A Comparison of Skyline Harvesting Costs for Alternative Commercial Thinning Prescriptions

Silvicultural treatments, fire, and insect outbreaks are the primary disturbance events currently affecting forests in the Sierra Nevada Mountains of California, a region where plants and wildlife are highly adapted to a frequent-fire disturbance regime that has been suppressed for decades. Although the effects of both fire and silviculture on wildlife have been studied by many, there are few studies that directly compare their long-term effects on wildlife communities. We conducted avian point counts from 2010 to 2019 at 1987 in situ field survey locations across eight national forests and collected fire and silvicultural treatment data from 1987 to 2016, resulting in a 20-year post-disturbance chronosequence. We evaluated two categories of fire severity in comparison to silvicultural management (largely pre-commercial and commercial thinning treatments) as well as undisturbed locations to model their influences on abundances of 71 breeding bird species. More species (48% of the community) reached peak abundance at moderate-high-severity-fire locations than at low-severity fire (8%), silvicultural management (16%), or undisturbed (13%) locations. Total community abundance was highest in undisturbed dense forests as well as in the first few years after silvicultural management and lowest in the first few years after moderate-high-severity fire, then abundance in all types of disturbed habitats was similar by 10 years after disturbance. Even though the total community abundance was relatively low in moderate-high-severity-fire habitats, species diversity was the highest. Moderate-high-severity fire supported a unique portion of the avian community, while low-severity fire and silvicultural management were relatively similar. We conclude that a significant portion of the bird community in the Sierra Nevada region is dependent on moderate-high-severity fire and thus recommend that a prescribed and managed wildfire program that incorporates a variety of fire effects will best maintain biodiversity in this region.

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Effects of commercial thinning on site occupancy and habitat use by spruce grouse in boreal Quebec

Canadian Journal of Forest Research ◽

10.1139/x10-226 ◽

2011 ◽

Vol 41 (3) ◽

pp. 501-508 ◽

Cited By ~ 9

Author(s):

Ambroise Lycke ◽

Louis Imbeau ◽

Pierre Drapeau

Keyword(s):

Habitat Use ◽

Boreal Forest ◽

Breeding Season ◽

Vegetation Cover ◽

Forest Cover ◽

Site Occupancy ◽

Lower Proportion ◽

Large Mammals ◽

Dense Vegetation ◽

Commercial Thinning

Partial cuts are increasingly proposed to maintain habitats for species negatively affected by clearcutting, even if their benefits on nonpasserine birds and large mammals are still poorly documented. Our main objective was to evaluate effects of commercial thinning (CT) on spruce grouse ( Falcipennis canadensis L.), a game bird of the boreal forest. Because this species is known to be associated with a dense vegetation cover, we hypothesized that habitat use would be lower in treated sites. In spring 2006, we evaluated site occupancy in 94 forest stands (50 CT and 44 uncut stands) in Quebec by visiting each on three occasions during the breeding season (March–May). Additionally, during the molting period (May–July), we used radiotelemetry to monitor habitat use by 19 males. As compared with uncut stands, results show that a lower proportion of CTs were used in spring (39% versus 60%, after accounting for detection). During the molting period, CTs were also used less than expected according to their availability. The significant reduction of lateral and vertical forest cover in CT may explain these results. We conclude that even if CT is perceived beneficial for wildlife, it does not completely fulfill the needs of species associated with dense understory vegetation, such as spruce grouse.

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Two prototypes for medium rotation forestry harvesting

Journal of Agricultural Engineering ◽

10.4081/jae.2013.363 ◽

2013 ◽

Vol 44 (2s) ◽

Author(s):

L. Pari ◽

V. Civitarese ◽

A. Del Giudice ◽

A. Scarfone

Keyword(s):

The Self ◽

Energy Crop ◽

High Yield ◽

Working Capacity ◽

Dynamic Phase ◽

Static Phase ◽

Area Unit ◽

Harvesting Costs ◽

Cutting System

Five years old poplar (Populus spp.) plantation represents an interesting model of productivity. The most attractive characteristics of this energy crop are the handling flexibility, the high yield of biomass per area unit and the good quality of the chips obtainable. The mechanical harvesting of five-years old poplar plantations requires the use of specialized forest machineries such as harvester, feller, forwarder and chipper. Usually, after felling, the working phases consist of extraction, stacking and chipping. Generally, the last one is carried out in a “static phase”, where the product is taken from staked logs by using a hydraulic arm having a gripper that feed the chipping machine. In order to introduce technological innovations for the medium rotation forestry harvesting, the Consiglio per la Ricerca e la sperimentazione in Agricoltura, Unità di ricerca per l’Ingegneria agraria (CRAING) of Monterotondo (Rome, Italy) has developed a five years poplar cutwindrower and a self-propelled chipper equipped with a pick up system. The prototype of cut-windrower is a semi-trailed machine powered by a 95 kW tractor (at least). It mounts a cutting system and a double pincer with variable positioning. During the cutting phase the plant is grasped by the double pincer which conveys and unloads the stem along the inter-row. The trees are placed parallel to the progress of the tractor, but oriented in the opposite direction. The biomass windrowed is then chipped in a dynamic phase directly from the inter row using the self-propelled chipper equipped with the pick-up head. In the first tests, the cut-windrower has reached an operative working capacity of 0.22 ha h-1, with an operative production of 44 t h-1. On the other hand, the self-propelled chipper has showed an operative working capacity equal to 0.18 ha h-1, and an operative production of 35 t h-1 about. Both machines have shown good quality of the work performed and the results obtained indicates that the work phases could be simplified in order to reduce both the time of use and the harvesting costs.

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Impact of Distance between Strip Roads on Productivity and Costs of a Forwarder in Commercial Thinning of Pinus Taeda Stands

Croatian journal of forest engineering ◽

10.5552/crojfe.2020.592 ◽

2020 ◽

Vol 41 (2) ◽

pp. 243-249

Author(s):

Oscar Manuel de Jesús Vera Cabral ◽

Eduardo da Silva Lopes ◽

Carla Krulikowski Rodrigues ◽

Afonso Figueiredo Filho

Keyword(s):

Pinus Taeda ◽

Value Added ◽

Wood Products ◽

Production Costs ◽

Working Cycle ◽

Time Motion ◽

Commercial Thinning ◽

Selective Harvest ◽

Thinning Operations ◽

The Impact

Demand for higher value-added wood products stimulates research for new, mainly mechanized, thinning operations in order to increase productivity and reduce production costs. In this context, the aim of this study was to evaluate the impact of distance between strip roads on forwarder productivity and costs of thinning operations in Pinus taeda stands. The study was carried out in 10-year-old Pinus taeda stands located in Parana State, Brazil. Two thinning methods were evaluated: (1) TH5: systematic harvest in every fifth tree row and selective harvest in adjacent rows; and (2) TH7: systematic harvest in every seventh tree row and selective harvest in adjacent rows. Working cycle times, productivity and costs were determined through a time-motion study of the forwarder. The additional variables evaluated were wood assortments (industrial wood and energy wood) and extraction distances (50, 100, 150 and 200 m), and mean values were compared between thinning methods using t tests for independent samples (α=0.05). Loading and unloading elements consumed the most time in the working cycle, with lower participation time in TH7 due to greater availability of logs along the strip roads (higher pile volumes), influencing total cycle time up to the mean distance of 150 m for both assortments. TH7 consequently showed 6% higher productivity, its energy yield was 5.3% lower and its production cost was 3.0% lower.

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Response of Sitka spruce and western hemlock to commercial thinning.

10.2737/pnw-rp-334 ◽

1985 ◽

Author(s):

Joseph N. Graham ◽

John F. Bell ◽

Francis R. Herman

Keyword(s):

Sitka Spruce ◽

Western Hemlock ◽

Commercial Thinning

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An evaluation of harvesting costs in present and planned operations: case study—Waston District of Mazandaran Wood and Paper Industries

Journal of Forestry Research ◽

10.1007/s11676-017-0435-2 ◽

2017 ◽

Vol 29 (1) ◽

pp. 215-220

Author(s):

Majid Lotfalian ◽

Mohammad Ali Akbari Gorji ◽

Seyed Ataollah Hoseini ◽

Maryam Kazemi

Keyword(s):

Harvesting Costs

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Advances in soilless culture strawberry production

Burleigh Dodds Series in Agricultural Science - Advances in horticultural soilless culture ◽

10.19103/as.2020.0076.17 ◽

2021 ◽

pp. 381-400

Author(s):

Mike Nichols ◽

Keyword(s):

Popular Media ◽

Soilless Culture ◽

Plant Environment ◽

Future Production ◽

Solid Media ◽

The World ◽

Media Systems ◽

Viable System ◽

Harvesting Costs ◽

Robotic Harvesting

The majority of strawberries produced in the world are grown in the open field, and only in the past 50 years has protected cropping become established as a commercially viable system. Soilless culture (hydroponics) is an important component of this form of intensive production because it enables the strawberry crop to be grown above the ground (table top system) which can provides an improved root environment, nutrition and irrigation and at the same time easier fruit harvesting. Solid media systems predominate over liquid based systems with peat and coir being the most popular media. Future production appears to be increasingly towards year round production by the improved control of the plant environment, combined with reducing harvesting costs by robotic harvesting.

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Developing Optimal Commercial Thinning Prescriptions: A New Graphical Approach

Northern Journal of Applied Forestry ◽

10.1093/njaf/22.3.170 ◽

2005 ◽

Vol 22 (3) ◽

pp. 170-174

Author(s):

KaDonna C. Randolph ◽

Robert S. Seymour ◽

Robert G. Wagner

Keyword(s):

Net Present Value ◽

Biological Response ◽

Stand Density ◽

Annual Increment ◽

Management Objectives ◽

Commercial Thinning ◽

Stand Density Management ◽

Growth Simulator ◽

Arcview Gis ◽

Final Harvest

Abstract We describe an alternative approach to the traditional stand-density management diagrams and stocking guides for determining optimum commercial thinning prescriptions. Predictions from a stand-growth simulator are incorporated into multiple nomograms that graphically display postthinning responses of various financial and biological response variables (mean annual increment, piece size, final harvest cost, total wood cost, and net present value). A customized ArcView GIS computer interface (ThinME) displays multiple nomograms and serves as a tool for forest managers to balance a variety of competing objectives when developing commercial thinning prescriptions. ThinME provides a means to evaluate simultaneously three key questions about commercial thinning: (1) When should thinning occur? (2) How much should be removed? and (3) When should the final harvest occur, to satisfy a given set of management objectives? North. J. Appl. For. 22(3):170 –174.

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Tree Size and Species, Stand Volume, and Tract Size: Effects on Southern Harvesting Costs

Southern Journal of Applied Forestry ◽

10.1093/sjaf/13.3.145 ◽

1989 ◽

Vol 13 (3) ◽

pp. 145-152 ◽

Cited By ~ 3

Author(s):

Frederick W. Cubbage ◽

W. Dale Greene ◽

John P. Lyon

Keyword(s):

Tree Species ◽

Size Effects ◽

Timber Harvesting ◽

Tree Size ◽

Labor Costs ◽

Production Rates ◽

Stand Volume ◽

Factors Affecting ◽

Harvesting Costs ◽

Significant Factors

Abstract Timber harvesting production rates and equipment and labor costs were used to estimate average logging costs for a variety of tract volumes and sizes, stand structures, and tree species. Average costs were estimated for conventional logging systems typical in the South. Regression analysiswas used to identify significant factors affecting the costs for each system. Highly mechanized systems were generally cheapest for harvesting southern pines, but were not much cheaper for harvesting hardwoods. Hardwoods were substantially more expensive to harvest, as were tracts of lessthan 250 cords in total volume. South. J. Appl. For. 13(3):145-152.

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