Opportunities for making wood products from small diameter trees in Colorado

Abstract Southern pine stands have the potential to provide significant feedstocks for the growing biomass energy and biofuel markets. Although initial feedstocks likely will come from low-value small-diameter trees, understory vegetation, and slash, a sustainable and continuous supply of biomass is necessary to support and grow a wood bioenergy market. As long as solidwood products are more valuable, bioenergy production will not be the primary market for southern pine. A study exploring a dual-cropping system for southern pine bioenergy and solidwood products was begun in 1982 in Louisiana to determine the phosphorus (P) nutritional requirements of the system. Fertilization of 60 kg ha−1 of P was required to produce 90% of the maximum volume at the age of 22 years. Direct-seeding pine in the interrows of a traditional pine plantation produced about 10.2 Mg ha−1 of biomass for energy at the age of 5 years but had no lasting effect on the planted pine height, diameter, or standing volume. The system is a viable method to produce both bioenergy and solidwood products. Herbaceous competition control and nitrogen (N) fertilization likely would make the system even more productive and profitable.

Download Full-text

Evaluation of moisture reduction in small diameter trees after crushing

Bioresource Technology ◽

10.1016/0960-8524(91)90111-v ◽

1991 ◽

Vol 37 (1) ◽

pp. 53-60 ◽

Cited By ~ 4

Author(s):

Donald L. Sirois ◽

Cynthia L. Rawlins ◽

Bryce J. Stokes

Keyword(s):

Small Diameter ◽

Small Diameter Trees

Download Full-text

Chipping Whole Trees for Fuel Chips: A Production Study

Southern Journal of Applied Forestry ◽

10.1093/sjaf/31.4.176 ◽

2007 ◽

Vol 31 (4) ◽

pp. 176-180 ◽

Cited By ~ 16

Author(s):

Dana Mitchell ◽

Tom Gallagher

Keyword(s):

Loblolly Pine ◽

Longleaf Pine ◽

Small Diameter ◽

Wage Rates ◽

Time And Motion ◽

Motion Study ◽

Average Production ◽

Production Study ◽

Small Diameter Trees ◽

The Cost

Abstract A time and motion study was conducted to determine the productivity and cost of an in-woods chipping operation when processing whole small-diameter trees for biomass. The study removed biomass from two overstocked stands and compared the cost of this treatment to existing alternatives. The treatment stands consisted of a 30-year-old longleaf pine stand and a 37-year-old loblolly pine stand. In the longleaf pine stand, 71% of the trees removed were less than 5 in. dbh. In the loblolly pine stand, approximately 81% of the stems removed were less than 5 in. dbh. The harvesting system consisted of conventional ground-based harvesting equipment and a three-knife chipper that processed the biomass into fuel chips. The average production time to fill a chip van was 24.61 minutes. The chip moisture content averaged 94.11% (dry basis). Using machine rates and federal labor wage rates, the in-woods cost of producing fuel chips was $9.18/green ton (gt). The cost of the biomass chipping operation ($15.18/gt), including transportation, compared favorably to existing alternative treatments of cut-and-pile or mulching.

Download Full-text

Influence of feeding damage by small mammals on tree growth and wood quality in young lodgepole pine

Canadian Journal of Forest Research ◽

10.1139/x93-104 ◽

1993 ◽

Vol 23 (5) ◽

pp. 799-809 ◽

Cited By ~ 10

Author(s):

Thomas P. Sullivan ◽

Harry Coates ◽

Les A. Jozsa ◽

Paul K. Diggle

Keyword(s):

Lodgepole Pine ◽

Wood Quality ◽

Ring Width ◽

Small Diameter ◽

Height Growth ◽

Diameter Increment ◽

Significant Difference ◽

Small Diameter Trees ◽

Severe Degree ◽

The Impact

This study assessed the impact of feeding injuries by snowshoe hare (Lepusamericanus Erxleben) and red squirrel (Tamiasciurushudsonicus Erxleben) on diameter growth, height growth, and wood quality of juvenile lodgepole pine (Pinuscontorta Dougl. var latifolia Engelm.) at Prince George and in the Cariboo Region, British Columbia. In the Prince George control stand, severe girdling damage (50–99% stem circumference) suppressed diameter and height growth of small-diameter (4.1–6.0 cm) trees, but had no effect on larger stems (6.1–8.0 cm). In the spaced stand, diameter and height increments also declined significantly with degree of partial girdling, particularly in small-diameter (3.1–5.0 cm) trees. Paradoxically, diameter increment increased significantly with degree of partial girdling in both stands at the Cariboo study area. Presumably squirrels prefer to feed on vigorous stems, and the lost growth of these trees may be substantial. There was no significant difference in amount of compression wood nor total solvent and water extractives between undamaged and damaged trees. Fiber lengths in wound-associated wood were consistently 19–21% lower than in controls. Damaged trees had greater average ring width and density than undamaged trees. The average increase in relative density of damaged over undamaged trees was 0.0343. These results suggest that a severe degree of partial girdling (which likely occurs more often in small-diameter trees) may significantly affect growth of lodgepole pine, particularly small (<5.0 cm DBH) trees.

Download Full-text

Production Costs and Markets for Pellet Chips: Case Studies in Northern Sweden

International Journal of Forestry Research ◽

10.1155/2012/302014 ◽

2012 ◽

Vol 2012 ◽

pp. 1-12 ◽

Cited By ~ 1

Author(s):

Gunnar Eriksson ◽

Dimitris Athanassiadis ◽

Dan Bergström ◽

Tomas Nordfjell ◽

Urban Bergsten

Keyword(s):

Raw Materials ◽

Small Diameter ◽

National Forest Inventory ◽

Production Costs ◽

Raw Material ◽

Small Scale ◽

Northern Sweden ◽

Forest Residues ◽

Logging Residues ◽

Small Diameter Trees

Increasing use of woody fuels requires that nontraditional types of raw materials are exploited, including logging residues and small-diameter trees. Although medium-scale combustors often use pellets, they could conceivably use dried chips of sufficiently narrow size distribution (henceforth pellet chips). The influence of the following factors on the relative cost-effectiveness of producing pellets and pellet chips was investigated for three plant sites in northern Sweden: (1) harvesting and transporting of forest residues; (2) the potential of existing energy plants to supply drying heat in periods of capacity surplus; (3) the distance to potential end-users. Data from the national forest inventory were used to estimate raw material costs. The resulting production costs were 144–176 $ per oven-dry tonnes (OD t) for pellets (27.4–33.5 $ MWh−1) and 143–173 $ OD t−1(27.2–33.0 $ MWh−1) for pellet chips, with harvesting, forwarding, chipping, and transporting of logging residues to the sites amounting to 114–122 $ OD t−1(21.7–23.2 $ MWh−1) for both fuels. Even though the differences in production costs were minor, the production of pellet chips requires significantly less electricity input per OD t of produced fuel. For cost reductions improved methods for wood fuel procurement, compacting and transporting of chips, small-scale low-temperature drying and foliage and bark separation are needed.

Download Full-text

Dimensional Stabilization of Wood Originating from Small-diameter Trees through Heat Treatment

BioResources ◽

10.15376/biores.9.3.4844-4861 ◽

2014 ◽

Vol 9 (3) ◽

Cited By ~ 2

Author(s):

Cristina Marinela Olarescu ◽

Mihaela Campean ◽

Alin Olarescu

Keyword(s):

Heat Treatment ◽

Small Diameter ◽

Small Diameter Trees

Download Full-text

Frost Crack Incidence in Northern Hardwood Forests of the Southern Boreal–North Temperate Transition Zone

Northern Journal of Applied Forestry ◽

10.1093/njaf/25.3.133 ◽

2008 ◽

Vol 25 (3) ◽

pp. 133-138 ◽

Cited By ~ 7

Author(s):

Julia I. Burton ◽

Eric K. Zenner ◽

Lee E. Frelich

Keyword(s):

Structural Characteristics ◽

Regional Climate ◽

Small Diameter ◽

Basal Area ◽

Selective Logging ◽

Tree Level ◽

Diameter Class ◽

Northern Hardwood ◽

Second Growth ◽

Small Diameter Trees

Abstract Frost cracks are common in northern hardwood stands near their northern range limits. Although they have long been attributed to the regional climate, temperature fluctuations result in surface cracks largely when internal wounds are present. We examined the relationship between the proportion of trees with frost cracks and both tree-level diameter class and stand structural characteristics in primary stands with a history of minimal logging (n = 4) and 67- to 97-year-old second-growth stands subjected to past heavy partial cuts and high grading (n = 8). We hypothesized that frost crack incidence would (1) be greater in the second-growth stands and (2) be associated with differences in structural attributes between the two stand types. High levels of frost cracking in primary stands indicated that cracks are not completely avoidable. However, the proportion of trees with frost cracks was significantly higher in second-growth than primary stands, particularly on small-diameter trees. For example, the odds for frost cracking were 1.66–3.74 times greater in second-growth than in primary stands in the 15-cm diameter class, but were not different in the 45+-cm diameter class. Frost cracking was positively associated with increasing diameter in both stand types. Structural characteristics reflecting tree size, stand basal area, and basal area of hardwoods were positively associated with the proportion of trees with frost cracks in second-growth stands but not in primary stands. Although the basal area of conifers was negatively associated with frost cracking, the effect was likely due to a reduction in hardwood basal area in the vicinity of conifers. We suggest that greater frost crack incidence in second-growth stands is likely a consequence of injuries to residual trees during selective logging.

Download Full-text