Journal articles on the topic 'Large coarse wood'
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Scaranello, Marcos A. S., Michael Keller, Marcos Longo, Maiza N. dos-Santos, Veronika Leitold, Douglas C. Morton, Ekena R. Pinagé, and Fernando Del Bon Espírito-Santo. "Estimation of coarse dead wood stocks in intact and degraded forests in the Brazilian Amazon using airborne lidar." Biogeosciences 16, no. 17 (September 13, 2019): 3457–74. http://dx.doi.org/10.5194/bg-16-3457-2019.
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Abstract. Coarse dead wood is an important component of forest carbon stocks, but it is rarely measured in Amazon forests and is typically excluded from regional forest carbon budgets. Our study is based on line intercept sampling for fallen coarse dead wood conducted along 103 transects with a total length of 48 km matched with forest inventory plots where standing coarse dead wood was measured in the footprints of larger areas of airborne lidar acquisitions. We developed models to relate lidar metrics and Landsat time series variables to coarse dead wood stocks for intact, logged, burned, or logged and burned forests. Canopy characteristics such as gap area produced significant individual relations for logged forests. For total fallen plus standing coarse dead wood (hereafter defined as total coarse dead wood), the relative root mean square error for models with only lidar metrics ranged from 33 % in logged forest to up to 36 % in burned forests. The addition of historical information improved model performance slightly for intact forests (31 % against 35 % relative root mean square error), not justifying the use of a number of disturbance events from historical satellite images (Landsat) with airborne lidar data. Lidar-derived estimates of total coarse dead wood compared favorably with independent ground-based sampling for areas up to several hundred hectares. The relations found between total coarse dead wood and variables quantifying forest structure derived from airborne lidar highlight the opportunity to quantify this important but rarely measured component of forest carbon over large areas in tropical forests.
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Copoț, Ovidiu, and Cătălin Tănase. "Substrate properties, forest structure and climate influences wood-inhabiting fungal diversity in broadleaved and mixed forests from Northeastern Romania." Forest Systems 29, no. 3 (December 29, 2020): e021. http://dx.doi.org/10.5424/fs/2020293-16728.
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Aim of the study: The main objective of this study was to find the factors which best explains the wood-inhabiting fungal species’ richness in beech and oak-dominated forests.Area of study: We focused on broadleaved and mixed forests found in Northeastern Romania.Materials and methods: 59 plots were randomly set up in broadleaved and mixed forest stands, in which vegetation structure, composition, and topoclimatic factors were quantified along with wood-inhabiting fungal richness. Generalized linear models were used to characterize relationship between fungal diversity and biotic and abiotic factors.Main results: 374 taxa were identified, with numerous species found to cohabitate, the highest sharing being between Fine Woody Debris and Downed Coarse Woody Debris. The best predictors of total diversity were related to the substrate, management, stand structure, and macroclimate. Higher volumes of logs and large branches in various decay stages increased fungal richness. The same effect was found in diverse forests, with large snags. Macroclimate and topoclimate positively influenced diversity, through De Martonne Aridity Index and snow cover length, both indicating macrofungi preferences for higher moisture of substrate. Silvicultural interventions had an ambivalent effect to fungal diversity, phenomenon observed through stump numbers and proportion.Research highlights: Particular environmental characteristics proved significantly important in explaining different wood-inhabiting fungal richness patterns. Substrate-related variables were the most common ones found, but they were closely linked to climate and forest stand variables.Keywords: Wood-inhabiting fungi; oak, beech and coniferous forests; substrate diversity; dead wood types; coarse woody debris; fine woody debris; climatic variables.Abbreviations used:ALT, elevation; ASPI, Aspect Index; BIO1, mean annual temperature; BIO4, temperature seasonality; BIO7, annual temperature range; BIO12, annual precipitation; BIO15, precipitation seasonality; CWD, coarse woody debris; DBH, diameter at breast height; DCWD, downed coarse woody debris; DCWD_DECAY, DCWD decay diversity; DCWD_DIV, DCWD taxonomic diversity; DCWD_SV, surface-volume ratio of DCWD; DCWD_VOL, DCWD volume; DMAI, De Martonne Aridity Index; DMAI_AU, Autumn DMAI; DMAI_SP, Spring DMAI; DMAI_SU, Summer DMAI; DMAI_WI, Winter DMAI; FAI, Forestry Aridity Index; FWD, fine woody debris; L_SNAG_BA, large snag basal area; OLD_BA, basal area of old trees; POI, Positive Openness Index; RAI, Recent Activity Index; SCL, snow cover length; SLOPE, slope; SNAG_N, snag density; STUMP_N, stump density; TPI, Topographic Position Index; TREE_BA, mean basal area of trees; TREE_DIV, tree' Shannon diversity.
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Dai, Zhaohua, Carl C. Trettin, Andrew J. Burton, Martin F. Jurgensen, Deborah S. Page-Dumroese, Brian T. Forschler, Jonathan S. Schilling, and Daniel L. Lindner. "Coarse woody debris decomposition assessment tool: Model development and sensitivity analysis." PLOS ONE 16, no. 6 (June 4, 2021): e0251893. http://dx.doi.org/10.1371/journal.pone.0251893.
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Coarse woody debris (CWD) is an important component in forests, hosting a variety of organisms that have critical roles in nutrient cycling and carbon (C) storage. We developed a process-based model using literature, field observations, and expert knowledge to assess woody debris decomposition in forests and the movement of wood C into the soil and atmosphere. The sensitivity analysis was conducted against the primary ecological drivers (wood properties and ambient conditions) used as model inputs. The analysis used eighty-nine climate datasets from North America, from tropical (14.2° N) to boreal (65.0° N) zones, with large ranges in annual mean temperature (26.5°C in tropical to -11.8°C in boreal), annual precipitation (6,143 to 181 mm), annual snowfall (0 to 612 kg m-2), and altitude (3 to 2,824 m above mean see level). The sensitivity analysis showed that CWD decomposition was strongly affected by climate, geographical location and altitude, which together regulate the activity of both microbial and invertebrate wood-decomposers. CWD decomposition rate increased with increments in temperature and precipitation, but decreased with increases in latitude and altitude. CWD decomposition was also sensitive to wood size, density, position (standing vs downed), and tree species. The sensitivity analysis showed that fungi are the most important decomposers of woody debris, accounting for over 50% mass loss in nearly all climatic zones in North America. The model includes invertebrate decomposers, focusing mostly on termites, which can have an important role in CWD decomposition in tropical and some subtropical regions. The role of termites in woody debris decomposition varied widely, between 0 and 40%, from temperate areas to tropical regions. Woody debris decomposition rates simulated for eighty-nine locations in North America were within the published range of woody debris decomposition rates for regions in northern hemisphere from 1.6° N to 68.3° N and in Australia.
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Stewart, Bruce J., Peter D. Neily, Eugene J. Quigley, and Lawrence K. Benjamin. "Selected Nova Scotia old-growth forests: Age, ecology, structure, scoring." Forestry Chronicle 79, no. 3 (June 1, 2003): 632–44. http://dx.doi.org/10.5558/tfc79632-3.
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A study of four old-growth stands in Nova Scotia was conducted to document the ecological characteristics of these currently rare Acadian forest ecosystems. Stands were selected to represent the two dominant climax forest types, hemlock–red spruce–eastern white pine, and sugar maple–yellow birch–beech. Data include measurements of age structure, species composition, diameter distribution, basal area, height, coarse woody debris, snags, vertical structure, and canopy condition. All stands were determined to be uneven-aged. Old-growth reference ages calculated for the stands ranged from 164 to 214 years. All stands displayed broad diameter distributions that had peak basal area representation in the 40- to 50-cm diameter classes. Volumes of dead wood ranged from 111 to 148 m3/ha in the softwood stands and from 63 to 83m3/ha in the hardwood stands. Dead wood consisted of approximately one-third snags and two thirds downed coarse woody debris. Measurements from the stands were used to evaluate Nova Scotia's recently developed Old Forest Scoring System. Six stand attributes were rated for a maximum score of 100: stand age, primal value, number of large-diameter trees, length of large-diameter dead wood, canopy structure, and understorey structure. Based on the age attribute, three of the four stands were classed as Mature Old Growth and one was very close, indicating that all are in the shifting mosaic stage of late forest succession. The scores for all stands were relatively high, ranging from 75 to 85, as would be expected from some of the best old-growth stands in the province. Key words: old growth, climax, primal, late succession, uneven-aged, scoring, coarse woody debris, age structure, diameter, Acadian forest, northern hardwood, red spruce, eastern hemlock, white pine, sugar maple, yellow birch, American beech
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Stewart, Glenn H., and Larry E. Burrows. "Coarse woody debris in old-growth temperate beech (Nothofagus) forests of New Zealand." Canadian Journal of Forest Research 24, no. 10 (October 1, 1994): 1989–96. http://dx.doi.org/10.1139/x94-255.
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The volume, biomass, and carbon and nitrogen content of coarse woody debris were measured on three 1-ha reference plots in old-growth Nothofagusfusca (Hook. f.) Oerst.–Nothofagusmenziesii (Hook. f.) Oerst. forest on the South Island of New Zealand. Two decay sequences for logs and one for standing dead trees (snags) were recognised from two-way indicator species analysis (TWINSPAN) of up to 30 variables related to physical characteristics and structural integrity. Wood volume (up to 800 m3•ha−1) and biomass were high (up to 300 Mg•ha−1), and the inside-out decay sequence from heartwood to sapwood was unusual compared with that of other temperate hardwood forests. Coarse woody debris represented significant carbon and nitrogen pools, with ca. 150 Mg•ha−1 and 370 kg•ha−1, respectively, in one stand. The coarse woody debris component of these broad-leaved evergreen hardwood forests was much higher than that reported for other temperate hardwood forests and approaches that of many northern hemisphere conifer forests. The large coarse woody debris pools are discussed in relation to live stand biomass, natural disturbances and tree mortality, and decomposition processes.
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Wang, Fei, Qiu Liang Zhang, Xiao Mei Li, Chun Sheng Bao, and Xiao Wei Gao. "Characteristics of Coarse Woody Debris in Different-Age Natural Larix gmelinii Forests in Daxing’anling Mountains." Advanced Materials Research 347-353 (October 2011): 107–11. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.107.
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Coarse woody debris (CWD) is composed of dry wood, fallen wood and large branches, and it is an important element for structure and function in forest ecosystems. In this paper, we studied the characteristics of coarse woody debris (CWD) of natural Larix gmelinii forests with different ages in Daxing’anling Mountains. The results show that (1) the CWD volumes in near-mature, middle-age and young forests are 88.55 m3•hm-2, 52.07 m3•hm-2 and 3.96 m3•hm-2, respectively; and their biomasses are 52.96 t•hm-2, 36.22 t•hm-2 and 2.35t•hm-2, respectively. Which indicate that the CWD volumes and biomasses increase with forest ages addition; (2) The CWD volume and biomass follow normal distribution in middle and near-mature forest; (3) the CWD volume and biomass decrease with forest age increasing within decay classes I and II, whereas increase in decay classes III, IVand V; (4) the volume of middle-age and young forests present a near normal distribution with decay class increasing.
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Bunnell, Fred L., and Isabelle Houde. "Down wood and biodiversity — implications to forest practices." Environmental Reviews 18, NA (December 2010): 397–421. http://dx.doi.org/10.1139/a10-019.
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Many species require or use down wood (fine and coarse woody debris) as habitat. Where forestry has been practiced for several rotations large proportions of these species are considered threatened. Key attributes determining the suitability of down wood as habitat are decay stage, tree species, and size, specifically diameter. Both quantity and distribution of suitable down wood influence species’ presence and abundance. We present a simple framework describing use of down wood based on broad natural history features, derive predictions from the framework, then test these by review and summary of literature. Our focus is terrestrial vertebrates, particularly in the Pacific Northwest. Species other than vertebrates are addressed to ensure that metrics derived for vertebrates also are appropriate for other organisms. Basic metrics are the same, but appropriate values span a larger range among nonvertebrates. Current evidence suggests that the “extinction debt” apparent for nonvertebrates is approaching for vertebrates. Predictions derived from underlying natural history hold when tested. From that basis we derive broad guidelines for forest planning and practice, and suggest how regional target values can be derived.
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Marañón-Jiménez, Sara, Jorge Castro, Emilia Fernández-Ondoño, and Regino Zamora. "Charred wood remaining after a wildfire as a reservoir of macro- and micronutrients in a Mediterranean pine forest." International Journal of Wildland Fire 22, no. 5 (2013): 681. http://dx.doi.org/10.1071/wf12030.
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Large amounts of logs and coarse woody debris remain in the ecosystem after wildfires. However, the relevance of the nutrient reservoir contained in the remaining post-fire woody debris for the ecosystem nutrient reserves is rarely considered. In this paper, we determine the carbon and nutrient concentrations in the partially charred wood after a wildfire along an altitudinal gradient and assess the relative magnitude of the nutrient reservoir in the wood in relation to those existing in the first 10-cm soil layer. Soils were poorly developed and nutrients limiting for the vegetation requirements. Charred woody material still contained a relatively high concentration of nutrients compared to those reported for unburnt pine wood, and in general, this decreased with altitude. Partially charred wood represented a considerable pool of nutrients, due to both the relatively high concentrations and to the great amount of biomass still present after the fire. Potential contributions of the charred wood were particularly relevant for N and micronutrients Na, Mn, Fe, Zn and Cu, as wood contained 2–9 times more nutrients than the soil. Post-fire woody debris constitutes therefore a valuable natural element as a potential source of nutrients, which would be lost from ecosystems in cases where it is removed.
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Caron, Jean, Louis-Marie Rivière, and Gilles Guillemain. "Gas diffusion and air-filled porosity: Effect of some oversize fragments in growing media." Canadian Journal of Soil Science 85, no. 1 (February 1, 2005): 57–65. http://dx.doi.org/10.4141/s03-086.
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Large particles are often added to growing media to improve air-filled porosity, an often-reported growth-limiting factor. Previous studies have shown that large fragments can leave air-filled porosity unchanged and actually decrease the air exchange characteristics in peat:bark and pure peat media, with an adverse effect on plant growth. Thirteen different growing mixes composed of perlite, bark, peat, sand, rockwool, wood and coco fibre, in which the size of the larger fractions was varied, were tested. Air-filled porosity, easily available water, pore effectiveness coefficient, and diffusivity were examined in these mixes. Air-filled porosity was found to be the highest in mixes where the largest fraction was composed of coarser particles. Pore effectiveness coefficient was found to decrease with the increasing coarseness of the largest fractions. Gas diffusivity was found to be highest when intermediate (2–4 mm) fragments were used as the largest fraction of the mixes. These findings applied to impermeable, disk- or spherically shaped, coarse fragments (perlite, coco hulls, bark), but did not apply to threadlike coarse material (wood fibres). Gas diffusivity values (at a water potential of −0.75 kPa) obtained for rockwool, the peat:bark mix containing 2- to 4-mm bark particles, the peat:medium wood fibre mix, the peat:fine perlite (0.8–2 mm) mix and the pure fine coconut medium were not statistically different one from another. Air-filled porosity was negatively correlated to the fractions less than 1 mm, between 0 and 0.2 mm and between 0.2 and 0.8 mm. Easily available water, pore effectiveness coefficient and gas diffusivity were not correlated to particle size distribution, indicating that these properties cannot be estimated based on particle size and must instead be measured directly. Key words: Aetion, peat substrates, perlite, bark, available water
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Lõhmus, Asko, and Piret Lõhmus. "Coarse woody debris in mid-aged stands: abandoned agricultural versus long-term forest land." Canadian Journal of Forest Research 35, no. 6 (June 1, 2005): 1502–6. http://dx.doi.org/10.1139/x05-047.
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During the 20th century, large agricultural areas in Eastern Europe became forested after their abandonment. To explore the value of these new forests for biota, we assessed volumes of coarse woody debris (CWD) on random transects in mid-aged (4075 years old) stands. In mixed and deciduous forests that were not forested in the 1930s, downed tree (log) volumes were about two times lower than in cutover sites. The effect on snag volume depended on site type and was generally nonsignificant. Large-diameter CWD showed similar proportions in the long-term and new forest areas, but large, well-decayed trunks tended to be less frequent in the latter. No reduction of dead wood volume was found in new pine stands, 98% of which had previously been classified as mires (bogs). Hence the origin of mid-aged successional forests had affected their CWD supply (particularly logs) to some extent, but the general scarcity of CWD all over the forest land indicated much larger (at least five-fold) losses due to timber harvesting. We conclude that naturally reforested areas should not be automatically excluded from reserve establishment or other CWD-related conservation programmes.
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Goodburn, John M., and Craig G. Lorimer. "Cavity trees and coarse woody debris in old-growth and managed northern hardwood forests in Wisconsin and Michigan." Canadian Journal of Forest Research 28, no. 3 (March 1, 1998): 427–38. http://dx.doi.org/10.1139/x98-014.
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The effects of uneven-aged management on the availability of coarse woody debris habitat were examined in northern hardwood forests (with and without a hemlock component) in north-central Wisconsin and adjacent western Upper Michigan. Snags, cavity trees, fallen wood, and recent tip-up mounds in 15 managed uneven-aged (selection) stands were compared with levels in 10 old-growth stands and six unmanaged even-aged second-growth stands. Amounts of coarse woody debris in selection stands were generally intermediate between old-growth and even-aged stands. Density of snags >30 cm DBH in northern hardwood selection stands averaged 12/ha, approximately double that found in even-aged northern hardwoods, but only 54% of the level in old-growth northern hardwoods. Highest densities of snags >30 cm DBH occurred in old-growth hemlock-hardwood stands, averaging over 40 snags/ha. For combined forest types, the volume of fallen wood (>10 cm in diameter) was significantly lower in selection stands (60 m3/ha) and even-aged stands (25 m3/ha) than in old-growth stands (99 m3/ha). Volume differences were even more pronounced for large-diameter debris (>40 cm). Cavity tree density in selection stands averaged 11 trees/ha, 65% of the mean number in old-growth stands. Densities of snags (>30 cm DBH) and large-diameter cavity trees (>45 cm) present in selection stands exceeded current guidelines for wildlife tree retention on public forests.
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Dai, Zhaohua, Carl C. Trettin, Andrew J. Burton, Martin F. Jurgensen, Deborah S. Page-Dumroese, Brian T. Forschler, Jonathan S. Schilling, and Daniel L. Lindner. "Coarse Woody Debris Decomposition Assessment Tool: Model validation and application." PLOS ONE 16, no. 7 (July 9, 2021): e0254408. http://dx.doi.org/10.1371/journal.pone.0254408.
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Coarse woody debris (CWD) is a significant component of the forest biomass pool; hence a model is warranted to predict CWD decomposition and its role in forest carbon (C) and nutrient cycling under varying management and climatic conditions. A process-based model, CWDDAT (Coarse Woody Debris Decomposition Assessment Tool) was calibrated and validated using data from the FACE (Free Air Carbon Dioxide Enrichment) Wood Decomposition Experiment utilizing pine (Pinus taeda), aspen (Populous tremuloides) and birch (Betula papyrifera) on nine Experimental Forests (EF) covering a range of climate, hydrology, and soil conditions across the continental USA. The model predictions were evaluated against measured FACE log mass loss over 6 years. Four widely applied metrics of model performance demonstrated that the CWDDAT model can accurately predict CWD decomposition. The R2 (squared Pearson’s correlation coefficient) between the simulation and measurement was 0.80 for the model calibration and 0.82 for the model validation (P<0.01). The predicted mean mass loss from all logs was 5.4% lower than the measured mass loss and 1.4% lower than the calculated loss. The model was also used to assess the decomposition of mixed pine-hardwood CWD produced by Hurricane Hugo in 1989 on the Santee Experimental Forest in South Carolina, USA. The simulation reflected rapid CWD decomposition of the forest in this subtropical setting. The predicted dissolved organic carbon (DOC) derived from the CWD decomposition and incorporated into the mineral soil averaged 1.01 g C m-2 y-1 over the 30 years. The main agents for CWD mass loss were fungi (72.0%) and termites (24.5%), the remainder was attributed to a mix of other wood decomposers. These findings demonstrate the applicability of CWDDAT for large-scale assessments of CWD dynamics, and fine-scale considerations regarding the fate of CWD carbon.
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Korai, Hideaki. "Effects of Density Profile on Bending Strength of Commercial Particleboard." Forest Products Journal 72, no. 2 (March 1, 2022): 85–91. http://dx.doi.org/10.13073/fpj-d-21-00070.
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Abstract Face layer density is widely known to be important for increasing bending strength (i.e., modulus of rupture [MOR]), whereas outer core layer density is not regarded as such. This study reports the importance of the outer core layer density for commercial particleboards. The core and face layers were manufactured with coarse and fine particles, respectively. The coarse particles increased MOR because of the long wood fibers retained in the particle, whereas fine particles did not increase MOR because of the absence of long wood fibers. Long wood fibers in the outer core layer, as opposed to face layers, increase MOR. Moreover, the sampling position of the density profile specimen was important for the MOR. The MOR was influenced with the density profile specimens obtained near the center of the MOR specimen; thus, the low-density part near the center of the MOR specimen exerted a large influence by significantly decreasing the MOR.
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Iršėnaitė, Reda, and Ernestas Kutorga. "Wood-inhabiting fungi on pedunculate oak coarse woody debris in relation to substratum quantity and forest age." Acta Mycologica 42, no. 2 (December 23, 2013): 169–78. http://dx.doi.org/10.5586/am.2007.018.
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Wood-inhabiting fungi on pedunculate oak (<em>Quercus robur</em>) coarse woody debris (CWD) was investigated in 50 plots of 0.1 ha in oak stands of different ages in Lithuania. In maturing stands (50-120 years) the average volume of oak CWD was 4.7 m<sup>3</sup>/ha, and in mature stands (over 120 years) – 13.9 m3/ha. Both in maturing and mature stands, the greatest fraction of CWD consisted of fallen oak branches (81 % and 84 % respectively), whereas fallen trunks comprised about 10 % of the total units of CWD. In total 1350 records of 203 species (49 ascomycetes and 154 basidiomycetes) were collected during 2 years of investigation. Species richness and abundance increased significantly with the increase of volume and abundance of CWD. Higher species richness was detected in mature stands than in maturing ones. Wood-inhabiting species composition varied greatly at stand scale, and one third of all detected species occurred only in one plot. Red-listed fungi were found only in mature stands. We conclude that, even in managed oak stands, oak CWD maintains a rather diverse species composition of ascomycetes and basidiomycetes. However, the current practice of forestry in Lithuania of removing dying or dead wood of large volume, e.g. standing and fallen trunks, reduce the distribution of highly specialized, usually rare, and endangered fungi.
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Hammond, HE James, David W. Langor, and John R. Spence. "Saproxylic beetles (Coleoptera) using Populus in boreal aspen stands of western Canada: spatiotemporal variation and conservation of assemblages." Canadian Journal of Forest Research 34, no. 1 (January 1, 2004): 1–19. http://dx.doi.org/10.1139/x03-192.
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Saproxylic beetles associated with Populus coarse woody material were sampled from two age classes of fire-origin aspen stands in north-central Alberta, Canada. A combination of rearings from wood bolts and window traps attached to snags yielded 9571 beetles representing 257 taxa over the 3-year period (19931995). We investigated faunal variation across regions, stand ages (mature, 6090 years; old, >100 years), decay classes, wood types, and years in terms of species richness, abundance, and trophic differences. Although trophic structure was similar, faunal composition differed between the two study regions. Species richness and abundance were similar across stand ages; however, many species were collected exclusively or in great majority from old stands and from snags of large diameter, which suggested that truncation of stand age structure through widespread industrial harvest could have serious consequences for saproxylic assemblages. Beetle species richness increased with the level of wood decay, whereas the total catch of beetles tended to be higher in early stages of decay. Wood borer abundance tended to be higher in snags; however, total species richness was higher in logs. Our analyses suggest that (i) many beetle species in the Canadian boreal forest depend directly upon standing and fallen large-diameter woody material from Populus trees, (ii) variation in stage of decay is critical to beetle diversity, and (iii) provision for retention of representative old stands is critical to conservation of saproxylic communities.
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Sefidi, Kiomars, and Vahid Etemad. "Dead wood characteristics influencing macrofungi species abundance and diversity in Caspian natural beech (Fagus orientalis Lipsky) forests." Forest Systems 24, no. 2 (July 27, 2015): eSC03. http://dx.doi.org/10.5424/fs/2015242-06039.
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<p><em>Aim of study</em>: This study aimed to examine the dead wood inhabiting macrofungi communities occurring on dead beech and hornbeam trees in Caspian forests.<strong></strong></p><p><em>Area of study</em>: The Kheiroud forest in the north of Iran.</p><p><em>Material and Methods</em>: Data from 205 sampling dead tree were analyzed by means of Generalized Linear Models (GLM) to test the effects of decay stage, DBH, Length or Height on macrofungi diversity. Additionally, tree species, dead wood size, log position, decay stage were used as predictor factors for the number of sporocarps species (NSS) as a fungal species richness and diversity in each dead log using analysis of variance</p><p><em>Main results</em>: The number of sporocarps species (NSS) varied in different dead wood size and decay classes. The different stages of decay and the different size classes of dead wood had significantly different species richness of macrofungi. Deadwood in the high-decayed stages contained the highest diversity of fungi. Most of fungi identified on both logs and snags belonged to Basidiomycetes and Ascomycetes. The highest value for richness and evenness indices calculated in large diameter dead wood in decay class III. The results indicated the size and decay class of dead wood describe the greatest variance of the model that means the highest number of sporocarps species inhabited on the large dead wood in advanced stage of decaying.</p><p><em>Research highlights</em>: Macrofungi diversity varied significantly across pieces of dead wood with downed logs, larger pieces, and wood in later stages of decay having the highest macrofungi diversity.</p><p> <strong>Keywords</strong>: Caspian forest; coarse woody debris; down woody debris; Iran.<strong></strong></p>
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Guyette, Richard P., and Mike Stambaugh. "THE AGE AND DENSITY OF ANCIENT AND MODERN OAK WOOD IN STREAMS AND SEDIMENTS." IAWA Journal 24, no. 4 (2003): 345–53. http://dx.doi.org/10.1163/22941932-90000340.
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Large wood of oak trees (Quercus spp.) has resided in the streams and sediments of north Missouri, USA for many thousands of years. This wood affords the opportunity to compare a chronosequence of differences in wood density over a very long period. We analyzed the relationship between the age (residence time) and density of heartwood from oak boles using tree-ring and 14C dating methods and discuss their implications. The residence time of large oak wood (> 25 cm diameter) sampled in the streams and sediments ranged from less than 14 years to more than 12,320 years. The oak wood ranged in density from 0.82 g cm-3 for a tree that had recently fallen into the stream to 0.14 g cm-3 for ancient oak wood. Two regression equations relate age (residence time) and density of oak wood and explain 88 percent of the variance in the dependent variables. Equation 1, heartwood density = age, can be used for studies in carbon cycling, wood as invertebrate habitat, or other questions related to the density and ecology of wood in streams such as wood retention and export. Equation 2, age = heartwood density, can be used for estimating when oak wood was formed on a very coarse scale over many thousands of years.
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Kruys, Nicholas, Clas Fries, Bengt Gunnar Jonsson, Tomas Lämås, and Göran Ståhl. "Wood-inhabiting cryptogams on dead Norway spruce (Picea abies) trees in managed Swedish boreal forests." Canadian Journal of Forest Research 29, no. 2 (February 1, 1999): 178–86. http://dx.doi.org/10.1139/x98-191.
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We surveyed the quantity and quality of dead Norway spruce (Picea abies (L.) Karst.) trees and wood-inhabiting cryptogams in a managed boreal forest landscape in northern Sweden. Size and decay of dead trees was related to substrate utilization by wood-inhabiting species. Coarse woody debris (CWD) was surveyed along 34 strip transects. CWD and wood-inhabiting cryptogams were surveyed in eight circular plots at each site. A total of 6195 spruce CWD units occurred along strip transects and 809 spruce CWD units in circular plots. On average 2.2 m3/ha spruce CWD was found on the plots. The majority (63%) of the transect CWD units were <10 cm diameter and in early to intermediate decay stages. Sixty-eight wood-specific species of fungi, lichens, mosses, and hepatics occurred on the plots. Of these, 13 occurred on [Formula: see text]5% of the 809 CWD units surveyed for wood-inhabiting species. Eight species occur on the Swedish red lists, indicating that such species are indeed uncommon in managed forests. Red-listed species showed strong preferences for large diameter CWD and CWD in late decay stages, i.e., substrates that are poorly represented in managed forests. Frequently occurring species, however, showed utilization patterns that correspond with the distribution of the substrate types.
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Briedis, Julia I., Jeremy S. Wilson, Jeffrey G. Benjamin, and Robert G. Wagner. "Logging Residue Volumes and Characteristics following Integrated Roundwood and Energy-Wood Whole-Tree Harvesting in Central Maine." Northern Journal of Applied Forestry 28, no. 2 (June 1, 2011): 66–71. http://dx.doi.org/10.1093/njaf/28.2.66.
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Abstract Integrated roundwood and energy-wood whole-tree, partial harvesting has become common in Maine over the past decade, yet there is limited information about the volume and characteristics of logging residues left behind on such harvest sites. To better inform forest managers about the downed woody material remaining after whole-tree partial harvesting, we measured downed wood volume and characteristics on 12 harvested sites in central Maine using line intersect sampling. All sites were harvested using mechanical systems (feller-bunchers and grapple skidders) within a year prior to sampling. The mean volume of downed wood across all sites was 726 ± 57 ft3/ac (±SE), 47% of which was residue generated by the harvest. The variability of residue volumes was higher within sites (coefficients of variation between 36 and 69%) than between sites (coefficient of variation, 27%). Coarse woody material between 3 and 6 in. in diameter at the large end dominated the postharvest debris, while logs greater than 10 in. in diameter were scarce. The majority of harvest-generated downed wood was in decay class 1, whereas preharvest debris consisted of mostly decay classes 2, 3, and 4. The volumes of downed wood remaining on the study sites were within the range of volumes found on other managed sites of similar forest types. However, further research is necessary to assess whether these amounts and characteristics are adequate for long-term maintenance of ecological processes.
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Baker, T. R., O. L. Phillips, W. F. Laurance, N. C. A. Pitman, S. Almeida, L. Arroyo, A. DiFiore, et al. "Do species traits determine patterns of wood production in Amazonian forests?" Biogeosciences 6, no. 2 (February 25, 2009): 297–307. http://dx.doi.org/10.5194/bg-6-297-2009.
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Abstract. Understanding the relationships between plant traits and ecosystem properties at large spatial scales is important for predicting how compositional change will affect carbon cycling in tropical forests. In this study, we examine the relationships between species wood density, maximum height and above-ground, coarse wood production of trees ≥10 cm diameter (CWP) for 60 Amazonian forest plots. Average species maximum height and wood density are lower in Western than Eastern Amazonia and are negatively correlated with CWP. To test the hypothesis that variation in these traits causes the variation in CWP, we generate plot-level estimates of CWP by resampling the full distribution of tree biomass growth rates whilst maintaining the appropriate tree-diameter and functional-trait distributions for each plot. These estimates are then compared with the observed values. Overall, the estimates do not predict the observed, regional-scale pattern of CWP, suggesting that the variation in community-level trait values does not determine variation in coarse wood productivity in Amazonian forests. Instead, the regional gradient in CWP is caused by higher biomass growth rates across all tree types in Western Amazonia. Therefore, the regional gradient in CWP is driven primarily by environmental factors, rather than the particular functional composition of each stand. These results contrast with previous findings for forest biomass, where variation in wood density, associated with variation in species composition, is an important driver of regional-scale patterns in above-ground biomass. Therefore, in tropical forests, above-ground wood productivity may be less sensitive than biomass to compositional change that alters community-level averages of these plant traits.
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Herrmann, Steffen, and Jürgen Bauhus. "Comparison of methods to quantify respirational carbon loss of coarse woody debris." Canadian Journal of Forest Research 38, no. 11 (November 2008): 2738–45. http://dx.doi.org/10.1139/x08-115.
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Carbon (C) loss from coarse woody debris (CWD) may be important in forest ecosystem C budgets, yet there are no standard methods of quantifying it. Here we assessed respirational C loss of log segments of European beech ( Fagus sylvatica L.) and Norway spruce ( Picea abies (L.) Karst.), to compare the two main measurement approaches (the static and dynamic methods using soda lime and an infrared gas analyser, IRGA) with three different measurement options for CWD logs. These included (i) incubation of the whole log segment, (ii) the use of small in situ chambers on the curved log surface, and (iii) extracted wedges of wood. On average, significantly higher amounts of CO2 were measured with the IRGA (125%) compared with soda lime. In addition, the soda lime method requires careful calibration of incubation length and amounts of soda lime used. Regardless of the measurement method and tree species, substantially higher amounts of CO2 were measured for whole log segments than for the other two options. Measuring respiration with small in situ chambers on logs or extracted wedges might underestimate real CO2 flux by up to 74%. We therefore recommend measurement of CWD respiration using gas analysers for large log segments.
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Carlquist, Sherwin. "Wood and Stem Anatomy of Petiveria and Rivina (Caryophyllales); Systematic Implications." IAWA Journal 19, no. 4 (1998): 383–91. http://dx.doi.org/10.1163/22941932-90000659.
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Petiveria and Rivina have been placed by various authors close to each other within Phytolaccaceae; widely separated from each other but both within Phytolaccaceae; and within a segregate family (Rivinaceae) but still within the order Caryophyllales. Wood of these monotypic genera proves to be alike in salient qualitative and even quantitative features, including presence of a second cambium, vessel morphology and pit size, nonbordered perforation plates, vasicentric axial parenchyma type, fiber-tracheids with vestigially bordered pits and starch contents, narrow multiseriate rays plus a few uniseriate rays, ray cells predominantly upright and with thin lignified walls and starch content, and presence of both large styloids and packets of coarse raphides in secondary phloem. Although further data are desirable, wood and stern data do not strongly support separation of Petiveria and Rivina from Phytolaccaceae. Quantitative wood features correspond to the short-lived perennial habit ofboth genera, and are indicative ofaxeromorphic wood pattern.
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Chojnacky, David C., and Thomas M. Schuler. "Technical Note—Amounts of Down Woody Materials for Mixed-Oak Forests in Kentucky, Virginia, Tennessee, and North Carolina." Southern Journal of Applied Forestry 28, no. 2 (May 1, 2004): 113–17. http://dx.doi.org/10.1093/sjaf/28.2.113.
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Abstract Fallen or down dead wood is a key element in healthy forest ecosystems. Although the amount of down wood and shrubs can provide critical information to forest resource managers for assessing fire fuel build up, data on biomass of down woody materials (DWM) are not readily accessible using existing databases. We summarized data collected by the USDA Forest Service's Forest Inventory and Analysis (FIA) program into biomass for mixed-oak forest types in Kentucky, Virginia, Tennessee, and North Carolina to obtain a baseline average for Appalachian mixed-oak forests. We sampled a subset of 76 plots from 16 oak forest types and computed biomass for each DWM component, using slightly different equations for each. Biomass of DWM components was summarized using simple statistics. The mean of all DWM components combined was 32 Mg/ha, and the median was 29 Mg/ha. Over half the mean DWM was duff and litter (18 Mg/ha combined); coarse woody material (CWM) was less than 15% of mean DWM; and fine woody material (FWM) (7 Mg/ha) was almost twice CWM. The range of mass for individual components was quite large. These estimates compare favorably to those found in studies for other forest types. South. J. Appl. For. 28(2):113–117.
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Marston, Richard, and Robin Gray. "Spatial Distribution of Large Woody Debris on the Snake River, Grand Teton National Park." UW National Parks Service Research Station Annual Reports 23 (January 1, 1999): 119–23. http://dx.doi.org/10.13001/uwnpsrc.1999.3385.
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Large woody debris (LWD) plays a key role in controlling the ecology and geomorphology of streams. Woody debris traps coarse particulate organic matter and sediments (Andersen and Sedell, 1979; Bilby and Likens, 1980; Marston, 1982); provides habitat for aquatic insects (Angermeier and Karr, 1984; Benke et al., 1985); and provides cover in pools and slow water areas (Bisson et al., 1982, 1987; Tschaplinski and Hartman, 1983; Fausch and Northcote, 1992). The role of wood in affecting stream morphology is dependent on the size of the stream (Bilby and Ward, 1989). In smaller streams, woody debris can create step pool sequences (Heede, 1972, 1985; Marston, 1982), increase pool area (Murphy and Hall, 1981; Ralph et al., 1994), and reduce sediment transport (Bilby, 1984). Nakamura and Swanson (1993) noted that the importance of woody debris to the morphology of first order streams can be limited by the size of the debris, which is often large enough to bridge the channel and not interact with the flow. Woody debris plays a larger role when it enters the channel bottom, where it can divert flow and affect erosion and deposition. The scale issues raised by Bilby and Ward (1989) and Nakamura and Swanson (1993) are critical to understanding the role of woody debris. To date, LWD has not been adequately studied at watershed scales in larger rivers. In fact, there is little understanding of the relationship between LWD and the geomorphic pattern of the river channel (Piegay and Marston, 1998; Piegay and Gumell, 1997; Piegay, 1993). The purpose of this study is to document the distribution of LWD jams on the Snake River in Grand Teton National Park, Wyoming in order to understand the effects of LWD on channel morphology in large river systems.
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Trepanier, Kaitlyn E., Laura Manchola-Rojas, and Bradley D. Pinno. "Effects of Buried Wood on the Development of Populus tremuloides on Various Oil Sands Reclamation Soils." Forests 13, no. 1 (January 1, 2022): 42. http://dx.doi.org/10.3390/f13010042.
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Buried wood is an important but understudied component of reclamation soils. We examined the impacts of buried wood amounts and species on the growth of the common reclamation tree species trembling aspen (Populus tremuloides). In a greenhouse study, aspen seedlings were planted into four soil types, upland derived fine forest floor-mineral mix (fFFMM), coarse forest floor-mineral mix (cFFMM), and lowland derived peat and peat-mineral mix (PMM), that were mixed with either aspen or pine wood shavings at four concentrations (0%, 10%, 20% and 50% of total volume). Height and diameter growth, chlorophyll concentration, and leaf and stem biomass were measured. Soil nutrients and chemical properties were obtained from a parallel study. Buried wood primarily represents an input of carbon to the soil, increasing the C:N ratio, reducing the soil available nitrogen and potentially reducing plant growth. Soil type had the largest impact on aspen growth with fFFMM = peat > PMM > cFFMM. Buried wood type, i.e., aspen or pine, did not have an impact on aspen development, but the amount of buried wood did. In particular, there was an interaction between wood amount and soil type with a large reduction in aspen growth with wood additions of 10% and above on the more productive soils, but no reduction on the less productive soils.
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Mattson, Kim G., Wayne T. Swank, and Jack B. Waide. "Decomposition of woody debris in a regenerating, clear-cut forest in the Southern Appalachians." Canadian Journal of Forest Research 17, no. 7 (July 1, 1987): 712–21. http://dx.doi.org/10.1139/x87-114.
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Mass losses were estimated for coarse (>5 cm) and fine (≤5 cm) woody debris (CWD and FWD, respectively) during the first 7 years following clear-cutting of a mixed hardwood forest at the Coweeta Hydrologie Laboratory in the Southern Appalachians of North Carolina. Estimates were based on (i) precut forest biomass, (ii) volume and density of CWD and mass of FWD at year 1, and (iii) wood density changes of CWD by year 6 and mass changes of FWD by year 7. Mass estimates of CWD at years 0, 1, and 6 were 91.2, 74.8, and 53.0 Mg/ha, respectively. Mass estimates of FWD at years 0, 1, and 7 were 30.3, 21.3, and 7.8 Mg/ha, respectively. Decay constants (k) for mass losses were relatively high compared with other studies of wood decomposition, 0.083 and 0.185 year−1 for CWD and FWD, respectively, and 0.108 year−1 for total (CWD + FWD) debris. Mass loss of CWD occurred largely through wood density decreases and bark fragmentation. CO2−efflux estimates accounted for over 90% of the CWD density loss and for two-thirds (40.4 Mg/ha) of the total debris mass loss. The remaining mass loss of total debris (20.3 Mg/ha) is a source of large, organic matter inputs to the forest floor via solution fluxes and fragmentation of CWD bark and FWD. The large variation in wood-density loss among logs was examined statistically as a function of various decay factors. Density loss varied by more than 10-fold among tree species. Density loss rates were 40% higher in logs on the ground versus those off the ground, 100% higher in logs with observable fungi versus those without fungi, and 40% higher in logs that occurred in plots with south and east aspects versus those in plots with west aspects.
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Ranius, Thomas, Bengt Gunnar Jonsson, and Nicholas Kruys. "Modeling dead wood in Fennoscandian old-growth forests dominated by Norway spruce." Canadian Journal of Forest Research 34, no. 5 (May 1, 2004): 1025–34. http://dx.doi.org/10.1139/x03-271.
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If equilibrium is assumed in unmanaged forests, the volume of coarse woody debris (CWD), VCWD, may be calculated from (i) the volume of living trees, Vliving, (ii) average volume of a dead stem in relation to when it was alive, k, (iii) tree mortality rate, m, and (iv) residence time of CWD, t, by the equation VCWD = Vlivingkmt. We parameterized this equation with data from Norway spruce (Picea abies (L.) Karst.) dominated forests in Fennoscandia. The Vliving was assumed to be directly proportional to forest productivity. Tree mortality data were from the National Forest Inventory, while it was difficult to find quantitative data on k and t. The predicted amounts (74138 m3/ha, with larger amounts in the south) and size distribution (a negative exponential distribution of the number of stems) of CWD corresponded fairly well to averages from field inventories. By using a computer simulation program, the variability in tree mortality, density of living trees, and residence time of CWD were considered. In the simulations, the amount of CWD varied widely between 1-ha plots, especially for individual decay classes. Therefore, this model could be used to predict averages from larger landscapes unaffected by large disturbances, while no model can predict the amount of CWD at individual plots.
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Mackensen, J., J. Bauhus, and E. Webber. "Decomposition rates of coarse woody debris—A review with particular emphasis on Australian tree species." Australian Journal of Botany 51, no. 1 (2003): 27. http://dx.doi.org/10.1071/bt02014.
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We reviewed the decay patterns and lifetimes (time to reach 95% mass loss) of coarse woody debris (CWD) on the forest floor. The objectives were to identify the factors influencing the decomposition process of CWD and to provide estimates of lifetimes for CWD from Australian tree species. This information is required for greenhouse accounting of forestry activities and land use change as well as the sustainable management of CWD in forest ecosystems. The analysis of a global data set on decay rates of CWD showed that, in particular, the mean annual temperature was a main driver of decomposition, accounting for 34% of the variation in decay rates. The Q10, the factor by which biological processes accelerate when temperature increases by 10�C, was 2.53. Additional determinants of CWD decay rates were the initial density of wood and the diameter of logs. Median and average lifetimes derived from 184 decay rates were 49 and 92 years, respectively, which is considerably higher than the 10-year default for all litter proposed by the Intergovernmental Panel on Climate Change. The pattern of decay in most cases followed a negative exponential curve. To overcome the paucity of information on decomposition of CWD in Australian forests and woodlands, decay rates for a large number of species were derived from wood durability and decay resistance studies. For native Australian species, lifetimes ranged from 7 years in Eucalyptus regnans to 375 years in E. camaldulensis. The lifetimes for timber durability Classes 1–4 were 54, 39, 26 and 11 years, respectively, below 30� latitude and without the influence of termites. However, the experimental conditions under which durability and decay resistance are commonly determined are substantially different from the situation under which CWD decomposes in the field. These estimates must therefore be regarded as minimum lifetimes for CWD of most species. To determine decay rates of CWD with greater certainty, long-term field experiments in a wide range of ecosystems are required.
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Bissonnette, Jean, Louis Bélanger, Stéphane Marchand, Pierre Larue, and Jean Huot. "L'inventaire forestier multiressource : les variables critiques de l'habitat faunique." Forestry Chronicle 73, no. 2 (April 1, 1997): 241–47. http://dx.doi.org/10.5558/tfc73241-2.
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A multiresource forest inventory can be defined as a coherent group of methods used to collect the information required for integrated forest management. It represents a management tool that can provide a common data base to evaluate simultaneously wood production, wildlife habitat quality and sensitive ecological variables. The objective of this study was to develop a multiresource inventory adapted to the needs of wood and wildlife habitat supply analysis in Quebec's public forests. Special attention was given to identifying the additional variables needed in the present forest inventory to adequately evaluate wildlife habitat quality. Most of the critical habitat variables used in Habitat Suitability Indices Models for a large number of species are already integrated in Quebec's forest inventory. However, two critical habitat variables should be added : the shrub layer and snags. The former plays a major ecological role for the survival of most not hibernating herbivores such as snowshoe hare and moose. These species are major game species and the staple prey of many furbearers. The low shrub layer provides both browse and escape cover. Large diameter snags are a limiting factor of many species for nesting. Moreover, those two components are vulnerable to an intensification of forestry practices. In certain situations other variables could be added, notably vegetation physionomy and coarse wood debris.
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Raheem, Akeem A., and Bolanle Deborah Ikotun. "Investigation of Workability and Compressive Strength of Wood Ash Cement Concrete Containing Nanosilica." Advanced Materials Research 1154 (June 2019): 129–36. http://dx.doi.org/10.4028/www.scientific.net/amr.1154.129.
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Studies have revealed that wood ash cement concrete just like other pozzolanic cement concrete has lower early strength compared to plain cement concrete. Nanoparticles have been found to improve the early strength of concrete due to its small size and large surface area. This paper reports the findings on influence of nanosilica on the workability and compressive strength of wood ash cement concrete. Wood ash was obtained as a waste product from Ladoke Akintola University of Technology (LAUTECH) bread bakery, Ogbomoso. Biological synthesis of nanosilica using kola pod extract and silica precursor (1:5) was conducted at Nanotechnology research group laboratory at LAUTECH. The chemical composition, specific gravity and grading of wood ash, fine and coarse aggregate used were determined. Concrete with 10% wood ash replacement for cement was produced using 1:2:4 mix proportion and water to binder ratio of 0.5. Nanosilica was added at 0.5, 1.0, 1.5 and 2.0% levels. Concrete with no wood ash and nanosilica served as the control. Workability and compressive strength of the plain and composite concrete were determined. The results showed that concrete workability was enhanced with introduction of nanosilica. The compressive strength also increased with the addition of nanosilica. Maximum compressive strength of 27.53MPa was achieved at 90 days with 1.5% nanosilica addition. It was concluded that nanosilica enhanced workability and improved both early and later strength development in wood ash concrete with 1.5% as the optimum addition.
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King, J. S., C. P. Giardina, K. S. Pregitzer, and A. L. Friend. "Biomass partitioning in red pine (Pinus resinosa) along a chronosequence in the Upper Peninsula of Michigan." Canadian Journal of Forest Research 37, no. 1 (January 1, 2007): 93–102. http://dx.doi.org/10.1139/x06-217.
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Carbon (C) allocation to the perennial coarse-root system of trees contributes to ecosystem C sequestration through formation of long-lived live wood biomass and, following senescence, by providing a large source of nutrient-poor detrital C. Our understanding of the controls on C allocation to coarse-root growth is rudimentary, but it has important implications for projecting belowground net primary production responses to global change. Age-related changes in C allocation to coarse roots represent a critical uncertainty for modeling landscape-scale C storage and cycling. We used a 55 year chronosequence approach with complete above- and below-ground harvests to assess the effects of stand development on biomass partitioning in red pine (Pinus resinosa Ait.), a commercially important pine species. Averaged within site, individual-tree root/shoot ratios were dynamic across stand development, changing from 0.17 at 2-, 3-, and 5-year-old sites, to 0.80 at the 8-year-old site, to 0.29 at the 55-year-old site. The results of our study suggest that a current research challenge is to determine the generality of patterns of root-shoot biomass partitioning through stand development for both coniferous and hardwood forest types, and to document how these patterns change as a function of stand age, tree size, environment, and management.
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Chave, Jérôme, Jean Olivier, Frans Bongers, Patrick Châtelet, Pierre-Michel Forget, Peter van der Meer, Natalia Norden, Bernard Riéra, and Pierre Charles-Dominique. "Above-ground biomass and productivity in a rain forest of eastern South America." Journal of Tropical Ecology 24, no. 4 (July 2008): 355–66. http://dx.doi.org/10.1017/s0266467408005075.
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AbstractThe dynamics of tropical forest woody plants was studied at the Nouragues Field Station, central French Guiana. Stem density, basal area, above-ground biomass and above-ground net primary productivity, including the contribution of litterfall, were estimated from two large permanent census plots of 12 and 10 ha, established on contrasting soil types, and censused twice, first in 1992–1994, then again in 2000–2002. Mean stem density was 512 stems ha−1 and basal area, 30 m2 ha−1. Stem mortality rate ranged between 1.51% and 2.06% y−1. In both plots, stem density decreased over the study period. Using a correlation between wood density and wood hardness directly measured by a Pilodyn wood tester, we found that the mean wood density was 0.63 g cm−3, 12% smaller than the mean of wood density estimated from the literature values for the species occurring in our plot. Above-ground biomass ranged from 356 to 398 Mg ha−1 (oven-dry mass), and it increased over the census period. Leaf biomass was 6.47 Mg ha−1. Our total estimate of aboveground net primary productivity was 8.81 MgC ha−1 y−1 (in carbon units), not accounting for loss to herbivory, branchfalls, or biogenic volatile organic compounds, which may altogether account for an additional 1 MgC ha−1 y−1. Coarse wood productivity (stem growth plus recruitment) contributed to 4.16 MgC ha−1 y−1. Litterfall contributed to 4.65 MgC ha−1 y−1 with 3.16 MgC ha−1 y−1 due to leaves, 1.10 MgC ha−1 y−1 to twigs, and 0.39 MgC ha−1 y−1 to fruits and flowers. The increase in above-ground biomass for both trees and lianas is consistent with the hypothesis of a shift in the functioning of Amazonian rain forests driven by environmental changes, although alternative hypotheses such as a recovery from past disturbances cannot be ruled out at our site, as suggested by the observed decrease in stem density.
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Jochner, M., J. M. Turowski, A. Badoux, M. Stoffel, and C. Rickli. "The role of log jams and exceptional flood events in mobilizing coarse particulate organic matter in a steep headwater stream." Earth Surface Dynamics 3, no. 3 (July 14, 2015): 311–20. http://dx.doi.org/10.5194/esurf-3-311-2015.
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Abstract. Coarse particulate organic matter (CPOM) fulfills important functions in the physical and ecological system of a stream. CPOM delivery to and export from the stream has implications for the stream's morphology and sediment transport capacity as well as the energy budget and food availability. Export rates of CPOM from mountain catchments have been observed to strongly increase with rising discharge, but the mechanism leading to this strong relationship is unclear. Here, we show that log jams in the Erlenbach, a steep headwater stream in the Swiss Prealps, are an effective barrier for the transport of CPOM pieces, and thus become sites of storage of large quantities of material over time. Exceptional discharge events with return periods exceeding 20 years play a dual role in CPOM transport in the Erlenbach. First, they appear to destroy existing log jams, releasing the stored material (wood and sediment). Second, they intensify channel–hillslope coupling, thereby recruiting new logs to the channel, around which new jams can form. This allows for the formulation of a new, fully episodic end-member in a four-end-member model of CPOM dynamics of steep mountain streams based on wood delivery and export.
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Ssazipius, Gava Job, Maiteki James Miiro, David Muzoora, Sylvia Kpange, and Mohammed Babu. "Sawdust as a filtering media in sludge drying beds." International Journal of Biological and Chemical Sciences 15, no. 7 (April 22, 2022): 53–61. http://dx.doi.org/10.4314/ijbcs.v15i7.5s.
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Conventional wastewater treatment is a common method of domestic wastewater treatment in Sub Saharan Africa. Lubigi wastewater treatment plant (LSTP) in Kampala – Uganda is a unique wastewater treatment system combining treatment of on-site faecal sludge and domestic wastewater. High solids content of on-site faecal sludge mean large volumes of the same, thus limited sludge drying space. This means need to optimize sludge drying bed use (improving the sludge drying efficiency) by reducing their drying times. This study investigated use of wood sawdust as a filtering layer in the faecal sludge drying process. Comparison of performance between sand, fine and coarse sawdust as a filtering media was conducted at LSTP. Sludge shrinkage depth (cm) and moisture content (%) were key parameters used to analyze and determine the most ideal media for sludge dewatering. The study was conducted during both wet and dry seasons to determine the impact of seasonal changes. Dry season results showed a drastic decrease in the sludge depth (shrinkage) for all the three media types after a period of 8 days followed by a gradual decrease in sludge depth up to 28 days. This implies that effective dewatering happens for the first 8 days, which goes on for the rest of the remaining days. Overall, the best performing media was fine sawdust, coarse sawdust and lastly sand. Independent two sample t-tests assuming equal variances show that there is a significant difference between the mean sludge depth of sand and fine sawdust t(df) = 56, P<0.05). There was no significant difference in the mean sludge shrinkage depth of fine sawdust and coarse sawdust. Similar results were obtained during the wet season. Comparisons of similar media types during the dry and wet seasons shows that the mean sludge shrinkage for the dry season were significantly lower than that of the wet season (P<0.05). This implies that seasonal changes significantly affect the sludge dewatering. In terms of moisture content (MC), the results for dry season showed that fresh fine and fresh coarse wood sawdust achieved MC of 28% and 31% respectively after 28 days. Sand produced faecal sludge with a higher MC of 49% after 28 days. Similar results of the performance of the three types of media was observed during the wet season. In conclusion, fine sawdust performs better than coarse sawdust and sand media in faecal sludge dewatering. Sludge dewatering is affected by seasonal changes.
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Ssazipius, Gava Job, Maiteki James Miiro, David Muzoora, Sylvia Kpange, and Mohammed Babu. "Sawdust as a filtering media in sludge drying beds." International Journal of Biological and Chemical Sciences 15, no. 7 (April 22, 2022): 53–61. http://dx.doi.org/10.4314/ijbcs.v15i7.5s.
Full textAbstract:
Conventional wastewater treatment is a common method of domestic wastewater treatment in Sub Saharan Africa. Lubigi wastewater treatment plant (LSTP) in Kampala – Uganda is a unique wastewater treatment system combining treatment of on-site faecal sludge and domestic wastewater. High solids content of on-site faecal sludge mean large volumes of the same, thus limited sludge drying space. This means need to optimize sludge drying bed use (improving the sludge drying efficiency) by reducing their drying times. This study investigated use of wood sawdust as a filtering layer in the faecal sludge drying process. Comparison of performance between sand, fine and coarse sawdust as a filtering media was conducted at LSTP. Sludge shrinkage depth (cm) and moisture content (%) were key parameters used to analyze and determine the most ideal media for sludge dewatering. The study was conducted during both wet and dry seasons to determine the impact of seasonal changes. Dry season results showed a drastic decrease in the sludge depth (shrinkage) for all the three media types after a period of 8 days followed by a gradual decrease in sludge depth up to 28 days. This implies that effective dewatering happens for the first 8 days, which goes on for the rest of the remaining days. Overall, the best performing media was fine sawdust, coarse sawdust and lastly sand. Independent two sample t-tests assuming equal variances show that there is a significant difference between the mean sludge depth of sand and fine sawdust t(df) = 56, P<0.05). There was no significant difference in the mean sludge shrinkage depth of fine sawdust and coarse sawdust. Similar results were obtained during the wet season. Comparisons of similar media types during the dry and wet seasons shows that the mean sludge shrinkage for the dry season were significantly lower than that of the wet season (P<0.05). This implies that seasonal changes significantly affect the sludge dewatering. In terms of moisture content (MC), the results for dry season showed that fresh fine and fresh coarse wood sawdust achieved MC of 28% and 31% respectively after 28 days. Sand produced faecal sludge with a higher MC of 49% after 28 days. Similar results of the performance of the three types of media was observed during the wet season. In conclusion, fine sawdust performs better than coarse sawdust and sand media in faecal sludge dewatering. Sludge dewatering is affected by seasonal changes.
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Ssazipius, Gava Job, Maiteki James Miiro, David Muzoora, Sylvia Kpange, and Mohammed Babu. "Sawdust as a filtering media in sludge drying beds." International Journal of Biological and Chemical Sciences 15, no. 7 (April 22, 2022): 53–61. http://dx.doi.org/10.4314/ijbcs.v15i7.5s.
Full textAbstract:
Conventional wastewater treatment is a common method of domestic wastewater treatment in Sub Saharan Africa. Lubigi wastewater treatment plant (LSTP) in Kampala – Uganda is a unique wastewater treatment system combining treatment of on-site faecal sludge and domestic wastewater. High solids content of on-site faecal sludge mean large volumes of the same, thus limited sludge drying space. This means need to optimize sludge drying bed use (improving the sludge drying efficiency) by reducing their drying times. This study investigated use of wood sawdust as a filtering layer in the faecal sludge drying process. Comparison of performance between sand, fine and coarse sawdust as a filtering media was conducted at LSTP. Sludge shrinkage depth (cm) and moisture content (%) were key parameters used to analyze and determine the most ideal media for sludge dewatering. The study was conducted during both wet and dry seasons to determine the impact of seasonal changes. Dry season results showed a drastic decrease in the sludge depth (shrinkage) for all the three media types after a period of 8 days followed by a gradual decrease in sludge depth up to 28 days. This implies that effective dewatering happens for the first 8 days, which goes on for the rest of the remaining days. Overall, the best performing media was fine sawdust, coarse sawdust and lastly sand. Independent two sample t-tests assuming equal variances show that there is a significant difference between the mean sludge depth of sand and fine sawdust t(df) = 56, P<0.05). There was no significant difference in the mean sludge shrinkage depth of fine sawdust and coarse sawdust. Similar results were obtained during the wet season. Comparisons of similar media types during the dry and wet seasons shows that the mean sludge shrinkage for the dry season were significantly lower than that of the wet season (P<0.05). This implies that seasonal changes significantly affect the sludge dewatering. In terms of moisture content (MC), the results for dry season showed that fresh fine and fresh coarse wood sawdust achieved MC of 28% and 31% respectively after 28 days. Sand produced faecal sludge with a higher MC of 49% after 28 days. Similar results of the performance of the three types of media was observed during the wet season. In conclusion, fine sawdust performs better than coarse sawdust and sand media in faecal sludge dewatering. Sludge dewatering is affected by seasonal changes.
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Jochner, M., J. M. Turowski, A. Badoux, M. Stoffel, and C. Rickli. "The role of log jams and exceptional flood events in mobilizing coarse particulate organic matter in a steep headwater stream." Earth Surface Dynamics Discussions 3, no. 1 (February 26, 2015): 173–96. http://dx.doi.org/10.5194/esurfd-3-173-2015.
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Abstract. Export rates of coarse particulate organic matter (CPOM) from mountain catchments have been observed to strongly increase with rising discharge, but the mechanism leading to this strong relationship is unclear. Here, we show that log jams in the Erlenbach, a steep headwater stream in the Swiss Prealps, are an effective barrier for the transport of CPOM pieces, and thus become sites of storage of large quantities of material over time. Exceptional discharge events with return periods exceeding 20 years play a dual role in CPOM transport. First, they destroy existing log jams, releasing the stored material (wood and sediment). Second, they intensify channel-hillslope coupling, thereby recruiting new logs to the channel, around which new jams can form.
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Lalande, Roger, Valentin Furlan, Denis A. Angers, and Gilles Lemieux. "Soil Improvement Following Addition of Chipped Wood from Twigs." American Journal of Alternative Agriculture 13, no. 3 (September 1998): 132–37. http://dx.doi.org/10.1017/s0889189300007815.
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AbstractWood residues are applied to soils to improve their organic matter content and related biological, physical, and chemical properties. We monitored the changes in soil total C and N content, the bacterial, fungal and actinomycetal populations, and microbial biomass and activity during 20 weeks in the first season following the application of chipped wood from twigs (CWT), and as residual effects during the second growing season on a loamy soil (coarse loamy, mixed, frigid, Humic Fragiorthod) in Sainte-Brigitte-des-Saults (Québec) Canada. Wet-aggregate stability and the content of nutrients of the soil also were determined. Adding CWT stimulated the bacterial and actinomycetal populations very rapidly (within 8 weeks); in the second season the effect was less pronounced and gradually disappeared. The most significant and long-lasting effect was on the fungal population in two consecutive years of observation, with increases of up to 24-fold. This stimulation of fungi possibly was responsible for the large and significant increase in wet-aggregate stability observed in the second year. The effect of CWT on alkaline phosphatase activity and total C and N was observed only in the second season. Someimmobilization was seen only in the season immediately following residue application. The addition of the CWT also supplied micronutrients, in particular Zn, which would make it a useful source of some elements in deficient soils. Application of CWT to this soil greatly improved its quality, as revealed by its biological, chemical, and physical attributes.
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Schoennagel, Tania, Erica A. H. Smithwick, and Monica G. Turner. "Landscape heterogeneity following large fires: insights from Yellowstone National Park, USA." International Journal of Wildland Fire 17, no. 6 (2008): 742. http://dx.doi.org/10.1071/wf07146.
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We characterised the remarkable heterogeneity following the large, severe fires of 1988 in Yellowstone National Park (YNP), in the northern Rocky Mountains, Wyoming, USA, by focussing on spatial variation in post-fire structure, composition and ecosystem function at broad, meso, and fine scales. Ecological heterogeneity at multiple scales may enhance resilience to large, severe disturbances by providing structural, biological and functional redundancy. Post-fire heterogeneity in stand age, coarse wood abundance, microbial and understorey communities reflected interactions between existing pre-fire patterns and fire severity at different scales, suggesting that environmental context plays an important role in successional responses to large fires. In response to these post-fire patterns, heterogeneity in carbon (C) and nitrogen (N) storage, N mineralisation, decomposition, and productivity was also evident at multiple scales and may confer resiliency to large fires. For example, at broad scales, C storage in YNP appears resistant to changes in age-class structure associated with large stand-replacing fires. In summary, the YNP landscape is recovering rapidly from the 1988 fires through natural mechanisms, owing to the abundance and spatial heterogeneity of post-fire residuals, but other systems with fewer biotic legacies may be less resilient to such large, severe fires.
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Campbell, John L., Daniel C. Donato, and Joseph B. Fontaine. "Effects of post-fire logging on fuel dynamics in a mixed-conifer forest, Oregon, USA: a 10-year assessment." International Journal of Wildland Fire 25, no. 6 (2016): 646. http://dx.doi.org/10.1071/wf15119.
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Removal of fire-killed trees (i.e. post-fire or salvage logging) is often conducted in part to reduce woody fuel loads and mitigate potential reburn effects. Studies of post-salvage fuel dynamics have primarily used chronosequence or modelling approaches, with associated limitations; longitudinal studies tracking fuels over time have been rare. We resampled a network of post-fire plots, comprising a range of logging intensities, 10 years after the 2002 Biscuit Fire (Oregon, USA). For surface woody fuels, which started from large treatment differences immediately following logging (stepwise increases with harvest intensity), we found converging trends among treatments at 10 years, with convergence nearly complete for fine fuels but not for coarse fuels. Fire-killed snags for the dominant species (Pseudotsuga menziesii) decayed while standing at a statistically significant rate (single-exponential k = 0.011), similar to or only slightly slower than down wood, suggesting that not all snag biomass will reach the forest floor. Live vegetation (largely resprouting sclerophyllous vegetation) is beginning to dominate surface fuel mass and continuity (>100% cover) and likely moderates differences associated with woody fuels. Post-fire logging had little effect on live fuels or their change over time, suggesting high potential for stand-replacing early-seral fire regardless of post-fire harvest treatments.
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Henriques-Oliveira, A. L., J. L. Nessimian, and L. F. M. Dorvillé. "Feeding habits of Chironomid larvae (Insecta: Diptera) from a stream in the Floresta da Tijuca, Rio de Janeiro, Brazil." Brazilian Journal of Biology 63, no. 2 (May 2003): 269–81. http://dx.doi.org/10.1590/s1519-69842003000200012.
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Chironomids larvae are frequently one of the most abundant and diverse groups of insects in several kinds of aquatic environments. Also, they play a major role in the aquatic food webs, representing a major link among producers and secondary consumers. This work investigates the feeding behavior of the chironomid larvae present in the Rio da Fazenda, situated in the Parque Nacional da Tijuca, Rio de Janeiro, Brazil, between August 1994 and May 1995. Algae, fungi, pollen, leaf and wood fragments, animal remains, detritus and silt were the main gut contents found in the larvae studied. The main food item ingested by the larvae was detritus, except for the Stenochironomus whose main food source was leaf and wood fragments. Tanypodinae exhibited a large quantity of animal remains of several kinds in the diet. During the period studied it was observed that the diet of 16 genera (out of 24 studied) varied. Tanypodinae had mainly coarse particulate organic matter (> 1 mm) in the gut contents, while Chironominae and Orthocladiinae had fine particulate organic matter (< 1 mm).
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Rouvinen, S., T. Kuuluvainen, and L. Karjalainen. "Coarse woody debris in old Pinus sylvestris dominated forests along a geographic and human impact gradient in boreal Fennoscandia." Canadian Journal of Forest Research 32, no. 12 (December 1, 2002): 2184–200. http://dx.doi.org/10.1139/x02-144.
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Coarse woody debris (CWD) was studied in old Pinus sylvestris L. dominated forests in three geographic regions in the middle boreal vegetation zone: (i) in Häme in southwestern Finland, characterized by a long history of forest utilization, (ii) in Kuhmo in northeastern Finland, with a more recent history of forest utilization, and (iii) in the Vienansalo wilderness area in northwestern Russia, characterized by large areas of almost natural forest. Within the geographic regions the measured 0.2-ha plots were divided into three stand types according to the degree of human impact: (i) natural stands, (ii) selectively logged stands, and (iii) managed stands. The results showed that compared with natural forests, forest management has strongly reduced both the amount and diversity of CWD. The highest total CWD volumes were found in the natural stands in Häme (mean 67 m3·ha1) and Kuhmo (92 m3·ha1) and in the selective logged stands in Vienansalo (80 m3·ha1), while the lowest CWD volumes were found in the managed stands in Häme (7 m3·ha1) and Kuhmo (22 m3·ha1). The duration of forest utilization also plays a role, as forests with short management histories (Kuhmo region) still carried structural legacies from earlier more natural stages of the forest. In addition to lower total CWD volumes, managed stands also largely lacked certain dead wood characteristics, particularly large dead trees and standing dead trees with structural diversity characteristics (such as stem breakage, leaning stems, and fire scars) when compared with natural and selectively logged stands. The CWD characteristics of stands selectively logged in the past were often comparable with those of natural stands, suggesting that old selectively logged stands can be of high value from the nature conservation point of view.
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Farnell, Ingrid, Ché Elkin, Erica Lilles, Anne-Marie Roberts, and Michelle Venter. "The effects of variable retention forestry on coarse woody debris dynamics and concomitant impacts on American marten habitat after 27 years." Canadian Journal of Forest Research 50, no. 9 (September 2020): 925–35. http://dx.doi.org/10.1139/cjfr-2019-0417.
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Coarse woody debris (CWD) in the form of logs, downed wood, stumps and large tree limbs is an important structural habitat feature for many small mammal species, including the American marten (Martes americana). At a long-term experimental trial in northern temperate hemlock-cedar forests of British Columbia, Canada, we analysed the impact of varying amounts of overstory basal area retention: 0% (clearcut), 40%, 70%, and 100% (unharvested) on CWD volume, decay class, and inputs from windthrow over 27 years. We used CWD attributes (diameter, length, decay class, and height above the ground) known to be favourable for martens to create an index for assessing the impact of harvesting intensity on CWD habitat features. 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 to a habitat that was less valuable, compared with stands that had higher retention. Over the 27-year period, windthrown trees were the majority of CWD inputs, and volume change was positively related to percent retention. Our results highlight that forest management influences CWD size and input dynamics over multiple decades, and the need for consideration of these impacts when undertaking long-term multiple-use forestry planning.
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Korboulewsky, Nathalie, Isabelle Bilger, and Abdelwahab Bessaad. "How to Evaluate Downed Fine Woody Debris Including Logging Residues?" Forests 12, no. 7 (July 6, 2021): 881. http://dx.doi.org/10.3390/f12070881.
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Volume or biomass estimates of downed woody debris are crucial for numerous applications such as forest carbon stock assessment, biodiversity assessments, and more recently for environmental evaluations of biofuel harvesting practices. Both fixed-area sampling (FAS) and line-intersect sampling (LIS) are used in forest inventories and ecological studies because they are unbiased and accurate methods. Nevertheless, most studies and inventories take into account only coarse woody debris (CWD, >10 cm in diameter), although fine woody debris (FWD) can account for a large part of the total downed biomass. We compared the LIS and FAS methods for FWD volume or biomass estimates and evaluated the influence of diameter and wood density measurements, plot number and size. We used a Test Zone (a defined surface area where a complete inventory was carried out, in addition to FAS and LIS), a Pilot Stand (a forest stand where both LIS and FAS methods were applied) and results from 10 field inventories in deciduous temperate forest stands with various conditions and amounts of FWD. Both methods, FAS and LIS, provided accurate (in trueness and precision) volume estimates, but LIS proved to be the more efficient. Diameter measurement was the main source of error: using the mean diameter, even by diameter class, led to an error for volume estimates of around 35%. On the contrary, wood density measurements can be simplified without much influence on the accuracy of biomass estimates (use of mean density by diameter class). We show that the length and number of transects greatly influences the estimates, and that it is better to apply more, shorter transects than fewer, longer ones. Finally, we determined the optimal methodology and propose a simplification of some measurements to obtain the best time-precision trade-off for FWD inventories at the stand level.
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Work, Timothy T., Matti Koivula, Jan Klimaszewski, David Langor, John Spence, Jon Sweeney, and Christian Hébert. "Evaluation of carabid beetles as indicators of forest change in Canada." Canadian Entomologist 140, no. 4 (August 2008): 393–414. http://dx.doi.org/10.4039/n07-ls07.
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AbstractOur objective was to assess the potential of carabid beetles (Coleoptera: Carabidae) as effective bioindicators of the effects of forest management at a Canadian national scale. We present a comparison of carabid beetle assemblages reported from large-scale studies across Canada. Based on the initial response following disturbance treatment, we found that carabid assemblages consistently responded to disturbance, but responses of individual species and changes in species composition were nested within the context of regional geography and finer scale differences among forest ecosystems. We also explored the relationship between rare and dominant taxa and species characteristics as they relate to dispersal capacity and use of within-stand habitat features such as coarse woody debris. We found no relationship between life-history characteristics (such as body size, wing morphology, or reported associations with downed wood) and the relative abundance or frequency of occurrence of species. Our results suggest that carabids are better suited to finer scale evaluations of the effects of forest management than to regional or national monitoring programs. We also discuss several knowledge gaps that currently limit the full potential of using carabids as bioindicators.
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Yusuf, Muhammad, Liana Herlina, Akbar Triandhika Budiman, M. Mubaarak Alvian, and Vindy Talahatu. "PENGGUNAAN SERAT KAYU PINUS PENGGANTI AGREGAT HALUS PADA CAMPURAN BETON MUTU NORMAL." INDONESIAN JOURNAL OF CONSTRUCTION ENGINEERING AND SUSTAINABLE DEVELOPMENT (CESD) 5, no. 2 (December 29, 2022): 24–29. http://dx.doi.org/10.25105/cesd.v5i2.15740.
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The use of concrete materials is an important element in sustainable development in every part of the world. Sustainable development must of course support various aspects, from the aspect of development to the maintenance of the development process to the establishment of a building. Departing from this, innovations emerged in which in terms of the development process, construction projects can run better, of course taking into account global climate conditions. The construction project itself certainly has an impact in the form of large-scale waste, as is the case with the construction of houses which still tend to use wood construction. Utilization of construction waste can be optimized by utilizing this waste. The material substitute is a form of innovation to make concrete that is different from normal concrete. Substitutes for this material vary from cement substitutes, fine aggregate to coarse aggregate. In this case sawdust became a substitute for fine aggregate with a 5% substitution. Mix design using SNI 7656:2012. The results obtained from concrete with a 5% substitution of wood fiber were lighter by 4% than normal concrete, but the compressive strength results also decreased by 10.7%.
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Eaton, Robert J., and Felipe G. Sanchez. "Quantitative and Qualitative Measures of Decomposition: Is There a Link?" Southern Journal of Applied Forestry 33, no. 3 (August 1, 2009): 137–41. http://dx.doi.org/10.1093/sjaf/33.3.137.
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Abstract Decomposition rates of loblolly pine coarse woody debris (CWD) were determined by mass loss and wood density changes for trees that differed in source of mortality (natural, girdle-poison, and felling). Specifically, three treatments were examined: (1) control (CON): natural mortality; (2) CD: 5-fold increase in CWD compared with the CON; and (3) CS: 12-fold increase in snags compared with the CON. The additional CWD in the CD treatment plots and the additional snags in the CS plots were achieved by felling (for the CD plots) or girdling followed by herbicide injection (for the CS plots) select trees in these plots. Consequently, mortality on the CD plots is due to natural causes and felling. Likewise, mortality on the CS plots is due to natural causes and girdle-poison. In each treatment plot, mortality due to natural causes was inventoried since 1997, whereas mortality due to girdle-poison and felling were inventoried since 2001. No significant difference was detected between the rates of decomposition for the CWD on these treatment plots, indicating that source of the tree mortality did not influence rates of decomposition once the tree fell. These experimental measures of decomposition were compared with two decay classification systems (three- and five-unit classifications) to determine linkages. Changes in wood density did not correlate to any decay classification, whereas mass loss had a weak correlation with decay class. However, the large degree of variation limits the utility of decay classification systems in estimating mass loss.
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Fambrini, Gelson Luís, Virgínio Henrique M. L. Neumann, José Acioli B. Menezes-Filho, Wellington F. Da Silva-Filho, and Édison Vicente De Oliveira. "Facies architecture of the fluvial Missão Velha Formation (Late Jurassic–Early Cretaceous), Araripe Basin, Northeast Brazil: paleogeographic and tectonic implications." Acta Geologica Polonica 67, no. 4 (December 1, 2017): 515–45. http://dx.doi.org/10.1515/agp-2017-0029.
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Abstract Sedimentological analysis of the Missão Velha Formation (Araripe Basin, northeast Brazil) is the aim of this paper through detailed facies analysis, architectural elements, depositional systems and paleocurrent data. The main facies recognized were: (i) coarse-grained conglomeratic sandstones, locally pebbly conglomerates, with abundant silicified fossil trunks and several large-to-medium trough cross-stratifications and predominantly lenticular geometry; (ii) lenticular coarse-to-medium sandstones with some granules, abundant silicified fossil wood, and large-to-medium trough cross-stratifications, cut-and fill features and mud drapes on the foresets of cross-strata, (iii) poorly sorted medium-grained sandstones with sparse pebbles and with horizontal stratification, (iv) fine to very fine silty sandstones, laminated, interlayered with (v) decimetric muddy layers with horizontal lamination and climbing-ripple cross-lamination. Nine architectural elements were recognized: CH: Channels, GB: Gravel bars and bed forms, SB: Sand bars and bedforms, SB (p): sand bedform with planar cross-stratification, OF: Overbank flow, DA: Downstream-accretion macroforms, LS: Laminated sandsheet, LA: Lateral-accretion macroforms and FF: Floodplain fines. The lithofacies types and facies associations were interpreted as having been generated by alluvial systems characterized by (i) high energy perennial braided river systems and (ii) ephemeral river systems. Aeolian sand dunes and sand sheets generated by the reworking of braided alluvial deposits can also occur. The paleocurrent measurements show a main dispersion pattern to S, SE and SW, and another to NE/E. These features imply a paleodrainage flowing into the basins of the Recôncavo-Tucano-Jatobá.
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Gurtz, Martin E., G. Richard Marzolf, Keith T. Killingbeck, David L. Smith, and J. Vaun McArthur. "Hydrologic and Riparian Influences on the Import and Storage of Coarse Particulate Organic Matter in a Prairie Stream." Canadian Journal of Fisheries and Aquatic Sciences 45, no. 4 (April 1, 1988): 655–65. http://dx.doi.org/10.1139/f88-079.
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The hydrologic regime and zonation of riparian vegetation influenced the quantity and quality of coarse particulate organic matter (CPOM; >1 mm) stored in the channel and upper bank of a prairie stream. In a 5.4-km intermittent reach of the South Branch of Kings Creek on Konza Prairie, Kansas, total annual import was lowest in headwater reaches and increased downstream. Total storage of benthic CPOM in the dry channel and on the bank before the flow period was highest in the fourth- and fifth-order gallery forest zone (999 g ash-free dry mass∙m−2) and less in upstream reaches (320–341 g∙m−2). These longitudinal patterns of CPOM annual import and storage (before the flow period) were opposite those predicted by the river continuum concept for streams draining forested regions. Following flow, headwater channels had more CPOM (291 g∙m−2) than downstream reaches. On the bank, storage was always highest in downstream reaches. Composition of CPOM both in the channel and on the bank varied with changes in riparian vegetation; grass tissues dominated in headwater channels, while wood and leaves of trees and shrubs were more abundant downstream. During the flow period, storage of CPOM increased only in headwater channels, where retention was high despite the lack of woody debris. In this intermittent prairie stream, benthic CPOM may not contribute consistently to the terrestrial/aquatic linkages that are suggested in the river continuum concept because of (1) a paucity of large CPOM sources (e.g. trees, shrubs) in the upper reaches and (2) a hydrologic regime that reduces the amount, as well as the predictability, of stored CPOM. The biota of prairie streams must have opportunistic food gathering and reproductive strategies to take advantage of variable food resources in a flow environment that is itself very unpredictable.
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Schulze, E. D., L. Bouriaud, H. Bussler, M. Gossner, H. Walentowski, D. Hessenmöller, O. Bouriaud, and K. v. Gadow. "Opinion Paper: Forest management and biodiversity." Web Ecology 14, no. 1 (March 7, 2014): 3–10. http://dx.doi.org/10.5194/we-14-3-2014.
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Abstract. In this opinion paper we investigate the effects of forest management on animal and plant biodiversity by comparing protected areas with intensively and extensively managed forests in Germany and in Romania. We want to know the extent to which differences in diversity of Romanian compared to German forests are based on management. The number of tree species was not different in protected and managed forests ranging between 1.8 and 2.6 species per plot in Germany and 1.3 and 4.0 in Romania. Also herbaceous species were independent of management, ranging between 13 species per plot in protected forests of Romania and 38 species per plot in German coniferous forest. Coarse woody debris was generally low, also in protected forests (14 to 39 m3 ha−1). The main difference between Romania and Germany was the volume of standing dead trees (9 to 28 m3 ha−1 for Romania), which resulted in larger numbers of forest relict saproxylic beetles independent of management. Large predators (wolves, bears and lynxes) are only found in regions with low human intervention. Thus, we identified a "cut and leave" type of management in Romania, in which clear-felling of forest are followed by long periods of no human intervention. Forests managed in the "cut and leave" mode contained the highest diversity, due to a natural succession of plant species and due to habitat continuity for animals. In Germany intensive management eliminates poorly formed tree individual and species of low market value during stand development. Forest protection does not ensure the maintenance of more light demanding key species of earlier stages of succession unless competition by shade-tolerant competitors is reduced through disturbances. We compare the economics of intensive and extensive management. The "cut and leave" mode delivers less wood to the wood market, but saves expenses of tending, thinning and administration. Thus the net income could be quite similar to intensive management at a higher level of biodiversity. Our analysis suggests that forest protection per se does not yet ensure the maintenance of species. Clear-felling followed by natural succession may even be superior to the protection of old growth forests, regarding biodiversity. Further research is needed to substantiate this hypothesis.