Tree age and tree species shape positive and negative interactions in a montane meadow

Botany ◽  
2010 ◽  
Vol 88 (5) ◽  
pp. 488-499 ◽  
Author(s):  
Ryan D. Haugo ◽  
Charles B. Halpern
Keyword(s):  
Pinus Contorta ◽  
Canopy Cover ◽  
Woody Species ◽  
Tree Age ◽  
Herbaceous Species ◽  
Negative Effects ◽  
Positive Effects ◽  
Forest Herbs ◽  
Montane Meadow ◽  
Meadow Species

Few studies have considered how interactions between woody and herbaceous species change in direction or magnitude over time or with traits of the dominant woody species. We used a chronosequence approach to explore these interactions in a montane meadow in which Pinus contorta Dougl. ex Loud. and Abies grandis (Dougl. ex. D. Don) Lindl. have established gradually over a period of >70 years. Effects of individual trees (18–73 years old) were quantified by comparing plant community structure and composition under and adjacent to each tree. Trees generally exerted negative effects on cover and richness of resident meadow species and positive effects on colonizing forest herbs. Despite the average decline of meadow species under the canopy, cover was elevated (compared with adjacent meadow) under 33% of trees — most often under younger Pinus . Cover (but not richness) of meadow species declined with tree age, but the rate and magnitude of this decline did not differ under Pinus or Abies . In contrast, the cover and richness of forest herbs increased steeply with age under Abies, but not under Pinus. Our results illustrate the potential for complex and sometimes unpredictable interactions between woody and herbaceous species. A dynamic view of these relationships is critical for understanding or predicting the consequences of woody plant establishment in grassland and other herb-dominated ecosystems.

Vegetation responses to conifer encroachment in a western Cascade meadow: a chronosequence approach

2007 ◽  
Vol 85 (3) ◽  
pp. 285-298 ◽  
Author(s):  
Ryan D. Haugo ◽  
Charles B. Halpern
Keyword(s):  
Forest Structure ◽  
Vegetation Change ◽  
Light Availability ◽  
Basal Area ◽  
Tree Age ◽  
Long Term Effects ◽  
Conifer Encroachment ◽  
Forest Herbs ◽  
Meadow Species ◽  
Chronosequence Approach

Conifer invasion of mountain meadows is pervasive in western North America, but its consequences for plant composition and diversity have not been studied. We used a chronosequence approach to reconstruct temporal patterns of vegetation change in response to ~200 years of conifer encroachment of a dry, montane meadow in the western Cascade Range, Oregon. Tree age distributions, forest structure, light, and vegetation composition were determined for three hundred and fifty-six 10 m × 10 m samples representing a gradient from open meadow to old forest (>90 years). Nonmetric multidimensional scaling revealed strong turnover in species composition from open meadow to old forest. Ordination axes were highly correlated with light availability and density/basal area of encroaching grand fir, Abies grandis (Dougl. ex D. Don) Lindl., and lodgepole pine, Pinus contorta Dougl. ex Loud. Cover of meadow species declined steeply with establishment of A. grandis ; richness declined more gradually and extirpations of meadow species were rare. Forest herbs colonized within two decades of tree establishment and within 60–80 years dominated the understory flora. In contrast with meadow species, changes in richness and cover of forest herbs were weakly related to changes in forest structure. Rapid replacement of meadow by forest species and long-term effects of trees on soils may limit potential for restoration of these unique habitats.

scholarly journals Residents' Attitudes towards the Residential Urban Forest in Metropolitan City: A Case Study from Bharatpur City in Nepal

2019 ◽  
Vol 16 ◽  
pp. 72-85
Author(s):  
Yam Bahadur K.C. ◽  
Sagarika Sedhai
Keyword(s):  
Urban Areas ◽  
Urban Forest ◽  
Canopy Cover ◽  
Urban Trees ◽  
Critical Element ◽  
Negative Effects ◽  
Positive Effects ◽  
Metropolitan City ◽  
Local Residents ◽  
Risk Of Fall

Urban forests are critical element in ameliorating urban habitats and building sustainable cities. Local residents are the key players in maintaining greenery of the city as they collectively own majority of land in most cities. Therefore, they need to engage in planting and retaining trees on their properties in order to reach canopy cover in urban areas. The project surveyed 200 local residents in Bharatpur Metropolitan City to examine their attitude towards trees on their property on the basis of 'Affective', 'Behavioral' and 'Cognitive' ABC model of attitude. Results show that majority of the residents have positive attitude towards trees as they have high cognitive intention towards trees, and showed willingness to retain the existing trees and add more in future. However, very few are cognizant of the environmental values of trees. The most common positive effects of trees on their property are food, shade, and clean and fresh air. The most common negative effects are increase in bushes and weeds, wildlife hazards and risk of fall due to wind. Urban planners interested in influencing residents' decisions about urban trees need to work on public outreach. Residents need to be motivated and made aware of the long term and multifunctional benefits of trees for retaining the existing trees and planting more in their property. They should also, be made aware of the type of trees that are suitable for plantation on residential property in order to avoid the problems that can be created due to trees.

Effects of post-thinning density and repeated fertilization on the growth and development of young lodgepole pine

2005 ◽  
Vol 35 (8) ◽  
pp. 1952-1964 ◽  
Author(s):  
R P Brockley
Keyword(s):  
Growth And Development ◽  
Radial Growth ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Tree Height ◽  
Negative Effects ◽  
Stand Volume ◽  
Thinning Intensity ◽  
Positive Effects ◽  
Nutrient Additions

The effects of factorial combinations of post-thinning density and fertilization on the growth and development of young lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) were investigated in central British Columbia. The effects of density and fertilization (repeated every 5 years) on tree height were small relative to the effects on stem radial growth. Tree radial growth increased with thinning intensity, whereas per-hectare growth was greatest at the highest residual density. Fertilizer effects varied across the range of residual densities tested. Tree and stand volume gains following fertilization were less, in both relative and absolute terms, at 600 trees/ha than at 1100 or 1600 trees/ha. Vigorous response of understory vegetation to nutrient additions (and strong competition for water and nutrients) may have reduced the effectiveness of fertilization on tree growth at 600 trees/ha relative to higher stand densities. Results indicate that the combined positive effects of thinning and fertilization on the growth of young lodgepole pine will accelerate stand development, thereby shortening technical rotation length. Results also indicate that significant growth gains following fertilization of thinned lodgepole pine will partially compensate for stand volume losses due to thinning. However, fertilization may be less effective at low stand densities, where negative effects of thinning on harvest volume are greatest.

scholarly journals PRE-FORCING TREATMENTS HELP BREAK BUD DORMANCY OF FORCED WOODY PLANT SPECIES

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 685d-685
Author(s):  
Guochen Yang ◽  
Paul E. Read
Keyword(s):  
Woody Plant ◽  
Woody Species ◽  
Optimum Concentration ◽  
Bud Dormancy ◽  
Bud Break ◽  
Negative Effects ◽  
Positive Effects ◽  
Forcing Solution ◽  
Almost All

A certain period of cold is needed to break bud dormancy for almost all woody species. A pre-forcing bleach soak has been demonstrated to at least partially replace this requirement (Yang and Read, 1989). Therefore, new softwood growth can be produced in the off-season. Such supple softwood growth is excellent material to be used either as explants for in vitro culture, or as cuttings for macropropagation of woody species. Further studies on pre-forcing bleach soaks were conducted to investigate optimum concentration and duration of soak, and to find the most suitable depth of bleach solution soak, in order to maximize the breaking of bud dormancy. Optimum bud break was obtained by soaking the basal 1/3 of dormant stems in 10% bleach solution for 10 minutes prior to forcing. Soaking dormant woody stems in alcohol solutions prior to placing stems in the forcing solution was also studied. The alcohol soak had negative effects on bud break of spirea, although it showed positive effects for lilac and privet.

Undesirable Effects of Goal Setting on Perceived Fairness, Commitment, and Unethical Behavior

2018 ◽  
Vol 62 (2) ◽  
pp. 97-107 ◽  
Author(s):  
Nina Keith
Keyword(s):  
Goal Setting ◽  
Unethical Behavior ◽  
The United States ◽  
Goal Commitment ◽  
Management Technique ◽  
Long Term Effects ◽  
Perceived Fairness ◽  
Negative Effects ◽  
Positive Effects ◽  
And Performance

Abstract. The positive effects of goal setting on motivation and performance are among the most established findings of industrial–organizational psychology. Accordingly, goal setting is a common management technique. Lately, however, potential negative effects of goal-setting, for example, on unethical behavior, are increasingly being discussed. This research replicates and extends a laboratory experiment conducted in the United States. In one of three goal conditions (do-your-best goals, consistently high goals, increasingly high goals), 101 participants worked on a search task in five rounds. Half of them (transparency yes/no) were informed at the outset about goal development. We did not find the expected effects on unethical behavior but medium-to-large effects on subjective variables: Perceived fairness of goals and goal commitment were least favorable in the increasing-goal condition, particularly in later goal rounds. Results indicate that when designing goal-setting interventions, organizations may consider potential undesirable long-term effects.

Mobilizing for Some

2016 ◽  
Vol 28 (3) ◽  
pp. 123-135 ◽  
Author(s):  
Raffael Heiss ◽  
Jörg Matthes
Keyword(s):  
High School ◽  
Social Media ◽  
High School Students ◽  
Experimental Design ◽  
Collective Efficacy ◽  
Political Efficacy ◽  
Negative Effects ◽  
School Students ◽  
Positive Effects ◽  
Specific Factors

Abstract. This study investigated the effects of politicians’ nonparticipatory and participatory Facebook posts on young people’s political efficacy – a key determinant of political participation. We employed an experimental design, using a sample of N = 125 high school students (15–20 years). Participants either saw a Facebook profile with no posts (control condition), nonparticipatory posts, or participatory posts. While nonparticipatory posts did not affect participants’ political efficacy, participatory posts exerted distinct effects. For those high in trait evaluations of the politician presented in the stimulus material or low in political cynicism, we found significant positive effects on external and collective efficacy. By contrast, for those low in trait evaluations or high in cynicism, we found significant negative effects on external and collective efficacy. We did not find any effects on internal efficacy. The importance of content-specific factors and individual predispositions in assessing the influence of social media use on participation is discussed.

On the diversity of the effects of the state support for agriculture

2019 ◽  
pp. 59-73 ◽  
Author(s):  
Nikolai M. Svetlov ◽  
Renata G. Yanbykh ◽  
Dariya A. Loginova
Keyword(s):  
Agricultural Production ◽  
The State ◽  
Russian Regions ◽  
Negative Effects ◽  
State Support ◽  
Soft Budget Constraints ◽  
Institutional Conditions ◽  
Positive Effects ◽  
Production Factors ◽  
Corporate Farms

In this paper, we assess the effects of agricultural state support of corporate farms on their revenues from agricultural production sales in 14 Russian regions that differ in technology, environment and institutional conditions. In addition to the direct effect of the state support, the indirect effects via labor and capital are revealed. For this purpose, we identify production functions and statistical models of production factors for each of these regions separately. We find out diverse effects of the state support on revenues among the regions. Positive effects prevail. Negative effects are mainly caused by labor reductions that follow subsidy inflows. Another cause of negative effects is the soft budget constraints phenomenon.

MORPHOLOGICAL AND BIOCHEMICAL RESPOSES OF COW PEA (CV. PUSA BARSATI) GROWN ON FLY ASH AMENDED SOIL IN PRESENCE AND ABSENCE OF MELOIDOGYNE JAVANICA AND RHIZOBIUM LEGUMINOSARUM

1970 ◽  
Vol 17 ◽  
pp. 17-22 ◽  
Author(s):  
Kamal Singh ◽  
A. A. Khan ◽  
Iram Khan ◽  
Rose Rizvi ◽  
M. Saquib
Keyword(s):  
Fly Ash ◽  
Plant Growth ◽  
Rhizobium Leguminosarum ◽  
Growth Yield ◽  
Maximum Growth ◽  
Meloidogyne Javanica ◽  
Growth And Yield ◽  
Negative Effects ◽  
Positive Effects ◽  
Insignificant Difference

Plant growth, yield, pigment and protein content of cow-pea were increased significantly at lower levels (20 and 40%) of fly ash but reverse was true at higher levels (80 and 100%). Soil amended by 60% fly ash could cause suppression in growth and yield in respect to 40% fly ash treated cow-pea plants but former was found at par with control (fly ash untreated plants). Maximum growth occurred in plants grown in soil amended with 40% fly ash. Nitrogen content of cow-pea was suppressed progressively in increasing levels of fly ash. Moreover,  Rhizobium leguminosarum  influenced the growth and yield positively but Meloidogyne javanica caused opposite effects particularly at 20 and 40% fly ash levels. The positive effects of R. leguminosarum were marked by M. javanica at initial levels. However, at 80 and 100% fly ash levels, the positive and negative effects of R. leguminosarum and/or M. javanica did not appear as insignificant difference persist among such treatments.Key words:  Meloidogyne javanica; Rhizobium leguminosarum; Fly ash; Growth; YieldDOI: 10.3126/eco.v17i0.4098Ecoprint An International Journal of Ecology Vol. 17, 2010 Page: 17-22 Uploaded date: 28 December, 2010  

Remedies in BRICS Countries

2018 ◽  
Author(s):  
Svetlana Avdasheva ◽  
Tatiana Radchenko
Keyword(s):  
South Africa ◽  
Division Of Labor ◽  
Market Performance ◽  
International Division ◽  
Negative Effects ◽  
Positive Effects ◽  
Managerial Decisions ◽  
Brics Countries ◽  
Target Company ◽  
Specific Position

Within the group of BRICS, China, Russia, and South Africa use conduct remedies more often than developed jurisdictions. Remedies are applied under merger approval or as an outcome of investigation of anticompetitive conducts. Effects of conduct remedies on companies’ decisions and market performance still need explanation. This chapter explains the use of conduct remedies, with special emphasis on Russia, by the specific position of BRICS in international division of labor, which allows the large companies, and first of all domestic ones, to discriminate customers in BRICS home markets, vis-à-vis international customers. Together with positive effects on domestic customers, competition economics predicts the possibility of negative effects of remedies on the managerial decisions within the target company. Under some circumstances, remedies may even weaken competition in the global product markets.

scholarly journals The Experiences of Grief and Personal Growth in University Students: A Qualitative Study

2021 ◽  
Vol 18 (4) ◽  
pp. 1899
Author(s):  
Jovita Tan ◽  
Karl Andriessen
Keyword(s):  
University Students ◽  
Emerging Adults ◽  
Personal Growth ◽  
Lessons Learned ◽  
Continuing Bonds ◽  
Structured Interviews ◽  
Supportive Services ◽  
Negative Effects ◽  
Positive Effects ◽  
Formal Services

Background: Experiencing the death of a close person, especially in emerging adults and students, can have profound effects on the bereaved individual’s life. As most research in this field has focused on negative effects of a loss, little is known about potential positive effects experienced by bereaved university students. This study investigated the experience of grief and personal growth in a sample of students from The University of Melbourne, Australia. Methods: Semi-structured interviews via Zoom/telephone with bereaved students (n = 14), who were invited to reflect on their loss and any personal growth potentially experienced. Thematic analysis of the data was based on a deductive and inductive approach. Results: The analysis identified four themes: (i) sharing of grief as a coping mechanism, (ii) balance between grief reactions and moving forward in life, (iii) lessons learned and personal growth, and (iv) adopting values from the deceased person and continuing bonds. Conclusions: Participants emphasized personal growth regarding self-perception and philosophical views on life. Following the loss, they preferred peer support, and used formal services only when they had a specific need. The findings indicate the importance of social support for bereaved students, and the complimentary role of peer and professional support. Hence, academic institutions should offer supportive services tailored to both students and professionals to help bereaved students.

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