A silvicultural systems perspective on changing Canadian forestry practices

2005 ◽  
Vol 81 (1) ◽  
pp. 50-55 ◽  
Author(s):  
A. Groot ◽  
J -M. Lussier ◽  
A K Mitchell ◽  
D A MacIsaac
Keyword(s):  
Timber Harvesting ◽  
Long Term Effects ◽  
Forestry Practices ◽  
Management Objectives ◽  
Tree Retention ◽  
Silvicultural Practice ◽  
Structural Retention ◽  
Changing Practices ◽  
Silvicultural System

Canadian forestry practices are changing to meet evolving forest management objectives, and these changes are frequently accompanied by new terminology.We examine the interaction among changing objectives, changing practices, and terminology in three forest types across Canada. Altered silvicultural practices and systems can generally be described using traditional terminology, and applying new terminology may create confusion. The most notable developments in silvicultural practice involve timber harvests with greater levels of tree retention, and new terminology is being applied mainly to designate changed harvest patterns. Timber harvesting is a crucial silvicultural practice, but does not by itself constitute a silvicultural system. It is necessary to more thoroughly define long-term stand-level management objectives, and to delineate complete silvicultural systems that address these objectives. This will require better knowledge of the long-term effects of forestry practices, particularly those resulting in structurally complex stands. Key words: silvicultural systems, forestry practices, terminology, harvesting, Canada, structural retention

scholarly journals Long-term effects of timber harvesting on hemicellulolytic microbial populations in coniferous forest soils

2015 ◽  
Vol 10 (2) ◽  
pp. 363-375 ◽  
Author(s):  
Hilary T C Leung ◽  
Kendra R Maas ◽  
Roland C Wilhelm ◽  
William W Mohn
Keyword(s):  
Forest Soils ◽  
Coniferous Forest ◽  
Timber Harvesting ◽  
Microbial Populations ◽  
Long Term Effects

Long-Term Effects of Group-Selection Timber Harvesting on Abundance of Forest Birds

2007 ◽  
Vol 21 (5) ◽  
pp. 1218-1229 ◽  
Author(s):  
STEVEN P. CAMPBELL ◽  
JACK W. WITHAM ◽  
MALCOLM L. HUNTER
Keyword(s):  
Group Selection ◽  
Timber Harvesting ◽  
Forest Birds ◽  
Long Term Effects

Simulated long-term effects of varying tree retention on wood production, dead wood and carbon stock changes

2017 ◽  
Vol 201 ◽  
pp. 37-44 ◽  
Author(s):  
Francesca Santaniello ◽  
Line B. Djupström ◽  
Thomas Ranius ◽  
Jan Weslien ◽  
Jörgen Rudolphi ◽  
...  
Keyword(s):  
Carbon Stock ◽  
Dead Wood ◽  
Long Term Effects ◽  
Wood Production ◽  
Tree Retention

scholarly journals Transformation to irregular structure of an upland conifer forest

1999 ◽  
Vol 75 (3) ◽  
pp. 407-412 ◽  
Author(s):  
E. R. Wilson ◽  
H. Whitney McIver ◽  
D. C. Malcolm
Keyword(s):  
Sitka Spruce ◽  
Douglas Fir ◽  
Conifer Forest ◽  
Forest Research ◽  
Research Areas ◽  
Key Words Transformation ◽  
Management Objectives ◽  
Irregular Structure ◽  
Silvicultural System

The Glentress Trial was established by M.L. Anderson in 1952 as a demonstration of transformation to irregular structure of an upland conifer forest in southern Scotland. The trial area (117 ha) is one of the longest continuously-studied forest research areas in Britain. The dominant tree species are Sitka spruce, European larch, Scots pine and Douglas-fir. The most important silvicultural system is group selection, with group size varying from 0.1 to 0.2 ha. Groups are restocked by planting or natural regeneration. Interim results point to the development of an irregular forest structure, although the transformation will not be complete until 2033. The trial demonstrates the value of continuous cover forests in meeting multiple forest management objectives, and is a resource of increasing importance for silviculture education and long-term research. Key words: transformation, irregular structure, uneven-aged management, Sitka spruce, Douglas-fir, long-term silviculture research

scholarly journals Comparison of Regeneration and Yield Status between Community Forest and Collaborative Forest

2019 ◽  
Vol 2 (1-2) ◽  
pp. 26-36
Author(s):  
Pitamber Gaire ◽  
Pramod Ghimire
Keyword(s):  
Systematic Sampling ◽  
First Year ◽  
Long Term Effects ◽  
Community Forest ◽  
Regeneration Status ◽  
Sal Forest ◽  
Notable Increase ◽  
Second Year ◽  
Silvicultural System

The present article primarily addresses the silvicultural system (i.e., irregular shelter wood system) in Sal forest adopted in both community and collaborative forest in Kapilbastu district of Nepal. Systematic sampling with 0.5 percent sampling intensity along with statistical tools like SPSS and MS-Excel were used for resource inventory and data analysis, respectively. The result of the study shows notable increase in seedling status during the first year (2015/16) in community forest. A decrease in sapling number during the second year (2016/17) was noticed in Tilaurakot collaborative forest at its initial level of implementation. At the same time, community forest has higher yield status with a smaller number of trees felled in Tilaurakot collaborative forest under regeneration felling. The regeneration status of species varied insignificantly (p>0.05) between the community forest and Tilaurakot collaborative forest. A recommendation is made for proper implementation of irregular shelter wood system for managing the existing degraded Sal forests of the Terai region of Nepal; however, its long-term effects on plant species diversity should also be further studied in detail.

scholarly journals Long-term effects of timber harvesting on coarse woody debris dynamics and marten habitat

2021 ◽  
Author(s):  
◽  
Ingrid Farnell
Keyword(s):  
Laser Scanning ◽  
Woody Debris ◽  
Timber Harvesting ◽  
Long Term Effects ◽  
Habitat Features ◽  
Airborne Laser ◽  
Decay Class ◽  
Harvesting Intensity ◽  
The Impact

At a long-term experimental trial in northern British Columbia, Canada, I analysed the impact of varying amounts of timber retention: 0% (clearcut), 40%, 70%, 100% (unharvested) on CWD volume, decay class, and inputs from windthrow over 27 years. I used attributes (diameter, length, decay class, and height above the ground) known to be favourable to marten to create an index for assessing the impact of harvesting intensity on CWD habitat features. I then used airborne laser scanning (ALS) to predict CWD volume, habitat value, and piece attributes over the landscape. Stands with 70% retention had CWD attributes that resulted in CWD habitat features similar to unharvested stands. Clearcuts contained pieces that were smaller, more decayed, and closer to the ground, which contributed less valuable habitat, compared to stands with higher retention. Windthrown trees were the majority of CWD inputs and volume change was positively related to percent retention.

scholarly journals Biogeography and organic matter removal shape long-term effects of timber harvesting on forest soil microbial communities

2017 ◽  
Vol 11 (11) ◽  
pp. 2552-2568 ◽  
Author(s):  
Roland C Wilhelm ◽  
Erick Cardenas ◽  
Kendra R Maas ◽  
Hilary Leung ◽  
Larisa McNeil ◽  
...  
Keyword(s):  
Organic Matter ◽  
Microbial Communities ◽  
Forest Soil ◽  
Soil Microbial Communities ◽  
Timber Harvesting ◽  
Long Term Effects ◽  
Organic Matter Removal ◽  
Soil Microbial

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

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