Seven decades of stand development in mixed and pure stands of conifers and nitrogen-fixing red alder

2003 ◽  
Vol 33 (11) ◽  
pp. 2274-2279 ◽  
Author(s):  
Dan Binkley
Keyword(s):  
Pseudotsuga Menziesii ◽  
Mixed Stand ◽  
Alnus Rubra ◽  
Stand Development ◽  
Soil N ◽  
Ecosystem Productivity ◽  
Red Alder ◽  
The Past ◽  
River Site

Early insights on the effects of N2-fixing red alder (Alnus rubra Bong.) on conifer forests came largely from two case studies dating from the 1920s at Wind River, Washington (low soil N), and Cascade Head, Oregon (high soil N). These classic experiments were remeasured after 70 years of stand development. The pure conifer stand at Wind River showed near-zero net increment in stem mass for the past 20 years, with stem mass remaining near 120 Mg/ha. Conifer stem mass in the mixed stand continued to increase at 4.5 Mg·ha–1·year–1, reaching 230 Mg/ha at age 72. The alder mass declined over this period from about 70 Mg/ha near age 50 to just 10 Mg/ha at age 72 as a result of increasing dominance of tall Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. The pure conifer plot at Cascade Head reached a stem mass of 600 Mg/ha at age 74 years compared with 312 Mg/ha in the mixed stand (conifers, 200 Mg/ha; alder, 112 Mg/ha) and 173 Mg/ha in the pure alder plot. The long-term impacts of alder appeared to remain very strong after seven decades, greatly increasing ecosystem productivity at the N-poor Wind River site and reducing productivity at the N-rich Cascade Head site.

Spatial extent of impact of red alder on soil chemistry of adjacent conifer stands

1992 ◽  
Vol 22 (9) ◽  
pp. 1434-1437 ◽  
Author(s):  
Charles C. Rhoades ◽  
Dan Binkley
Keyword(s):  
Soil Ph ◽  
Soil Chemistry ◽  
Douglas Fir ◽  
Spatial Extent ◽  
N Availability ◽  
Soil N ◽  
Mixed Stands ◽  
Red Alder ◽  
Soil N Availability ◽  
River Site

We examined patterns in soil N availability and pH along transects extending from mixed stands of conifers (mostly Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco)) and red alder (Alnusrubra Bong.) to pure conifer stands at two locations. At the relatively infertile Wind River site, increased N availability was apparent for about 8–12 m downslope of the alder–conifer stand, but no effect was apparent upslope. At the fertile Cascade Head site, no trend was apparent in N availability across the stand boundaries, but soil pH in the conifer stand was depressed for about 5 m from the alder–conifer stand. Overall, the effects of alder on soil chemistry appeared limited to a distance of less than half the height of the trees.

scholarly journals Ten-Year Survival and Growth of Planted Douglas-Fir and Western Redcedar After Seven Site-Preparation Treatments

1997 ◽  
Vol 12 (3) ◽  
pp. 74-80 ◽  
Author(s):  
William I. Stein
Keyword(s):  
Pseudotsuga Menziesii ◽  
Site Preparation ◽  
Douglas Fir ◽  
Thuja Plicata ◽  
Alnus Rubra ◽  
Red Alder ◽  
Preparation Methods ◽  
Western Redcedar ◽  
Oregon Coast ◽  
Survival And Growth

Abstract Western redcedar (Thuja plicata) and Douglas-fir (Pseudotsuga menziesii) were planted together after applying seven site-preparation methods at one site in the Oregon Coast Ranges. Survival and growth of cedar were markedly less than Douglas-fir on this favorable site where both species were components of the original stand. Repeated browsing severely impeded the cedar. Site preparation by broadcast burning generally yielded the best results, but sowing grass after broadcast burning produced Douglas-fir responses similar to those for no site preparation. Where grass was sown, herbaceous cover was more abundant and taller, salmonberry differed little in density but was slightly taller, and development of red alder (Alnus rubra) was delayed. Red alder is currently overtopping conifers in all treatments, and release is needed to ensure sufficient conifer survival. This single example illustrates that much more effort than just planting a mix of species is required to establish a desired mixed stand. West. J. Appl. For. 12(3):74-80.

Silvicultural Value of Chemical Brush Control in the Management of Douglas-fir

1986 ◽  
Vol 1 (3) ◽  
pp. 69-73
Author(s):  
J. D. Walstad ◽  
J. D. Brodie ◽  
B. C. McGinley ◽  
C. A. Roberts
Keyword(s):  
Economic Value ◽  
Douglas Fir ◽  
Alnus Rubra ◽  
Economic Returns ◽  
Red Alder ◽  
The Third ◽  
Brush Control ◽  
Phenoxy Herbicides ◽  
Stand Conditions

Abstract Retrospective analyses of three conifer sites in western Oregon and Washington were conducted to determine the long-term silvicultural impact and economic value of chemical brush control treatments performed 10 to 25 years earher. Comparisons between areas treated with phenoxy herbicides and untreated areas of the sites revealed significant differences in stocking and growth of Douglas-fir (Pseudotsuga menziesii). On two sites, invading red alder (Alnus rubra) virtually excluded conifers in the absence of brush control. On the untreated area of the third site, dense growth of varnishleaf ceanothus (Ceanothus velutinus var. laevigatus) reduced Douglas-fir stocking and diameter growth. On all three sites, projections of mature yield and economic returns based on current stand conditions indicated substantial benefits for areas where brush control treatments were applied. West. J. Appl. For. 1:69-73, July 1986.

Density and rectangularity of planting influence 20-year growth and development of red alder

2002 ◽  
Vol 32 (7) ◽  
pp. 1244-1253 ◽  
Author(s):  
Dean S DeBell ◽  
Constance A Harrington
Keyword(s):  
Tree Growth ◽  
Growth And Development ◽  
Tree Height ◽  
Planting Density ◽  
Alnus Rubra ◽  
Stand Development ◽  
Red Alder ◽  
Management Guidelines ◽  
Stand Characteristics ◽  
Related Mortality

Red alder (Alnus rubra Bong.) seedlings were planted in northwestern Oregon, U.S.A., at five initial spacings: 0.6 × 1.2 m, 1.2 × 1.2 m, 1.2 × 1.8 m, 1.8 × 1.8 m, and 2.5 × 2.5 m. Up to about age 10, tree and stand characteristics were correlated primarily with initial planting density in the expected manner; through age 20, however, tree growth and stand development in plots planted at rectangular spacings were substantially more rapid than in the two closest square spacings. Mean stand diameter ranged from 19.2 cm in the widest spacing to 14.0 cm in the closest square (1.2 × 1.2 m) spacing; mean tree height decreased from nearly 24 m in the widest (2.5 × 2.5 m) spacing to about 18 m in the closest square spacing. Diameter–density relationships in the widest spacing were consistent with existing density management guidelines, but very dense spacings and rectangular plantings began to experience substantial mortality at smaller diameters than assumed in the guidelines. We suggest that rectangular planting of red alder at dense spacing enhanced stand differentiation, accelerated competition-related mortality, and thus led to improved growth of surviving trees.

Potential effects of climate change on stand development in the Pacific Northwest

1989 ◽  
Vol 19 (12) ◽  
pp. 1581-1590 ◽  
Author(s):  
Virginia H. Dale ◽  
Jerry F. Franklin
Keyword(s):  
Leaf Area ◽  
Pacific Northwest ◽  
Aboveground Biomass ◽  
Stem Density ◽  
Stand Development ◽  
Climatic Warming ◽  
Climate Trends ◽  
The Past ◽  
The Pacific

Long-term climate and stand structure records and projections from a simulation model are used to explore effects of predicted changes in temperature on forest development in the Pacific Northwest. Few climate trends have occurred during the past 92 years, although there have been variations in September temperatures. The lack of climate trends makes it impossible to relate past changes in stand development to climate. Measures of stand development from six long-term forest plots over the past 7 decades are typical of Douglas-fir stands: stem density declines, leaf area stabilizes, aboveground biomass increases, and shifts in size distribution occur. These changes are consistent with patterns of natural succession. A computer model projected forest development under two climate scenarios: current temperature conditions and temperature warming (such as that predicted under a doubling of atmospheric CO2). The model predicted changes in species composition, leaf area, and stem density in response to temperature increases. Total aboveground biomass is not sensitive to the simulated temperature alterations. Predicted biomass stability suggests that the Pacific Northwest forest would continue to store large amounts of carbon in the living trees even with climatic warming. Therefore, the predicted temperature change would not alter the role of the Pacific Northwest forests as a major storage location of terrestrial carbon. Changes in precipitation patterns or in disturbance frequency or intensity that might occur with climatic warming could alter these predictions.

Enabling Community Well-being Self-Monitoring in the Context of Mining: The Naskapi Nation of Kawawachikamach

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Robert Klinck ◽  
Ben Bradshaw ◽  
Ruby Sandy ◽  
Silas Nabinacaboo ◽  
Mannie Mameanskum ◽  
...  
Keyword(s):  
Indigenous Peoples ◽  
Well Being ◽  
Aboriginal Community ◽  
Self Monitoring ◽  
Community Engaged Research ◽  
The Past ◽  
Mineral Development ◽  
Iron Deposits ◽  
Term Monitoring

The Naskapi Nation of Kawawachikamach is an Aboriginal community located in northern Quebec near the Labrador Border. Given the region’s rich iron deposits, the Naskapi Nation has considerable experience with major mineral development, first in the 1950s to the 1980s, and again in the past decade as companies implement plans for further extraction. This has raised concerns regarding a range of environmental and socio-economic impacts that may be caused by renewed development. These concerns have led to an interest among the Naskapi to develop a means to track community well-being over time using indicators of their own design. Exemplifying community-engaged research, this paper describes the beginning development of such a tool in fall 2012—the creation of a baseline of community well-being against which mining-induced change can be identified. Its development owes much to the remarkable and sustained contribution of many key members of the Naskapi Nation. If on-going surveying is completed based on the chosen indicators, the Nation will be better positioned to recognize shifts in its well-being and to communicate these shifts to its partners. In addition, long-term monitoring will allow the Naskapi Nation to contribute to more universal understanding of the impacts of mining for Indigenous peoples.

Courting the Youth Vote in 2008: The Obama Effect

2009 ◽  
Vol 5 ◽  
Author(s):  
Lindsey C Bohl
Keyword(s):  
Presidential Elections ◽  
Voter Registration ◽  
The Internet ◽  
The Past ◽  
Several Variables ◽  
High Turnout ◽  
Short And Long Term ◽  
Use Of The Internet ◽  
Youth Vote

This paper examines a few of the numerous factors that may have led to increased youth turnout in 2008 Election. First, theories of voter behavior and turnout are related to courting the youth vote. Several variables that are perceived to affect youth turnout such as party polarization, perceived candidate difference, voter registration, effective campaigning and mobilization, and use of the Internet, are examined. Over the past 40 years, presidential elections have failed to engage the majority of young citizens (ages 18-29) to the point that they became inclined to participate. This trend began to reverse starting in 2000 Election and the youth turnout reached its peak in 2008. While both short and long-term factors played a significant role in recent elections, high turnout among youth voters in 2008 can be largely attributed to the Obama candidacy and campaign, which mobilized young citizens in unprecedented ways.

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