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

2008 ◽  
Vol 140 (4) ◽  
pp. 437-452 ◽  
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.

scholarly journals Compared to Wildfire, Management Practices Reduced Old-Growth Forest Diversity and Functionality in Primary Boreal Landscapes of Eastern Canada

2021 ◽  
Vol 4 ◽  
Author(s):  
Maxence Martin ◽  
Pierre Grondin ◽  
Marie-Claude Lambert ◽  
Yves Bergeron ◽  
Hubert Morin
Keyword(s):  
Boreal Forests ◽  
Economic Value ◽  
Industrial Scale ◽  
Old Growth ◽  
Ecosystem Based Management ◽  
Old Growth Forest ◽  
Old Growth Forests ◽  
Boreal Landscapes ◽  
The Impact ◽  
Primary Forests

Large primary forest residuals can still be found in boreal landscapes. Their areas are however shrinking rapidly due to anthropogenic activities, in particular industrial-scale forestry. The impacts of logging activities on primary boreal forests may also strongly differ from those of wildfires, the dominant stand-replacing natural disturbance in these forests. Since industrial-scale forestry is driven by economic motives, there is a risk that stands of higher economic value will be primarily harvested, thus threatening habitats, and functions related to these forests. Hence, the objective of this study was to identify the main attributes differentiating burned and logged stands prior to disturbance in boreal forests. The study territory lies in the coniferous and closed-canopy boreal forest in Québec, Canada, where industrial-scale logging and wildfire are the two main stand-replacing disturbances. Based on Québec government inventories of primary forests, we identified 427 transects containing about 5.5 circular field plots/transect that were burned or logged shortly after being surveyed, between 1985 and 2016. Comparative analysis of the main structural and environmental attributes of these transects highlighted the strong divergence in the impact of fire and harvesting on primary boreal forests. Overall, logging activities mainly harvested forests with the highest economic value, while most burned stands were low to moderately productive or recently disturbed. These results raise concerns about the resistance and resilience of remnant primary forests within managed areas, particularly in a context of disturbance amplification due to climate change. Moreover, the majority of the stands studied were old-growth forests, characterized by a high ecological value but also highly threatened by anthropogenic disturbances. A loss in the diversity and functionality of primary forests, and particularly the old-growth forests, therefore adds to the current issues related to these ecosystems. Since 2013, the study area is under ecosystem-based management, which implies that there have been marked changes in forestry practices. Complementary research will be necessary to assess the capacity of ecosystem-based management to address the challenges identified in our study.

scholarly journals Seven Decades of Spontaneous Forest Regeneration after Large-Scale Clear-Cutting in Białowieża Forest do not Ensure the Complete Recovery of Collembolan Assemblages

Forests ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 948
Author(s):  
Marek Sławski ◽  
Małgorzata Sławska
Keyword(s):  
Large Scale ◽  
Life Form ◽  
Group Structure ◽  
Complete Recovery ◽  
Long Term Effects ◽  
Old Growth ◽  
Soil Microarthropods ◽  
Clear Cutting ◽  
Białowieża Forest ◽  
Large Scale Disturbance

The long-term effects of large-scale disturbance on forest ecosystem processes and structure are poorly understood. To assess the effects of large-scale clear-cutting on the taxonomic and functional structure of collembolan assemblages, 18 plots were established in the Polish part of Białowieża Forest. All plots, situated in a mixed Tilio-Carpinetum broad-leaved forest, had eutrophic Cambisol developed on rich glacial deposits. The Collembola assemblages in the stands that had naturally regenerated on large-scale clear-cuts performed at the beginning of the 20th century were compared to those in old-growth forests (i.e., the endpoint of stand development following stand-replacing disturbance). Collembolans, one of the most numerous soil microarthropods, are successfully used to assess the consequences of forest management and ecosystem restoration. Our study tested whether seven decades of spontaneous forest development after large-scale anthropogenic disturbance ensures the complete recovery of the soil Collembola. Using complementary taxonomic and life-form approaches, we provide evidence that the collembolan assemblages associated with the tree stands that had spontaneously developed in large harvesting plots distinctly differed from those in old-growth deciduous forests in this region despite seven decades of regenerative forest succession. The species diversity of the assemblages in the naturally regenerated tree stands was significantly lower, and their life-form structure was noticeably different from those in the reference forests. Moreover, the shift in the functional group structure of the collembolan assemblages in the stands that had regenerated after clear-cutting indicates that their activity seven decades after disturbance is concentrated mainly on the decomposition of the litter in the upper layers, whereas the processes controlled by these organisms in the deeper soil layers are not fully restored.

The effects of partial cutting on forest plant communities of western hemlock – Sitka spruce stands in southeast Alaska

2001 ◽  
Vol 31 (12) ◽  
pp. 2067-2079 ◽  
Author(s):  
Robert L Deal
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Plant Community ◽  
Basal Area ◽  
Plant Species Richness ◽  
Plant Community Structure ◽  
Old Growth ◽  
Partial Cutting ◽  
Southeast Alaska ◽  
Clear Cutting

The effects of partial cutting on plant species richness, community structure, and several understory species that are important for deer forage were evaluated on 73 plots in 18 stands throughout southeast Alaska. These partially cut stands were harvested 12–96 years ago when 16–96% of the former stand basal area was removed. The species richness and community structure of understory plants were similar in uncut and partially cut plots. However, plots where more than 50% of the basal area was cut had a significantly different plant community structure. Species composition and abundance also appeared to be distinctly different between hemlock-dominated and spruce-dominated stands. Partial cutting did not significantly change abundance for most of the important forage species for deer. The similarity in plant community structure between partially cut and uncut old-growth stands may be related to forest stand structures. The heterogeneous stand structures that develop after partial cutting are more similar to old-growth stands than to the uniform young-growth stands that develop after stand replacing disturbances such as clear-cutting.

Spruce resins constitute a strong sink for methane (CH4)

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

<p>Woody plants are known to emit methane (CH<sub>4</sub>) as an important greenhouse gas into the atmosphere. Recent studies show that tree stems might be also sinks for CH<sub>4</sub>; however, the mechanisms of CH<sub>4</sub> uptake and its fate are unknown. Norway spruce (<em>Picea abies)</em> is characterised as negligible CH<sub>4 </sub>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 CH<sub>4</sub> exchange potential in the temperate zone.</p><p>We determined stems of Norway spruce growing in a temperate zone aiming to find out whether the tree stems exchange CH<sub>4</sub> with the atmosphere and how they contribute to the forest trace gas exchange.</p><p>The measurements were performed at the experimental station of the ‘Kranzberg Forest Roof Experiment’ near Freising, Germany, in June 2019. Fluxes of CH<sub>4</sub> 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 CH<sub>4</sub> 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.</p><p>Our preliminary results show that the spruce stems can be a strong sink for CH<sub>4</sub> (-0.288 ± 0.053 mg CH<sub>4</sub> m<sup>-2</sup> stem area h<sup>-1</sup>, mean ± s.e.), even if a small amount of resin is present on the bark. The stems exuded resins to different extent (covering 4.8 ± 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 “injuries” released small amounts of resins for unknown reasons (response to drought, bark-beetle attack, etc.?). The incubated resin samples consistently consumed CH<sub>4</sub> (-12.0 ± 1.7 mg CH<sub>4</sub> m<sup>-2</sup> resin area h<sup>-1</sup>). Moreover, the detected stem CH<sub>4</sub> uptake negatively correlated with the resin occurrence in the stem chambers (R² = 0.884). After re-calculation of the stem fluxes to resin area, the CH<sub>4</sub> consumption rates of stems and resin samples were in the same order of magnitude at median level (-13.2 and -12.0 mg CH<sub>4</sub> m<sup>-2</sup> resin area h<sup>-1</sup>, resp.).</p><p>Concluded, the spruce resins appear to be a very strong and until now undiscovered sink for CH<sub>4</sub>. Even one small droplet of resins on bark can turn the known negligible CH<sub>4</sub> exchange of intact spruce stems into strong CH<sub>4</sub> sinks, having thus severe impact on the overall forest CH<sub>4</sub> balance. This consumption potential of fresh resins should be considered by estimation of forest ecosystem CH<sub>4</sub> balance especially in areas, where resin bleeding is widely spread or is to be expected (bark-beetle areas, drought events, tree harvest, clear-cutting).</p><p> </p><p><em>Acknowledgement</em></p><p><em>This 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 Hrdlička and Thomas Feuerbach for their technical support.</em></p><p> </p><p> </p>

Are the old-growth forests of the Clay Belt part of a fire-regulated mosaic?

2005 ◽  
Vol 35 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Dominic Cyr ◽  
Yves Bergeron ◽  
Sylvie Gauthier ◽  
Alayn C Larouche
Keyword(s):  
Fire Hazard ◽  
Natural Disturbance ◽  
Great Variability ◽  
Stand Age ◽  
Old Growth ◽  
Fire Cycle ◽  
Old Growth Forests ◽  
Ring Method ◽  
Forest Mosaic ◽  
Macroscopic Charcoal

Old-growth forests make up a substantial proportion of the forest mosaic in the Clay Belt region of Ontario and Quebec, Canada, despite fire cycles that are presumed to be relatively short. Two hypotheses have been suggested as explanations for this phenomenon: (1) the old-growth forests in question are located on sites that are protected from fire or (2) the fire hazard is just as great there as elsewhere, and that part of the mosaic is simply the tail of the distribution, having been spared from fire merely by chance. The tree-ring method has proven inadequate as a means of determining the date of the most recent fire in these old-growth forests, as the time that has elapsed since that date probably exceeds the age of the oldest trees. Accordingly, a paleoecological study was conducted with a view to determining the date of the last fire in these forests. Charcoal horizons were located and radiocarbon dated in six old-growth forests. The possibility that these forests have never burned at all is ruled out by the fact that macroscopic charcoal fragments were found at all sites. The proximity of potential firebreaks has a significant influence in the survival model, suggesting fire-cycle heterogeneity throughout the landscape. However, the proportion of old-growth forests observed is in agreement with what would be expected assuming that fire hazard is independent of stand age. Old-growth stands could thus be incorporated into natural disturbance based management, although the great variability of the intervals between catastrophic disturbances should be carefully considered.

Adapting forestry practices to address old-growth concerns in the Great Lakes–St.Lawrence forests of Ontario

2003 ◽  
Vol 79 (3) ◽  
pp. 613-620 ◽  
Author(s):  
Fred Pinto
Keyword(s):  
Great Lakes ◽  
Populus Tremuloides ◽  
Pinus Banksiana ◽  
Natural Disturbance ◽  
Red Pine ◽  
Forest Composition ◽  
White Birch ◽  
Site Factors ◽  
Old Growth ◽  
Old Growth Forests

The Great Lakes–St. Lawrence forest, particularly the eastern white (Pinus strobus L.) and red pine (P. resinosa Ait.) forests around Temagami and Sault Ste. Marie, was the centre of controversy regarding the treatment of old-growth forests in Ontario in the 1980s and 1990s. The controversy stemmed from changes in forest composition and structure occurring in the forest. For example, the Ontario public was concerned with the obvious reduction in numbers of large eastern white and red pine trees and their replacement with small, often poor quality, white birch (Betula papyrifera Marsh.), aspen (Populus tremuloides Michx.), and jack pine (Pinus banksiana Lamb.) trees. Over the past two decades, changes in legislation, forest planning and stand prescriptions have been made in Ontario and practices at the forest and stand levels have also changed significantly. The new practices are based on linking forest activities to a better understanding of ecological processes in the forest; in particular, linking harvest and regeneration activities to our current understanding of natural disturbances and plant adaptations. These practices attempt to match more closely the conditions found in forests with a heritage of natural disturbance and reproduction, i.e., old-growth forests. For example, stand-initiating disturbances result in some trees being killed, some being damaged, and some surviving. The new harvest practices consider tree adaptations and site factors when deciding whether a tree will be cut or not. This paper provides examples of how this ecosystem-based forestry is being applied in Ontario. Key words: old growth in Ontario, conservation of old growth, application of old growth conservation practices, stand practices for old growth, landscape practices for old growth

Stand-level response of breeding forest songbirds to multiple levels of partial-cut harvest in four boreal forest types

2005 ◽  
Vol 35 (7) ◽  
pp. 1553-1567 ◽  
Author(s):  
R Bruce Harrison ◽  
Fiona K.A Schmiegelow ◽  
Robin Naidoo
Keyword(s):  
Boreal Forest ◽  
Natural Disturbance ◽  
Partial Cutting ◽  
Clear Cutting ◽  
Partial Harvesting ◽  
Undisturbed Forest ◽  
Forest Songbirds ◽  
Multiple Levels ◽  
Partial Retention ◽  
Forest Habitats

We investigated whether impacts on boreal forest songbird communities in northwestern Alberta could be mitigated through a harvesting system that attempts to emulate the local natural disturbance regime. The EMEND (Ecosystem Management by Emulating Natural Disturbance) project is a multidisciplinary experiment to compare clearcuts and partial-retention cuts in four upland cover types with uncut forest and with experimentally burned stands. We studied breeding birds at EMEND between 1998 (pretreatment) and 2000, focusing on their responses to partial harvesting. Partial cuts were generally intermediate (and varied in a linear fashion) between clearcuts and undisturbed forest for community and species measures. Species that declined in abundance in partial cuts were typically dependent on shrubs and trees, whereas species that benefited were typically ground nesters. While partial cutting offered some advantages over clear-cutting in conserving short-term avian diversity, we suggest that low retention levels (i.e., 10%, 20%) cannot be justified from this perspective. The benefits that accrued in these treatments were relatively small, and species that declined or disappeared were typically characteristic of mature forest habitats. Higher retention levels (i.e., 50%, 75%) may conserve some species of concern, but the extent to which these treatments offer productivity advantages over lower residuals requires further study.

scholarly journals Predicting the potential for old-growth forests by spatial simulation of landscape ageing patterns

2003 ◽  
Vol 79 (3) ◽  
pp. 621-631 ◽  
Author(s):  
Ajith H Perera ◽  
David J.B. Baldwin ◽  
Dennis G Yemshanov ◽  
Frank Schnekenburger ◽  
Kevin Weaver ◽  
...  
Keyword(s):  
Temporal Variation ◽  
Large Scale ◽  
Simulation Modelling ◽  
Spatial Simulation ◽  
Old Growth ◽  
Disturbance Regimes ◽  
Old Growth Forest ◽  
Large Scale Disturbance ◽  
Old Growth Forests ◽  
Spatio Temporal

Planning for old-growth forests requires answers to two large-scale questions: How much old-growth forest should exist? And where can they be sustained in a landscape? Stand-level knowledge of old-growth physiognomy and dynamics are not sufficient to answer these questions. We assert that large-scale disturbance regimes may provide a strong foundation to understand the spatio-temporal ageing patterns in forest landscapes that determine the potential for old growth. Approaches to describe large-scale disturbance regimes range from scenarios reconstructed from historical evidence to simulation of landscapes using predictive models. In this paper, we describe a simulation modelling approach to determine landscape-ageing patterns, and thereby the landscape potential of old-growth forests. A spatially explicit stochastic simulation model of landscape fire–forest cover dynamics was applied to a 1.8 million-ha case study boreal forest landscape to quantify the spatio-temporal variation of landscape ageing. Twenty-five replicates of 200-year simulation runs of the fire disturbance regime, at a 1-ha resolution, generated a suite of variables of landscape ageing and their error estimates. These included temporal variation of older age cohorts over 200 years, survivorship distribution at the 200th year, and spatial tendencies of ageing. This information, in combination with spatial tendency of species occurrence, constitutes the contextual framework to plan how much old-growth forest a given landscape can sustain, and where such forest could be located. Key words: landscape management, old growth, spatial simulation modelling, landscape ecology, boreal forest, Ontario, fire regime simulation, natural forest disturbances, stochastic models, age-class distribution

scholarly journals Fungus gnats (Diptera: Bolitophilidae, Diadocidiidae, Keroplatidae and Mycetophilidae) new to Finland

2006 ◽  
Vol 17 (2) ◽  
Author(s):  
Alexei Polevoi ◽  
Jevgeni Jakovlev ◽  
Alexander Zaitzev
Keyword(s):  
Male Genitalia ◽  
Large Scale ◽  
General Distribution ◽  
Original Material ◽  
Old Growth ◽  
Fungus Gnats ◽  
Old Growth Forests ◽  
First Time ◽  
Eastern Finland

Thirty-seven species of fungus gnats new to Finland are reported. Eleven of these are reported in Fennoscandia for the first time: Diadocidia fissa Zaitzev, Macrocera estonica Landrock, M. nigricoxa Winnertz, M. pusilla Meigen, Boletina pallidula Edwards, Mycetophila morata Zaitzev, M. ostentanea Zaitzev, Trichonta nigritula Edwards, T. subterminalis Zaitzev & Menzel, Neoempheria winnertzi Edwards and Neuratelia sintenisi Lackschewitz. The records are based on original material collected in large-scale trapping projects in Southern and Eastern Finland mainly in old-growth forests during 1997–1998. Detailed information on Finnish findings, and data on the general distribution of the species are given. Several species are known with only one (typematerial) or a few previous records ranging from Norway to Sakhalin. For two poorly-known species, Neuratelia sintenisi Lackschewitz and Rymosia pinnata Ostroverkhova, new figures of male genitalia are presented.

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