Download or read book Growth of Bear Damaged Trees in a Mixed Plantation of Douglas Fir and Red Alder written by U S Department of Agriculture and published by CreateSpace. This book was released on 2015-06-26 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Incidence and effects of tree damage by black bear (Ursus americanus altifrontalis) in a 50-year-old, coast Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) plantation are described. Bears girdled or partially girdled 35 dominant or codominant Douglas-fir trees per acre, but only in that portion of the plantation that had been interplanted at age 4 with red alder (Alnus rubra Bong). No red alder were damaged. Bears damaged Douglas-fir in this stand on at least four occasions between 1929 (planting) and 1991. Fully girdled Douglas-fir (six per acre in 1976) died within 2 to 14 years. Of the 29 per acre partially girdled trees, 17 percent died in the 16 years of observation, compared to 9 percent of nondamaged trees. Crosssectional growth of surviving damaged trees exceeded that of matched, nondamaged trees by about 30 percent at three heights on the bole: 6 ft, 4.5 ft, and immediately above the damaged area. Death of six large Douglas-fir trees per acre reduced live stand volume of this species for about 6 years after bear damage until growth of the remaining trees compensated for the volume lost to mortality. Confirmation of the stimulating effects of bear damage on subsequent tree growth is needed at other locations.

Download or read book Growth of Bear damaged Trees in a Mixed Plantation of Douglas fir and Red Alder written by and published by . This book was released on 2007 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Growth of Bear damaged Trees in a Mixed Plantation of Douglas fir and Red Alder written by and published by . This book was released on 2007 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research Paper PNW RP written by and published by . This book was released on 1986 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Research Paper PNW written by and published by . This book was released on 1978 with total page 272 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 1993 with total page 1296 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Forest Stewardship Notes written by and published by . This book was released on 1997 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Multi Spatial Scale Economic Analysis of the Impacts of Bear Damage to Douglas fir on Private Timberlands in the Pacific Northwest written by Kristina N. Kline and published by . This book was released on 2016 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt: Black bears (Ursus americanus) in western Oregon and Washington peel bark from conifers in early spring to forage on the sugar-rich phloem and cambial tissues. This provides important energy at a time when similarly attractive forage is scarce. Bears often damage Douglas-fir (Pseudotsuga menziesii) trees in stands that are intensively managed for timber production, as management activities including thinning and fertilization increase productivity. Fully girdled trees result in a complete economic loss while partial girdling reduces survival rates as well as merchantable volume. Previous studies on economic impacts have assessed only those losses to fully girdled trees, but not additional impacts from wounded trees. We surveyed four severely damaged stands to assess economic impacts at the stand-level, and surveyed 122 randomly selected vulnerable stands to assess economic impacts at the landscape-level. Two damage scenarios were considered. Scenario one accounted for the additional mortality and volume losses from partially girdled trees, whereas scenario two assumed that all bear-peeled trees resulted in a complete loss. Stand volumes were estimated using the Forest Vegetation Simulator growth and yield model. Economic losses were estimated using the Fuel Reduction Cost Simulator and present value models. At the stand-level, economic losses to severe bear damage in scenario one ranged from $6,100 to $24,500. Economic losses in scenario two ranged from $19,500 to $74,700. Undamaged stands were valued from $43K-$250K. At the landscape level, economic losses to vulnerable stands in scenario one ranged from $44,500 to $726,000. Economic losses in scenario two ranged from $169,000 to $2.8M. Undamaged stands were valued from $48M-$780.5M. Root disease was a more prevalent damage agent than black bear damage. The majority of bear damage observed (92%) was older (>2 yrs) and existed at a low frequency (1.5 bear damaged trees/ha) and severity across the landscape. Our results suggest that bear damage management over the last two decades may have reached a level of efficiency at reducing damage, and if continued, bear damage may remain at low levels across the landscape. On-the-ground monitoring of the status of bear damage frequency and severity across western Oregon and Washington at both the stand and landscape levels will provide an understanding of these changes over time as a result of management decisions.

Download or read book Factors Influencing Growth of Young Douglas fir and Red Alder in the Oregon Coast Range written by Laura Angélica Fuentes-Rodríquez and published by . This book was released on 1993 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Red alder (Alnus rubra Bong.) is a common associate and a potentially severe competitor of Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) in the Oregon Coast Range. However, because it fixes nitrogen and increases rates of soil nutrient cycling, red alder has the potential to benefit Douglas-fir. The objective of this study was to quantify and attempt to explain differences in growth of young Douglas-fir and red alder, growing in mixed and pure stands, by analyzing six-year trends in survival, growth, animal damage of saplings, cover of understory vegetation, and foliar and soil nutrients. In March 1986, a replacement series study was established by planting Douglas-fir and red alder at 3-m spacing in 0.073-ha plots with the following species proportions (Douglas-fir/red alder): 1/0, 0.9/0.1, 0.7/0.3, 0.5/0.5, 0.25/0.75, 0/1. Each proportion was replicated three times in a randomized complete block design. Six annual measurements (fall 1986-1991) of survival, growth, and animal damage and one measurement of stand yield (1991 basal area, volume, and predicted biomass) were used in response surface analyses to test for significant polynomial relationships (a=0.05) between tree response and species proportion. Relationships of Douglas-fir height increment to red alder proportion varied from positive linear (year 2) to no relationship (years 3-4) to negative linear (years 5-6). Relationships of Douglas-fir diameter increment to red alder proportion varied from no relationship (years 2-3) to negative linear (year 4) to negative quadratic (years 5-6). In the sixth year, competition from red alder caused relative yield (relative to monoculture yield) of Douglasfir volume index and predicted biomass to be significantly less than the yield that would be expected in the absence of intraspecific competition (expected yield). Increasing proportion of Douglas-fir decreased intraspecific competition of red alder, and as a result, relative yield of basal area and predicted biomass for red alder was significantly greater than its expected yield. Two easurements (March 1986 and 1991) of mineralizable nitrogen (NH4 and NO3); total N, P, and C; and pH from 3 soil depths (0-15, 15-30, and 60-90 cm) were used in analysis of variance to test for significant differences (a=O.05) in sixth-year amount and five-year change in these variables among three species proportions (Douglas-fir/red alder): 1/0, 0.5/0.5, and 0/i. There was no net N accretion; however, there was higher mineralizable N as NH4 in pure Douglas-fir stands than in mixed stands. One explanation for these results is that possibly the more open conditions of Douglas-fir stands increased rates of N mineralization. Douglas-fir foliar N and P also were significantly higher in pure stands than in mixed stands, probably because of the increased ability of large, vigorous saplings growing in absence of red alder to absorb soil nutrients rather than because of greater supplies of soil nutrients. The effect of increased Douglas-fir vigor and size in enhancing nutrient uptake was more prominent for P than for N. These data indicate that the effects of red alder on Douglas-fir can range from positive to neutral to negative. In general, competition was the most important factor limiting survival and growth of Douglas-fir; animal damage and understory vegetation under red alder canopies caused further limitations in Douglas-fir response. In addition, results of this research suggest that red alder competition can be tolerated with little loss of Douglas-fir survival and growth through an age of 4 years.

Download or read book Fifth year Growth Responses of Douglas fir to Crowding and Other Competition written by Elizabeth C. Cole and published by . This book was released on 1984 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis examines the competitive aspects of Douglas-fir trees growing with two commonly associated competitors--red alder and grass--at varying densities. Two Nelder plots in three different environments in the Oregon Coast Range were studied. The sites represented the warm, dry climate of the Willamette Valley; the warm, moist climate of the valleys of the mid-range; and the cool, moist climate found along the fog belt a few miles from the Pacific Ocean. Plots ranged in spacing from 300 to 15250 cm2/tree and consisted of six "pie-shaped" treatments. The plots had been previously planted in the spring of 1978 with 2-0 bare root Douglas-fir nursery stock. Two sections were interplanted with red alder, and two sections were broadcast seeded with grass the following year. Measurements indicate that Douglas-fir growth is inhibited by red alder and grass competition as well as competition from other Douglas-fir. Grass competition is severe only during the initial years of the plantation, while red alder competition becomes more pronounced with time. Growth is a function of density, competitor type, and site, and significant interactions occur among the three. Leaf area per tree of Douglas-fir under competition can be predicted by leaf weight, stand density, and competitor type. The formation of shade needles in response to density and competitor type increases the leaf area:leaf weight ratio. Growth efficiency (stemwood volume production/unit of leaf area) is not highest for the most vigorous trees. On a per hectare basis, high productivity is correlated with high leaf area index, but the relation is reversed on a per tree basis.

Download or read book Case Studies of Red Alder and Sitka Alder in Douglas fir Plantations written by Dan Binkley and published by . This book was released on 1982 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seven case studies of 11 ecosystems were used to examine the effects of nitrogen-fixing alders in Douglas-fir plantations. The first case study quantified nitrogen (N) fixation and aboveground net primary production in a young Sitka alder [Alnus sinuata (Regel) Rydb.] ecosystem. At 5 yr of age, the N fixation (C22H2 reduction) rate of 35 kg ha−1 yr−1 was near the middle of the reported range for this shrubby species. The second case study compared N fixation rates of Sitka alder and red alder (Alnus rubra Bong.) on the same sites. These species exhibited similar nodule activities and had similar nodule:leaf biomass ratios of 7-8%. A mixture of Sitka alder and Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] was estimated to have a current N fixation rate of 20 kg ha−1 yr−1 based on acetylene reduction; N accretion measurements indicated an average N fixation rate of 30 kg ha−1 yr−1 for 23 yr. A mixture of red alder and Douglas-fir on the same site had a current N fixation rate of 130 kg ha−1 yr−1 based on acetylene reduction, with an N accretion rate of 65 kg ha−1 yr−1 for 23 yr. The third case study evaluated the effects of Sitka alder on Douglas-fir growth and nutrition, and on ecosystem production and litterfall. Current Douglas-fir stem growth was 40% greater with Sitka alder, and aboveground ecosystem net primary production was increased 70% with the alder. Litterfall nutrient content was 3 to 7 times greater under the mixed canopy. The fourth and fifth case studies looked at 23 yr-old mixtures of red alder and Douglas-fir in comparison with pure Douglas-fir, on an infertile site and on a fertile site. Red alder had little effect on Douglas-fir size or growth rate on the infertile site, but ecosystem net primary production was tripled. Conversely, net primary production was not increased by red alder on the fertile site, and Douglas-fir size and growth were reduced. The final two case studies evaluated: (1) the conclusions reached in the previous case studies for applicability to red alder/Douglas-fir mixtures in general, and (2) trends in production with stand development up to age 50. These case studies were consistent with the general conclusions of site fertility interactions with red alder/Douglas-fir mixtures. With further stand development, red alder continued to enhance ecosystem production and Douglas-fir growth on infertile sites, with opposite effects on fertile sites. Sitka alder demonstrated a high potential usefulness for interplanting with Douglas-fir, and red alder greatly boosted ecosystem production on infertile sites. Both species merit further development as tools for forest management on N deficient sites.

Download or read book Stand Development After 20 years of Growth in Douglas fir and Red Alder Mixtures written by Brennan T. Garrelts and published by . This book was released on 2009 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study examines the long-term role of interference on stand development of Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) and red alder (Alnus rubra Bong.) planted mixtures in the Central Cascades of Oregon, USA. The two species are common associates in naturally regenerated and planted conifer stands in the Pacific Northwest. Due to red alder's rapid height growth, Douglas-fir is often impeded when in the presence of red alder. However, because of red alder's ability to fix nitrogen and increase soil nutrient cycling rates Douglas-fir development can potentially be enhanced when in red alder presence. The relationship between current stand structure, tree mortality, tree size and varying mixtures of species proportions were examined in this study. Treatments included four proportions of red alder either planted simultaneously with the Douglas-fir or delayed 5-years after initial Douglas-fir planting. The objectives of this study were to determine if species mixtures were capable of a greater yield when compared to monocultures and then to determine which form of interference was taking place within and between species. A long-term replacement series study was established in 1986 to understand the role of interference on two commercially valuable species. Six treatments of each planting time were created with the following proportions (Douglas-fir/red alder, respectively): 1.0/0.0, 0.9/0.1, 0.7/0.3, 0.5/0.5, 0.25/0.75, 0.0/1.0. Each treatment was replicated three times in a randomized complete-block design. Measurement of diameter at breast height (cm) of each stem, total height (m), and number of live/dead stems were determined in 1988-1991, 1993, 1995, 1998 and 2007. Yields of both the 0.5/0.5 simultaneous and delayed treatment mixtures were notably higher than the monocultures. Per-tree basal area, height, and survival decreased for both the Douglas-fir and red alder as the relative density (proportion) of red alder increased in the simultaneously planted mixtures. In the delayed mixtures, Douglas-fir per-tree basal area, height, and survival increased as red alder density increased. Red alder development indicated only minor decreases in survival as its density increased in the delayed treatment mixtures. Competition was the dominant mechanism of stand development for all treatments. In the simultaneously planted treatments the Douglas-fir was driven most by interspecific competition, while red alder development exhibited trends for intraspecific competition. In the delayed planted treatments both species experienced intraspecific competition, although this effect was minor for red alder. These results support the competitive effects of red alder on Douglas-fir and itself when seedlings are established at the same time. The delayed treatments however, showed the importance of density on individual tree development over time.

Download or read book Bibliography of Agriculture written by and published by . This book was released on 1990 with total page 1254 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bibliography of Agriculture written by and published by . This book was released on 1989-08 with total page 742 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Real Gardens Grow Natives written by Eileen M Stark and published by Mountaineers Books. This book was released on 2014-09-24 with total page 645 pages. Available in PDF, EPUB and Kindle. Book excerpt: CLICK HERE to download sample native plants from Real Gardens Grow Natives For many people, the most tangible and beneficial impact they can have on the environment is right in their own yard. Aimed at beginning and veteran gardeners alike, Real Gardens Grow Natives is a stunningly photographed guide that helps readers plan, implement, and sustain a retreat at home that reflects the natural world. Gardening with native plants that naturally belong and thrive in the Pacific Northwest’s climate and soil not only nurtures biodiversity, but provides a quintessential Northwest character and beauty to yard and neighborhood! For gardeners and conservationists who lack the time to read through lengthy design books and plant lists or can’t afford a landscape designer, Real Gardens Grow Natives is accessible yet comprehensive and provides the inspiration and clear instruction needed to create and sustain beautiful, functional, and undemanding gardens. With expert knowledge from professional landscape designer Eileen M. Stark, Real Gardens Grow Natives includes: * Detailed profiles of 100 select native plants for the Pacific Northwest west of the Cascades, plus related species, helping make plant choice and placement. * Straightfoward methods to enhance or restore habitat and increase biodiversity * Landscape design guidance for various-sized yards, including sample plans * Ways to integrate natives, edibles, and nonnative ornamentals within your garden * Specific planting procedures and secrets to healthy soil * Techniques for propagating your own native plants * Advice for easy, maintenance using organic methods

Download or read book Saplings written by Noel Streatfeild and published by Persephone Books. This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "First published in 1945 by Collins"--Copyright page.

Download or read book The Dictionary of Forestry written by John A. Helms and published by Society of American Foresters.. This book was released on 1998 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: