Effects of partial cutting on the ectomycorrhizae of Picea glauca forests in northwestern Alberta

2005 ◽  
Vol 35 (6) ◽  
pp. 1442-1454 ◽  
Author(s):  
Lance W Lazaruk ◽  
Gavin Kernaghan ◽  
S Ellen Macdonald ◽  
Damase Khasa
Keyword(s):  
Picea Glauca ◽  
Effective Means ◽  
White Spruce ◽  
Root Tip ◽  
Root Tips ◽  
Partial Cutting ◽  
Disturbance Intensity ◽  
Tree Retention ◽  
Green Tree Retention ◽  
The Impact

This study assessed the impact of various harvesting practices (including those designed to emulate natural disturbances) on ectomycorrhizae (ECM) associated with white spruce (Picea glauca (Moench) Voss) in northwestern Alberta, Canada. Treatments included clearcuts, partial cuts (dispersed green-tree retention with 20%, 50%, and 75% residual live trees, and aggregated green-tree retention), unharvested control sites, and a burned stand. The percentage of active white spruce root tips and ECM richness and diversity, as observed in soil cores collected throughout the study site, all decreased with increasing disturbance intensity. Effects were particularly pronounced in clearcuts, machine corridors used for access by harvesting equipment in the dispersed green-tree retention stands, and in burned areas. Reductions in ECM biodiversity could be attributed to the sensitivity of late-stage ectomycorrhizae (e.g., Cortinarius spp., Lactarius spp., and Russula spp.) to soil disturbances and changes in microclimate associated with harvesting or burning. Areas of dispersed and aggregated green-tree retention were not dramatically different than unharvested forest in terms of root tip density and ECM richness, diversity, and composition. Harvesting practices that retain a percentage of residual live trees, either dispersed throughout the cutting unit or in aggregated patches, could be an effective means of maintaining ectomycorrhizal biodiversity at the stand level.

scholarly journals Ecosystem Management of Eastern Canadian Boreal Forests: Potential Impacts on Wind Damage

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 578
Author(s):  
Jean-Claude Ruel
Keyword(s):  
Ecosystem Management ◽  
Management Practices ◽  
Fire Regime ◽  
Management Strategies ◽  
Wind Damage ◽  
Old Growth ◽  
Partial Cutting ◽  
Tree Retention ◽  
Green Tree Retention ◽  
The Impact

Research Highlights: Windthrow can interfere significantly with ecosystem management practices. In some cases, their goal could still be reached but this may prove more complex in other cases, like the partial cutting of old-growth stands. In situations where windthrow is common without any human intervention, the use of partial cutting to maintain some stand structures may lead to a feedback loop leading to additional windthrow. Background and Objectives: Forest ecosystem management using natural disturbances as a template has become the management paradigm in many regions. Most of the time, the focus is on fire regime and effects. However, windthrow can be common in some places or can interfere with practices implemented in an ecosystem management strategy. This paper looks at interactions between ecosystem management and windthrow. Materials and Methods: The paper builds on three case studies looking at various elements that could be part of ecosystem management strategies. The first one looks at the impact of green tree retention, while the second one looks at the impact of reducing the size and dispersing clearcuts, and the last one examines the impact of a range of cutting practices in irregular old-growth stands. Results: Green tree retention leads to increased windthrow, especially when applied within mature even-aged stands. Reducing the size of clearcuts and dispersing them over the landscape also involves substantial windthrow along edges. Partial cutting in old-growth stands can lead to relatively high mortality, but part of it is not necessarily related to wind since it occurs as standing dead trees. Differences in the amount of damage with tree size and species have been found and could be used to reduce wind damage. Conclusions: Approaches to minimize wind damage in ecosystem management can be designed using existing knowledge. However, using windthrow as a template to design management strategies would prove more complex.

scholarly journals Impact of Endochitinase-Transformed White Spruce on Soil Fungal Biomass and Ectendomycorrhizal Symbiosis

2010 ◽  
Vol 76 (8) ◽  
pp. 2607-2614 ◽  
Author(s):  
Franck O. P. Stefani ◽  
Philippe Tanguay ◽  
Gervais Pelletier ◽  
Yves Pich� ◽  
Richard C. Hamelin
Keyword(s):  
Root Exudates ◽  
Picea Glauca ◽  
Fungal Biomass ◽  
White Spruce ◽  
Soil Samples ◽  
Analysis Of Covariance ◽  
Root Tips ◽  
Dark Septate Endophyte ◽  
Phialocephala Fortinii ◽  
The Impact

ABSTRACT The impact of transgenic white spruce [Picea glauca (Moench) Voss] containing the endochitinase gene (ech42) on soil fungal biomass and on the ectendomycorrhizal fungi Wilcoxina spp. was tested using a greenhouse trial. The measured level of endochitinase in roots of transgenic white spruce was up to 10 times higher than that in roots of nontransformed white spruce. The level of endochitinase in root exudates of three of four ech42-transformed lines was significantly greater than that in controls. Analysis soil ergosterol showed that the amount of fungal biomass in soil samples from control white spruce was slightly larger than that in soil samples from ech42-transformed white spruce. Nevertheless, the difference was not statistically significant. The rates of mycorrhizal colonization of transformed lines and controls were similar. Sequencing the internal transcribed spacer rRNA region revealed that the root tips were colonized by the ectendomycorrhizal fungi Wilcoxina spp. and the dark septate endophyte Phialocephala fortinii. Colonization of root tips by Wilcoxina spp. was monitored by real-time PCR to quantify the fungus present during the development of ectendomycorrhizal symbiosis in ech42-transformed and control lines. The numbers of Wilcoxina molecules in the transformed lines and the controls were not significantly different (P > 0.05, as determined by analysis of covariance), indicating that in spite of higher levels of endochitinase expression, mycorrhization was not inhibited. Our results indicate that the higher levels of chitinolytic activity in root exudates and root tissues from ech42-transformed lines did not alter the soil fungal biomass or the development of ectendomycorrhizal symbiosis involving Wilcoxina spp.

Pre-dispersal seed predation of white spruce cones in logged boreal mixedwood forest

2003 ◽  
Vol 33 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Susan Peters ◽  
Stan Boutin ◽  
Ellen Macdonald
Keyword(s):  
Seed Predation ◽  
Picea Glauca ◽  
Natural Regeneration ◽  
White Spruce ◽  
Tamiasciurus Hudsonicus ◽  
Red Squirrels ◽  
Tree Crowns ◽  
Tree Retention ◽  
Boreal Mixedwood Forest ◽  
Mixedwood Boreal Forest

Predation of white spruce (Picea glauca (Moench) Voss) cones by red squirrels (Tamiasciurus hudsonicus Erxleben) was quantified in the mixedwood boreal forest of Alberta in cutblocks with seed tree retention and in adjacent uncut forest, during 3 years with varying levels of cone crop (1998, 1999, 2000). Percent cone loss was quantified by comparison of paired pre- and post-caching photographs of tree crowns. Cone loss from seed trees in cutblocks was significantly lower than from control trees in adjacent uncut forest (48.5 vs. 54.9%). Although the number of cones produced per tree declined by 42% and the percentage of trees producing cones declined by approximately 48% between 1998 and 2000, there was no corresponding increase in the percentage of cones harvested by squirrels. Percent cone loss was significantly lower from single seed trees in cutblocks, as compared with seed trees left in patches of more than 20 trees (33.4 vs. 50.5%). Cone predation significantly reduced the amount of seed available for natural regeneration using a seed tree system. Although blowdown may be reduced if seed trees are left in patches, leaving white spruce seed trees as singles in cutblocks may reduce the level of cone predation.

Orchid abundance in hemiboreal forests: stand-scale effects of clear-cutting, green-tree retention, and artificial drainage

2011 ◽  
Vol 41 (6) ◽  
pp. 1352-1358 ◽  
Author(s):  
Asko Lõhmus ◽  
Tiiu Kull
Keyword(s):  
Scale Effects ◽  
Current Knowledge ◽  
Timber Harvesting ◽  
Clear Cutting ◽  
Artificial Drainage ◽  
Tree Retention ◽  
Green Tree Retention ◽  
Retention Trees ◽  
The Impact ◽  
Site Types

The current knowledge on the impact of forest management on plant species of conservation concern is poor. We asked how three basic silvicultural techniques (clear-cutting, green-tree retention, and artificial drainage) affect the abundance of terrestrial orchid species and their communities in Estonia, hemiboreal Europe. Fixed-area, fixed-effort surveys (4 h per 2 ha plot) were used in 29 plot clusters representing five site types, with each cluster including plots of four treatments (old growth, mature managed forest, and cutover with and without live retention trees). Altogether 11 species of orchids were recorded in those 116 plots, with the most complete sets of species in artificially drained plots and mature stands. Five species were widely distributed among treatments and site types, but most site types also hosted shade-tolerant orchids (six species) that characteristically disappeared after timber harvesting. Cutover areas (3–7 years after harvest) hosted no species absent from uncut forest stands, and retention of solitary trees had no effect on orchid abundance over clear-cuts. Modern Estonian forest landscapes appear to support viable populations of many orchids, with rotation ages sufficient for population development of the majority of shade-tolerant species.

Stem- and stand-level growth and mortality following partial cutting in eastern boreal poplar – white spruce stands

2019 ◽  
Vol 49 (5) ◽  
pp. 463-470 ◽  
Author(s):  
Suzanne Brais ◽  
Brian D. Harvey ◽  
Arun K. Bose
Keyword(s):  
Growth Rates ◽  
Picea Glauca ◽  
Basal Area ◽  
Natural Disturbance ◽  
White Spruce ◽  
Primary Objective ◽  
Post Treatment ◽  
Tree Level ◽  
Growth Responses ◽  
Partial Cutting

Variable retention (VR) and partial cutting are both considered important silvicultural tools of natural disturbance or ecosystem based forest management approaches. Partial harvesting differs from VR in that post-treatment growth responses and stand regeneration are the primary objective rather than the maintenance of biodiversity. This partial cutting study is undertaken in mixed poplar (Populus spp.) – white spruce (Picea glauca (Moench) Voss) stands in the eastern Canadian boreal mixedwood forest. It compares, at the tree level, absolute growth rates (AGR) and relative growth rates (RGR) of basal area (BA) and stem survival; and at the stand level, it also compares absolute BA growth, mortality, and sapling density 10 years following treatment. The completely randomized experiment was established with four intensities of partial cutting (0, 50%, 65%, and 100% of poplar BA). All partial cutting intensities had a significant and similar positive effect on AGR of residual spruce stems. Complete poplar removal resulted not only in the highest increase in RGR of suppressed and intermediate spruce stems, but also in higher spruce mortality. Removal of 50% of the initial poplar stand BA provided the best trade-off between positive residual stem growth of spruce and poplar and limited post-treatment mortality.

The effect of mechanical site preparation on ectomycorrhizae of planted white spruce seedlings in conifer-dominated boreal mixedwood forest

2008 ◽  
Vol 38 (7) ◽  
pp. 2072-2079 ◽  
Author(s):  
Lance W. Lazaruk ◽  
S. Ellen Macdonald ◽  
Gavin Kernaghan
Keyword(s):  
Picea Glauca ◽  
Untreated Control ◽  
White Spruce ◽  
Site Preparation ◽  
Organic Layer ◽  
Root Tips ◽  
Mechanical Site Preparation ◽  
Clear Cut ◽  
Mixed Treatment ◽  
Boreal Mixedwood Forest

We characterized the ectomycorrhizae (ECM) of planted white spruce ( Picea glauca (Moench) Voss) seedlings as affected by mechanical site preparation (MSP) of clear-cut conifer-dominated boreal mixedwood forest. Relative abundance, richness, and composition of the ECM community were compared among untreated control, mixed, mounded, and scalped site preparation treatments. On >11 000 root tips, we observed 16 ECM morphotypes. Those common to the nursery in which the seedlings were raised were most abundant ( Thelephora americana , Wilcoxina -like (E-strain), Amphinema byssoides , Phialocephala -like (MRA)). Seedlings in the untreated controls had lower abundances of these, but higher abundances of other ECM, which were not present in the nursery of origin but were indigenous to these forest stands. In terms of ECM composition, the “mixed” treatment was most similar to the untreated control, while the “scalped” and “mound” treatments showed significantly different ECM communities than the controls. Our results suggest that MSP may facilitate continued dominance by ECM that establish on seedlings in the nursery while slowing the natural succession towards the natural forest ECM. MSP treatments that leave some surface organic matter relatively intact may impact ECM less than those that remove or bury the organic layer.

Development of white spruce (Picea glauca) seedling roots

1985 ◽  
Vol 63 (3) ◽  
pp. 456-462 ◽  
Author(s):  
Anne M. Johnson-Flanagan ◽  
John N. Owens
Keyword(s):  
Root System ◽  
Picea Glauca ◽  
Lateral Roots ◽  
Root Apex ◽  
White Spruce ◽  
Growth Cycle ◽  
Root Tip ◽  
System A ◽  
Seedling Roots ◽  
Specific Phase

The root system of container-grown white spruce seedlings (Picea glauca (Moench) Voss) consists of a taproot and many lateral roots. The lateral roots can be divided into three classes on the basis of external morphology. Although growth cycles of individual roots are independent, there are overall trends of growth in the root system. A preponderance of one morphological root class is usually associated with a specific phase of the growth cycle. Apical organization in absorbing and elongating roots is similar. When elongation ceases, roots become brown as a result of two separate processes, suberization of the endodermis and metacutization of a discrete layer enveloping the root apex. Zonation in the apex is reduced in brown roots. Renewed growth is marked by swelling of the brown root apex followed by the emergence of a white root tip.

Biodiversity of foliar fungal endophytes in white spruce (Picea glauca) from southern Québec

2006 ◽  
Vol 84 (5) ◽  
pp. 777-790 ◽  
Author(s):  
F.O.P. Stefani ◽  
J.A. Bérubé
Keyword(s):  
Picea Glauca ◽  
Sequence Similarity ◽  
Fungal Endophytes ◽  
Biological Significance ◽  
Its Region ◽  
White Spruce ◽  
Nuclear Ribosomal Dna ◽  
High Sequence Similarity ◽  
Forestry Practices ◽  
The Impact

The objective of this study was to investigate the foliar endophyte biodiversity of white spruce ( Picea glauca (Moench) Voss to establish a baseline for future comparative studies examining the impact of forestry practices. It identifies for the first time endophytic fungi living inside the needles of white spruce from 280 needles collected in seven natural stands in southern Québec. The endophyte colonization rate on surface sterilized needles was 53.2%. We performed a PCR-RFLP and sequence analysis on the ITS region of the nuclear ribosomal DNA to achieve molecular identification. Isolate ITS sequences were compared with data from GenBank presenting the best similarity and were analyzed by a maximum of parsimony and Bayesian inference. Relationships between morphological groups, digestion groups, and sequence groups were investigated. In all, 23 morphotypes were found to belong to 14 sequence groups and we demonstrated that morphological groups are poor indicators for estimating species diversity. This study is the first to establish species richness values for foliar endophytes. Among the 141 isolates in this study, 75.15% have a high sequence similarity with Lophodermium piceae , 10.95% with an unknown species of Mycosphaerella , and 5.5% with two species of the genus Hypoxylon . Distribution, incidence and biological significance of all the endophytes found in this study are discussed.

scholarly journals Comparisons of Root Morphology in Susceptible and Tolerant Melon Cultivars before and after Infection by Monosporascus cannonballus

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 681-683 ◽  
Author(s):  
Kevin Crosby ◽  
David Wolff ◽  
Marvin Miller
Keyword(s):  
Root Length ◽  
Root Rot ◽  
Growth Period ◽  
Root Systems ◽  
Root Tip ◽  
Total Root Length ◽  
Root Tips ◽  
Monosporascus Cannonballus ◽  
Vine Decline ◽  
The Impact

The fungus Monosporascus cannonballus Pollock and Uecker infects melon (Cucumis melo L.) roots and causes root rot/vine decline disease, which has reduced productivity of commercial muskmelon and honeydew cultivars in South Texas. To assess the impact of the fungus on several root traits, two greenhouse experiments were carried out over two seasons. A comparison of inoculated vs. control root systems was carried out with four melon cultivars representing both susceptible (`Magnum 45' and `Caravelle') and tolerant types (`Deltex' and `Doublon'). The sand medium was inoculated with 50–60 colony forming units (CFUs) per gram of the severe Monosporascus strain, TX90-25. After a 30-day growth period, the control and inoculated root systems were carefully cleaned and evaluated. Roots were scanned by a computer and the data were analyzed by the Rhizo Pro 3.8 program. The traits of interest included total root length, average root diameter, number of root tips, number of fine roots (0–0.5 mm), and number of small roots (0.5–1 mm). Significant differences existed between the two tolerant cultivars and the two susceptible ones for four of the traits. Total root length, fine and small root length, and root tip number were greater for `Deltex' than for both susceptible cultivars and greater for `Doublon' than for `Caravelle'. The results suggest that tolerance to this pathogen is closely linked to the integrity of the root structure. The potential for improving root vigor to combat root rot/vine decline merits further investigation.

scholarly journals Seed Rain and Seedling Establishment of Picea glauca and Abies balsamea after Partial Cutting in Plantations and Natural Stands

Forests ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 221
Author(s):  
Laurent Gagné ◽  
Luc Sirois ◽  
Luc Lavoie
Keyword(s):  
Picea Glauca ◽  
Incident Light ◽  
Mineral Soil ◽  
Abies Balsamea ◽  
Strong Relationship ◽  
White Spruce ◽  
Growth Conditions ◽  
Partial Cutting ◽  
Rotten Wood ◽  
Natural Stands

The conditions for natural regeneration of white spruce (Picea glauca) and balsam fir (Abies balsamea) in 12 natural stands and five plantations containing both species were investigated 9 to 30 years after partial cutting. We estimated seed input on the ground, measured light reaching the understory, and recorded the presence and age of seedlings smaller than 150 cm in height on six different substrates: mineral soil, moss, rotten wood, litterfall, herbaceous, and dead wood. Partial cutting generally prompted the establishment and growth of seedlings. The number of fir and spruce seedlings is always greater in natural stands than in plantations, a trend likely associated with the reduced abundance of suitable substrate for establishment in the latter. White spruce is significantly associated to rotten wood while fir settles on all types of substrates that cover at least 10% of the forest floor. There is a strong relationship between light intensity and the median height of spruce seedlings, but this relationship is non-significant for fir. Seedlings of both species can survive at incident light intensities as low as 3%, but an intensity of 15% or more seems to offer the best growth conditions. The results of this study provide guidelines for successful forest regeneration following partial cuts in spruce-fir stands.

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