Case Studies of Red Alder and Sitka Alder in Douglas-fir Plantations PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Case Studies of Red Alder and Sitka Alder in Douglas-fir Plantations PDF full book. Access full book title Case Studies of Red Alder and Sitka Alder in Douglas-fir Plantations by Dan Binkley. Download full books in PDF and EPUB format.
Author: Dan Binkley Publisher: ISBN: Category : Forest management Languages : en Pages : 230
Book Description
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.
Author: Dan Binkley Publisher: ISBN: Category : Forest management Languages : en Pages : 230
Book Description
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.
Author: Publisher: ISBN: Category : Douglas fir Languages : en Pages : 36
Book Description
Five randomly assigned treatments were used to quantify effects of adding varying numbers of red alder (Alnus rubra Bong.) or nitrogen (N) fertilization on growth of a 10-year-old conifer plantation at a medium quality site in the western Washington Cascade Range. Zero, 20, 40, and 80 alder trees per acre were retained along with about 300 conifers per acre. Nearly all conifers were coast Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco). A fifth treatment substituted N fertilizer for N-fixing alder. Changes in average tree height, and in numbers of trees, basal area, and volume per acre between plantation ages of 10 and 27 are compared. In pure conifer plots, gross volume growth averaged 26 percent greater on fertilized than nonfertilized plots, indicating measurable benefits of additional N. On both fertilized and nonfertilized plots, an average of 13 percent of the original conifers died. Retaining 20, 40, or 80 alder per acre (7, 13, and 27 percent of the associated conifer trees per acre, respectively) was associated with reduced numbers of Douglas-fir by about 19, 5, and 17 percent, respectively, in the next 17 years. Mortality and growth of Douglas-fir were not related to alder density, but losses of Douglas-fir were especially large on plots where relatively large red alder (20 per acre) were retained. Neither total stand nor conifer yields were changed by retaining alder. Additional comparisons are needed at other locations, especially those with known N deficiency.
Author: Dan Binkley Publisher: John Wiley & Sons ISBN: 9780471818830 Category : Nature Languages : en Pages : 308
Book Description
An integrated treatment of forest nutrition management that draws on the fields of silviculture, soil studies, ecology, and economics to provide broad-based information on how to enhance the nutritional status of forest soils in order to increase their long-term stand productivity. Covers the use of fertilizers to enhance biological nitrogen fixation and how the nutrition status of forests is affected by other operations, such as harvesting and site preparation. Includes methods for assessing nutrient status, the economics of nutrition management, and models to aid in decision making. Written for the non-specialist needing a clear conceptual base for applying forest nutrition science to management. Numerous examples of successful forest management illustrate concepts.
Author: Amy T. Grotta Publisher: ISBN: Category : Douglas fir Languages : en Pages : 218
Book Description
When Douglas-fir and red alder grow in mixture, interactions between the two species can be competitive, facilitative, or a combination of both over time. A number of factors have recently led to increased interest in managing these two species together for commercial production, and ongoing investigations are yielding important information about how interactions between the two species affect stand structure and productivity. Many wood quality attributes are ultimately controlled by physiological processes, which in turn are affected by competition within a forest stand. This research addressed how stand structure in young, mixed red alder/Douglas-fir plantations was associated with variations in growth form and wood quality. Branch attributes and cambial growth patterns in Douglas-fir and stem form attributes in red alder were analyzed as a function of species proportion and timing of establishment in 15-year-old mixed plantations in the Oregon coast range. When the two species were planted simultaneously, only mixed stands with low (10% of total stand density) proportions of red alder had low Douglas-fir mortality. In these stands, red alder stem form was poor, with a high incidence of multiple stems, low live crown bases, and considerable stem lean and sweep. Douglas-fir trees had a relatively short season of cambial growth and many were highly suppressed. When red alder planting was delayed five years, Douglas-fir trees had a short cambial growth season when the proportion of red alder in the stand was high (75%). Douglas-fir crown base height was low when the proportion of red alder was high, but branch sizes were relatively consistent across species proportions. Percent latewood in Douglas-fir was not affected by species proportion. Red alder stem form was consistent across all levels of species proportion. It is suggested that the differences observed are a result of differential juvenile growth rates of the two species and subsequent different levels of light availability to individual tree crowns through stand age 15. Simultaneous planting of the two species at these spacings results in either unacceptable Douglas-fir growth and mortality rates or poor red alder stem form, depending on species proportion. Delayed planting of red alder appears to improve red alder stem form and results in acceptable Douglas-fir wood quality attributes, if red alder proportion is 50% or less. Because these stands are not yet of harvestable size, further monitoring is needed to assess how the patterns of growth and wood quality described would affect eventual product recovery.
Author: A.D. Akkermans Publisher: Springer Science & Business Media ISBN: 9400961588 Category : Science Languages : en Pages : 260
Book Description
Five years have now passed since the first symposium on frankiae was held at Harvard Forest, Petersham, Massachusetts, USA and the inauguration of the term actinorhiza. Many advances have been made during these five years in our understanding of the actinorhizal symbioses. Evidence for this was provided by the papers presented at the Wageningen Workshop on Frankia symbioses, held in Wageningen at the Department of Microbiology of the Agricultural University. Most of these papers are now published in this volume of PLANT AND SOIL. We kindly acknowledge the assistance of Anton Houwers, editor of the journal, in planning, reviewing and publishing these studies. Although the papers presented at Wageningen described the active research areas, they also illuminated those aspects of these symbioses which remain beyond our understanding. Primary among the areas of our ignorance is the concept of species within the bacterial symbiont, Frankia. At present groupings of bacterial strains are based on cell chemistry, physiology, serology, DNA homology and symbiotic capa bilities (cross-inoculation). When these classification schemes are merged no clear species framework is obtained. Undoubtedly part of the difficulty is due to a lack of strains for analysis. Currently bacterial strains from only half of the actinorhizal symbioses known to exist, have been isolated and studied in pure culture. We must postpone there fore any comprehensive taxonomic classification until a larger majority of the symbioses are represented. Another research area wherein our understanding is insufficient is host-symbiont interaction.
Author: Dan Binkley
Author: Dan Binkley
Author: 
Author: Richard E. Miller
Author: Constance A. Harrington
Author: Tricia L. Wurtz
Author: 
Author: 
Author: Dan Binkley
Author: Amy T. Grotta
Author: A.D. Akkermans