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Статті в журналах з теми "Residual tree stands"
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Roy, Vincent, Robert Jobidon, and Louis Blais. "Étude des facteurs associés au dépérissement du bouleau à papier en peuplement résiduel après coupe." Forestry Chronicle 77, no. 3 (2001): 509–17. http://dx.doi.org/10.5558/tfc77509-3.
Повний текст джерелаАнотація:
Following harvesting operations within the Quebec mixedwood region, decadence symptoms are frequently observed on residual paper birch trees, compromising future harvests. Simultaneously, these residual stands are often a constraint to the establishment and growth of valuable regeneration. In the context of intensive forest management and preservation of the conifer component in mixedwood stands, it is important to identify factors associated with paper birch post-logging decadence. Ninety-eight (98) stands were sampled along a partial cutting chronosequence of 1 to 11 years old in order to examine five site variables and six stand variables susceptible of explaining post-logging decadence. Classification and regression tree (CART) models indicated that stand variables, mainly residual basal area and time since harvest, were the best predictor variables of decadence. This study suggests maintaining a basal area of at least 16 m2/ha and preserving larger diameter stems when the objective is to maintain healthy paper birch for further harvesting. When the silvicultural objective is to regenerate softwoods, this study recommends keeping a residual basal area after partial cutting of no more than 4 m2/ha. Keywords: residual trees, competition, mixed stands, partial cutting, tree regression, regeneration
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Seablom, Thomas J., and David D. Reed. "Assessment of Factors Contributing to Residual Tree Damage from Mechanized Harvesting in Northern Hardwoods." Northern Journal of Applied Forestry 22, no. 2 (2005): 124–31. http://dx.doi.org/10.1093/njaf/22.2.124.
Повний текст джерелаАнотація:
Abstract Seven northern hardwood stands were evaluated for damage after mechanized harvesting. Four different harvesting systems were evaluated: harvester and grapple skidder, processor and forwarder, chainsaw and cable skidder, and chainsaw and forwarder. There was not an excessive amount of damage occurring to any of the residual stands, and there was an adequate number of residual trees per acre in all diameter classes to meet residual stand structure goals. The majority of the damage that did occur was to the bole portion of the tree and to the 2–8-in. dbh size classes. There was no strong relationship between amount of damage occurring to residual trees and the number of residual trees per acre, residual basal area per acre, or distance to skid trail. These results indicate that mechanized harvesting can be used in northern hardwoods without causing excessive damage to the residual stand. Recommendations are to continue with current silvicultural prescriptions and to increase forester-operator communication to minimize residual tree damage.North. J. Appl. For. 22(2):124–131.
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Smyth, Cheryl, Jim Schieck, Stan Boutin, and Shawn Wasel. "Influence of stand size on pattern of live trees in mixedwood landscapes following wildfire." Forestry Chronicle 81, no. 1 (2005): 125–32. http://dx.doi.org/10.5558/tfc81125-1.
Повний текст джерелаАнотація:
Burned areas and patches of residual live trees were mapped from post-fire aerial photographs of 168 mixedwood stands (a total of 9367 ha), in eight large wildfires in the boreal forest of northern Alberta. The stands were stratified into three size classes: small (<10 ha), medium (10–60 ha), and large (>60 ha).We described the area occupied by single live residual trees, unburned patches of live trees and partially burned patches of live trees within these mixedwood stands. Although results from individual stands were highly variable, there was proportionally more area covered by live residual trees in large fire-killed stands compared to medium stands, which in turn had proportionally more than small stands. For most sizes and types of live tree patches, larger fire-killed stands had a greater proportion of live tree area compared to smaller stands. Results of this study are compared to similar studies and current harvest guidelines. We outline the amount and distribution of live tree patches that would be needed to create harvest areas similar to that found after wildfire. Key words: natural disturbance, wildfire, live residual trees, ecosystem management, forest harvest pattern, boreal mixedwood
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Sokol, Kerry A., Michael S. Greenwood, and William H. Livingston. "Impacts of Long-Term Diameter-Limit Harvesting on Residual Stands of Red Spruce in Maine." Northern Journal of Applied Forestry 21, no. 2 (2004): 69–73. http://dx.doi.org/10.1093/njaf/21.2.69.
Повний текст джерелаАнотація:
Abstract Diameter-limit harvesting has long been suspected as a dysgenic forestry practice, but a conclusive, practical demonstration of the effects of this selection technique on residual tree performance is lacking. To determine the effects of repeated diameter-limit harvesting on the phenotypes of residual trees, we compared radial growth patterns of residual red spruce trees (with ages greater than 100 years) after diameter-limit harvests with those of residual trees in stands subjected to positive selection harvesting. After nearly 50 years of repeated harvesting, residual trees in the diameter-limit stands were nearly 40% smaller and had grown 32% slower than residual trees in positive selection stands. Furthermore, diameter-limit residuals were initially smaller and remained significantly smaller than positive selection residuals throughout their lifespan, despite major release events. After release, the diameter-limit trees responded with increased growth rates, but the increase was relatively small. Growth rates were consistently and significantly lower for diameter-limit residuals until the final 20 yr when growth rates in each treatment converged. Our results indicate that red spruce stands subjected to repeated diameter-limit harvesting will develop progressively less valuable growing stock with limited growth potential.
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Perry, Roger W., and Ronald E. Thill. "Initial Effects of Reproduction Cutting Treatments on Residual Hard Mast Production in the Ouachita Mountains." Southern Journal of Applied Forestry 27, no. 4 (2003): 253–58. http://dx.doi.org/10.1093/sjaf/27.4.253.
Повний текст джерелаАнотація:
Abstract We compared indices of total hard mast production (oak and hickory combined) in 20, second-growth, pine-hardwood stands under five treatments to determine the effects of different reproduction treatments on mast production in the Ouachita Mountains. We evaluated mast production in mature unharvested controls and stands under four reproduction cutting methods (single-tree selection, group selection, shelterwood, and clearcut with wildlife tree retention) during the first 6 yr after initial harvest. Mean Whitehead mast production indices were greater in shelterwoods and clearcuts with wildlife tree retention than in unharvested stands 5 of the 6 yr of study, indicating individual trees in these stands produced greater amounts of hard mast. Stand production values for the 6 yr combined indicated group selections generally produced the greatest amounts of total hard mast, probably because competing pines in the matrix were thinned and hard mast-producing tree densities were unchanged after harvest. However, wide variation in residual density of mast trees existed among stands of the same treatment. Our results indicate hard mast production can be affected by different silvicultural treatments and managers should consider the importance of residual mast production along with other objectives when determining silvicultural treatments to apply. South. J. Appl. For. 27(4):253–258.
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Miller, Gary W., and H. Clay Smith. "A Practical Alternative to Single-Tree Selection?" Northern Journal of Applied Forestry 10, no. 1 (1993): 32–38. http://dx.doi.org/10.1093/njaf/10.1.32.
Повний текст джерелаАнотація:
Abstract When landowners want to develop and maintain an uneven-aged tree structure in eastern hardwood stands, single-tree selection often is suggested as the only advisable, long-term partial regeneration harvest method. Single-tree selection is preferred because it provides a means for improving quality and controlling stocking of the residual stand necessary for sustained yield of desired products. Although studies have shown that single-tree selection is feasible where desirable shade-tolerant species can be regenerated, it is rarely applied because marking stands for harvest can be difficult and time consuming. Instead, diameter-limit cutting is the most common partial regeneration practice used in eastern hardwoods, primarily because it is much easier to apply. Unfortunately, strict diameter-limit cuts do not provide for control of residual stocking or improve the quality of residual trees. However, based on 20-yr results, most objectives of single-tree selection can be attained with flexible diameter-limit harvest guidelines based on potential value increase of individual trees combined with an improvement cut in small sawtimber trees at each periodic cut. North. J. Appl. For. 10(1):32-38.
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Heitzman, Eric, and Adrian G. Grell. "Residual Tree Damage Along Forwarder Trails from Cut-to-Length Thinning in Maine Spruce Stands." Northern Journal of Applied Forestry 19, no. 4 (2002): 161–67. http://dx.doi.org/10.1093/njaf/19.4.161.
Повний текст джерелаАнотація:
Abstract In Maine and adjacent eastern Canadian provinces, cut-to-length harvesting has emerged as an ecologically attractive method of thinning conifer plantations and natural stands. Yet regional information on the extent of residual stand damage associated with this system is lacking. Eight naturally regenerated red spruce (Picea rubens) stands in northern Maine were studied; all stands were thinned in 1997–1998 with a processor and forwarder combination. Field methods consisted of examining individual trees near forwarder trails for bole damage and measuring the size and aboveground height of individual wounds. The frequency of trees damaged in each stand ranged from 25–46%. The four sites with the highest pre- and post-cut tree densities generally had the greatest number of damaged trees. Trees located along forwarder trails were more frequently damaged than nontrailside trees. The average individual wound size ranged from 2.6–8.7 in.2; 82–98% of the wounds in each stand were less than or equal to 10 in.2 in size. Usually, wounds on trailside trees were not significantly larger than wounds on nontrailside trees. Regardless of tree location, most wounds were located 3–6 ft above ground level.
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Walter, Scott T., and Chris C. Maguire. "Conifer response to three silvicultural treatments in the Oregon Coast Range foothills." Canadian Journal of Forest Research 34, no. 9 (2004): 1967–78. http://dx.doi.org/10.1139/x04-068.
Повний текст джерелаАнотація:
This study assessed growth, condition, and mortality of residual trees one decade after harvest across three silvicultural treatments in thirty 85- to 125-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in the Oregon Coast Range foothills. Group-selection cuts had 33% of the entire stand volume extracted as patches approximately 0.20.8 ha in size; two-story regeneration harvests had 75% of the volume extracted, and 2030 residual trees/ha were left; clearcuts had all trees removed, except for 1.2 trees/ha. One decade after harvest, tree basal area, diameter, and height growth, and crown width and fullness did not differ between silvicultural treatments. In contrast, live crown ratio was largest in clearcuts (0.74), and the proportion of trees with epicormic branching was highest in two-story stands (35%). Overall, 45% of trees had more basal area growth in the decade after harvest than in the previous decade. Residual green trees in clearcuts and group-selection stands experienced the highest and lowest percentage mortality, respectively (30.6% vs. 0.2%). Our results reflect little differentiation in the characteristics of trees growing under three silvicultural conditions one decade after harvest. However, percent residual green tree mortality increased with increasing harvest intensity.
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Howard, Andrew F. "Damage to residual trees from cable yarding when partial cutting second-growth stands in coastal British Columbia." Canadian Journal of Forest Research 26, no. 8 (1996): 1392–96. http://dx.doi.org/10.1139/x26-155.
Повний текст джерелаАнотація:
Damage to residual trees associated with a specific combination of stand conditions, silvicultural treatment, and harvesting system must be known if this information is to guide foresters in the design of prescriptions for individual stands planned for partial cutting. A study was made of residual tree damage in two stands of second growth in coastal British Columbia that were partially cut and the timber was yarded with cable systems. Damage to residual trees was found to be high at both sites. The percentage of trees damaged decreased with increasing distance from the skyline corridor, and bigger trees were less likely to be damaged than small ones. Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) was shown to be the least susceptible to damage, followed by western hemlock (Tsugaheterophylla (Raf.) Sarg.) and finally western redcedar (Thujaplicata Donn ex D. Don). Wider spacing of skyline corridors is suggested as one means for reducing stand damage.
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Acker, S. A., E. K. Zenner, and W. H. Emmingham. "Structure and yield of two-aged stands on the Willamette National Forest, Oregon: implications for green tree retention." Canadian Journal of Forest Research 28, no. 5 (1998): 749–58. http://dx.doi.org/10.1139/x98-039.
Повний текст джерелаАнотація:
Green tree retention, a practice based on ecosystem science, has been integrated into forest management as a working hypothesis, requiring research and monitoring to quantify its effects. We undertook a retrospective study of natural, two-aged forest stands on the Willamette National Forest to provide preliminary estimates of the effects of green tree retention on forest structure and yield. Fourteen stands in the western hemlock (Tsuga heterophylla (Raf.) Sarg.) zone (mostly dominated by Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco) were sampled using adjacent, paired plots: one with residual trees over a younger cohort (median age of younger cohort, 97 years) and one with only the younger cohort. The younger cohorts all had much higher densities of trees than typical of local Douglas-fir plantations. Basal area, volume, and mean annual increment (MAI) of the younger cohort all declined with increasing residual tree basal area. These relationships were best described by curvilinear models; the greatest effect per unit of residual tree basal area occurred at low residual tree levels (5-10 m2/ha). For 10 m2/ha residual tree basal area (equivalent to about 12 average (diameter at breast height 105 cm) residual trees per hectare), we predicted a 26% decline in younger cohort MAI (95% confidence interval: -30% to -22%).
Дисертації з теми "Residual tree stands"
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Debruler, Daniel Gary. "Soil Carbon, Nutrients, and Phosphorus Fractions: Responses to Weed Control and Harvest Residual Retention in two 10-Year-Old Douglas-fir (Pseudotsuga menziesii) Stands of the Pacific Northwest." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/50486.
Повний текст джерелаАнотація:
Intensive forest management techniques such as whole-tree harvesting and use of herbicides to control weeds can have an effect on nutrient cycling and nutrient pool sizes in the mineral soil. This study was conducted to measure differences in soil carbon (C), nutrient pools, or phosphorus (P) fractions associated with harvest-intensity (bole-only vs. whole-tree harvest) and weed-control treatments (initial weed control vs. five years of annual weed control) after ten years. Soil C, nitrogen (N), and P, and exchangeable calcium (Ca), potassium (K), magnesium (Mg), and Hedley P fractions were measured prior to treatment establishment and after ten years in two Douglas-fir (Pseudotsuga menziesii) plantations in the Pacific Northwest. We observed increases in most nutrient concentrations with initial weed control compared with annual weed control at Matlock, with opposite trends at Molalla. Exchangeable Ca and Mg content showed responses to weed control treatments. Harvesting treatments had no significant effects on soil C and nutrient pools at either site. Total P and many of the Hedley P fractions decreased over time, but these effects were ameliorated with the less-intensive initial-weed-control-only treatment at Matlock and the more-intensive annual-weed-control at Molalla. Ten-year responses suggest that harvesting intensity has not impacted potential for maintaining soil C and nutrient pools, with the exception of P, for long-term productivity. Knowledge of the on-site vegetative communities and their role in nutrient cycling is required to anticipate what effect weed control might have on nutrient pools through ensuing stand development.<br>Master of Science
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DeGomez, Tom, Christopher J. Fettig, Joel D. McMillin, John A. Anhold, and Christopher Hayes. "Managing Slash to Minimize Colonization of Residual Leave Trees by Ips and Other Bark Beetle Species Following Thinning in Southwestern Ponderosa Pine." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2008. http://hdl.handle.net/10150/146727.
Повний текст джерелаАнотація:
12 pp.<br>Pine Bark Beetles, THE PIÑON IPS BARK BEETLE, FIREWOOD AND BARK BEETLES IN THE SOUTHWEST, USING INSECTICIDES TO PREVENT BARK BEETLE ATTACKS ON CONIFERS, GUIDELINES FOR THINNING PONDEROSA PINE FOR IMPROVED FOREST HEALTH AND FIRE PREVENTION<br>Various techniques to reduce brood production of Ips and Dendroctonus spp. in ponderosa pine slash are discussed.
Частини книг з теми "Residual tree stands"
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Kumuli Gusamo, Benson. "Importance of Araucariaceae for plantation development in Papua New Guinea." In Conifers - From Seed to Sustainable Stands [Working Title]. IntechOpen, 2024. http://dx.doi.org/10.5772/intechopen.1003277.
Повний текст джерелаАнотація:
This article reviews the potential of Araucaria hunsteinii, Araucaria cunninghamii, and Agathis robusta for developing plantations in Papua New Guinea (PNG). The species are propagated from recalcitrant (A. hunsteinii) and orthodox (A. cunninghamii and A. robusta) seeds. The viable seeds are extracted from ripened cones and kept in controlled rooms to maintain seed quality. The seeds are raised in nurseries for seedlings and transplanted in the field. The Bulolo and Wau plantations (PNG) are managed on a 30–40-year cutting cycle. Silviculturally, a 3 × 4 m spacing (12 m2/tree) is applied with 833 trees/ha as initial stocking. Tending is executed in the initial stages and two medium- to high-intensity thinning operations are employed to boost the growth of residual stands. Also, synthetic fertilizers and termiticides are applied to enhance plant growth and control termite infestation in young plantations, respectively. Next, non-commercial (low) thinning is scheduled at 5–7 years with 416 stems/ha stocking (estimated volume 5.522 m3/ha) followed by commercial (crown) thinning conducted at 17–20 years with 208 stems/ha stocking (estimated volume 17.790 m3/ha). The 208 stems/ha is maintained as final crops up to 30–40 years with expected 30.206 m3 volume.
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Malico, Isabel, Ana Cristina Gonçalves, and Adélia M.O. Sousa. "Evergreen Oak Biomass Residues for Firewood." In Forest Biomass - From Trees to Energy. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.95417.
Повний текст джерелаАнотація:
This chapter presents the assessment of the availability for residential heating of residual biomass from cork and holm oaks in a 12,188 ha agroforest area in Portugal. First, the above-ground biomass of evergreen oaks using very high spatial resolution satellite images was determined, followed by the definition of different scenarios for residues removal from the stands. The useful energy potential of the firewood that can be collected from the study area under the various silviculture scenarios was determined considering different energy conversion technologies: open fireplaces (still popular in Portugal) and more efficient closed burning appliances. Additionally, emissions of airborne pollutants from combusting all the available residual biomass in the study area were determined. Depending on the percentage of residues collected when the trees are pruned and on the conversion technologies used, the energy potential of evergreen oak firewood ranged from 5.0 × 106 MJ year−1 to 7.5 × 107 MJ year−1. Heavier pruning combined with the use of open fireplaces generates less useful heat and much higher emissions of pollutants per unit useful energy produced than lighter pruning combined with a more efficient technology. This case study illustrates the need to promote the transition from inefficient to more efficient and cleaner technologies.
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Cabrera, Omar, Pablo Ramón, Bernd Stimm, Sven Gunter, and Reinhard Mosandl. "Damaged Trees Caused by Selective Thinning in Two Tropical Mountain Rain Forest Types in Southern Ecuador." In Tropical Forests - Ecology, Diversity and Conservation Status [Working Title]. IntechOpen, 2023. http://dx.doi.org/10.5772/intechopen.109566.
Повний текст джерелаАнотація:
The proportion of damaged trees and the type caused by the selective thinning can have serious impacts on the ecological and economic sustainability of forests. So far, the damage caused by thinning operations in montane tropical forests is unknown. In this study, we try to quantify the damages caused by selective thinning in two types of humid montane forests in southern Ecuador. For this, we installed 52 permanent plots of 50 m x 50 m in two force types. In the valley forest (VF), we extracted an average basal area of 2.75 m² ha–1, in the ridge forest (RF) an average basal area of 0.8 m² ha–1 was extracted. For each felled tree, we counted and categorized the damage separated by large (>20cm DBH) and small (<20cm DBH) residual trees. Using a generalized linear model (GLM) we could determine that the diameter of the felled tree significantly influences the number of large as well as small trees temporarily or permanently damaged. Basal area thinned in the VF significantly influenced the proportion of trees < 20 cm DBH affected by Permanente Damage (PD) and Temporal Damage (TD). In the RF, the crown area of felled trees influences the proportion of (PD) trees with DBH > 20 cm. The extracted basal area significantly influences the proportion of (TD) trees with DBH < 20 cm. In general, the proportion of temporarily damaged (TD) trees is greater than the proportion of permanently damaged (PD) trees in both types of forest. Considering only the heavily damaged trees we can conclude that the damage in total is acceptable.
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Fidalgo Fonseca, Teresa, Renato N.M. Costa, Carlos Pacheco Marques, José Luis Louzada, and Ana Cristina Gonçalves. "Exploring the Biometric Traits and Potential of Radiata Pine (Pinus radiata D. Don) as a Non-Native Species for Sustainable Forest Systems in Portugal." In Conifers - From Seed to Sustainable Stands. IntechOpen, 2024. http://dx.doi.org/10.5772/intechopen.1003815.
Повний текст джерелаАнотація:
This chapter aims to provide information on biometric traits of radiata pine (Pinus radiata D. Don) outside its natural range, considering as a case study the use of the species in Portugal. The specific objectives of this study are: i) characterising the species; ii) its management; iii) its provisioning potential. To achieve the latter, data on the biometric characteristics of radiata pine trees in Portugal was compiled and analyzed. Briefly, the approach followed employs an equation developed to predict the stem volume of individual trees, which is then coupled with the inherent wood basic density to provide oven-dried biomass estimates. The volume equation demonstrated a noticeable goodness-of-fit (R2 = 0.994 and standard error of the residuals = 0.026 m3) across the entire range of diameters within the dataset (ranging from 7.5 to 45 cm). Additionally, a proposed wood density value of 460 kg/m3 is put forth as a representative value for the species. The tree stem biomass (and sequestered carbon) is then generalized to the stand unit. The results show that the species compares favourably with maritime pine in terms of wood provisioning and usage, broadening the options of pine species to consider in Portugal for reforestation or afforestation programs.
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Ziegler, Justin Paul, Chad M. Hoffman, Russel A. Parsons, Morris Johnson, and James Menakis. "Numerical Investigation of Crown Fuels Arrangements on Wildfire Behavior Following Fuels Treatments." In Advances in Forest Fire Research 2022. Imprensa da Universidade de Coimbra, 2022. http://dx.doi.org/10.14195/978-989-26-2298-9_229.
Повний текст джерелаАнотація:
Conventional fuels treatments often simplify forest structure in an attempt to optimize fire hazard reduction. Conversely, forest restoration treatments, aimed at achieving ecological multiple objectives in addition to fire hazard reduction, purposefully retain complex forest structures. The comparative advantage of conventional fuels versus restoration treatments may depend on the severity of the burning environment, residual tree stocking and surface fuel loads. Here, we performed a suite of simulations with the Wildland-urban interface Fire Dynamics Simulator to compare stand-level fire behavior between silvicultural cuttings that either emphasized or reduced forest structural complexity under a range of residual basal areas, surface fuel loads, and burning conditions. These cuttings included distance-based retention, variable retention, and random cuttings, optionally with thinning from below. Rate of spread did increase under more severe burning conditions, and slightly increased after thinning from below or after variable retention cuttings due to the creation of openings. Canopy consumption was lowest when thinning from below and highest after variable retention. While all treatments reduced fire behavior, the differences we observed support the advantage of using conventional fuels treatments where fire hazard reduction is of primary importance. Additionally, the effects of residual basal area, surface fuel load, and burning conditions highlight the multivariate considerations required when planning fuels treatments and assessing performance at stand or landscape scales.
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Cristina Gonçalves, Ana, Isabel Malico, and Adélia M.O. Sousa. "Energy Production from Forest Biomass: An Overview." In Forest Biomass - From Trees to Energy. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.93361.
Повний текст джерелаАнотація:
As long as care is taken regarding stand and forest sustainability, forest biomass is an interesting alternative to fossil fuels because of its historical use as an energy source, its relative abundance and availability worldwide, and the fact that it is carbon-neutral. This study encompasses the revision of the state of the sources of forest biomass for energy and their estimation, the impacts on forests of biomass removal, the current demand and use of forest biomass for energy, and the most used energy conversion technologies. Forests can provide large amounts of biomass that can be used for energy. However, as the resources are limited, the increasing demand for biomass brings about management challenges. Stand structure is determinant for the amount of residues produced. Biomass can be estimated with high accuracy using both forest inventory and remote sensing. Yet, remote sensing enables biomass estimation and monitoring in shorter time periods. Different bioenergy uses and conversion technologies are characterized by different efficiencies, which should be a factor to consider in the choice of the best suited technology. Carefully analyzing the different options in terms of available conversion technologies, end-uses, costs, environmental benefits, and alternative energy vectors is of utmost importance.
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Schindlbacher, Andreas, Mathias Mayer, Robert Jandl, Stephan Zimmermann, and Frank Hagedorn. "Optimizing forest management for soil carbon sequestration." In Understanding and fostering soil carbon sequestration. Burleigh Dodds Science Publishing, 2022. http://dx.doi.org/10.19103/as.2022.0106.18.
Повний текст джерелаАнотація:
Afforestation and reforestation of arable land enhances soil C sequestriationn. Optimized forest management to sustainably maximize stocks of soil organic carbon. Coniferous forests store more C in the topsoil whereas broadleaf forests store more C in the subsoil. However, on the landscape scale total soil C stocks are similar. Current forest management focuses on increased resistance and resilience. Thinning intensity leads to stable SOC stocks in the long run. Stand replacing disturbances impose significant soil C losses. Controlling the density of browsing game populations is a required ancillary management measure. Tree harvesting operations lead to transient soil C losses. The magnitude depends on the severity of interventions. On nutrient rich soils with low C stocks in the forest floor, whole tree harvest might not affect soil C sequestration, whereas at nutrient poor soils as well as at erosion prone sites, removal of biomass and/or harvest residues reduces soil C sequestration.
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Bosona, Techane, and Girma Gebresenbet. "Logistics Chain and Cost Assessment of Pruning-to-Energy Value Chains: Application of Life Cycle Cost Analysis Approach." In Prunus - Recent Advances [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.101428.
Повний текст джерелаАнотація:
Biomass from agricultural residue has significant potential as renewable energy resource. Therefore, cost-efficient processing and supply of agricultural residues are important to strategically plan and utilize this energy resource. This chapter describes the agricultural pruning to energy (PtE) value chains and presents the life cycle cost analysis (LCCA)-based cost assessment results, focusing on almond and peach tree pruning data obtained from Spain during 2015–2016. Along the main life cycle stages of PtE system, costs of harvesting, off-farm storage, transport, biomass loss, and management of biomass supply chain were considered. In terms of functional unit cost, the life cycle cost (LCC) was calculated to be about 126 €/t for almond PtE and 115 €/t for peach PtE value chain. In both cases, the harvesting stage was found to be cost at hot stage followed by the storage stage. The cost at harvesting stage was about 83% (of 126 €/t) and 82% (of 115 €/t) in the case of almond and peach cases, respectively. Similarly, the share of operational cost was about 74% and 76% for almond and peach cases, respectively. Therefore, more efforts should be made to improve the performance of logistics operations and management of such PtE initiatives.
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Savill, Peter, Julian Evans, Daniel Auclair, and Jan Falck. "Protection from wind." In Plantation Silviculture in Europe. Oxford University PressOxford, 1997. http://dx.doi.org/10.1093/oso/9780198549093.003.0012.
Повний текст джерелаАнотація:
Abstract Wind damage to forests is a recurrent hazard in many parts of the world. High winds can uproot trees, break stems, cause malformations, and retard growth. They can also disrupt planned management, causing economic losses from higher logging costs, damage during storage, unharvested wood, lowered increment in residual stands, and shortened rotations, besides reducing landscape quality and habitats for wildlife. Forests in temperate maritime regions suffer most seriously from wind damage, but those in continental mountainous regions can be badly affected too. In some places wind may be the ecological factor most responsible for the species composition of natural forests through destruction by storms. This leads to successions which favour colonizing, rather than climax, species. Storm damage is a constant risk, rather than an unforeseeable event, in many places where it occurs. It is the most important influence affecting the viability of commercial forestry in the British uplands.
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Montagnini, Florencia. "Nutrient Considerations in the Use of Silviculture for Land Development and Rehabilitation in the Amazon." In The Biogeochemistry of the Amazon Basin. Oxford University Press, 2001. http://dx.doi.org/10.1093/oso/9780195114317.003.0010.
Повний текст джерелаАнотація:
Tropical plantations serve diverse economic, social, political, and ecological functions. With considerably higher yields than managed native forests, tropical and subtropical plantations make substantial contributions to world timber and pulp production (Wadsworth 1983, Evans 1992). Tree plantations can also be a source of cash, savings, and insurance for individual farmers. Plantations may help stabilize rural populations in regions where shifting agriculture is the predominant land use. In combination with subsistence and commercial crops (agroforestry) or cattle (agrosilvopastoral systems), plantations have been used as tools in rural development projects worldwide. Plantations are often seen as alternatives to deforestation as they can provide products that otherwise would be taken from natural forests (Fearnside 1990, McNabb et al. 1994). Nutrient cycling characteristics of tropical plantations differ from those of natural forests in a number of ways. Natural forests are adapted to ecological niches by intricate and effective physiological adaptations of growth in the environment (see Cuevas, this volume). Instead, tropical plantations are simplified, generally monospecific ecosystems that occupy the site for a limited period of time that can range from 4-12 years (for biomass, pulpwood, or fuelwood) up to 20-40 years (timber). In many instances plantations are composed of species that are exotic to the region, or even when indigenous, are new to the particular plantation site. Since plantation tree species have been generally selected for production of timber or other aboveground tree parts, they tend to maintain a smaller fraction of total tree biomass nutrients in roots than natural forests (Vogt et al. 1997). In rain forests growing on poor soils, high tree productivity is in part due to the existence of important nutrient conserving mechanisms mediated by the root system (Cuevas, this volume). The smaller biomass of plantation root systems may thus make them more susceptible to nutrient and water stress. Smaller root systems may also make plantation forests more susceptible to disturbances from strong winds and pathogens that attack aerial parts (Vogt et al. 1997). Nutrient demands by plantation trees vary from season to season and with the developmental age of the stand (Drechsel and Zech 1993). During the life of the plantation, large quantities of nutrients are returned to the soil by above- and belowground litter, harvest residues, stem flow, and throughfall.
Тези доповідей конференцій з теми "Residual tree stands"
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Jansone, Diāna, Roberts Matisons, Inga Straupe, and Aris Jansons. "Radial growth response of Japanese walnut (Juglans ailantifolia) to meteorological conditions in Latvia." In Research for Rural Development 2024 : annual 30th international scientific conference. Latvia University of Life Sciences and Technologies, 2024. https://doi.org/10.22616/rrd.30.2024.005.
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The introduction of non-native tree species has been used as a climate change mitigation tool. To ensure the anticipated benefits, the analysis of species radial growth reactions to meteorological factors should be carried out. Initially, tree species were introduced to non-native regions as food resources, yet the focus has now shifted towards favourable wood properties and growth rates. This study used tree ring width measurements of Japanese walnut Juglans ailantifolia and climate data to examine the relationships between these variables. A total of 30 trees were sampled from a stand located in the southern part of Latvia. Tree ring width (TRW) was measured, and residual chronology was derived. Pearson correlation analysis was used to detect the correlating meteorological factors, and a linear mixed-effects model was used to detect the key factors. The correlation analysis indicated generally low correlation coefficients between TRW and meteorological factors, primarily correlating with summer precipitation, both the current and preceding summer, highlighting carry-over effects. Furthermore, signature years underscored the negative effect of low temperatures and summer droughts on the radial growth of Japanese walnuts. However, the observed variation in TRW between years, not fully explained by meteorological factors, suggests a dynamic rather than stable relationship.
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KLAVINS, Ivars, Arta BARDULE, and Zane LIBIETE. "CHANGES IN MACRONUTRIENT CONCENTRATIONS IN SOIL SOLUTION FOLLOWING REGENERATION FELLING IN PINE AND SPRUCE STANDS: WHOLE-TREE HARVESTING VERSUS STEM-ONLY HARVESTING." In RURAL DEVELOPMENT. Aleksandras Stulginskis University, 2018. http://dx.doi.org/10.15544/rd.2017.172.
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While conventional forest management in boreal and hemiboreal conditions has traditionally been targeted to use and enhance mainly provisioning services like timber production, the main goal of national and European forest policy is to ensure sustainable management of European forests in all aspects. Regeneration felling is a major disturbance in boreal and hemiboreal forests resulting in significant increase of organic matter on the forest floor in the form of logging residues (bark, small branches, tree tops) and severed roots (in case of stump harvesting), and can increase the risk of nutrient leaching. Recently, concern about the effect of forest management impact on macronutrient leaching potentially decreasing nutrient availability for the next forest generations and causing deterioration of water quality has been raised. In 2011, three objects to study the impact of different intensity regeneration felling (stem-only harvesting and whole-tree harvesting) were established in scientific research forests in Kalsnava forest district, eastern part of Latvia. Two sites were located on mineral soils (Myrtillosa and Hylocomiosa site type, dominant tree species Pinus sylvestris L.) and one on drained peat soil (Oxalidosa turf. mel. site type, dominant tree species Picea abies (L.) Karst.). Felling was performed in early spring 2013 with harvester, timber was extracted and logging residues were removed with forwarder, following “business as usual” principle. Soil solution samples were collected once or twice a month in 2012, 2013, 2014, 2015 and 2016. This study presents trends of pH and macronutrient (NO3--N, PO43--P, K) concentrations during five years – one year before harvesting and four years following harvesting. In general, significant forest management impact expressed as increase of macronutrient concentrations in soil solution was detected in the second and third year after harvesting, but in the fourth year concentrations started to decrease again.
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Platts, Norman, David R. Tice, and Jennifer Nicholls. "Study of Fatigue Initiation of Austenitic Stainless Steel in a High Temperature Water Environment and in Air Using Blunt Notch Compact Tension Specimens." In ASME 2015 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/pvp2015-45844.
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Fatigue life assessment procedures for components exposed to high temperature pressurised water environments are typically based on NUREG/CR-6909 or broadly similar codes (e.g. proposed ASME code case N-792). The effects of a high temperature water environment on the fatigue life are accounted for by simply adjusting the fatigue life in ambient temperature air by an environmental factor (FEN). This adjustment assumes that the environment affects both initiation (nucleation) and propagation equally, which is potentially over-conservative. Blunt notch compact tension (CT) specimens (along with direct current potential drop (DCPD) crack detection) have been proposed as a means of determining the “true” fatigue initiation life, enabling the relative impact of the environment on initiation and growth to be characterised and the level of conservatism in the FEN approach assessed. The current work uses a combination of finite element analysis and fatigue testing in both air and water to assess the feasibility of blunt notch CT testing to detect initiation and to quantify the environmental impact. This work indicates significant difficulties with the blunt notch CT test methodology both in terms of quantifying the applicable strain and in terms of detection of the very early stages of initiation which preclude the quantitative application of the technique to study true initiation. Qualitatively, the results suggest that there is still a significant impact of the high temperature water environment on the earliest detectable stages of crack growth in austenitic stainless steels; however the earliest defects detectible by DCPD techniques still involve a significant contribution from short crack growth. Nevertheless, the technique provides a valuable insight into initiation and residual life of components subjected to through wall strain gradients.
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Siyal, Amaar, Waleed AlAmeri, Emad W. Al-Shalabi, Shehzad Ahmed, Shehadeh K. Masalmeh, and Ali M. Al-Sumaiti. "New Insights into the Understanding of Capillary Trapping of Residual Oil in Carbonate Rocks Using Capillary Desaturation Curves." In SPE Reservoir Characterisation and Simulation Conference and Exhibition. SPE, 2023. http://dx.doi.org/10.2118/212621-ms.
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Abstract Most of the oil remain trapped in the reservoir after both primary and secondary recovery stages. Enhanced oil recovery (EOR) techniques are usually implemented in the tertiary stage to recover the trapped oil. Accordingly, the inaccurate determination of residual oil saturation after waterflooding (Sorw) in the secondary stage affects the success and economics of the EOR processes in the tertiary stage. Thus, the capillary desaturation curve (CDC) is usually introduced as guidance to estimate the mobilized residual oil. The objectives of this study include determining the true Sorw for carbonate Indiana limestone outcrops under harsh conditions, then investigating the effect of trapping number, permeability, and initial oil saturation on Sorw, and finally characterizing the CDC for carbonate rocks by further reducing the Sorw using surfactant flooding. For this purpose, six carbonate Indiana limestone outcrop samples with different permeabilities (4-69 mD) and fluid samples i.e., field-representative oil, formation water, seawater, and surfactant solutions were utilized. The drainage process was performed systematically using a coreflooding system to establish initial water saturation by injecting heavy oil followed by crude oil and aging for two weeks. Afterward, all six cores were subjected to spontaneous imbibition using Amott cell. This was further followed by forced imbibition using both ultra-centrifuge and coreflooding systems for comparison purposes and achieving Sorw condition. Finally, forced imbibition was performed on all cores using coreflood to generate CDC using three different surfactants with varying IFT values. The results showed that all rock samples achieved initial water saturation (Swi) in the range of 18-32% with no correlation between Swi and rock permeability. In addition, spontaneous imbibition tests showed slight oil production which reflect the oil-wetness of these cores used. It was noted that this slight production varied among cores with the same rock permeability range, which indirectly indicating the existence of heterogeneity within each permeability range. Furthermore, Sorw of 20-30% was reached using ultra-centrifuge and coreflooding method, indicating no correlation of permeability with Sorw. Based on the CDC studies, the critical trapping number was in the range between 10−5 and 10−4 for the tested cores, which is higher than the reported values in literature (10−8 to 10−6). This work provides a new insight into the understanding of capillary trapping effect on residual oil using CDC in carbonates. The complications in carbonate rocks, including the complex nature of high heterogeneity, mixed-to-oil wettability, high temperature, and high salinity, render accurate determination of true Sorw is a challenge at lab-scale. Sorw determination and CDC characterization aid in EOR screening to find the effective and economically viable methods for production enhancement.
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Burden, Dane, Nic Roniger, and Matt Romney. "Puddling Puddle Welds." In 2020 13th International Pipeline Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/ipc2020-9476.
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Abstract Unique characteristics of individual pipelines come from over a century of evolving design, construction, maintenance, regulation and operation. These characteristics are especially true for legacy, pre-regulated pipelines. Due to the unique nature of the threats present on these assets, there is a need for unique inspection technologies and techniques that can increase pipeline integrity. Reconditioned and repaired pipe utilizing puddle weld repairs is one such threat. An advanced analysis was completed on a 10-inch, 68-mile light products pipeline. The pipeline was constructed with reconditioned pipe that was estimated to contain tens of thousands of puddle welds. Historical in-line inspection (ILI) data generally underperformed in classifying and discriminating puddle welds versus metal loss features. The primary objective of this project was to assess the probability of identification (POI) of a multiple dataset ILI tool utilizing multiple magnetic flux leakage (MFL) magnetization directions and residual (RES) magnetization measurements. A secondary objective was to scrutinize data for signs of coincident features. Hydrostatic testing failures showed that puddle welds with porosity and cracking were susceptible to failure and that the identification of these features would be beneficial. Analysis of historical puddle weld investigations and newly completed multiple dataset ILI data revealed strong identification capabilities in the RES dataset. The high-field magnetizations offered secondary confirmation but often saturated out thermal effects or material differences. The final report included over 40,000 identified puddle welds and five classifications for further investigation. Field investigations for 212 features were completed and the results compared to the ILI data to assess performance. A confusion matrix was created for true positive (TP), true negative (TN), false positive (FP) and false negative (FN) conditions. The smallest TP puddle weld dimension was 0.7″ × 0.7″, and the population had a statistical sensitivity value of 98% (132 TP and 3 FP). Three additional anomalies denoted as atypical were also investigated. The ILI signatures at these locations were consistent with previous repairs in which puddle welds with cracking were found and repaired. Two of the three features investigated were found to have cracking. Crack propagation was found to be both axial and non-axial in orientation. The results show that puddle welds can be detected and identified with extremely high accuracy. In addition, the preliminary classification results for atypical puddle welds show a high potential for identifying secondary coincident features. This paper details the stages, deliverables and results from an ILI advanced analysis focused on puddle welds.
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Li, James, Andrew Howard, and Amin Kalbasi. "Hazard Management Plan for Mass Transit System." In 2022 Joint Rail Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/jrc2022-78000.
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Abstract The literature has recognized that developing a Hazard Management Plan is the most efficient way to outline the process of identifying hazards, assessing the hazard risks, and eliminating hazards or mitigating the hazard risks to the acceptable level for a Mass Transit System. Hazard management is a comprehensive, collaborative approach to manage hazards. It brings different hazard analyses and hazard management tools together to identify the hazard, control the hazard, eliminate the hazard, or mitigate the hazard risk to an acceptable level at an early stage. Hazard management is a top-down hazard management process which involves the Hazard Management Plan (HMP) to outline the hazard management process from the initial stages of identifying a hazard to the final stage in the process of closing a hazard. Hazard analyses that are identified by the HMP include: Preliminary Hazard Analysis (PHA) to provide an early assessment of the top-level hazards associated with a design or concept; Operating and Support Hazard Analysis (OSHA) to identify and analyze hazards associated with personnel and procedures during production, installation, testing, training, operations, maintenance, and emergencies; Interface Hazard Analysis (IHA) to capture interface hazards introduced because of fault or failures in the interaction or interface between systems and between system and Civil works which covers both internal and external interfaces; Subsystem Hazard Analysis (SSHA) to identify previously unidentified hazards associated with the design of subsystems, including component failure modes, critical human error inputs, and hazards resulting for functional relationships between components and equipment comprising each subsystem and recommend actions necessary to eliminate identified hazards or control their associated risk to acceptable levels; System Hazard Analysis (SHA) to evaluate top-level hazards to ensure at the system level the hazards are mitigated to an acceptable level; Fault Tree Analysis (FTA) to identify weakness in the design (i.e., common mode failures); Failure Modes, Effect Analysis (FMEA) to identify and analyze possible failures early in the design phase so that appropriate actions are taken to eliminate, minimize, or control safety. A Hazard Log is a hazard management tool to collect all the hazards identified from various hazard analyses and manage the hazards to closure. In some cases, where hazards are owned by other parties the HMP process will define Hazard Transfer Forms (HTF) to transfer the hazard to the responsible party who will be responsible to supply the evidence of closure or accept the residual risk. This paper will introduce the HMP, various hazard analyses, hazard log and hazard management process that applies to a Mass Transit System.
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Jayaweera, J. A. N. N., and H. M. S. T. Herath. "Design-informed optimization of 2D skeletal structures using convolutional neural networks." In Civil Engineering Research Symposium 2024. Department of Civil Engineering, University of Moratuwa, 2024. http://dx.doi.org/10.31705/cers.2024.14.
Повний текст джерелаАнотація:
Structural optimization aims to find the most efficient material distribution within a design domain by minimizing material usage, self-weight, and strain energy, while maximizing strength. Optimization approaches often use compliance as the objective function and volume as a constraint, which can result in designs that may not fully meet the practical requirements of civil and structural engineering due to potential inadequacies in structural integrity. To address this issue, design-informed optimization integrates structural optimization with design codes such as EN 1993-1-1, ensuring that optimized designs comply with structural integrity requirements and real-world applicability. Existing design-informed optimization algorithms typically rely on iterative schemes, which are computationally intensive and require specialized expertise. To overcome these challenges, this study introduces a novel computer vision-based framework that predicts design-informed optimized frames and accurately identifies member sizes using image processing techniques coupled with probabilistic section classifiers. This framework utilizes input parameters such as span, height, and load to predict the topology, size, and layout of optimized frames that satisfy structural adequacy criteria. It is particularly beneficial for assembly-based manufacturing, where precise member section prediction is crucial for construction efficiency and material optimization. The framework consists of three stages. In Stage 1, the CNN64 model generates a low-resolution layout of the optimized frame using input parameters such as span, height of the design domain, and load. In Stage 2, the CNN512 model refines this layout to produce a high-resolution image of the optimized frame, where section sizes are assigned. These models are trained on varying parameters including fixity, design domain, and load conditions. Stage 3 involves a member section identification algorithm that classifies the optimal structural section sizes through image processing techniques. The efficacy of the framework was validated using simply supported and cantilever beam datasets, achieving pixel accuracies of 94.6% and 91.8%, respectively. Post-calibration, the section identification algorithm, which accounts for unavoidable errors such as generator residuals and section identification errors, achieved near 100% accuracy, demonstrating the robustness of the probabilistic section classifier. Compared to alternative architectures, the CNN64+CNN512 framework consistently outperformed others in metrics such as pixel accuracy, true positive rate, and binary cross-entropy in both datasets. It also demonstrated a significant reduction in computational loss, further confirming its computational efficiency. Overall, the analysis reveals that the CNN64+CNN512 model not only provides superior performance in prediction accuracy but also strikes an effective balance between computational efficiency and model complexity.
Звіти організацій з теми "Residual tree stands"
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Skojac, Daniel A. Jr, Andrew W. Ezell, James S. Meadows, and John D. Hodges. First-year growth and quality response of residual ahrdwood poletimber trees following thinning in an even-aged sawtimber stand. U.S. Department of Agriculture, Forest Service, Southern Research Station, 2007. http://dx.doi.org/10.2737/srs-rn-13.
Повний текст джерела
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Skojac, Daniel A. Jr, Andrew W. Ezell, James S. Meadows, and John D. Hodges. First-year growth and quality response of residual ahrdwood poletimber trees following thinning in an even-aged sawtimber stand. U.S. Department of Agriculture, Forest Service, Southern Research Station, 2007. http://dx.doi.org/10.2737/srs-rn-13.
Повний текст джерела
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Jalkanen, Jukka-Pekka, Erik Fridell, Jaakko Kukkonen, et al. Environmental impacts of exhaust gas cleaning systems in the Baltic Sea, North Sea, and the Mediterranean Sea area. Finnish Meteorological Institute, 2024. http://dx.doi.org/10.35614/isbn.9789523361898.
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Description: Shipping is responsible for a range of different pressures affecting air quality, climate, and the marine environment. Most social and economic analyses of shipping have focused on air pollution assessment and how shipping may impact climate change and human health. This risks that policies may be biased towards air pollution and climate change, whilst impacts on the marine environment are not as well known. One example is the sulfur regulation introduced in January 2020, which requires shipowners to use a compliant fuel with a sulfur content of 0.5% (0.1% in SECA regions) or use alternative compliance options (Exhaust Gas Cleaning Systems, EGCS) that are effective in reducing sulfur oxide (SOx) emissions to the atmosphere. The EGCS cleaning process results in large volumes of discharged water that includes a wide range of contaminants. Although regulations target SOx removal, other pollutants such as polycyclic aromatic hydrocarbons (PAHs), metals and combustion particles are removed from the exhaust to the wash water and subsequently discharged to the marine environment. Based on dilution series of the Whole Effluent Testing (WET), the impact of the EGCS effluent on marine invertebrate species and on phytoplankton was found to vary between taxonomic groups, and between different stages of the invertebrate life cycle. Invertebrates were more affected than phytoplankton, and the most sensitive endpoint detected in the present project was the fertilisation of sea urchin eggs, which were negatively affected at a sample dilution of 1 : 1,000,000. Dilutions of 1: 100,000 were harmful to early development of several of the tested species, including mussels, polychaetes, and crustaceans. The observed effects at these low concentrations of EGCS effluent were reduced egg production, and deformations and abnormal development of the larvae of the species. The ecotoxicological data produced in the EMERGE project were used to derive Predicted No Effect Concentration values. Corresponding modelling studies revealed that the EGCS effluent can be considered as a single entity for 2-10 days from the time of discharge, depending on the environmental conditions like sea currents, winds, and temperature. Area 10-30 km outside the shipping lanes will be prone to contaminant concentrations corresponding to 1 : 1,000,000 dilution which was deemed harmful for most sensitive endpoints of WET experiments. Studies for the Saronikos Gulf (Aegean Sea) revealed that the EGCS effluent dilution rate exceeded the 1 : 1,000,000 ratio 70% of the time at a distance of about 10 km from the port. This was also observed for 15% of the time within a band of 10 km wide along the shipping lane extending 500 km away from the port of Piraeus. When mortality of adult specimens of one of the species (copepod Acartia tonsa) was used as an endpoint it was found to be 3-4 orders of magnitude less sensitive to EGCS effluent than early life stage endpoints like fertilisation of eggs and larval development. Mortality of Acartia tonsa is commonly used in standard protocols for ecotoxicological studies, but our data hence shows that it seriously underestimates the ecologically relevant toxicity of the effluent. The same is true for two other commonly used and recommended endpoints, phytoplankton growth and inhibition of bioluminescence in marine bacteria. Significant toxic effects were reached only after addition of 20-40% effluent. A marine environmental risk assessment was performed for the Öresund region for baseline year 2018, where Predicted Environmental Concentrations (PECs) of open loop effluent discharge water were compared to the PNEC value. The results showed modelled concentrations of open loop effluent in large areas to be two to three orders of magnitude higher than the derived PNEC value, yielding a Risk Characterisation Ratio of 500-5000, which indicates significant environmental risk. Further, it should be noted that between 2018-2022 the number of EGCS vessels more than quadrupled in the area from 178 to 781. In this work, the EGCS discharges of the fleet in the Baltic Sea, North Sea, the English Channel, and the Mediterranean Sea area were studied in detail. The assessments of impacts described in this document were performed using a baseline year 2018 and future scenarios. These were made for the year 2050, based on different projections of transport volumes, also considering the fuel efficiency requirements and ship size developments. From the eight scenarios developed, two extremes were chosen for impact studies which illustrate the differences between a very high EGCS usage and a future without the need for EGCS while still compliant to IMO initial GHG strategy. The scenario without EGCS leads to 50% reduction of GHG emissions using low sulfur fuels, LNG, and methanol. For the high EGCS adoption scenario in 2050, about a third of the fleet sailing the studied sea areas would use EGCS and effluent discharge volumes would be increased tenfold for the Baltic Sea and hundredfold for the Mediterranean Sea when compared to 2018 baseline discharges. Some of the tested species, mainly the copepods, have a central position in pelagic food webs as they feed on phytoplankton and are themselves the main staple food for most fish larvae and for some species of adult fish, e.g., herring. The direct effect of the EGSE on invertebrates will therefore have an important indirect effect on the fish feeding on them. Effects are greatest in and near shipping lanes. Many important shipping lanes run close to shore and archipelago areas, and this also puts the sensitive shallow water coastal ecosystems at risk. It should be noted that no studies on sub-lethal effects of early 19 life stages in fish were included in the EMERGE project, nor are there any available data on this in the scientific literature. The direct toxic effects on fish at the expected concentrations of EGCS effluent are therefore largely unknown. According to the regional modelling studies, some of the contaminants will end up in sediments along the coastlines and archipelagos. The documentation of the complex chemical composition of EGCS effluent is in sharp contrast to the present legislation on threshold levels for content in EGCS effluent discharged from ships, which includes but a few PAHs, pH, and turbidity. Traditional assessments of PAHs in environmental and marine samples focus only on the U.S. Environmental Protection Agency (EPA) list of 16 priority PAHs, which includes only parent PAHs. Considering the complex PAHs assemblages and the importance of other related compounds, it is important to extend the EPA list to include alkyl-PAHs to obtain a representative monitoring of EGCS effluent and to assess the impact of its discharges into the marine environment. An economic evaluation of the installation and operational costs of EGCS was conducted noting the historical fuel price differences of high and low sulfur fuels. Equipment types, installation dates and annual fuel consumption from global simulations indicated that 51% of the global EGCS fleet had already reached break-even by the end of 2022, resulting in a summarised profit of 4.7 billion €2019. Within five years after the initial installation, more than 95% of the ships with open loop EGCS reach break-even. The pollutant loads from shipping come both through atmospheric deposition and direct discharges. This underlines the need of minimising the release of contaminants by using fuels which reduce the air emissions of harmful components without creating new pollution loads through discharges. Continued use of EGCS and high sulfur fossil fuels will delay the transition to more sustainable options. The investments made on EGCS enable ships to continue using fossil fuels instead of transitioning away from them as soon as possible as agreed in the 2023 Dubai Climate Change conference. Continued carriage of residual fuels also increases the risk of dire environmental consequences whenever accidental releases of oil to the sea occur.