 and strongly associated with birch regeneration. The regeneration of browse-resistant plants such as white spruce ( Picea glauca (Moench) Voss) in some areas at high deer density favored the maintenance of many shrub-dependent songbirds but also species usually associated with forest canopy. Active management of deer populations in Canadian harvested boreal forests will mitigate losses in vegetation and songbirds caused by over-browsing.

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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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Effects of experimental harvesting on spider (Araneae) assemblages in boreal deciduous forests

The Canadian Entomologist ◽

10.4039/n07-ls01 ◽

2008 ◽

Vol 140 (4) ◽

pp. 437-452 ◽

Cited By ~ 17

Author(s):

Christopher M. Buddle ◽

David P. Shorthouse

Keyword(s):

Indicator Species ◽

Boreal Forests ◽

Large Scale ◽

Wolf Spider ◽

Natural Disturbance ◽

Old Growth ◽

Partial Cutting ◽

Clear Cutting ◽

Old Growth Forests ◽

Geographic Separation

AbstractTwo large-scale forestry experiments, in Quebec (Sylviculture et aménagement forestiers écosystémique (SAFE)) and Alberta (Ecosystem Management by Emulating Natural Disturbance (EMEND)), were established in the late 1990s to test the effects of alternative silvicultural strategies (e.g., partial cutting) on biodiversity in northern boreal forests. We collected spiders in pitfall traps 2 years after the application of partial-cutting treatments in deciduous stands at EMEND and 6 years after similar treatments in deciduous stands at SAFE. Although we are aware of the challenges imposed by disparate locations and whole-scale experimental methods, our objective was to compare the effects of partial cutting on spider assemblages (diversity and community composition), and in doing so, to formulate a few general statements. Overall, 98 species (6107 individuals) were collected from Alberta and 86 species (3414 individuals) from Quebec. Of these, 44 species were common to both regions. Ordination and indicator-species analyses revealed a distinct effect of geographic separation: the spider assemblages in deciduous stands within the boreal plains ecoregion of Alberta and the boreal shield in Quebec were distinct. However, the effects of partial cutting on spider assemblages within each project were similar: removal of 25%–33% of trees shifted a characteristic old-growth fauna toward one more typical of clearcuts. Indicator-species analysis also revealed the dominance of wolf spider (Lycosidae) species in clearcuts within both experiments and we present evidence that clear-cutting homogenizes spider assemblages. Old-growth forests contain spider faunas that are easily disrupted by moderate partial cutting. In the face of intense harvesting practices, managing for the maintenance of biodiversity and conservation of spider faunas in northern forests will require retention of old-growth forests.

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