scholarly journals Maintaining attributes of old-growth forests in coastal B.C. through variable retention

2003 ◽  
Vol 79 (3) ◽  
pp. 570-578 ◽  
Author(s):  
W J Beese ◽  
B G Dunsworth ◽  
K. Zielke ◽  
B. Bancroft
Keyword(s):  
British Columbia ◽  
Pacific Northwest ◽  
Biological Diversity ◽  
Woody Debris ◽  
Structural Complexity ◽  
Structural Features ◽  
Management Program ◽  
Old Growth ◽  
Variable Retention ◽  
Old Growth Forests

Variable retention is a new approach to harvesting and silvicultural systems that was developed by ecologists in the Pacific Northwest region of North America to address a wide array of forest management goals. Variable retention recognizes that natural disturbances, such as fire, wind or disease, nearly always leave some standing structure from the original forest. This structural complexity plays an important role in forest ecosystem function and biological diversity. A new "retention silvicultural system" was defined that leaves trees distributed throughout harvested areas. This system facilitates retention of structural features of old-growth forests, such as live and dead trees of varying sizes, multiple canopy layers, and coarse woody debris. Weyerhaeuser's British Columbia Coastal Group will use the variable retention approach for all harvesting by 2003. More than 75% of the company's coastal harvesting in British Columbia used variable retention in 2001. Company guidelines describe the amount, type, and spatial distribution of retention for groups and individual trees. An adaptive management program is monitoring the amount and type of structural attributes retained in relation to the original forest. Key words: old-growth forests, variable retention, silvicultural systems, biodiversity, landscape zoning

scholarly journals Monitoring late-successional forest biodiversity in the Pacific Northwest, U.S.A.

2006 ◽  
Vol 82 (3) ◽  
pp. 364-367 ◽  
Author(s):  
Thomas A Spies ◽  
Jon R Martin
Keyword(s):  
Endangered Species ◽  
Pacific Northwest ◽  
Satellite Imagery ◽  
Ecosystem Management ◽  
Biological Diversity ◽  
Old Growth ◽  
Monitoring Plan ◽  
Effectiveness Monitoring ◽  
The Pacific ◽  
Old Growth Forests

The era of ecosystem management for federal forest lands in the Pacific Northwest began in 1994 with the adoption of the Northwest Forest Plan. This plan was designed to maintain and restore species and ecosystems associated with late successional and old-growth forests on over 10 million ha of federal lands in Washington, Oregon and California. The plan called for implementation monitoring, effectiveness monitoring, and validation monitoring for a variety of ecological and socio-economic components. Monitoring has become a central part of management of the federal forests in the region and managers and scientists have gained considerable experience in implementing this large and complex program. The components of the monitoring plan include late-successional/old growth vegetation, northern spotted owls, marbled murrelets, aquatic habitat and social conditions. The monitoring plan is strongly based on vegetation layer created with TM satellite imagery and on a regional grid of forest inventory plots. The lessons learned from the implementation of this monitoring plan include: 1) agencies need to devote considerable resources to insure that effective monitoring will occur at broad scales; 2) aggregation of local monitoring efforts is not a substitute for a designed regional monitoring plan; 3) vegetation structure and composition, measured with satellite imagery and inventory plots, is a cost-effective, broad-scale indicator of biological diversity; 4) some species, such as threatened and endangered species, are not necessarily covered with habitat approaches and may require population monitoring; 5) our scientific understanding of monitoring components will vary widely as will the approaches to data collection and analysis; 6) monitoring requires research support to develop and test metrics and biodiversity models; 7) links of monitoring to decision-making (adaptive management) are still being forged. Key words: aquatic ecosystems, endangered species, old-growth forests, Pacific Northwest, USA, regional ecosystem management

scholarly journals Coarse woody debris in the old-growth forests of British Columbia

2003 ◽  
Vol 11 (S1) ◽  
pp. S135-S157 ◽  
Author(s):  
M C Feller
Keyword(s):  
British Columbia ◽  
Coarse Woody Debris ◽  
Functional Role ◽  
Animal Species ◽  
Woody Debris ◽  
Douglas Fir ◽  
Forest Age ◽  
Old Growth ◽  
Old Growth Forests

This paper synthesizes data extracted from the literature and data collected in various studies by the author on the quantity, characteristics, and functional importance of coarse woody debris (CWD) in the old-growth forests of British Columbia (B.C.). There is little agreement in the literature about the minimum diameter of CWD or the number of decay classes recognized. In western North America, five decay classes are commonly used, but recent studies suggest fewer decay classes are preferable. Comparisons among decay classes and biogeoclimatic zones and subzones in B.C. reveal that quantities and volumes are greatest (up to approximately 60 kg/m2 and approximately 1800 m3/ha, respectively), and CWD persists the longest (sometimes in excess of 1000 years) in the Coastal Western Hemlock (CWH) biogeoclimatic zone. The quantity and ground cover of CWD increase with forest productivity. Persistence of CWD has varied from less than 100 to over 800 years in two coastal (CWH and Mountain Hemlock (MH)) and three interior (Interior Douglas-fir (IDF), Interior Cedar–Hemlock (ICH), and Engelmann Spruce – Subalpine Fir (ESSF)) biogeoclimatic zones. Trends in CWD quantity with forest age in managed coastal B.C. forests suggest a U-shaped curve, with greater quantities occurring in recent cutovers than in old-growth forests, and lowest quantities occurring in middle-aged forests. This may be the normal trend in CWD with forest age, with departures from this trend resulting from disturbance- or environment-specific factors. Relatively large amounts of data exist on the characteristics of CWD in the CWH, IDF, ICH, ESSF, and Boreal White and Black Spruce (BWBS) biogeoclimatic zones, but such data for the Coastal Douglas-fir, Sub-Boreal Pine–Spruce, Sub-Boreal Spruce (SBS), and Spruce–Willow–Birch biogeoclimatic zones appear relatively sparse. There have been few studies of the functional role of CWD in B.C. forests, but those studies that have been completed indicate that CWD is an important habitat component for some plant and animal species. A total of 169 plant species, including >95% of all lichens and liverworts, were found to grow on CWD in old-growth forests in the CWH, MH, IDF, ICH, and ESSF biogeoclimatic zones. One third of these species were restricted to CWD. Studies in several biogeoclimatic zones have found that CWD provided preferred habitat for and was associated with higher populations of some small animal species, such as shrews, some voles, and some salamanders, in old-growth forests, but the effects varied with species and biogeoclimatic zone. The nutrient cycling role of CWD is not yet well known, but it currently appears to be relatively insignificant in B.C. old-growth forests. Although it has been considered that CWD could increase mineral soil acidification and eluviation, no evidence for this was found in a study of the CWH, MH, IDF, ICH, ESSF, BWBS, and SBS biogeoclimatic zones. Future studies of the functional role of CWD should consider both scale (square metre vs. hectare) and temporal (changes in CWD with forest age) issues, as studies including these are sparse and both may be important. Key words: biogeoclimatic zones, British Columbia, coarse woody debris, old-growth forests.

scholarly journals Indicators to assess biological diversity: Weyerhaeuser's coastal British Columbia forest project

2003 ◽  
Vol 79 (3) ◽  
pp. 590-601 ◽  
Author(s):  
Laurie Kremsater ◽  
Fred Bunnell ◽  
Dave Huggard ◽  
Glen Dunsworth
Keyword(s):  
British Columbia ◽  
Adaptive Management ◽  
Management Practices ◽  
Biological Diversity ◽  
Management Program ◽  
Carabid Beetles ◽  
Ecosystem Functions ◽  
Transfer Energy ◽  
Variable Retention ◽  
Biological Richness

Adaptive management is a key component of a forest project being implemented across all of Weyerhaeuser's coastal forest tenures. This project uses two main tools to accomplish the British Columbia (BC) Coastal Group's ecological and socio-economic goals: variable retention (VR) harvesting and broad zoning of the land base. The adaptive management program was designed to examine the effectiveness of retention systems and zoning in maintaining those forest attributes necessary to sustain biological richness and essential ecosystem functions, such as nutrient transfer, energy flow, decomposition, and dispersal of seeds, spores, and animals. The program is grounded on three biological indicators evaluated in both operational and experimental contexts: 1) representation of habitat types in a relatively unmanaged state to ensure that little-known species are retained; 2) structure of stands and landscapes to ensure that key elements are present through time; and 3) indicator organisms to track whether retaining structures and patterns, while addressing representation, will maintain species and populations whose life needs are well understood. Representation of ecosystems in unmanaged conditions has been examined. Habitat structure is being assessed in VR blocks and in unmanaged blocks. Studies on several organisms (breeding birds, owls, gastropods, amphibians, bryophytes, lichen, squirrels, mycorrhizae, and carabid beetles) have been underway for various lengths of time. These studies collected baseline information to begin comparisons of the effectiveness of the various types of VR for maintaining biological richness. The current focus in the adaptive management program is refining the lists of specific elements to monitor and beginning to create tools to help extrapolate relationships and findings over large areas and long time frames, with the expectation of operational implementation in 2003. The first two years of pilot work are also being used to examine how the results will link to management practices to strengthen areas that most need improvement. This paper describes three indicators used in Weyerhaeuser's adaptive management program. Key words: adaptive management, variable retention harvesting, indicators for monitoring forests

Comparison of structural and compositional characteristics in old-growth and mature, managed hardwood forests of Minnesota, U.S.A.

1999 ◽  
Vol 29 (10) ◽  
pp. 1479-1489 ◽  
Author(s):  
C M Hale ◽  
J Pastor ◽  
K A Rusterholz
Keyword(s):  
Species Composition ◽  
Plant Species ◽  
Coarse Woody Debris ◽  
Woody Debris ◽  
Structural Features ◽  
Hardwood Forests ◽  
Plant Species Composition ◽  
Managed Forests ◽  
Old Growth ◽  
Old Growth Forests

Extended rotation of managed temperate hardwood forests is sometimes presumed to provide the important compositional and structural features of old-growth hardwood forests. However, the features of temperate hardwood old-growth and managed stands of extended rotation age have not been fully quantified and compared. This study compared quantitative parameters (density and volume of logs and snags, coarse woody debris volume (volume of logs + volume of snags), the proportion of hollow logs, basal area and tree, sapling, large seedling and small seedling densities), distributional patterns (diameter class and rot class of live trees, decay class of logs), and vascular plant species composition and diversity in old-growth and mature, managed sugar maple (Acer saccharum L.) - basswood (Tilia americana L.) and northern red oak (Quercus rubra L.) stands. Old-growth forests had higher coarse woody debris volumes and higher proportions of hollow logs, of live trees in large diameter classes, of logs in decay classes 1 and 2, and of live trees in rot classes 3-5 than the mature, managed forests. Old-growth and mature, managed forests did not differ significantly in plant species composition. These results indicate that, while older extended-rotation, managed stands can be very similar compositionally to old-growth forests, they differ quantitatively in structural features.

Is regulated even-aged management the right strategy for the Canadian boreal forest?

2004 ◽  
Vol 80 (4) ◽  
pp. 458-462 ◽  
Author(s):  
Yves Bergeron
Keyword(s):  
Forest Management ◽  
Boreal Forest ◽  
Biological Diversity ◽  
Fire Regime ◽  
Age Distribution ◽  
Fire Frequency ◽  
Stand Age ◽  
Old Growth ◽  
Old Growth Forests ◽  
Canadian Boreal Forest

Over the past decade, there has been an increasing interest in the development of forest management approaches that are based on an understanding of historical natural disturbance dynamics. The rationale for such an approach is that management to favour landscape compositions and stand structures similar to those of natural ecosystems should also maintain biological diversity and essential ecological functions. In fire-dominated landscapes, this approach is possible only if current and future fire frequencies are sufficiently low, in comparison to pre-industrial fire frequency, that we can substitute fire with forest management. I address this question by comparing current and future fire frequency to historical reconstruction of fire frequency from studies in the Canadian boreal forest. Current and simulated future fire frequencies using 2× and 3×CO2 scenarios are lower than the historical fire frequency for most sites, suggesting that forest management could potentially be used to recreate the forest age structure of fire-controlled pre-industrial landscapes. Current even-aged management, however, tends to reduce forest variability: for example, fully regulated, even-aged management will tend to truncate the natural forest stand age distribution and eliminate overmature and old-growth forests from the landscape. The development of silvicultural techniques that maintain a spectrum of forest compositions and structures at different scales in the landscape is one avenue to maintain this variability. Key words: boreal forest, even aged management, fire regime, old-growth forests, climate change, partial cutting

scholarly journals Bryophyte Conservation in Managed Boreal Landscapes: Fourteen-Year Impacts of Partial Cuts on Epixylic Bryophytes

2021 ◽  
Vol 4 ◽  
Author(s):  
Jeffrey Opoku-Nyame ◽  
Alain Leduc ◽  
Nicole J. Fenton
Keyword(s):  
Species Composition ◽  
Coarse Woody Debris ◽  
Black Spruce ◽  
Woody Debris ◽  
Permanent Plots ◽  
Old Growth ◽  
Clear Cut ◽  
Old Growth Forest ◽  
Old Growth Forests ◽  
Over Time

Clear cut harvest simplifies and eliminates old growth forest structure, negatively impacting biodiversity. Partial cut harvest has been hypothesized (1) to have less impact on biodiversity than clear cut harvest, and (2) to encourage old growth forest structures. Long-term studies are required to test this hypothesis as most studies are conducted soon after harvest. Using epixylic bryophytes as indicators, this study addresses this knowledge gap. Fourteen years after harvest, we examined changes in epixylic bryophyte community composition richness and traits, and their microhabitats (coarse woody debris characteristics and microclimate) along an unharvested, partial cuts and clear cuts harvest treatment in 30 permanent plots established in the boreal black spruce (Picea mariana) forests of northwestern Quebec, Canada. Our results were compared to those of an initial post-harvest study (year 5) and to a chronosequence of old growth forests to examine species changes over time and the similarity of bryophyte communities in partial cut and old growth forests. Coarse woody debris (CWD) volume by decay class varied among harvest treatments with partial cuts and clear cuts recording lower volumes of early decay CWD. The epixylic community was richer in partial cuts than in mature unharvested forests and clear cuts. In addition, species richness and overall abundance doubled in partial and clear cuts between years 5 and 14. Species composition also differed among treatments between years 5 and 14. Furthermore, conditions in partial cut stands supported small, drought sensitive, and old growth confined species that are threatened by conditions in clear cut stands. Lastly, over time, species composition in partial cuts became more similar to old growth forests. Partial cuts reduced harvest impacts by continuing to provide favorable microhabitat conditions that support epixylic bryophytes. Also, partial cut harvest has the potential to encourage old growth species assemblages, which has been a major concern for biodiversity conservation in managed forest landscapes. Our findings support the promotion of partial cut harvest as an effective strategy to achieve species and habitat conservation goals.

Greater risk of physical damage caused by debris fall to understory plants and tree seedlings in old-growth forests than in young forests

2013 ◽  
Vol 43 (12) ◽  
pp. 1203-1206 ◽  
Author(s):  
Andrew J. Larson
Keyword(s):  
Woody Debris ◽  
Canopy Structure ◽  
Snow Accumulation ◽  
Stand Age ◽  
Tree Seedlings ◽  
Physical Damage ◽  
Old Growth ◽  
Understory Plants ◽  
Old Growth Forests ◽  
Young Forests

Falling canopy debris causes injury and mortality of tree seedlings and understory plants in a wide variety of forests. Canopy structure and dynamics differ between young and old-growth forests: old forests are taller and have more aboveground biomass and greater annual mortality of bole biomass. I predicted that risk of damage caused by debris fall in the understory is greater in old-growth forests than in young forests. I tested this prediction by tracking for 1 year the fates of artificial seedlings placed in young (stand age 31 to 61 years) and old-growth (stand age circa 500 years) Pseudotsuga–Tsuga forests. The risk of physical damage caused by debris fall in old-growth forests was significantly greater than in young forests (P = 0.001). Seedling models were damaged by falling debris at a rate of 4.4%·year−1 and 0.8%·year−1 in old-growth and young forests, respectively. More seedling models were damaged by fallen coarse woody debris in old-growth forests than in young forests, although this trend was not significant (P = 0.134). Approximately 25% of seedling models in both young and old-growth forests were damaged by something other than fallen canopy debris, most likely snow accumulation.

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