Postfire dynamics of black spruce coarse woody debris in northern boreal forest of Quebec

2006 ◽  
Vol 36 (7) ◽  
pp. 1770-1780 ◽  
Author(s):  
Yan Boulanger ◽  
Luc Sirois
Keyword(s):  
Moisture Content ◽  
Boreal Forest ◽  
Nitrogen Content ◽  
Decomposition Rate ◽  
Coarse Woody Debris ◽  
Black Spruce ◽  
Woody Debris ◽  
Decomposition Rates ◽  
Asymbiotic Nitrogen Fixation ◽  
Study Sites

In this study, postfire coarse woody debris (CWD) dynamics in northern Quebec, Canada, were assessed using a 29-year chronosequence. Postfire woody-debris storage, decomposition rates, and variation of nitrogen and carbon contents of black spruce CWD (Picea mariana (Mill.) BSP) are estimated. The decomposition rate for postfire snags is exceptionally slow (k = 0.00), while the decomposition rate for logs (k = 0.019–0.021) is within previously recorded values for the boreal forest. The low decomposition rate for snags could be related to low moisture content associated with the position of debris and fast bark shedding. Given the low CWD decomposition rates and CWD storage (21.3–66.8 m3·ha–1), carbon losses from postfire CWD are relatively low, varying between 35.5 and 128.8 kg·ha–1·year–1 at the study sites. The nitrogen content in CWD drops quickly between living trees and snags and increases slightly with time since fire in logs. Nitrogen content is not related to wood density or to moisture content of deadwood. Rapid loss of nitrogen is associated with fast decomposition of subcortical tissues, leaching, and insect comminution. The increase in nitrogen content at the oldest site could result from asymbiotic nitrogen fixation, although a longer time span in the chronosequence would probably have revealed a greater nitrogen gain in increasingly decayed CWD.

Fire severity as a determinant factor of the decomposition rate of fire-killed black spruce in the northern boreal forest

2011 ◽  
Vol 41 (2) ◽  
pp. 370-379 ◽  
Author(s):  
Yan Boulanger ◽  
Luc Sirois ◽  
Christian Hébert
Keyword(s):  
Moisture Content ◽  
Boreal Forest ◽  
Decomposition Rate ◽  
Black Spruce ◽  
Woody Debris ◽  
Fire Severity ◽  
Decomposition Process ◽  
Vertical Position ◽  
Decomposition Rates ◽  
Considerable Impact

Several attributes might influence the decomposition process of fire-killed trees. Here, we tested various tree- and plot-level variables on the decomposition rate of fire-killed black spruce ( Picea mariana (Mill.) BSP) in the northern boreal forest. Data were collected from 474 individuals burned 17 years prior to sampling. Mean decomposition rate was relatively slow (k = 0.013) and was lowest for severely burned snags (k = 0.001) and highest for lightly burned logs (k = 0.027–0.036). Vertical position and fire severity were the most important variables influencing the decomposition rates, while plot-level variables were marginally significant. Both predictors strongly influenced the moisture content of fire-killed trees. Logs with greater contact with the ground and lightly burned trees had higher moisture content and faster decomposition rates. Very severely burned trees had lower moisture content because of faster bark shedding. This hampered the decomposition process by slowing the snag falling rate. Higher decomposition rates in lightly burned trees may result from greater colonization by early xylophagous species. By having a considerable impact on the decomposition of woody debris, fire severity may strongly influence many post-fire biological processes related to the woody necromass as well as carbon emission from burned stands.

scholarly journals Epixylic vegetation abundance, diversity, and composition vary with coarse woody debris decay class and substrate species in boreal forest

2018 ◽  
Vol 48 (4) ◽  
pp. 399-411 ◽  
Author(s):  
Praveen Kumar ◽  
Han Y.H. Chen ◽  
Sean C. Thomas ◽  
Chander Shahi
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Boreal Forest ◽  
Plant Communities ◽  
Coarse Woody Debris ◽  
Woody Debris ◽  
Percent Cover ◽  
Diverse Range ◽  
Decay Class ◽  
Wide Range

Although the importance of coarse woody debris (CWD) to understory species diversity has been recognized, the combined effects of CWD decay and substrate species on abundance and species diversity of epixylic vegetation have received little attention. We sampled a wide range of CWD substrate species and decay classes, as well as forest floors in fire-origin boreal forest stands. Percent cover, species richness, and evenness of epixylic vegetation differed significantly with both CWD decay class and substrate species. Trends in cover, species richness, and evenness differed significantly between nonvascular and vascular taxa. Cover, species richness, and species evenness of nonvascular species were higher on CWD, whereas those of vascular plants were higher on the forest floor. Epixylic species composition also varied significantly with stand ages, overstory compositions, decay classes, substrate species, and their interactions. Our findings highlight strong interactive influences of decay class and substrate species on epixylic plant communities and suggest that conservation of epixylic diversity would require forest managers to maintain a diverse range of CWD decay classes and substrate species. Because stand development and overstory compositions influence CWD decay classes and substrate species, as well as colonization time and environmental conditions in the understory, our results indicate that managed boreal landscapes should consist of a mosaic of different successional stages and a broad suite of overstory types to support diverse understory plant communities.

Source distances for coarse woody debris entering small streams in western Oregon and Washington

1990 ◽  
Vol 20 (3) ◽  
pp. 326-330 ◽  
Author(s):  
M. H. McDade ◽  
F. J. Swanson ◽  
W. A. McKee ◽  
J. F. Franklin ◽  
J. Van Sickle
Keyword(s):  
Coarse Woody Debris ◽  
Woody Debris ◽  
Mature Trees ◽  
Third Order ◽  
Old Growth ◽  
Channel Size ◽  
Side Slope ◽  
Stream Bank ◽  
Small Streams ◽  
Study Sites

Coarse woody debris from streamside forests plays important biological and physical roles in stream ecosystems. The distance from stream bank to rooting site was determined for at least 30 fallen trees at each study site on 39 streams in the Cascade and Coast ranges of Oregon and Washington. The study sites varied in channel size (first- through third-order), side-slope steepness (3 to 40°), and age of surrounding forest (mature or old-growth stands). The distribution of distances from rooting site to bank was similar among streams, with 11% of the total number of debris pieces originating within 1 m of the channel and over 70% originating within 20 m. Stands with taller trees (old-growth conifers) contributed coarse woody debris to streams from greater distances than did stands with shorter (mature) trees.

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.

Relationships between cellulose decomposition, Jenny's k, forest-floor nitrogen, and soil temperature in Alaskan taiga forests

1983 ◽  
Vol 13 (5) ◽  
pp. 789-794 ◽  
Author(s):  
John F. Fox ◽  
Keith Van Cleve
Keyword(s):  
Decomposition Rate ◽  
Forest Floor ◽  
Black Spruce ◽  
Nitrogen Concentration ◽  
Major Influence ◽  
Decomposition Rates ◽  
Cellulose Decomposition ◽  
Taiga Forest ◽  
Wide Range ◽  
Cellulose Filter

Forest-floor decomposition is compared among 16 Alaskan taiga forest stands. These include black spruce (Piceamariana (Mill.) B.S.P.), white spruce (Piceaglauca (Moench) Voss), and birch (Betulapapyrifera Marsh.), aspen {Populustremuloides Michx.), and balsam poplar (Populusbalsamifera L.) types, spanning a wide range in decomposition rates, forest-floor microclimates, and litter quality. Jenny's index of decomposition rate, k, is reasonably well correlated with annual cellulose (filter-paper) decomposition differences among stands. Both estimates of decomposition rate are correlated with forest-floor heat sum and forest-floor nitrogen concentration. These between-site correlations support inferences based upon experimental work claiming that temperature and forest-floor chemical quality have a major influence upon the level of decomposition in a particular stand. Inferences about the factors regulating decomposition rate around an average level within one stand cannot legitimately be made from the same correlations. Moisture has not been considered in this analysis, but could also be important to between-stand differences in decomposition rate.

scholarly journals Comparative effects of full-tree and tree-length shelterwood harvesting on residual tree damage and coarse woody debris volume in the Great Lakes – St. Lawrence forest

2012 ◽  
Vol 88 (06) ◽  
pp. 736-746 ◽  
Author(s):  
Trevor A. Jones ◽  
Scott McPherson
Keyword(s):  
Great Lakes ◽  
Coarse Woody Debris ◽  
Woody Debris ◽  
White Pine ◽  
Growing Stock ◽  
Forest Region ◽  
Tree Length ◽  
Residual Tree ◽  
Stand Damage ◽  
Study Sites

Residual stand damage and coarse woody debris loads were evaluated in 15 hardwood and white pine uniform shelterwood harvest blocks, in the Great Lakes – St. Lawrence Forest Region, using tree-length (TL) and full-tree (FT) harvesting techniques. Stand-level damage rates to residual stems in both the TL and FT harvest operations were below Ontario’s allowable “major” damage limits of 15% to all residual trees and 10% to acceptable growing stock (AGS) trees. No significant differences in damage rates were observed between the TL and FT harvest systems and were comparable to past assessments in TL and FT harvested blocks. Despite efforts to increase utilization of material from these study sites, no significant differences were observed in coarse woody debris (CWD) volume or the distribution of that volume across decay classes.

scholarly journals Decomposition rates of coarse woody debris in undisturbed Amazonian seasonally flooded and unflooded forests in the Rio Negro-Rio Branco Basin in Roraima, Brazil

2017 ◽  
Vol 397 ◽  
pp. 1-9 ◽  
Author(s):  
Reinaldo Imbrozio Barbosa ◽  
Carolina Volkmer de Castilho ◽  
Ricardo de Oliveira Perdiz ◽  
Gabriel Damasco ◽  
Rafael Rodrigues ◽  
...  
Keyword(s):  
Coarse Woody Debris ◽  
Woody Debris ◽  
Decomposition Rates ◽  
Rio Negro ◽  
Seasonally Flooded
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