scholarly journals Relationship Between Xerophyllum tenax and Canopy Density in the Southern Cascades of Washington

2004 ◽  
Vol 19 (2) ◽  
pp. 82-87 ◽  
Author(s):  
Keith Blatner ◽  
Stewart Higgins ◽  
Becky K. Kerns ◽  
Alexis Worthington
Keyword(s):  
Large Scale ◽  
Basal Area ◽  
The United States ◽  
Dry Mass ◽  
Tree Canopy ◽  
Silver Fir ◽  
Canopy Density ◽  
Long Term Study ◽  
The Pacific ◽  
Xerophyllum Tenax

Abstract Large-scale commercial harvest of beargrass (Xerophyllum tenax) has been taking place in the Cascades of Washington and Oregon for the past 15 to 20 years. The long, slender leaves are either used fresh or dried and dyed for use in the floral industries in the United States and Europe. Our objectives were to develop a better understanding of beargrass production under different tree canopy (overstory) densities in the Pacific silver fir/big huckleberry/beargrass and the mountain hemlock/big huckleberry/beargrass plant associations in and around the Cispus Adaptive Management Area. We examined differences in beargrass production for different overstory canopy conditions on 10 sites in each association. Results indicated that beargrass quality is not of commercial grade under open canopies (<60% overstory density). For medium and high densities, the interaction between plant association and overstory density was significant for all response variables except harvestable dry mass. Harvestable dry mass of beargrass did not differ between the two associations, but was greater under medium- compared with high-density conditions. For the Pacific silver fir association, the high-overstory-density class had greater basal area of beargrass per site, and plants were larger with longer leaves compared to medium-canopy-density sites. We did not find this relationship for the mountain hemlock association, except for the longest leaf variable. It is unclear why basal area and size of beargrass were more closely related to overstory conditions for the Pacific silver fir association. Evaluation of the sustainability of beargrass as a nontimber forest product will require long-term study of the relationships among environmental variables, beargrass productivity, and beargrass population dynamics. West. J. Appl. For. 19(2):82–87.

Structure and Regeneration of Sal (Shorea robusta Gaertn. f.) Forests in Shiwalik Region of Kumaun Himalaya, India

2017 ◽  
Vol 40 (1) ◽  
pp. 1-8
Author(s):  
Bhawna Adhikari ◽  
◽  
Bhawana Kapkoti ◽  
Neelu Lodhiyal ◽  
L.S. Lodhiyal ◽  
...  
Keyword(s):  
Tree Species ◽  
Basal Area ◽  
Tree Canopy ◽  
Canopy Density ◽  
Kumaun Himalaya ◽  
Shorea Robusta ◽  
Canopy Trees ◽  
Dense Forest ◽  
Open Forest ◽  
Sal Forest

Present study was carried out to assess the structure and regeneration of Sal forests in Shiwalik region of Kumaun Himalaya. Vegetation analysis and tree canopy density was determined by using quadrat and densitometer, respectively. Density of seedlings, saplings and trees was 490-14067, 37-1233, and 273-863 ind.ha-1 respectively. The basal area was 0.12-5.44 m2 ha-1 reported for saplings and 25.4-77.6 m2 ha-1 for trees. Regeneration of Sal was found good in Sal mixed dense forest followed by Sal open forest and Sal dense forest, respectively. Regeneration of Sal was assisted by the presence of associated tree species as well as the sufficient sunlight availability on ground due to adequate opening of canopy trees in Sal forest. Thus it is concluded that the density of tree canopy, sunlight availability and also associated tree species impacted the regeneration of Sal in the region.

scholarly journals Synoptic–Dynamic Climatology of Large-Scale Cyclones in the North Pacific

2006 ◽  
Vol 134 (12) ◽  
pp. 3567-3587 ◽  
Author(s):  
Linda M. Keller ◽  
Michael C. Morgan ◽  
David D. Houghton ◽  
Ross A. Lazear
Keyword(s):  
North Pacific ◽  
Large Scale ◽  
The United States ◽  
Height Anomaly ◽  
Maximum Frequency ◽  
Mean Flow ◽  
Central Pacific ◽  
The North ◽  
The Pacific ◽  
The North Pacific

Abstract A climatology of large-scale, persistent cyclonic flow anomalies over the North Pacific was constructed using the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) global reanalysis data for the cold season (November–March) for 1977–2003. These large-scale cyclone (LSC) events were identified as those periods for which the filtered geopotential height anomaly at a given analysis point was at least 100 m below its average for the date for at least 10 days. This study identifies a region of maximum frequency of LSC events at 45°N, 160°W [key point 1 (KP1)] for the entire period. This point is somewhat to the east of regions of maximum height variability noted in previous studies. A second key point (37.5°N, 162.5°W) was defined as the maximum in LSC frequency for the period after November 1988. The authors show that the difference in location of maximum LSC frequency is linked to a climate regime shift at about that time. LSC events occur with a maximum frequency in the period from November through January. A composite 500-hPa synoptic evolution, constructed relative to the event onset, suggests that the upper-tropospheric precursor for LSC events emerges from a quasi-stationary long-wave trough positioned off the east coast of Asia. In the middle and lower troposphere, the events are accompanied by cold thickness advection from a thermal trough over northeastern Asia. The composite mean sea level evolution reveals a cyclone that deepens while moving from the coast of Asia into the central Pacific. As the cyclone amplifies, it slows down in the central Pacific and becomes nearly stationary within a day of onset. Following onset, at 500 hPa, a stationary wave pattern, resembling the Pacific–North American teleconnection pattern, emerges with a ridge immediately downstream (over western North America) and a trough farther downstream (from the southeast coast of the United States into the western North Atlantic). The implications for the resulting sensible weather and predictability of the flow are discussed. An adjoint-derived sensitivity study was conducted for one of the KP1 cases identified in the climatology. The results provide dynamical confirmation of the LSC precursor identification for the events. The upper-tropospheric precursor is seen to play a key role not only in the onset of the lower-tropospheric height falls and concomitant circulation increases, but also in the eastward extension of the polar jet across the Pacific. The evolution of the forecast sensitivities suggest that LSC events are not a manifestation of a modal instability of the time mean flow, but rather the growth of a favorably configured perturbation on the flow.

Diverse and Transnational: Chinese (PRC) Immigrants in the United States

2007 ◽  
Vol 3 (1) ◽  
pp. 122-145 ◽  
Author(s):  
Xia-Huang Yin
Keyword(s):  
United States ◽  
Large Scale ◽  
The United States ◽  
Immigrant Group ◽  
Recent Immigrants ◽  
American Experience ◽  
The Pacific ◽  
Socioeconomic Diversity ◽  
American Society ◽  
The U.S

AbstractThis article studies characteristics of recent immigrants from China (PRC) in the United States, especially their socioeconomic status and networking with their native land. The unprecedented, large-scale, and highly diversified immigration from China to the U.S. since the late 1970s has not only turned the Chinese into the second largest immigrant group in American society, but has also created new opportunities for interpretation of the Chinese diasporic experience. By examining the socioeconomic diversity among PRC immigrants in their American life and the extensive networks they have established across the Pacific, the article shows how class, ethnicity, and transnationality work at cross purposes in the Chinese American experience and sheds light on the new dynamics in overseas Chinese communities in this rapidly changing era.

Soil seed banks in primary and secondary deciduous forest in Białowieża, Poland

1997 ◽  
Vol 7 (3) ◽  
pp. 281-292 ◽  
Author(s):  
Małgorzata Jankowska-Błaszczuk ◽  
Peter J. Grubb
Keyword(s):  
Seed Bank ◽  
Large Scale ◽  
Deciduous Forest ◽  
Secondary Forest ◽  
Dry Mass ◽  
Seed Banks ◽  
Tree Canopy ◽  
Soil Seed Banks ◽  
Soil Group ◽  
Group B

AbstractGermination over 3 years was followed in 25 soil samples of 31 × 31 × 5 cm each from primary and secondary stands in Białowieża forest, Poland. The number of seedlings emerging and the number of species declined over the 3 years. In year 1 the mean densities of emerging seedlings for the primary and secondary stands were similar (2142 m−2 and 2488 m−2 respectively); in year 3 the difference was greater (248 vs 498 m−2) but not statistically significant. The trend reflected the greater longevity of the seed bank species characteristic of the secondary forest. Two functional groups of herb and shrub species were distinguished in the seed bank based on (a) frequency as adults in the present vegetation, and (b) relative abundance in the seed banks of primary and secondary forest. Group A species need large-scale gaps in the tree canopy; most have very small seeds (<0.15 mg mean dry mass) and are very persistent in the soil. Group B species benefit from single-treefall gaps in the tree canopy, but appear to be suited primarily to gaps in the canopy of the herb layer and in the root layer made mainly by animals; their seeds are not as small (mostly >0.15 mg) and not as persistent in the soil. Group B species made up 86% of the seedlings emerging over 3 years in soil from the primary stand, and 56% of those from the secondary stand. In the laboratory all five Group B species tested showed some inhibition of germination in darkness, but only one showed unequivocal inhibition by far-red-enrichment of low irradiance light.

scholarly journals Herbicide Resistance, Tillage, and Community Management in the Pacific Northwest

2021 ◽  
Vol 13 (4) ◽  
pp. 1937
Author(s):  
Katherine Dentzman ◽  
Ian Cristofer Burke
Keyword(s):  
Pacific Northwest ◽  
Herbicide Resistance ◽  
Large Scale ◽  
Conservation Tillage ◽  
Resistance Management ◽  
The United States ◽  
Community Management ◽  
Herbicide Resistant ◽  
The Pacific ◽  
Fail Safe

The use of glyphosate as a replacement for tillage has been credited with spurring the adoption of conservation tillage in the United States. With herbicide-resistant weeds becoming a significant agronomic problem, however, it is unclear whether conservation tillage gains are in danger of being reversed as farmers turn to tillage to manage weeds that herbicides can no longer kill. Using 2015 focus groups, a 2016 national survey, and an ongoing Community Herbicide Resistance Management Initiative in four communities of the Pacific Northwest we assess the following questions: (1) How do U.S. farmers view tillage as an option for controlling herbicide-resistant weeds, (2) Do attitudes towards and experience with herbicide-resistant increase farmers’ usage of tillage, and (3) Can community management provide an avenue for maintaining conservation tillage while also increasing effective management of herbicide-resistant weeds? We find that many farmers consider tillage to be an emergency fail-safe in managing weeds, that there is a complex relationship between herbicide resistance awareness, concern, and tillage use that can be partly explained by experience and dedication to conservation tillage, and finally that community management has the potential to provide the support and resources necessary to prevent a large-scale increase in tillage related to herbicide resistance management.

Missionary Rescue and the Transnational Making of Family

Framed by War ◽  
2019 ◽  
pp. 86-111
Author(s):  
Susie Woo
Keyword(s):  
South Korea ◽  
Large Scale ◽  
The United States ◽  
Korean Children ◽  
American Missionaries ◽  
South Korean ◽  
The Pacific ◽  
National Welfare ◽  
Set Up ◽  
First World

The war resulted in over three million Korean deaths and an estimated 100,000 children left homeless. The scale of need opened the door wide to nongovernmental US citizens who flooded South Korea to spearhead recovery efforts. American missionaries led the call. They set up over five hundred orphanages by the war’s end and administered care in a country that, unlike the United States, did not have an established national welfare program. The chapter examines how US officials initially welcomed the work of missionaries because they helped to resolve the civilian crisis while promoting Cold War visions of American benevolence, but were soon at odds with missionaries who openly criticized US servicemen for abandoning their mixed-race children in Korea. What began as a humanitarian and proselytizing effort in South Korea turned into an adoption movement that spanned the Pacific. Missionaries like evangelist Harry Holt and internationalist Pearl Buck connected constituencies back home to Korean children, imbuing Americans with a perceived First World responsibility over Third World children. The mobilization of Americans interested in seeing these adoptions through pressured the US and South Korean governments to create permanent adoption laws that set the stage for large-scale transnational adoptions the world over.

scholarly journals Plentern mit Kiefern – Ergebnisse aus den USA

2017 ◽  
Vol 168 (2) ◽  
pp. 75-83 ◽  
Author(s):  
James M. Guldin ◽  
Don C. Bragg ◽  
Andreas Zingg
Keyword(s):  
Loblolly Pine ◽  
Tree Species ◽  
Large Scale ◽  
Stand Structure ◽  
Basal Area ◽  
Natural Disturbance ◽  
The United States ◽  
Volume Control ◽  
Pinus Echinata ◽  
Shortleaf Pine

Plentering with pines – results from the United States Until now, scientifically reliable data on plentering of light-demanding tree species in Europe have been lacking. This gap is filled with long-term trials from the USA, among others with southern yellow pines. In the southern state of Arkansas, two plots of 16 hectares were installed in 1936, in the context of a large-scale trial of mixed loblolly pine (Pinus taeda L.) and shortleaf pine (Pinus echinata Miller) stands, in which plentering has been applied using single-tree harvest of predominantly sawtimber-sized trees (dbh &gt;30 cm) with natural regeneration. The aim of the experiment is to investigate the possibilities and limits of uneven-aged silviculture with shade-intolerant tree species, and whether this can be applied in cutover southern yellow pine stands in order to improve the stand structure, to increase growth, and to make periodic harvests possible. The two plots were in different initial states – one more or less fully stocked, the other with poor initial stocking. Since 1936, 18 complete surveys have been conducted where all trees 10 cm and larger were tallied by diameter. During that same time period, 14 plenter harvests have been carried out using the Volume Control-Guiding Diameter Limit method in both plots. In order to check the variability of stand structure within the 16-hectare stands, each was subdivided into four quarters, and the diameter distributions were compared within each quarter. The uneven- aged structure was checked by a sample of tree-ring counts. Both stands retained continuous canopy cover throughout the observation period. The initial differences in the number of stems, the basal area, the standing volume, the proportion of sawtimber, the average basal area and the mean quadratic diameter dg became alike in the course of time, which shows the flexibility of plentering and the tendency to develop stands where the harvest of growth appears to be sustainable. The dg of the harvest was initially slightly more than 20 cm, but is today more than 50 cm. The average total growth is 6 m3/ha and year. The results show that these stands are uneven-aged stands in an advanced stage of the transformation to plentering. We suspect that in the absence of a major natural disturbance event, the plentering approach in southern yellow pines will continue to be promising in the future.

Use of Oyster Shell to Enhance Intertidal Habitat and Mitigate Loss of Dungeness Crab (Cancer magister) Caused by Dredging

1993 ◽  
Vol 50 (2) ◽  
pp. 381-390 ◽  
Author(s):  
Brett R. Dumbauld ◽  
David A. Armstrong ◽  
Trent L. McDonald
Keyword(s):  
Pacific Northwest ◽  
Large Scale ◽  
Oyster Shell ◽  
The United States ◽  
Dungeness Crab ◽  
Cancer Magister ◽  
Pacific Northwest Coast ◽  
Intertidal Crab ◽  
The Pacific ◽  
Scale 8

Juvenile Dungeness crab (Cancer magister) recruit to intertidal areas in estuaries along the Pacific Northwest coast of the United States in May and June of each year and survive best through their first summer in shell or eelgrass habitat. Experiments were initiated in Grays Harbor, Washington, to investigate the potential of using shell to enhance intertidal crab habitat as a means to augment the crab resource and mitigate losses from the subtidal population that occur during dredging. Experimental plots (225 m2) were constructed prior to crab settlement at each of three intertidal locations using three configurations of oyster shell (heavy layer, light scattering, and small piles of shell). Resulting crab densities were comparable with those found in naturally occurring shell with high numbers (20–60 crab∙m−2) observed during settlement that declined to a relatively stable density of 10 crab∙m−2 in July and August. Crab survival was highest in both heavy and pile configurations, but the heavy shell configuration remained intact the longest. This enhancement experiment has become the impetus for a large-scale (8 ha) mitigation program in 1992 as part of a dredging project completed in 1990 in Grays Harbor.

Quality Control of Data in a Large-Scale Cancer Register Program

1966 ◽  
Vol 05 (02) ◽  
pp. 67-74 ◽  
Author(s):  
W. I. Lourie ◽  
W. Haenszeland
Keyword(s):  
United States ◽  
Quality Control ◽  
Cancer Patients ◽  
Large Scale ◽  
The United States ◽  
Newly Diagnosed ◽  
Related Data ◽  
Cancer Register ◽  
Independent Review ◽  
End Results

Quality control of data collected in the United States by the Cancer End Results Program utilizing punchcards prepared by participating registries in accordance with a Uniform Punchcard Code is discussed. Existing arrangements decentralize responsibility for editing and related data processing to the local registries with centralization of tabulating and statistical services in the End Results Section, National Cancer Institute. The most recent deck of punchcards represented over 600,000 cancer patients; approximately 50,000 newly diagnosed cases are added annually.Mechanical editing and inspection of punchcards and field audits are the principal tools for quality control. Mechanical editing of the punchcards includes testing for blank entries and detection of in-admissable or inconsistent codes. Highly improbable codes are subjected to special scrutiny. Field audits include the drawing of a 1-10 percent random sample of punchcards submitted by a registry; the charts are .then reabstracted and recoded by a NCI staff member and differences between the punchcard and the results of independent review are noted.

Petrels collected by Titian Ramsay Peale in the Pacific Ocean during the United States Exploring Expedition of 1838–1842

2008 ◽  
Vol 35 (1) ◽  
pp. 143-149 ◽  
Author(s):  
W. R. P. BOURNE
Keyword(s):  
United States ◽  
Pacific Ocean ◽  
The United States ◽  
Important Type ◽  
The Pacific ◽  
The Pacific Ocean

The report by Titian Ramsay Peale on birds encountered during the Wilkes Expedition was withdrawn for inaccuracy when few copies had been distributed, and re-written by John Cassin. A survey of the accounts of the petrels shows that this was not an improvement. Two important type localities for Procellaria brevipes and Thalassidroma lineata are probably wrong, and could be exchanged.

Sign in / Sign up

Export Citation Format

Share Document