scholarly journals Effect of Day or Night and Cumulative Shift Time on the Frequency of Tree Damage during CTL Harvesting in Various Stand Conditions

Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 743 ◽  
Author(s):  
Mariusz Bembenek ◽  
Petros A. Tsioras ◽  
Zbigniew Karaszewski ◽  
Bogna Zawieja ◽  
Ewa Bakinowska ◽  
...  

Thinning is one of the most important tools of forest management, although thinning operations require the use of machines which ultimately cause damage to the remaining stand. The level of damage largely depends on the human factor, and a tired, less focused operator will create more injuries in the forest. With this in mind, the objectives of this research were to find out whether the probability of tree damage caused by an operator is also affected by: (1) the part of the day (dawn/day/dusk/night), and (2) the cumulative shift time. The research was carried out in pure pine stands of different ages, density and thinning intensities. Sample plots were selected that had an increasing number of trees per hectare and growing thinning intensities were applied. The same Komatsu 931.1 harvester was used for the thinning operations in each stand. In all the age classes combined, 5.41% of the remaining trees were wounded. There was a significant influence of the part of the day on the percentage of damaged trees, which was positively correlated with the cumulative shift time. Stand conditions, such as age class and stand density, as well as thinning characteristics—thinning intensity, number of harvested trees and productivity—have different effects on the distribution of damage intensity and on probability. The results may improve the planning of operators’ work shifts in forests of various ages and densities, allowing harvester productivity to be maintained while at the same time inflicting the lowest possible level of damage.

1943 ◽  
Vol 19 (2) ◽  
pp. 108-118 ◽  
Author(s):  
G. A. Mulloy

The findings of L. H. Reineke that a number of trees per acre on average diameter plotted on double logarithmic paper provides a straight line graph whose slope remains constant for all sites, age-classes and most species are checked against twenty years' record of sample plot data for red and white pine stands. The use of stand density index based on this principle in thinning technique and in forest management is developed.The practical application of these findings is shown. All that is necessary is to estimate the average diameter of the stand. The spacing for optimum development is then fixed.


Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 975 ◽  
Author(s):  
Ximena Herrera-Alvarez ◽  
Juan A. Blanco ◽  
J. Bosco Imbert ◽  
Willin Alvarez ◽  
Gabriela Rivadeneira-Barba

Research Highlights: Thinning and tree species alter the forest floor microclimate by modifying canopy cover, radiation, wind, and humidity. Thus, forest management can directly influence the edaphic mesofauna responsible for decomposing coarse woody debris (CWD). Background and Objectives: This research was carried out in the Southwestern Pyrenees Mountains (Northern Spain) and aimed to determine the influence of forest thinning and canopy type (pure Pinus sylvestris L. or a mix of P. sylvestris and Fagus sylvatica L.) on CWD colonization by edaphic fauna. Materials and Methods: CWD samples were collected belonging to intermediate and advanced decomposition stages, approximately 10 cm long and 5 cm in diameter. Using a design of three thinning intensities (0%, 20%, and 40% of basal area removed), with three replications per treatment (nine plots in total), four samples were taken per plot (two per canopy type) to reach 36 samples in total. Meso- and macrofauna were extracted from CWD samples with Berlese–Tullgren funnels, and individuals were counted and identified. Results: 19 taxonomic groups were recorded, the most abundant being the mesofauna (mites and Collembola). Mixed canopy type had a significant positive influence on richness, whereas advanced decay class had a positive significant influence on total abundance and richness. In addition, there were non-significant decreasing trends in richness and abundance with increasing thinning intensity. However, interactions among thinning intensity, canopy type, and decay class significantly affected mesofauna. Furthermore, some taxonomic groups showed differential responses to canopy type. CWD water content was positively correlated with total invertebrate abundance and some taxonomic groups. Our results suggest that stand composition has the potential to directly affect invertebrate communities in CWD, whereas stand density influence is indirect and mostly realized through changes in CWD moisture. As mesofauna is related to CWD decomposition rates, these effects should be accounted for when planning forest management transition from pure to mixed forests.


2003 ◽  
Vol 18 (1) ◽  
pp. 15-21
Author(s):  
Kevin L. O'Hara ◽  
Cassandra L. Kollenberg

Abstract Patterns of leaf area distribution in multiaged lodgepole pine stands were used to develop a stocking control model. This model, the Lodgepole Pine–Multi-aged Stocking Control Model (LPP–MASAM), allows the user to design multiaged stand structures for implementation in lodgepole pine stands in the northern Rocky Mountains. The model is suitable for designing stands with two or three age classes, or two canopy strata. These multiaged stands represent a management alternative to even-aged stands where vigorous stands exist and windthrow is not a major constraint. The model requires the user to divide stands into components such as age classes or canopy strata that are the basic unit for growing space allocation. Growing space is represented by leaf area index. Stocking regimes are assessed over a single cutting cycle using projections of volume increment, stand density and tree vigor. Example stocking regimes are provided as are internet links to access the model. West. J. Appl. For. 18(1):15–21.


2003 ◽  
Vol 18 (1) ◽  
pp. 5-14 ◽  
Author(s):  
Kevin L. O'Hara ◽  
Narayanan I. Valappil ◽  
Linda M. Nagel

Abstract Multi-aged management of forest stands in western North America is a viable option in many areas where traditional even-aged management is undesirable. Procedures for guiding stocking control for multi-aged ponderosa pine (Pinus ponderosa) stands were developed using the PP-MASAM model (Ponderosa Pine–Multi-aged Stocking Assessment Model). These procedures allow the user to divide stands into components such as age classes or canopy strata that are the basic unit for growing space allocation. Growing space is represented by leaf area index. Stocking regimes are assessed over a single cutting cycle through projections of volume increment, stand density, and tree vigor. The approach is flexible for guiding stocking in ponderosa pine stands for diverse structural objectives including retention of ancient trees, development of presettlement structures, stands with two to four age classes, or stands with short or long cutting cycles. Example stocking regimes and internet links are provided to access the model. West. J. Appl. For. 18(1):5–14.


2002 ◽  
Vol 78 (4) ◽  
pp. 539-549 ◽  
Author(s):  
Paul D Anderson ◽  
John C Zasada ◽  
Glen W Erickson ◽  
Zigmond A Zasada

A white pine (Pinus strobus L.) stand at the western margin of the species range, approximately 125 years of age at present, was thinned in 1953 from 33.5 m2 ha-1 to target residual basal areas of 18.4, 23.0, 27.5, and 32.1 m2 ha-1 . Repeated measurement over the following 43-years indicated that the greatest total volume production and the greatest number of large diameter trees occurred in the unit of highest residual density. Over time, the distribution of stems was predominantly random although mortality between 1979 and 1996 resulted in a tendency for clumping in the 23.0 and 27.5 m2 ha-1 treatments. DNA analysis indicated that thinning intensity had little effect on the genetic diversity of residual white pine. This study suggests that mature white pine stands in northern Minnesota may be managed at relatively high densities without loss of productivity. However, regardless of overstory density, there was little or no white pine regeneration occurring in this stand. Key words: thinning, growth, genetic diversity, molecular markers, spatial pattern, regeneration


Author(s):  
Meng Na ◽  
Xiaoyang Sun ◽  
Yandong Zhang ◽  
Zhihu Sun ◽  
Johannes Rousk

AbstractSoil carbon (C) reservoirs held in forests play a significant role in the global C cycle. However, harvesting natural forests tend to lead to soil C loss, which can be countered by the establishment of plantations after clear cutting. Therefore, there is a need to determine how forest management can affect soil C sequestration. The management of stand density could provide an effective tool to control soil C sequestration, yet how stand density influences soil C remains an open question. To address this question, we investigated soil C storage in 8-year pure hybrid larch (Larix spp.) plantations with three densities (2000 trees ha−1, 3300 trees ha−1 and 4400 trees ha−1), established following the harvesting of secondary mixed natural forest. We found that soil C storage increased with higher tree density, which mainly correlated with increases of dissolved organic C as well as litter and root C input. In addition, soil respiration decreased with higher tree density during the most productive periods of warm and moist conditions. The reduced SOM decomposition suggested by lowered respiration was also corroborated with reduced levels of plant litter decomposition. The stimulated inputs and reduced exports of C from the forest floor resulted in a 40% higher soil C stock in high- compared to low-density forests within 8 years after plantation, providing effective advice for forest management to promote soil C sequestration in ecosystems.


2009 ◽  
Vol 51 (1) ◽  
pp. 40-48
Author(s):  
Toomas Frey

Stand structure links up canopy processes and forest management Above- and belowground biomass and net primary production (Pn) of a maturing Norway spruce (Picea abies (L.) Karst.) forest (80 years old) established on brown soil in central Estonia were 227, 50 and 19.3 Mg ha correspondingly. Stand structure is determined mostly by mean height and stand density, used widely in forestry, but both are difficult to measure with high precision in respect of canopy processes in individual trees. However, trunk form quotient (q2) and proportion of living crown in relation to tree height are useful parameters allowing describe stand structure tree by tree. Based on 7 model trees, leaf unit mass assimilation activity and total biomass respiration per unit mass were determined graphically as mean values for the whole tree growth during 80 years of age. There are still several possible approaches not used carefully enough to integrate experimental work at instrumented towers with actual forestry measurement. Dependence of physiological characteristics on individual tree parameters is the missing link between canopy processes and forest management.


Author(s):  
Kezang Choden ◽  
Bhagat Suberi ◽  
Purna Chettri

Forests are natural carbon reservoirs that play an important role in the global carbon cycle for storing large quantities of carbon in vegetation and soils. Carbon stored in pool helps in mitigating climate change by carbon sequestration. The vulnerable countries to changing climate such as Bhutan, Nepal, and India require a full understanding of carbon dynamics as well as baseline data on carbon stock potential to mitigate anticipated risks and vulnerabilities (RVs) through climate change. The scope of such RVs are trans boundary in nature, however, the comparative studies at regional scale are still scanty. Therefore, the aim of this review is to assess the carbon stock potentials of selected forest types in the eastern Himalayan area, with an emphasis on Bhutan, India, and Nepal. This review paper is based on published articles, information from websites and considerable data from National forestry reports of India and Bhutan; emphasizing on aboveground biomass and soil organic carbon stock. The review showed that carbon stock potential is highly dependent on stand density, above-ground biomass, species richness and forest types. The sub-tropical forest was found to have larger carbon capacity and sequestration potential. SOC concentration and tree biomass stocks were significantly higher at the high altitude where there is less human disturbance. In general, forest coverage has increased compare to previous year in Bhutan, India and Nepal which ultimately leads to higher carbon stock potential. It is mainly due to strong policies and different strategies for conservation of forest management have reduced mass destruction despite a growing population. Despite the rules, deforestation continues to occur at various scales. However, it can be stated that the government and citizens are working hard to increase carbon stock potential, mostly through afforestation and community forest creation. In addition, it is recommended to practice sustainable forest management, regulated and planned cutting of trees and proper forest products utilization.


2007 ◽  
Vol 24 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Matthew J. Duveneck ◽  
William A. Patterson

Abstract Destructive sampling of 31 pitch pine (Pinus rigida P. Mill) trees ranging in dbh from 2.7 to 42.5 cm and in height from 4.1 to 23.8 m provided a complete inventory of needles and small-diameter branch weights used to characterize canopy fuels to predict fire behavior in pitch pine stands. Regression equations using dbh as an independent variable predict canopy bulk density with an r2 > 0.93. The results provide managers with a method of evaluating the effectiveness of thinning operations in reducing crown fire potential in well-stocked stands. To demonstrate the application of the method, we calculated the wind speed (Crowning Index [CI]) needed to sustain an active crown fire in thinned and unthinned pitch pine stands in Montague, Massachusetts. Thinning to 2.8 m2/ha basal area increased the CI from 34 to 98 km/hour.


2011 ◽  
Vol 28 (2) ◽  
pp. 84-91 ◽  
Author(s):  
Matthew B. Russell ◽  
Aaron R. Weiskittel

Abstract An extensive statewide data set for seven conifer and eight hardwood species commonly occurring in Maine was used in the development of maximum and largest crown width equations. To establish the characteristics of open-grown trees, quantile regression was used to estimate the biological maximum crown width for a species at a given diameter. To predict crown widths of trees in forested settings, a constrained nonlinear equation was used, using the predicted maximum crown width, tree diameter, and crown ratio. The models performed well across the wide range of stand conditions present in the data set and improved predictions over the currently used crown width equations for most species (reduction of mean absolute error ranged from 1 to 23%). In general, predictions of largest crown width were not greatly improved with the inclusion of crown ratio, and there was a high amount of unexplained variation for shade-tolerant hardwood species, such as American beech (Fagus grandifolia) and sugar maple (Acer saccharum). The equations presented herein can be used in examining tree crown profiles, computing measurements of stand density, and investigating canopy dynamics for species common to the forests of Maine.


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