scholarly journals Evaluating harvest costs and profit of commercial thinnings in softwood stands in west-central Maine: A case study

2015 ◽  
Vol 91 (02) ◽  
pp. 150-160 ◽  
Author(s):  
Patrick Hiesl ◽  
Jeffrey G. Benjamin ◽  
Brian E. Roth
Keyword(s):  
Block Design ◽  
Unit Cost ◽  
Small Diameter ◽  
Wood Chip ◽  
Basal Area ◽  
Stand Density ◽  
Cost Comparison ◽  
Positive Effects ◽  
Commercial Thinning ◽  
West Central

Precommercial thinning (PCT) is a common silvicultural treatment in the management of young conifer forests. The positive effects of PCT on tree growth are well documented, however, there have been few operational studies of thinning productivity associated with later harvests in such stands and associated cost comparison with high-density, small-diameter stands. In the winters of 2012/2013 and 2013/2014 a long-term herbicide and PCT study in west-central Maine was commercially thinned using cut-to-length (CTL) and whole-tree (WT) harvesting systems in PCT and non-PCT stands, respectively. Thinning prescriptions consisted of three nominal removal intensities (33%, 50%, and 66% of the standing softwood volume) in a randomized block design with three to four replications. Stand density, basal area, hardwood content, and removal intensity were not significant in explaining variation in harvester and feller-buncher productivity. An analysis of unit cost of production indicated that wood chip production using a WT system in non-PCT stands is less costly than the production of roundwood using a CTL system in PCT stands. Profit, however, is similar for products harvested by either system. Our conclusion is that the WT system used in the study is economically feasible to treat highdensity, small-diameter stands in a commercial thinning.

scholarly journals Effects of Thinning on Dynamics and Drought Resistance of Aspen-White Spruce Mixtures: Results From Two Study Sites in Saskatchewan

2021 ◽  
Vol 3 ◽  
Author(s):  
Philip G. Comeau
Keyword(s):  
Drought Stress ◽  
Drought Resistance ◽  
Basal Area ◽  
White Spruce ◽  
Tree Size ◽  
Average Height ◽  
Negative Effects ◽  
Positive Effects ◽  
Commercial Thinning ◽  
Study Sites

Drought stress associated with warm temperatures is causing increased mortality and reduced growth of trees in drier portions of the boreal forests of western Canada with both warming and drought expected to increase over the coming decades. While thinning is often shown to reduce drought stress, there is little information on its effects in stands comprised of mixtures of trembling aspen and white spruce that are common in the forests of this region. This study examined effects of pre-commercial thinning on aspen and spruce growth, response to drought stress, and stand dynamics for two study sites located in Saskatchewan, Canada. In unthinned plots aspen densities declined from initial densities of 40,000 to 200,000 trees ha−1 to 2,639 trees ha−1 at age 26. Twenty-one years after thinning (i.e., at age 26) diameter of aspen and spruce had increased, with largest trees being found at the lowest aspen densities (200 aspen ha−1 for aspen and 0 aspen ha−1 for spruce). Aspen density affected average height but not height of aspen top height trees. Spruce height decreased significantly with increasing aspen density. Crown width and live crown ratio of both aspen and spruce declined with increasing aspen density. Data from cores collected from aspen and spruce indicate significant positive effects of tree size (basal area at beginning of the year), and CMI (Climate Moisture Index) on basal area increment of both aspen and spruce while increasing aspen basal area (m2ha−1) had negative effects on aspen and spruce growth. Increasing tree size (basal area) and aspen competition (basal area ha−1) both had negative effects on drought resistance and resilience for both aspen and spruce. Yield projections provided by the Mixedwood Growth Model (MGM) suggest that the mixture of 1,500 aspen ha−1 and 1,000 spruce ha−1 has the potential to provide a 23% increase in total mean annual increment (MAI) with a single harvest at age 100, compared to unthinned aspen stands, but with a 44% reduction in spruce MAI compared to pure spruce stands. Thinning of aspen to densities below 4,000 trees ha−1 at age 5 resulted in reduced aspen yields but increased spruce yields.

scholarly journals Thinning Ponderosa Pine Affected by Armillaria Root Disease: 40 Years of Growth and Mortality on an Infected Site in Central Oregon

2009 ◽  
Vol 24 (2) ◽  
pp. 88-94 ◽  
Author(s):  
Gregory M. Filip ◽  
Stephen A. Fitzgerald ◽  
Kristen L. Chadwick ◽  
Timothy A. Max
Keyword(s):  
Ponderosa Pine ◽  
Tree Mortality ◽  
Basal Area ◽  
Stand Density ◽  
Root Disease ◽  
Precommercial Thinning ◽  
Fungal Host ◽  
Commercial Thinning ◽  
Armillaria Root Disease ◽  
Stand Density Index

Abstract Portions of a 30-year-old stand of ponderosa pine were precommercially thinned in 1966 and commercially thinned in 2000 at age 64 years to determine the effects of thinning from below on tree growth and mortality caused by Armillaria root disease in central Oregon. Thirty years after precommercial thinning, leave-tree mortality was significantly less in thinned plots than in unthinned plots, but leave-treeߝdiameter growth was not significantly increased by thinning. Leave-tree basal area (BA) per acre growth, however, was significantly greater in thinned plots.In 2007 at age 71 years, 7 years after commercial thinning of the same plots that were precommercially thinned in 1966, leave-tree mortality was less in thinned plots than in unthinned plots, but more time probably is necessary to adequately assess Armillaria-caused mortality after commercial thinning. Both tree diameter and BA growth were significantly increased by commercial thinning. Hypotheses on fungal-host dynamics are discussed, and recommendations for multiple thinning based on stand density index are given.

scholarly journals Long-Term Effects of Drainage, Bedding, and Fertilization on Growth of Loblolly Pine (Pinus taeda L.) in the Coastal Plain of Virginia

2005 ◽  
Vol 29 (4) ◽  
pp. 205-214 ◽  
Author(s):  
Thomas R. Fox ◽  
Kevin H. Kyle ◽  
Lisa J. Andrews ◽  
W. Michael Aust ◽  
James A. Burger ◽  
...  
Keyword(s):  
Loblolly Pine ◽  
Coastal Plain ◽  
Growth Response ◽  
Block Design ◽  
Basal Area ◽  
Stand Density ◽  
Site Preparation ◽  
The Other ◽  
Long Term Effects ◽  
Lime Treatment

Abstract A site preparation study was established in 1968 at three locations in the Coastal Plain of Virginia. Three treatments were installed in a randomized complete block design: (1) chop, (2) bed, and (3) ditch. In 1978, four fertilizer treatments were superimposed on the site preparation study: (1) check, (2) phosphorus (P) only, (3) P + nitrogen (N), and (4) P + N + lime, converting it into a split-plot design. At age 33 years, height of the dominant loblolly pine in the ditch treatment was significantly greater than in the other site preparation treatments. However, there were no differences in stand density, diameter at breast height (dbh), basal area, or volume because of site preparation. This contrasts with the data collected at age 21 years, when total volume in both the bed treatment and the ditch treatment was greater than in the chop treatment. Changes in water table depths through time were the probable cause for decreased response to bedding and ditching. There was a large response to fertilization through age 33 years in this study. The P + N + lime treatment had significantly greater dbh, basal area, and volume than the other fertilizer treatments, which significantly increased pine stumpage value. The size of the growth response was greater at age 33 years than it was at age 21 years. Soil and foliage analysis suggests that the sustained growth response at this site was due to the added Ca. South. J. Appl. For. 29(4):205–214.

The responses of black spruce growth to an increased proportion of aspen in mixed stands

2004 ◽  
Vol 34 (2) ◽  
pp. 405-416 ◽  
Author(s):  
Sonia Légaré ◽  
David Paré ◽  
Yves Bergeron
Keyword(s):  
Populus Tremuloides ◽  
Black Spruce ◽  
Basal Area ◽  
Stand Density ◽  
Mixed Stands ◽  
Stand Volume ◽  
Abiotic Conditions ◽  
Positive Effects ◽  
Dominant Height ◽  
The Relationship

In the southeastern boreal forest of Canada, the presence of mixed stands of black spruce (Picea mariana (Mill.) BSP) and trembling aspen (Populus tremuloides Michx.) growing in similar abiotic conditions offers the opportunity to study the influence of aspen on stand volume and spruce growth. A regression analysis performed on field data from the ministère des Ressources naturelles du Québec showed a significant relationship between the relative basal area of aspen (aspen relative basal area was determined by the ratio of aspen basal area to total basal area of the stand) and the total stand merchantable volume after accounting for stand density. However, the relationship between total black spruce volume and relative basal area of aspen was not significant, implying that the volume gain was, in fact, aspen fibre. The positive effects of aspen on black spruce DBH and height were only present when the proportion of aspen in the stand ranged between 0% and 41% of the total stand basal area. These results suggest that aspen uses a different niche than black spruce. Furthermore, the significant increase in black spruce dominant height along the aspen gradient suggests that aspen enhances soil fertility by its influence on nutrient availability. The management of mixed stands, which make up an important proportion on the landscape, offers an example as to how commercial management of the forest can be in agreement with ecosystem management.

INFLUENCE OF GREENHOUSE SHADING AND DIFFERENT NUTRIENT MANAGEMENT PRACTICES ON ALLEVIATING HEAT STRESS, IMPROVING PLANT NUTRIENTS STATUS, FLOWERING GROWTH AND YIELD OF TOMATO

2020 ◽  
Vol 51 (4) ◽  
pp. 1001-1014
Author(s):  
Sulaiman & Sadiq
Keyword(s):  
Heat Stress ◽  
Management Practices ◽  
Nutrient Management ◽  
Block Design ◽  
Nutrient Status ◽  
Growth And Yield ◽  
Reproductive Growth ◽  
Positive Effects ◽  
Nutrition Programs ◽  
The Impact

The experiment was conducted in a greenhouse during 2017 and 2018 growing seasons to evaluate the impact of the shading and various nutrition programs on mitigating heat stress, reducing the use of chemical minerals, improving the reproductive growth and yield of tomato plant. Split-plot within Randomized Complete Block Design (RCBD) with three replications was conducted in this study. Shading factor was allocated in the main plots and the nutrition programs distributed randomly in the subplots. Results indicate that shading resulted in the decrease of daytime temperature by 5.7˚C as an average for both seasons; thus a significant increasing was found in leaf contents of macro nutrients (Nitrogen, Phosphorous, and Potassium), and micro nutrients (Iron, Zinc and Boron), except the Iron content in 2018 growing season. Furthermore, shading improved significantly the reproductive growth and tomato yield. Among the plant nutrition programs, the integrated nutrient management (INM) including the application of organic substances, bio inoculum of AMF and 50% of the recommended dose of chemical fertilizers; lead to the enhancement of nutrients content, reproductive characteristics and plant yield. Generally, combination of both shading and INM showed positive effects on plants nutrient status and persisting balance on tomato flowering growth and fruits yield.

scholarly journals Irrigation Timing as a Practice of Effective Weed Management in Established Alfalfa (Medicago sativa L.) Crop

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 550
Author(s):  
Panagiotis Kanatas ◽  
Ioannis Gazoulis ◽  
Ilias Travlos
Keyword(s):  
Medicago Sativa ◽  
Weed Management ◽  
Cultural Practices ◽  
Block Design ◽  
Chenopodium Album ◽  
Stand Density ◽  
Climatic Conditions ◽  
Amaranthus Retroflexus ◽  
Forage Yield ◽  
Medicago Sativa L

Irrigation is an agronomic practice of major importance in alfalfa (Medicago sativa L), especially in the semiarid environments of Southern Europe. Field experimentation was conducted in Western Greece (2016–2018) to evaluate the effects of irrigation timing on weed presence, alfalfa yield performance, and forage quality. In a randomized complete block design (four replications), two cultivars (“Ypati 84” and “Hyliki”) were the main plots, while three irrigation timings were the subplots (split-plot). The irrigation timings were IT-1, IT-2, and IT-3, denoting irrigation 1 week before harvest, 1 week after harvest, and 2 weeks after harvest, respectively. IT-1 reduced Solanum nigrum L. density by 54% and 79% as compared to IT-3 and IT-2, respectively. Chenopodium album L. density was the highest under IT-2. IT-3 resulted in 41% lower Amaranthus retroflexus L. density in comparison to IT-2, while the lowest values were observed under IT-1. Stand density and stems·plant−1 varied between years (p ≤ 0.05). Mass·stem−1 and alfalfa forage yield were affected by the irrigation timings (p ≤ 0.001). Total weed density and forage yield were negatively correlated in both the second (R2 = 87.013%) and the fourth (R2 = 82.691%) harvests. IT-1 and IT-3 increased forage yield, leaf per stem ratio, and crude protein as compared to IT-2. Further research is required to utilize the use of cultural practices for weed management in perennial forages under different soil and climatic conditions.

scholarly journals Semiarid bunchgrasses accumulate molybdenum on alkaline copper mine tailings: assessing phytostabilization in the greenhouse

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Paul M. Antonelli ◽  
Matthew G. Coghill ◽  
Wendy C. Gardner ◽  
Lauchlan H. Fraser
Keyword(s):  
Mine Tailings ◽  
Soil Amendments ◽  
Block Design ◽  
Wood Chip ◽  
Biomass Accumulation ◽  
Shoot Biomass ◽  
Tissue Samples ◽  
Copper Mine ◽  
Copper Mine Tailings ◽  
Randomized Complete Block Design

AbstractPhytostabilization is the use of plants and soil amendments to physically stabilize and remediate contaminated mine wastes and to control wind and water erosion in semiarid environments. The aim of this study was to evaluate two native bunchgrass species’ (Pseudoroegneria spicata and Festuca campestris) biomass accumulation and metals uptake response to locally available soil amendments (compost, wood ash and wood chips) to determine their suitability for phytostabilization at an alkaline copper mine tailings site in British Columbia, Canada. In the greenhouse, bunchgrasses important as forage for livestock and wildlife were grown in tailings with various ash–compost–wood chip combinations and evaluated using a randomized complete block design with 13 treatments and 10 replicates. Plants were harvested after 90 d, and tissues were analyzed for root and shoot biomass. Tissue samples (n = 3) from three treatment subsets (ash, compost, blend) were selected for elemental analysis. Biomass increased with increasing compost applications, and the response was greatest for P. spicata. Shoot molybdenum exceeded the maximum tolerable level for cattle and was significantly higher when grasses were grown on the ash treatment (183–202 mg kg−1) compared to the others (19.7–58.3 mg kg−1). Translocation and root bioconcentration factors were highest on the ash treatment (2.53–12.5 and 1.75–7.96, respectively) compared to the other treatments (0.41–3.43 and 1.47–4.79, respectively) and indicate that both species are ‘accumulators.’ The findings suggest that these bunchgrasses were not ideal candidates for phytostabilization due to high shoot tissue molybdenum accumulation, but provide important considerations for mine restoration in semiarid grassland systems.

CLINICAL OUTCOME AND COST COMPARISON OF CARPAL TUNNEL WOUND CLOSURE WITH MONOCRYL® AND ETHILON®: A PROSPECTIVE STUDY

Hand Surgery ◽  
2013 ◽  
Vol 18 (02) ◽  
pp. 189-192 ◽  
Author(s):  
Anis Dosani ◽  
Sameer K. Khan ◽  
Sheila Gray ◽  
Steve Joseph ◽  
Ian A. Whittaker
Keyword(s):  
Carpal Tunnel ◽  
Wound Closure ◽  
Unit Cost ◽  
Cost Effective ◽  
Cost Comparison ◽  
Absorbable Suture ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
A Prospective Study

This prospective non-randomised two-cohort study compares the use of an absorbable suture (Poliglecrapone [Monocryl]: Group A) and a non-absorbable suture (Polyamide [Ethilon]: Group B) in wound closure after elective carpal tunnel decompression. The primary outcome was scar cosmesis as assessed by the Stonybrook Scar Evaluation Scale (SBSES); the financial cost of wound closure was compared as a secondary outocome. All fifty patients completed follow-up. At six weeks, there was no significant difference in the two groups regarding scar tenderness (p = 0.5), although residual swelling was more evident in the absorbable group (p = 0.2). The mean SBSES score at six weeks was 4.72 in Group A, and 4.8 in Group B (p = 0.3). The unit cost per closed wound of Monocryl was three times than Ethilon (p < 0.05). Ethilon is thus cost-effective without compromising the cosmetic outcome, and we recommend using this as the preferred suture for closure of carpal tunnel wounds.

Assessment of Biomass and Carbon Stock of planted teak forest in Terai region of Kumaun Himalaya, India

2018 ◽  
Vol 41 (4) ◽  
pp. 397-402
Author(s):  
Tanuja Gahlot ◽  
◽  
Prachi Joshi ◽  
Y.S. Rawat ◽  
◽  
...  
Keyword(s):  
Climate Change ◽  
Carbon Sequestration ◽  
Human Disturbance ◽  
Carbon Stock ◽  
Large Scale ◽  
Basal Area ◽  
Stand Density ◽  
Positive Contribution ◽  
Teak Plantation ◽  
Forest Division

The ability of forests in atmospheric carbon sequestration is increasingly gaining attention. Present study deals with the estimation of biomass and carbon stock of the teak plantation in the terai central forest division in Kumaun, Uttarakhand State of India. Very few scientific studies were done regarding the teak plantation and the estimation of its biomass in Kumaun. Therefore this study was carried out in this region to assess the role played by teak plantation in climate change. The information regarding the changes in pattern of carbon storage is vital and important because it can be used by government and policymakers to predict the deposit pattern for changing climate. Three sites i.e., Kamola block (Site I), Kamola beat (Site II) and East Gadappu beat (Site III) were selected for the study. Large scale variations in biomass and carbon stock were noted among all three sites. Site III (East Gadappu) showed the maximum biomass and carbon stock (297.03 tha-1 and 143.18 tha-1) followed by site I (Kamola block) (241.9 tha -1and 117.27 t ha-1) and site II ( Kamola beat ) (175.76 t ha-1and 85.79 t ha-1). Although stand density and total basal area of the forest showed almost similar value on all three sites, still the differences in biomass and carbon stock at all sites indicated the positive contribution of biodiversity as shown in the results and negative implications of human disturbance to the forest.

Technology and Effectiveness of Cast Iron Treatment by Gas Injection

2010 ◽  
Vol 457 ◽  
pp. 459-464
Author(s):  
Edis B. Ten
Keyword(s):  
Cast Iron ◽  
Gas Injection ◽  
Small Diameter ◽  
Multiple Use ◽  
Positive Effects ◽  
Injection Treatment ◽  
The Stability ◽  
Injection Technology ◽  
Stability Regime ◽  
Structure Stabilization

In this work the development of the technology and equipment for gas injection treatment of cast iron by inert gas (nitrogen) is presented. The equipment includes the plunging lance as a lined steel pipe with nozzles. The nozzles are thin channels, which are lined by ceramic tubes with small-diameter. The lance has a multiple use, as it has calibrated channel sizes, and provide the stability regime of gas injection treatment. The characteristic of the gas injection technology consists of blowing of melt by gas, which is injected into the liquid cast iron through thin jet with a speed near to the velocity of sound. In this case, the dispersion of gas jets in small-sized bubbles is reached, therefore the refining effectiveness increases. The gas injection treatment shows the promotion of casting properties, improvement of homogeneity and fineness of structure, stabilization or increasing of mechanical properties, decreasing of casting defectiveness. The positive effects of the gas injection treatment is the result of complex action of the injecting gas into the cast iron melt. Together with refining and homogenizing action at specified conditions, it offers the modifying and alloying effects also.

Sign in / Sign up

Export Citation Format

Share Document