Download or read book Temporal Effect of Vegetation Management on Growth and Wood Quality of Conifers in a Western Oregon Plantation written by Heidi S. Roe Goracke and published by . This book was released on 2010 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concern over the increasing proportion of juvenile wood grown in second growth plantations has led to a large amount of research on the effects of common silvicultural practices on wood quality. Lacking is research on the effect of timing and duration of vegetation control on wood quality near the pith of young trees. This study was designed to quantify differences in specific gravity, ring width, percent latewood, biomass increment and eight-year diameter growth of Douglas-fir seedlings among different vegetation control regimes applied over the first five years of stand establishment. Largest year-eight volumes were observed in plots having five consecutive years of vegetation control, resulting in 239% more volume than control plots with no vegetation control. Mean specific gravity values ranged from 0.41 to 0.45 in rings 3, 4, and 5 from the pith and from 0.37 to 0.41 in rings 6, 7, and 8, with no significant treatment effect. Average ring width increased with increasing years of vegetation control for both ring segments, reaching consistent lengths of approximately 30 mm after three years of initial treatment. Percent latewood decreased with increasing years of vegetation control, ranging from 3.73% to11.13% in rings 3, 4, and 5. No significant treatment effect was observed for percent latewood in rings 6, 7, and 8, indicating consistent ring width production over time. Biomass increment was significantly affected by treatment, increasing by a maximum of 376% with increasing intensity of vegetation control. The lack of significant differences in specific gravity among treatments and the significant gains in volume and biomass from a greater intensity of vegetation control suggests a lack of adverse impacts on wood quality. Future silvicultural treatment and age at the time of harvest will likely have a more significant influence on the end-use quality of the wood.

Download or read book Twenty Five Years of Managing Vegetation in Conifer Plantations in Northern and Central California Results Application Principles and Challenges written by Philip McDonald and published by CreateSpace. This book was released on 2012-10-17 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the late 1970s, the outlook for conifer seedlings in new plantations in the Western United States was dismal-too many were dying or growing below the potential of the site. This situation was untenable, and a large study aimed at increasing the survival and growth of planted conifer seedlings was implemented. This was the National Administrative Study on Vegetation Management of which the California portion is reported here. This "study" was really a program on plantation release with 32 individual studies that resulted in more than 60 publications over a 25-year timeframe. The authors emphasized plant community development and biological influences to help explain why some direct release methods were effective and some were not. Survival and growth of several species of conifer seedlings were correlated to the density, foliar cover, and height of various combinations of over 235 species of hardwoods, shrubs, forbs, and graminoids after application of five principal release techniques (herbicides, manual release, mulches, grazing, and mechanical [large machines]). Herbicide use was the most effective treatment followed by manual release and mulches. Domestic grazing, as currently practiced, was not effective, and release with large machines was worthwhile only if followed by an herbicide. Genetic enhancement of conifer seedlings showed promise as a vegetation management tool at first, but lost its efficacy later. Indirect vegetation management by using shade and organic material to reduce the growth and density of competing vegetation has potential, but needs more study. Nineteen principles and 10 conclusions resulted from this research program, but more work in the form of 11 challenges is recommended.

Download or read book Twenty Five Years of Managing Vegetation in Confier Plantations in Northern and Central California written by McDonald and published by CreateSpace. This book was released on 2015-02-14 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inadequate reforestation and poor conifer seedling survival and growth led to a national research and application program on vegetation management in young conifer plantations. Findings from the California part of this program, and more specifically on plantation release, are presented here. Results are from 32 study sites throughout northern and central California and reported in more than 60 publications over a 25-year timeframe. The study sites represent a wide variety of site qualities, soils, slopes, aspects, and vegetation types. Most of the planted conifer seedlings were ponderosa pine (Pinus ponderosa Dougl. ex Laws. var. ponderosa) and Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco var. menziesii).

Download or read book Effects of Fire Insect and Pathogen Damage on Wood Quality of Dead and Dying Western Conifers written by Eini C. Lowell and published by DIANE Publishing. This book was released on 2010-10 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contents: Intro.; The Changing Mgmt. Context; Previous Studies on Effects of Disturbance on Wood Quality; After the Fire: Changes in Dead and Dying Conifers; Predicting Conifer Mortality Following Fires; Types of Changes in the Wood of Dead Conifers; Insect Damage to Conifers; Stain and Decay Fungi Damage to Conifers; Factors Influencing the Rate of Deterioration; Species-Specific Changes in Wood Quality of Dead and Dying Conifers; Douglas-Fir; Englemann Spruce and White Spruce; Grand Fir and White Fir; Lodgepole Pine; Ponderosa, Sugar, Western White, and Jeffrey Pine; Subalpine Fir; Western Hemlock; Western Larch; Wood Quality Changes and Econ. Values; Visual Classification Systems; Volume and Value Loss. Conclusions.

Download or read book Twenty five Years of Managing Vegetation in Conifer Plantations in Northern and Central California written by Philip M. McDonald (Research forester) and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vegetation Trends in a Young Conifer Plantation After Grazing Grubbing and Chemical Release written by Philip M. McDonald and published by . This book was released on 1996 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book California Northern Forests Reestablishment written by and published by . This book was released on 1974 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comparing Structure and Development of Douglas fir Old growth Plantations and Young Natural Forests in Western Oregon written by Christopher D. Dowling and published by . This book was released on 2003 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ages, diameter growth, density, tree size, and species were studied in old-growth, plantation, and young natural Douglas-fir stands in three areas in western Oregon: the western and eastern Coast Range and the western Cascades. The purpose was to compare the development of these three stand types and to determine whether plantations and young natural stands would develop old-growth structures and characteristics. The Douglas-fir age ranges in plantations (8 to 15 yr) were much narrower and than the ranges of tree ages found in the young natural (21 to 102 yr) and in the old-growth stands (300 to 354 yr). This wide range of tree ages, along with diameter growth rates and tree and stand structural characteristics, supported the hypothesis that old-growth developed at low initial stand densities. These low initial stand densities, probably the result of prolonged stand establishment, likely enabled height and crown size advantages among old and younger trees. Dominant and large codominant trees maintained live crown ratios and sustained diameter growth resulting in large stable trees indicated by low height-to-diameter ratios. The mean diameters of the dominant trees in the old-growth and the dominant trees in the young natural stands were not significantly different at age 40 and 100, indicating the young natural stands appear to be growing at the same rates as the old-growth in its first 100 years. The mean dominant diameters in the plantations and old-growth at age 40 and 100 were significantly different, indicating the plantations are growing and developing differently than young natural and old-growth forests. Plantations had grown rapidly for the first 20 to 30 years, and computer simulation indicated that a significant rapid decline in radial growth would occur between ages 30 and 55. Simulations also indicate that during this period, the mean diameters of the dominant plantation trees would fall below those of the old-growth in two of the three stands by age 85. Pre-commercial thinning 20 to 25 years ago in the plantations has helped sustain high early growth rates for a longer period of time than would have occurred if thinning had not been performed. Additional thinning in the future is likely needed to maintain rapid current rates. When simulated to age 250 both the young natural stands and the plantations maintained higher densities of smaller diameter trees than the old-growth stands. This simulation result indicates the possible inability of these stands to self-thin to the densities found in old-growth stands without some sort of density-reducing disturbance. The broad range of tree ages in the old-growth stands suggests that stand disturbances are a normal part of old-growth development on these sites. Five different plantation thinning options were also simulated to age 250, including additional options with thinning of understory trees and ingrowth. The projections indicate that when the plantations are left unthinned they would generally develop trees with small live crowns and mean diameters but still produce stable dominant overstory trees (low H:D ratios). Shade tolerant understory trees and ingrowth, such as western hemlock, are a key part of old-growth development. These trees may reduce the rate of growth and alter crown structure of the overstory trees over extended periods of time (200+ years). Additional thinning, possibly in multiple entries, in both the overstory and understory may be necessary for dense plantations to develop the tree size heterogeneity found in local old-growth forests. I also demonstrated a methodology to determine site-specific management targets or goals for creating old-growth structure from plantations. This was performed using past and current forest structure and composition information within a local landscape scale of 500 to 1000 acres, typical of the public land checkerboard ownership pattern. Stand types making up the historical landscape are identified and described retrospectively using historical and current aerial photographs and digital orthophotos, cruise records, previous studies, and sample plots of standing and harvested forests. The degree of detail provided through this methodology will likely help forest managers to define complex late-successional characteristics of stands and landscapes. My results indicate that stand and project area-specific definitions of old-growth and clearly defined goals for young stand management will facilitate development of old forest characteristics.

Download or read book Early Growth Response of Conifer Plantations to Cleaning with Herbicides written by New Brunswick. Department of Forests, Mines and Energy and published by . This book was released on 1987 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seedling Response to Vegetation Management in Northeastern Oregon written by Amanda A. Lindsay and published by . This book was released on 2009 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: Northeastern Oregon geology and climate provides moderately productive conditions for forest management and timber production. Although site preparation and planting are commonly used silvicultural practices, little research exists on the efficacy of specific forest herbicides and responses of seedling survival and growth in this region. This research seeks to improve the knowledge and understanding of these practices by examining the short and long-term effects of controlling competing vegetation on early plantation establishment and growth. The first study re-evaluates ponderosa pine (Pinus ponderosa) growth and survival twenty years after hexazinone was applied in broadcast and spot treatments for control of competing vegetation. Early treatment differences in survival and growth were detected (Oester et al. 1995), and tree size has continued to diverge among treatments twenty years after planting. The second study evaluated a suite of chemical site preparation treatments and several responses: western larch (Larix occidentalis) and Douglas-fir (Pseudotsuga meziesii) seedling survival and growth, vegetation cover development, and change in growing season volumetric soil moisture. Seedling survival, seedling volume growth, and volumetric soil moisture at the end of the first and second growing seasons did not always differ among treatments, but consistently decreased where competing vegetation cover was greater. These studies provide evidence that controlling competing vegetation on these sites increases survival and growth of western larch and Douglas-fir seedlings in the first few years after planting. Although direct effects of treatment do not persist, differences in tree size among treatments are still evident after two years for Douglas-fir and western larch, and after 20 years for ponderosa pine. Results pertain directly to ponderosa pine, western larch, and Douglas-fir planted in Douglas-fir/spiraea (Pseudotsuga menziesii/Spiraea betulifolia) and Douglas-fir/common snowberry (Pseudotsuga menziesii/Symphoricarpos albus) plant associations in northeastern Oregon, but may reasonably be applied to similar sites with the same species composition throughout much of the Intermountain West.

Download or read book Bibliography of Agriculture written by and published by . This book was released on 1976 with total page 1732 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Report of the Chief of the Forestry Division written by United States. Forest Service and published by . This book was released on 1891 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Canadian Journal of Forest Research written by and published by . This book was released on 2014 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecosystem Effects of Vegetation Removal in Coastal Oregon Douglas fir Experimental Plantations written by Oktay Yildiz and published by . This book was released on 2000 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effects of partial understory removal on belowground and aboveground ecosystem properties were investigated in 5 and 15 yr old Douglas-fir (Pseudotsuga menziesll (Mirb.) Franco) experimental plantations in western Oregon. Seedling survival was not affected by understory removal at age 5 yr. But through age 15 yr, understory removal increased seedling survival up to 30% on some of the plots. At plantation age 5 yr, tree biomass accumulation was increased nearly 12-fold with complete shrub and herb removal from the sites. However, total aboveground biomass was the same among treatments at age 5 yr. At plantation age 15 yr, tree biomass accumulation was 336% greater with complete understory removal from the Douglas-fir only plots (DFO). Even though Douglas-fir needle N concentrations were significantly higher on DFC plots at age 5 yr, this difference was not detected at plantation age 15 yr. However, Douglas-fir foliar nutrient concentrations decreased significantly between 5 and 15 yr for: Ca, Mn, Fe, Cu, B, and Zn. The total aboveground N pool was greater for DEC plots due to the greater amount of aboveground biomass present in shrubs and herbs at age 5 yr. From plantation age 5 to 15 yr, the total aboveground N pool dramatically increased. However, the aboveground total N pool was not significantly different among plots. On the other hand, the aboveground P pool was 86% and Ca pool 87% higher on DFO than on DFC plots. At age 15 yr, the upper 15 cm of soil had more than 20% greater bulk density on DFO than on DEC plots. Soil C concentration in the

Download or read book Growth and Yield Structure Composition and Soil Compaction in a Western Oregon Douglas fir Forest After 35 Years of Modified Selection Thinning written by Darin S. Stringer and published by . This book was released on 1999 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modified selection thinning has been utilized by some non-industrial foresters in Douglas-fir forests of Western Oregon and Washington for at least 35 years. This silvicultural strategy has not been tested, but has often been associated with reduced volume production and other undesirable effects. It continues to be used on many small woodland properties. This case study evaluated a management system that has utilized modified selection thinning and natural regeneration since 1964, on a 250 acre private forest tract on the east slopes of the Oregon Coast Range. Six conditions (Types) were identified and mapped on the property based on the number of thinning entries and stand vegetation conditions. Current field data along with past cruise information and aerial photos were used to assess past and current volume production, stand structure, species composition arid soil compaction. Stand growth and yield was projected for 100 years using a simulation model to compare selection thinning and short rotation evenage management. At the Tract level, inventory records showed standing conifer volume from 1964-95 increased from 1,939 MBF (thousand board feet) to 2,150 MBF, while 5,606 MBF of volume was removed. Harvests occurred every 1-4 years with an average volume of 715 bd. ft./acre/year removed. Stands in early stages of conversion with modified selection thinning were growing at 80-100% of potential based on regional growth and yield tables for stands of similar site quality and stocking. Volume growth in stands in intermediate stages of conversion was 35-70% of potential compared to the same yield tables adjusted for stocking. Under a similar management regime, simulated total Tract standing volume increased to 4,250 MBF after a 100-year projection with harvests of 600 bd. ft./acre/year. Tract average periodic annual increment after 100 years was similar to current levels. Simulation studies showed that selection thinning yielded 9% less total Tract board foot volume (standing + harvest) than 50-year rotation evenage management after a 100- year simulation. Two of six stand Types simulated with selection thinning produced yields within 2% of the 50-year rotation evenage system after 100 years. The other four Types produced from 8-20% less volume. Under modified selection thinning the Tract contained 3 times more standing volume, and produced 2.8 times more volume in logs greater than 16 inches (scaling diameter) after 100 years. Management using modified selection thinning maintained a per acre average of at least 10 MBF/acre standing timber over 90% of simulation period vs. 40% for the evenage regime. Modified selection thinning between 1964-1995 led to changes in stand structure and composition. Both conifer reproduction and shrub cover increased in stands with more thinning. Conifer basal area decreased with thinning but the range of tree diameters increased. Composition of natural regeneration in the understory of stands thinned 9-12 times was dominated by Douglas-fir with 47% stocking and 290 trees per acre. Past and current cruise reports along with aerial photographs indicate hardwoods increased during the management period between 1964-97. Soil compaction was significantly higher in areas thinned 9-12 times vs. those thinned 1-4 times (p-value =.04), and was significantly higher in areas with less than 35% slope (p-value =.001). Across the Tract 60% of sampling points fell in a low compaction class, 33% in moderate, and 4% in high. Uneven-aged stand structure in a group selection sense was observed at the Tract level. Individual stands or plots did not contain functional individual tree selection uneven-aged structure. However, stands thinned repeatedly were two-storied in places. Based on comparison of different stand Types it appears modified selection thinning in Douglas-fir stands could be used to perpetuate even-aged structure, or to convert stands towards an uneven-aged condition. In either scenario, management is recommended to address increased hardwood stocking, inconsistent natural regeneration of conifer species, and understory growth losses caused by reserve "legacy" trees.

Download or read book Report of the Secretary of Agriculture written by United States. Department of Agriculture and published by . This book was released on 1890 with total page 756 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book REPORT OF THE SECRETARY OF AGRICULTURE written by and published by . This book was released on 1890 with total page 698 pages. Available in PDF, EPUB and Kindle. Book excerpt: