The economics of Douglas-fir and red alder management with stochastic price trends

1993 ◽  
Vol 23 (8) ◽  
pp. 1695-1703 ◽  
Author(s):  
Robert G. Haight
Keyword(s):  
Pacific Northwest ◽  
Financial Analysis ◽  
Probability Distributions ◽  
Low Cost ◽  
The United States ◽  
Douglas Fir ◽  
Mixed Species ◽  
Red Alder ◽  
Commercial Thinning ◽  
Price Trends

A financial analysis of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and red alder (Alnusrubra Bong.) management is conducted using yield projections from the Stand Projection Simulator for the Pacific Northwest region of the United States. The analysis includes uncertainty in the price trends and stocking levels of both species following reforestation. Results from a case study in which Douglas-fir price is likely to increase faster than red alder price show that (i) on more productive sites, greater regeneration investment is justified to increase the likelihood of Douglas-fir establishment; (ii) on less productive sites, low-cost regeneration options that produce mixed-species stands have expected present values close to or greater than a high-cost Douglas-fir regeneration effort; (iii) optimal precommercial removal of red alder depends on midrotation prices and regeneration success, and in many cases growing a mixed-species stand to maturity produces the highest economic return; (iv) commercial thinning of Douglas-fir increases the expected present value of the most intensive regeneration option by up to 10%. The low-cost regeneration options have relatively high expected returns because of low initial investments and the presence of two species that may have high values in the future. The sensitivity of these results to changes in the probability distributions of regeneration success and price trends is discussed.

Effects of species mixtures on growth and stand development of Douglas-fir and red alder

2006 ◽  
Vol 36 (3) ◽  
pp. 768-782 ◽  
Author(s):  
Steven R Radosevich ◽  
David E Hibbs ◽  
Claudio M Ghersa
Keyword(s):  
Pacific Northwest ◽  
Tree Mortality ◽  
Stand Structure ◽  
Stand Density ◽  
Douglas Fir ◽  
Forest Understory ◽  
Red Alder ◽  
Structure Tree ◽  
Species Proportions ◽  
Species Mixtures

In the Pacific Northwest, a mixture of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and red alder (Alnus rubra Bong.) often results when red alder regenerates naturally in planted conifer stands. The relationships among stand structure, tree mortality, tree size, and understory development in the two species mixtures were explored at two sites for the first 16 years after planting. Treatments included a range of species proportions, and red alder was either planted simultaneously with Douglas-fir or planting was delayed for 5 years. Red alder was also removed from some simultaneously planted proportions. Both replacement effects (total stand density held constant) and additive effects (stand density doubled) of the interaction were considered. Red alder grew relatively better at Cascade Head Experimental Forest in the Coast Range, while Douglas-fir grew better at H.J. Andrews Experimental Forest in the less temperate Cascade Mountains. Possible production benefits from mixed plantings were examined using two methods of calculation. Potential production benefits from certain planted proportions of the two species occurred at H.J. Andrews Experimental Forest. No planting time or species proportion resulted in yield improvements over monoculture stands at Cascade Head Experimental Forest. Understory species also varied because of differences in site and stand characteristics that resulted from the differences in planting times and species proportions.

A comparison of annual transpiration and productivity in monoculture and mixed-species Douglas-fir and red alder stands

2011 ◽  
Vol 262 (12) ◽  
pp. 2263-2270 ◽  
Author(s):  
Georgianne W. Moore ◽  
Barbara J. Bond ◽  
Julia A. Jones
Keyword(s):  
Douglas Fir ◽  
Mixed Species ◽  
Red Alder

Alders increase soil phosphorus availability in a Douglas-fir plantation

1995 ◽  
Vol 25 (10) ◽  
pp. 1652-1657 ◽  
Author(s):  
Christian Paul Giardina ◽  
Steve Huffman ◽  
Dan Binkley ◽  
Bruce A. Caldwell
Keyword(s):  
Pacific Northwest ◽  
Soil Phosphorus ◽  
Douglas Fir ◽  
P Availability ◽  
Red Alder ◽  
P Fractionation ◽  
Inorganic P ◽  
Soil P ◽  
P Limitation ◽  
Exchange Resins

The effect of red alder (Alnusrubra Bong.) on soil phosphorus (P) availability in conifer forests of the Pacific Northwest has been the focus of several recent studies. One study at the Thompson Research Center in Washington State, found Bray No. 2 extractable P to be lower in soils under pure alder than in soils under adjacent stands of pure conifer. The Thompson study, and others in forests of the Northwest, have also found that the quantity of P in aboveground litter fall is greater for conifer stands mixed with alder than in adjacent pure conifer stands, suggesting equal or greater soil P availability under the influence of alder. We assessed the effect of low densities of red alder on soil P, using a modified Hedley sequential P fractionation scheme, in a Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) plantation in coastal Oregon. We determined that soils under plots with 190 alder stems/ha and 740 Douglas-fir stems/ha had greater inorganic P availability than pure Douglas-fir plots (740 stems/ha). Inorganic P fractions, sequentially extracted from soils at 0–0.15 m depths by anion exchange resins, by sodium hydroxide, and by hydrochloric acid, were 65–225% greater in plots with alder. Soil phosphatase activity was nearly three times greater in plots mixed with alder. No significant pH differences between the treatments were found. We conclude that red alder appears to increase the availability of soil P at our site, but note that increased P supplies may not prevent a P limitation on productivity for either alder or conifers.

Annualized diameter and height growth equations for Pacific Northwest plantation-grown Douglas-fir, western hemlock, and red alder

2007 ◽  
Vol 250 (3) ◽  
pp. 266-278 ◽  
Author(s):  
Aaron R. Weiskittel ◽  
Sean M. Garber ◽  
Gregory P. Johnson ◽  
Douglas A. Maguire ◽  
Robert A. Monserud
Keyword(s):  
Pacific Northwest ◽  
Height Growth ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Red Alder ◽  
Growth Equations

Growth of Managed Older Douglas-fir Stands: Implications of the Black Rock Thinning Trial in the Coast Range of Western Oregon

2021 ◽  
Author(s):  
John Tappeiner ◽  
Darius Adams ◽  
Claire Montgomery ◽  
Douglas Maguire
Keyword(s):  
Pacific Northwest ◽  
Financial Analysis ◽  
Rapid Development ◽  
Large Diameter ◽  
Douglas Fir ◽  
Growth Patterns ◽  
Active Management ◽  
Stand Age ◽  
Opportunity Costs ◽  
Public And Private

Abstract The most recent remeasurement of growth (at approximate total stand age 100 years) from the Black Rock Thinning Trial in western Oregon provides useful information for forest owners interested in accelerating restoration of older forest characteristics in Douglas-fir stands of the Pacific Northwest. Thinnings at several intensities at total stand age of roughly 50 years effectively reset stand growth patterns. With quadratic mean diameters in thinned plots up to 40% higher than those of unthinned controls, thinned plot mean annual increments (MAIs) and periodic annual increments continue to rise 55 years after thinning, with the peak in board foot and cubic foot MAI apparently still decades in the future. Assuming repeatable future thinning responses similar to the Black Rock Trial, financial analysis of the opportunity costs of extending rotations to 100 years indicates that some thinning treatments can reduce opportunity costs by up to half at a 6% discount rate. Study Implications Active management through thinning may be a useful tool for public and private landowners interested in rapid development of stands with older forest characteristics to enhance output of some ecosystem services. Heavy thinning regimes, of the type described here, are compatible with growing trees with large diameter stems, large branches, and large crowns. They also reduce fuel accumulation by lowering mortality rates of stems less than 60 years old and slowing the rate of crown recession, branch mortality, and branch litterfall. Midrotation thinning revenues reduce opportunity costs of holding more rapidly growing stems to older ages, which may be a consideration for some owners.

scholarly journals 662 PAP Therapy: A Review of Resources for the Uninsured during COVID-19

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A259-A259
Author(s):  
Melissa Malinky ◽  
Abigail Oberla ◽  
Meena Khan ◽  
M Melanie Lyons
Keyword(s):  
Low Income ◽  
Web Search ◽  
Low Cost ◽  
Wait Time ◽  
The United States ◽  
Fixed Cost ◽  
United States Census ◽  
Lower Socioeconomic ◽  
Increased Risk ◽  
Available Resources

Abstract Introduction In 2019, the United States Census estimated 8% (26.1 million) people were without health insurance. Further, an estimated 3.5 million people became/remained uninsured from COVID-19-related job losses. Patients with OSA that belong to a lower socioeconomic status (SES) are less likely to have access to healthcare and may be under or uninsured. Untreated OSA can lead to increased risk of symptoms and associated co-morbidities. Resources to help the uninsured to obtain PAP therapy were available pre-COVID, including two main sources, American Sleep Apnea Association (ASAA) and our local branch serving central Ohio, The Breathing Association. However, the COVID pandemic limited access or closed these programs. Our Sleep Medicine clinics saw 148 uninsured OSA patients between March-December, 2020. Given these difficulties, we re-evaluated available resources for the uninsured. Methods We conducted a search for current low cost ($100 or less) PAP therapy options for the uninsured, March 15, 2020-December 3, 2020, by: (1) contacting pre-COVID-19 resources, including Durable Medical Equipment (DME) providers, (2) consulting social work, and (3) completing a librarian assisted web-search not limited to PubMed, Embase, CINAHL for academic related articles and electronic searches using a combination of English complete word and common keywords: OSA, PAP, uninsured, no insurance, cheap, medically uninsured, resources, self-pay, low-income, financial assistance, US. Resources such as private sellers were not investigated. Results During COVID-19, assistance for PAP machines/supplies have closed or required a protracted wait-time. Options including refurbished items range from low, one-time fixed cost or income-based discounts from: one local charity (Joint Organization for Inner-City Needs) and DME (Dasco), and four national entities (ASAA, Second Wind CPAP, Reggie White Foundation, CPAP Liquidators). An Electronic Health Record-based tool was developed and distributed to increase provider awareness of pandemic available resources. Conclusion Untreated OSA is associated with increased risk of cardiovascular co-morbidities. Access and cost may limit treatment in OSA patients from a lower SES. The COVID-19 pandemic has shuttered programs providing discount PAP and supplies, leaving fewer resources for these patients, thus further widening this health care disparity. Alternatives are needed and current resources are not easily accessible for providers and patients. Support (if any):

scholarly journals Solar Thermochemical Hydrogen Production in the USA

2021 ◽  
Vol 13 (14) ◽  
pp. 7804
Author(s):  
Christoph Falter ◽  
Andreas Sizmann
Keyword(s):  
Hydrogen Production ◽  
Large Scale ◽  
Low Cost ◽  
The United States ◽  
Solar Irradiation ◽  
Transport Sector ◽  
Fossil Energy ◽  
The Us ◽  
The Usa ◽  
Solar Thermochemical

Hydrogen produced from renewable energy has the potential to decarbonize parts of the transport sector and many other industries. For a sustainable replacement of fossil energy carriers, both the environmental and economic performance of its production are important. Here, the solar thermochemical hydrogen pathway is characterized with a techno-economic and life-cycle analysis. Assuming a further increase of conversion efficiency and a reduction of investment costs, it is found that hydrogen can be produced in the United States of America at costs of 2.1–3.2 EUR/kg (2.4–3.6 USD/kg) at specific greenhouse gas emissions of 1.4 kg CO2-eq/kg. A geographical potential analysis shows that a maximum of 8.4 × 1011 kg per year can be produced, which corresponds to about twelve times the current global and about 80 times the current US hydrogen production. The best locations are found in the Southwest of the US, which have a high solar irradiation and short distances to the sea, which is beneficial for access to desalinated water. Unlike for petrochemical products, the transport of hydrogen could potentially present an obstacle in terms of cost and emissions under unfavorable circumstances. Given a large-scale deployment, low-cost transport seems, however, feasible.

scholarly journals Pathogenicity and Virulence of Pythium Species Obtained from Forest Nursery Soils on Douglas-Fir Seedlings

Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 744-748 ◽  
Author(s):  
Jerry E. Weiland ◽  
Bryan R. Beck ◽  
Anne Davis
Keyword(s):  
Pseudotsuga Menziesii ◽  
Seedling Survival ◽  
The United States ◽  
Douglas Fir ◽  
Tree Seedlings ◽  
Pythium Species ◽  
Forest Nursery ◽  
Damping Off ◽  
Greenhouse Study ◽  
Forest Nurseries

Pythium species are common soilborne oomycetes that occur in forest nursery soils throughout the United States. Numerous species have been described from nursery soils. However, with the exception of P. aphanidermatum, P. irregulare, P. sylvaticum, and P. ultimum, little is known about the potential for other Pythium species found in nursery soils to cause damping-off of tree seedlings. A greenhouse study was conducted to evaluate the pathogenicity and virulence of 44 Pythium isolates representing 16 species that were originally recovered from soil at three forest nurseries in Washington and Oregon. Seeds of Douglas-fir (Pseudotsuga menziesii) were planted into soil infested with each of the isolates. Seedling survival, the number of surviving seedlings with necrotic root lesions, and taproot length were evaluated 4 weeks later. Responses of Douglas-fir to inoculation varied significantly depending on Pythium species and isolate. Eight species (P. dissotocum, P. irregulare, P. aff. macrosporum, P. mamillatum, P. aff. oopapillum, P. rostratifingens, P. sylvaticum, and P. ultimum var. ultimum) significantly reduced the number of surviving seedlings compared to the noninoculated treatment. However, all Pythium species caused a greater percentage of seedlings to develop root lesions (total mean 40%) than was observed from noninoculated seedlings (17%). Taproot length varied little among Pythium treatments and was not a useful character for evaluating pathogenicity. Results confirm the ability of P. irregulare, P. mamillatum, and P. ultimum var. ultimum to cause damping-off of Douglas-fir seedlings, and are indicative that other species such as P. dissotocum, P. aff. macrosporum, P. aff. oopapillum, P. rostratifingens, and P. sylvaticum may also be responsible for seedling loss.

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