Long-term effects of tanoak competition on Douglas-fir stand development

2009 ◽  
Vol 39 (4) ◽  
pp. 765-776 ◽  
Author(s):  
Timothy B. Harrington ◽  
John C. Tappeiner
Keyword(s):  
Woody Species ◽  
Douglas Fir ◽  
Long Term Effects ◽  
Canopy Layer ◽  
Mixed Stands ◽  
Stand Volume ◽  
Lithocarpus Densiflorus ◽  
Relative Cover ◽  
Selection Of

In 1- to 2-year-old Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii) plantations near Cave Junction and Glendale, Oregon, sprout clumps of tanoak (Lithocarpus densiflorus (Hook. & Arn.) Rehd.) and other hardwoods were removed with herbicides in April 1983 to leave relative covers of 0%, 25%, 50%, or 100% of the nontreated cover, which averaged 15%. In 1996 (Cave Junction) and 1998 (Glendale), precommercial thinning (PCT) of Douglas-fir and cutting of nonconifer woody species were operationally applied across the four densities of tanoak. In 2005, Douglas-fir in 0% relative cover of tanoak averaged 5–8 cm larger at breast height and 3–6 m taller, and had two to four times the net stand volume of those growing in 100% relative cover. From 1999 to 2005, Douglas-fir stand growth accelerated more rapidly in tanoak relative covers of 0% and 25% than in covers of 50% and 100%. Differential development of Douglas-fir and hardwoods in relative covers of 0%, 25%, and 100%, followed by selection of crop trees via PCT, resulted in three distinct stand structures: pure stands of Douglas-fir with a single canopy layer 12–16 m tall, mixed stands with overstory Douglas-fir (12 m) and midstory hardwoods (7 m), and mixed stands with a single canopy layer (8–9 m).

scholarly journals Crisis and Continuation: The Digital Relocation of Jain Socio-Religious Praxis during the COVID-19 Pandemic

Religions ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 342
Author(s):  
Tine Vekemans
Keyword(s):  
Digital Media ◽  
Long Term Effects ◽  
Religious Activities ◽  
Face To Face ◽  
The Social ◽  
Religious Praxis ◽  
Online Format ◽  
Media Channels ◽  
Selection Of

In early 2020, Jain diaspora communities and organizations that had been painstakingly built over the past decades were faced with the far-reaching consequences of the COVID-19 pandemic and its concomitant restrictions. With the possibility of regular face-to-face contact and participation in recurring events—praying, eating, learning, and meditating together—severely limited in most places, organizations were compelled to make a choice. They either had to suspend their activities, leaving members to organize their religious activities on an individual or household basis, or pursue the continuation of some of their habitual activities in an online format, relying on their members’ motivation and technical skills. This study will explore how many Jain organizations in London took to digital media in its different forms to continue to engage with their members throughout 2020. Looking at a selection of websites and social media channels, it will examine online discourses that reveal the social and mental impact of the pandemic on Jains and the broader community, explore the relocation of activities to the digital realm, and assess participation in these activities. In doing so, this article will open a discussion on the long-term effects of this crisis-induced digital turn in Jain religious praxis, and in socio-cultural life in general.

Immediate and potential long-term effects of consecutive heat waves on the photosynthetic performance and water balance in Douglas-fir

2016 ◽  
Vol 205 ◽  
pp. 57-66 ◽  
Author(s):  
André G. Duarte ◽  
Genki Katata ◽  
Yasutomo Hoshika ◽  
Mohitul Hossain ◽  
Jürgen Kreuzwieser ◽  
...  
Keyword(s):  
Water Balance ◽  
Heat Waves ◽  
Photosynthetic Performance ◽  
Douglas Fir ◽  
Long Term Effects

scholarly journals The 1912 Douglas-Fir Heredity Study: Long-Term Effects of Climatic Transfer Distance on Growth and Survival

2019 ◽  
Vol 118 (1) ◽  
pp. 1-13 ◽  
Author(s):  
J Bradley St. Clair ◽  
Glenn T Howe ◽  
Jennifer G Kling
Keyword(s):  
Pacific Northwest ◽  
Douglas Fir ◽  
Future Climate Change ◽  
Long Term Effects ◽  
Term Survival ◽  
Growth And Survival ◽  
Seed Sources ◽  
The Pacific ◽  
Near Term

Abstract The 1912 Douglas-Fir Heredity Study is one of the first studies undertaken by the US Forest Service, and one of the first forest genetics studies in North America. The study considers provenance variation of 120 parent trees from 13 seed sources planted at five test sites in the Pacific Northwest. The unique, long-term nature of the study makes it valuable to revisit and consider its biological and historical significance. This analysis considers how far climatically Douglas-fir populations may be moved without incurring unacceptable declines in growth and survival. Results indicate that Douglas-fir seed sources may be moved at least 2° C cooler or warmer and still retain good long-term survival and productivity. However, projected future climate change beyond 2° C may lead to lower survival and productivity. One option to address these concerns is assisted migration; however, if seed sources are moved beyond 2–3° C to a cooler climate in anticipation of warming, or from a more continental to a maritime climate, we are likely to see increased mortality and associated losses in productivity in the near-term. Lessons from this study include: (1) pay attention to good experimental design; we were able to overcome limitations from the design by using new statistical approaches; (2) maladaptation may take time to develop; poorer survival was not evident until more than two decades after planting; and (3) long-term studies may have value for addressing new, unforeseen issues in the future.

After the Dance is over: Some Issues and Suggestions for Follow-up Assessment in Behavior Therapy

1977 ◽  
Vol 41 (3_suppl) ◽  
pp. 1287-1308 ◽  
Author(s):  
Eric J. Mash ◽  
Leif G. Terdal
Keyword(s):  
Behavior Therapy ◽  
Intervention Programs ◽  
Long Term Effects ◽  
Long Time ◽  
Time Periods ◽  
Research Recommendations ◽  
Selection Of

Behavioral intervention programs have thus far failed to provide sufficient follow-up information for the evaluation of long-term effects. This omission is believed to be related to an inadequate conceptualization of follow-up assessment, as well as to the methodological and practical difficulties inherent in assessing behavior over long time periods. A framework for follow-up assessment that is consistent with current behavioral efforts to program generalization is described and is contrasted with traditional views of follow-up that look for effects following the termination of treatment. Several methodological features of follow-up assessment are discussed, along with research recommendations, including the determination of length of appropriate follow-up intervals, the frequency of follow-up assessments, the need for standardization of measures both within and between studies, reactivity of follow-up assessment, the selection of follow-up measures and attrition of subjects.

scholarly journals Social Movements and the National Question in Quebec: The Institutional Legacy of a Cleavage

2020 ◽  
Vol 53 (3) ◽  
pp. 658-675
Author(s):  
Pascale Dufour ◽  
Jean-Vincent Bergeron-Gaudin ◽  
Luc Chicoine
Keyword(s):  
Higher Education ◽  
Institutional Arrangements ◽  
Social Protest ◽  
General Level ◽  
The Political ◽  
Long Term Effects ◽  
National Question ◽  
Two Sectors ◽  
Selection Of

AbstractBy taking a historical perspective on the higher education and the housing sectors in Quebec, we demonstrate how the political cleavage around the national question has had long-term effects on the dynamic of contention in these two sectors. At a general level, the presence of this cleavage has favoured the adoption of institutional arrangements related to funding that have allowed the reproduction of social protest over time. Nevertheless, the institutional arrangements vary from one sector to another: in the case of higher education, Bill 32, adopted in 1983, facilitated the division of the student movement into two branches and, to some extent, its dynamism; in the case of housing, the AccèsLogis program and the contribution au secteur, implemented in 1997, ensured the selection of claims for social housing and favoured the grouping that leads this issue. In both cases, the national question is at the heart of the process that led to the adoption of these policies.

Modeling the long-term effects of disturbances on forest succession, Olympic Peninsula, Washington

1986 ◽  
Vol 16 (1) ◽  
pp. 56-67 ◽  
Author(s):  
Virginia H. Dale ◽  
Miles Hemstrom ◽  
Jerry Franklin
Keyword(s):  
Leaf Area ◽  
Pacific Northwest ◽  
Forest Succession ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Forest Composition ◽  
Silver Fir ◽  
Long Term Effects ◽  
Olympic Peninsula

A model of forest development has been adapted for the Pacific Northwest. The regeneration, growth, and death of individual trees are tracked for simulated 0.2 ha plots and tree attributes are aggregated to provide stand measures. The model includes the influence of temperature, soil moisture, light tolerance, and competition on tree growth. Long-term simulations for Douglas-fir dominated forests on the western Olympic Peninsula show that the stand is eventually dominated by western hemlock with silver fir being codominant. Even after 1200 years of subsequent stand development, silver fir fails to replace western hemlock indicating that this is a self-replicating and stable community. Fire, windthrows, insect disturbance, and clear-cut logging followed by replanting are incorporated into the model as single-event disturbances to a 500-year-old forest. For those cases where large Douglas-fir survive the disturbance, stand biomass and leaf area patterns are not significantly impacted until the death of the last large Douglas-fir. The projections were all carried out to the time when the forest is dominated by western hemlock and silver fir. At that time, the differential effect of the earlier disturbance is not apparent from the forest composition, biomass, or leaf area patterns except for the insect disturbance. Following the removal of all Douglas-fir by an insect, leaf area fluctuates regularly with a period of 600 years.

scholarly journals A Comparative Test on the Sensitivity of Freshwater and Marine Microalgae to Benzo-Sulfonamides, -Thiazoles and -Triazoles

2021 ◽  
Vol 11 (17) ◽  
pp. 7800
Author(s):  
Luca Canova ◽  
Michela Sturini ◽  
Federica Maraschi ◽  
Stefano Sangiorgi ◽  
Elida Nora Ferri
Keyword(s):  
Phaeodactylum Tricornutum ◽  
Aquatic Organisms ◽  
Long Term Effects ◽  
Unicellular Algae ◽  
Raphidocelis Subcapitata ◽  
Luminescent Bacteria ◽  
Contamination Levels ◽  
Species Specific ◽  
Selection Of

The evaluation of the ecotoxicological effects of water pollutants is performed by using different aquatic organisms. The effects of seven compounds belonging to a class of widespread contaminants, the benzo-fused nitrogen heterocycles, on a group of simple organisms employed in reference ISO tests on water quality (unicellular algae and luminescent bacteria) have been assessed to ascertain their suitability in revealing different contamination levels in the water, wastewater, and sediments samples. Representative compounds of benzotriazoles, benzothiazoles, and benzenesulfonamides, were tested at a concentration ranging from 0.01 to 100 mg L−1. In particular, our work was focused on the long-term effects, for which little information is up to now available. Species-specific sensitivity for any whole family of pollutants was not observed. On average, the strongest growth rate inhibition values were expressed by the freshwater Raphidocelis subcapitata and the marine Phaeodactylum tricornutum algae. R. subcapitata was the only organism for which growth was affected by most of the compounds at the lowest concentrations. The tests on the bioluminescent bacterium Vibrio fisheri gave completely different results, further underlining the need for an appropriate selection of the best biosensors to be employed in biotoxicological studies.

scholarly journals Further study of fOF2 and M(3000)F2 in different solar cycles

1994 ◽  
Vol 37 (2) ◽  
Author(s):  
P. A. Bradley
Keyword(s):  
Sunspot Number ◽  
Solar Cycles ◽  
Long Term Effects ◽  
Best Fit ◽  
Selection Of

Measured monthly median fOF2 and M(3000)F2 for Slough over six solar cycles from 1932 onwards are examined for a selection of hours and months. Data are shown as a function of twelve-monthly smoothed sunspot number. Comparisons are made for the different solar cycles and for the rising and falling halves of each cycle. Measurements for individual cycles are compared with best-fit parabolic regression lines over all cycles to investigate possible systematic long-term effects.

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