scholarly journals The Impact of Competition and Allelopathy on the Trade-Off between Plant Defense and Growth in Two Contrasting Tree Species

2016 ◽  
Vol 7 ◽  
Author(s):  
Catherine Fernandez ◽  
Yogan Monnier ◽  
Mathieu Santonja ◽  
Christiane Gallet ◽  
Leslie A. Weston ◽  
...  
Keyword(s):  
Plant Defense ◽  
Tree Species ◽  
Trade Off ◽  
The Impact

scholarly journals Effect of Competition and Climatic Conditions on the Growth of Beech in the Mixed Pine Beech Stand: Lithuanian Case Study

2020 ◽  
Vol 3 (1) ◽  
pp. 49
Author(s):  
Edgaras Linkevičius ◽  
Gerda Junevičiūtė
Keyword(s):  
Intraspecific Competition ◽  
Tree Species ◽  
Forest Growth ◽  
Competition Effect ◽  
Diameter Increment ◽  
Cart Analysis ◽  
Crown Width ◽  
Beech Stand ◽  
Negative Effect ◽  
The Impact

Climate change and warming will potentially have profound effects on forest growth and yield, especially for pure stands in the near future. Thus, increased attention has been paid to mixed stands, e.g., pine and beech mixtures. However, the interaction of tree species growing in mixtures still remains unknown. Thus, the aim of this study was to investigate the impact of the interspecific and intraspecific competition to diameter, height, and crown width of pine and beech trees growing in mixtures, as well as to evaluate the impact of climatic indicators to the beech radial diameter increment. The data was collected in 2017 at the mixed mature pine beech double layer stand, located in the western part of Lithuania. The sample plot of 1.2 hectare was established and tree species, diameter at the breast height, tree height, height-to-crown base, height-to-crown width, and position were measured for all 836 trees. Additionally, a representative sample of radial diameter increments were estimated only for the beech trees by taking out core discs at the height of 1 m when the stand was partially cut. Competition analysis was based on the distance-dependent competition index, which was further based on crown parameters. Climatic effect was evaluated using classification and regression tree (CART) analysis. We found almost no interspecific competition effect to diameter, height, or crown width for both tree species growing in the first layer. However, it had an effect on beeches growing in the second layer. The intraspecific competition effect was important for pine and beech trees, showing a negative effect for both of them. Our results show the possible coexistence of these tree species due to niche differentiation. An analysis of climatic indicators from 1991–2005 revealed that precipitation from February–May of the current vegetation year and mean temperatures from July to September expressed radial diameter increment effects for beech trees. Low temperatures during March and April, as well as high precipitation during January, had a negative effect on beech radial increments. From 2006–2016, the highest effect on radial diameter increments was the mean temperatures from July to September, as well as the precipitation in January of the current year. From 1991–2016, the highest effect on radial diameter increments was the temperature from July to September 1991–2016 and the precipitation in June 1991–2016. Generally, cool temperatures and higher precipitation in June had a positive effect on beech radial increments. Therefore, our results show a sensitivity to high temperatures and droughts during summer amid Lithuanian’s growth conditions.

scholarly journals Market buoyancy, information transparency and pricing strategy in the Scottish housing market

Urban Studies ◽  
2021 ◽  
pp. 004209802199178
Author(s):  
Nan Liu
Keyword(s):  
Pricing Strategy ◽  
Selling Price ◽  
Trade Off ◽  
Information Transparency ◽  
North East ◽  
Sealed Bid ◽  
Strategy Changes ◽  
The Impact ◽  
Role Of Information

In housing markets there is a trade-off between selling time and selling price, with pricing strategy being the balancing act between the two. Motivated by the Home Report scheme in Scotland, this paper investigates the role of information symmetry played in such a trade-off. Empirically, this study tests if sellers’ pricing strategy changes when more information becomes available and whether this, in turn, affects the trade-off between the selling price and selling time. Using housing transaction data of North-East Scotland between 1998Q2 and 2018Q2, the findings show that asking price has converged to the predicted price of the property since the introduction of the Home Report. While information transparency reduces the effect of ‘overpricing’ on selling time, there is little evidence to show that it reduces the impact of pricing strategy on the final selling price in the sealed-bid context.

Interrelationship Among Competition, Diversification and Liquidity Creation: Evidence from Indian Banks

2021 ◽  
Vol 15 (2) ◽  
pp. 183-204
Author(s):  
Pankaj Sinha ◽  
Naina Grover
Keyword(s):  
Inverse Relationship ◽  
Consumer Welfare ◽  
Adverse Impact ◽  
Public And Private ◽  
Jel Codes ◽  
Trade Off ◽  
Private Banks ◽  
Indian Banks ◽  
The Impact

This study analyses the impact of competition on liquidity creation by banks and investigates the dynamics between diversification, liquidity creation and competition for banks operating in India during the period from 2005 to 2018. Using the broad and narrow measures of liquidity creation, an inverse relationship is determined between liquidity creation and competition. The study also indicates a trade-off between pro-competitive policies to improve consumer welfare and the liquidity-destroying effects of competition, and it highlights how diversification affects liquidity creation. Highly diversified banks in India create less liquidity compared with less-diversified banks, both public and private. The liquidity-destroying effects of competition is intensified among highly diversified private banks, which suggest that diversification has not moderated the adverse impact of competition. JEL Codes: G01, G18, G21, G28

scholarly journals Beavers, Bugs and Chemistry: A Mammalian Herbivore Changes Chemistry Composition and Arthropod Communities in Foundation Tree Species

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 877
Author(s):  
Rachel M. Durben ◽  
Faith M. Walker ◽  
Liza Holeski ◽  
Arthur R. Keith ◽  
Zsuzsi Kovacs ◽  
...  
Keyword(s):  
Tree Species ◽  
Castor Canadensis ◽  
Habitat Type ◽  
Food Preferences ◽  
Woody Species ◽  
Juvenile Growth ◽  
Arthropod Community ◽  
Riparian Ecosystems ◽  
Arthropod Communities ◽  
The Impact

The North American beaver (Castor canadensis Kuhl) and cottonwoods (Populus spp.) are foundation species, the interactions of which define a much larger community and affect a threatened riparian habitat type. Few studies have tested the effect of these interactions on plant chemistry and a diverse arthropod community. We experimentally examined the impact of beaver foraging on riparian communities by first investigating beaver food preferences for one cottonwood species, Fremont cottonwood (P. fremontii S. Watson), compared to other locally available woody species. We next examined the impact of beaver foraging on twig chemistry and arthropod communities in paired samples of felled and unfelled cottonwood species in northern Arizona (P. fremontii) and southwestern Colorado (narrowleaf cottonwood, P. angustifolia James, and Eastern cottonwood, P. deltoides W. Bartram ex Marshall). Four major patterns emerged: (1) In a cafeteria experiment, beavers chose P. fremontii six times more often than other woody native and exotic species. (2) With two cottonwood species, we found that the nitrogen and salicortin concentrations were up to 45% greater and lignin concentration 14% lower in the juvenile resprout growth of felled trees than the juvenile growth on unfelled trees (six of seven analyses were significant for P. fremontii and four of six were significant for P. angustifolia). (3) With two cottonwood species, arthropod community composition on juvenile branches differed significantly between felled and unfelled trees, with up to 38% greater species richness, 114% greater relative abundance and 1282% greater species diversity on felled trees (six of seven analyses with P. fremontii and four of six analyses with P. angustifolia were significant). The above findings indicate that the highest arthropod diversity is achieved in the heterogenous stands of mixed felled and unfelled trees than in stands of cottonwoods, where beavers are not present. These results also indicate that beaver herbivory changes the chemical composition in 10 out of 13 chemical traits in the juvenile growth of two of the three cottonwood species to potentially allow better defense against future beaver herbivory. (4) With P. deltoides, only one of five analyses in chemistry was significant, and none of the four arthropod community analyses were significant, suggesting that this species and its arthropod community responds differently to beaver. Potential reasons for these differences are unknown. Overall, our findings suggest that in addition to their impact on riparian vegetation, other mammals, birds, and aquatic organisms, beavers also may define the arthropod communities of two of three foundation tree species in these riparian ecosystems.

Restoration of floral diversity through plantations on abandoned agricultural land

2006 ◽  
Vol 36 (5) ◽  
pp. 1218-1235 ◽  
Author(s):  
Steven G Newmaster ◽  
F Wayne Bell ◽  
Christopher R Roosenboom ◽  
Heather A Cole ◽  
William D Towill
Keyword(s):  
Plant Diversity ◽  
Tree Species ◽  
Agricultural Land ◽  
Structural Diversity ◽  
Geographic Region ◽  
Natural Forests ◽  
Community Interactions ◽  
Long Term Study ◽  
Floral Diversity ◽  
The Impact

Plantations have been claimed to be "monocultures", or "biological deserts". We investigated these claims in the context of a long-term study on plant diversity within plantations with different indigenous tree species, spacings, and soil types that were compared with 410 native stands. Soil type had no influence on plantation species diversity or abundance, and wider spacing resulted in higher richness, lower woody plant abundance, slightly higher cover of herbaceous plants, and large increases in cryptogam cover. We also found a canopy species × spacing interaction effect, where the impact of increased spacing on understory vegetation was more pronounced in spruce than in pine plantations. The dynamic community interactions among species of feathermoss appear to be in response to the physical impediment from varying amounts of needle rain from the different tree species. High light interception and needle fall were negatively correlated with understory plant diversity, as was lack of structural diversity. This study indicates that through afforestation efforts agricultural lands can be restored to productive forests that can harbour nearly one-half of the plant species found in equivalent natural forests within the same geographic region in as little as 50 years. We recommend applying afforestation using indigenous conifer species as a first step towards rehabilitating conifer forests that have been converted to agriculture and subsequently abandoned.

scholarly journals Assessing the evidence on case management

2002 ◽  
Vol 181 (1) ◽  
pp. 17-21 ◽  
Author(s):  
S. J. Ziguras ◽  
G. W. Stuart ◽  
A. C. Jackson
Keyword(s):  
Mental Health ◽  
Case Management ◽  
Statistical Power ◽  
Cochrane Collaboration ◽  
Randomised Trials ◽  
Inclusion Criteria ◽  
Management Effectiveness ◽  
Trade Off ◽  
The Cochrane Collaboration ◽  
The Impact

BackgroundEvidence on the impact of case management is contradictory.AimsTo discuss two different systematic reviews (one conducted by the authors and one conducted through the Cochrane collaboration) that came to contradictory conclusions about the impact of case management in mental health services.MethodWe summarised the findings of the two reviews with respect to case management effectiveness, examined key methodological differences between the two approaches and discuss the impact of these on the validity of the results.ResultsThe differences in conclusions between the two reviews result from the differences in inclusion criteria, namely non-randomised trials, data from unpublished scales and data from variables with skewed distributions. The theoretical and empirical effects of these are discussed.ConclusionsSystematic reviewers may face a trade-off between the application of strict criteria for the inclusion of studies and the amount of data available for analysis and hence statistical power. The available research suggests that case management is generally effective.

120 The Experience of Housing Need Amongst Families Caring for Children with Medical Complexity: A Qualitative Study

2021 ◽  
Vol 26 (Supplement_1) ◽  
pp. e85-e88
Author(s):  
Clara Moore ◽  
Kara Grace Hounsell ◽  
Arielle Zahavi ◽  
Danielle Arje ◽  
Natalie Weiser ◽  
...  
Keyword(s):  
Qualitative Study ◽  
Future Research ◽  
Complex Care ◽  
Housing Situation ◽  
Children With Medical Complexity ◽  
Trade Off ◽  
Housing Preferences ◽  
Medical Needs ◽  
Medical Complexity ◽  
The Impact

Abstract Primary Subject area Complex Care Background Caregivers of children with medical complexity (CMC) face many financial, social and emotional stressors related to their child’s medical condition(s). Previous research has demonstrated that financial stress among this population can have an impact on their housing situation. Families of CMC may face other unique housing challenges such as disability accommodations in the home and housing space and layout. Objectives The primary aim of this study was to explore families’ perspectives and experiences of housing need, and its relationship to their child’s health status as it pertains to CMC. Design/Methods We conducted a qualitative study using semi-structured interviews to identify themes surrounding families of CMC’s experiences of housing need. Parents of CMC were recruited through purposive sampling from the Complex Care Program at a tertiary pediatric health sciences centre. Recruitment ceased when thematic saturation was reached, as determined by consensus of the research team. Interviews were recorded, transcribed verbatim, coded, and analyzed using thematic analysis. Results Twenty parents completed the interview, of whom 89% were mothers and 42% identified a non-English language as their first language. Two major themes and five subthemes (in parentheses) were identified: 1) the impact of health on housing (housing preferences, housing possibilities, housing outcome as a trade-off) and 2) the impact of housing on health (health of the caregiver, health of the child). Some parents reported that their child’s medical needs resulted in specific preferences regarding the location and layout of their home. Parents also indicated that their caregiving role often affected their income and home ownership status, which in turn, affected their housing possibilities. Thus, the housing situation (location and layout of the home) was often the result of a trade-off between the parent’s housing preferences and possibilities. Conclusion Housing is a recognized social determinant of health. We found that among CMC, health also appears to be a significant determinant of housing as families reported that the health of their child impacted their housing preferences and the options available to them (possibilities). To support the health of CMC and their families, policies targeting improved access to subsidized housing, improved sources of funding and regulations allowing families who rent to make accessibility changes are vital. Future research should investigate the impact of household income on housing need and identify interventions to support appropriate housing for CMC.

scholarly journals Exploiting correlated molecular-dynamics networks to counteract enzyme activity–stability trade-off

2018 ◽  
Vol 115 (52) ◽  
pp. E12192-E12200 ◽  
Author(s):  
Haoran Yu ◽  
Paul A. Dalby
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Active Site ◽  
Dynamic Networks ◽  
Aromatic Aldehydes ◽  
Active Site Residues ◽  
Trade Off ◽  
Highly Correlated ◽  
Dynamics Simulations ◽  
The Impact

The directed evolution of enzymes for improved activity or substrate specificity commonly leads to a trade-off in stability. We have identified an activity–stability trade-off and a loss in unfolding cooperativity for a variant (3M) of Escherichia coli transketolase (TK) engineered to accept aromatic substrates. Molecular dynamics simulations of 3M revealed increased flexibility in several interconnected active-site regions that also form part of the dimer interface. Mutating the newly flexible active-site residues to regain stability risked losing the new activity. We hypothesized that stabilizing mutations could be targeted to residues outside of the active site, whose dynamics were correlated with the newly flexible active-site residues. We previously stabilized WT TK by targeting mutations to highly flexible regions. These regions were much less flexible in 3M and would not have been selected a priori as targets using the same strategy based on flexibility alone. However, their dynamics were highly correlated with the newly flexible active-site regions of 3M. Introducing the previous mutations into 3M reestablished the WT level of stability and unfolding cooperativity, giving a 10.8-fold improved half-life at 55 °C, and increased midpoint and aggregation onset temperatures by 3 °C and 4.3 °C, respectively. Even the activity toward aromatic aldehydes increased up to threefold. Molecular dynamics simulations confirmed that the mutations rigidified the active-site via the correlated network. This work provides insights into the impact of rigidifying mutations within highly correlated dynamic networks that could also be useful for developing improved computational protein engineering strategies.

Male Youth Activities and Metropolitan Context

1998 ◽  
Vol 30 (3) ◽  
pp. 385-399 ◽  
Author(s):  
S R Holloway
Keyword(s):  
Black Male ◽  
Metropolitan Areas ◽  
White Male ◽  
The United States ◽  
Theoretical Understanding ◽  
Trade Off ◽  
Black And White ◽  
Trade Offs ◽  
Activity Choices ◽  
The Impact

The research reported here examines the impact of metropolitan location on the activity choices of a sample of black and white male youths living in large metropolitan areas in the United States in 1980. The results of the analysis confirm that similar youths living in different metropolitan areas will make different activity choices. Furthermore, black male youths are found to be substantially more sensitive to metropolitan context than white male youths. The analysis also suggests that black and white disadvantaged youths respond differently to metropolitan context in terms of the trade-offs between activities. Disadvantaged black male youths are highly unlikely to be employed in all metropolitan areas and tend to trade-off staying in school with idleness, whereas disadvantaged white male youths tend to trade-off employment with idleness, depending on the metropolitan area they live in. This research confirms the importance of incorporating geographic context into our theoretical understanding of male youths' behavior. We must also, however, continue to address the implications of race as it shapes the context-dependent labor-market experiences of male youths.

Visible marking of wader nests to avoid damage by farmers does not increase nest predation

2017 ◽  
Vol 28 (2) ◽  
pp. 293-301 ◽  
Author(s):  
VÁCLAV ZÁMEČNÍK ◽  
VOJTĚCH KUBELKA ◽  
MIROSLAV ŠÁLEK
Keyword(s):  
Czech Republic ◽  
Nest Predation ◽  
Agricultural Land ◽  
Positive Experience ◽  
The Czech Republic ◽  
Trade Off ◽  
Nest Protection ◽  
Vanellus Vanellus ◽  
The Impact ◽  
Ground Nesting

SummaryOnly a few studies have assessed the predation risk on artificially marked nests, or have examined ways of marking nests to avoid destruction by machinery. Until now, however, neither type of study has directly addressed this apparent trade-off experimentally. The impact of marking the nests of Northern Lapwing Vanellus vanellus with thin 2 m-long conspicuous bamboo poles with the top end highlighted with reflective red or orange spray has been tested for three years in two breeding areas of waders in the Czech Republic. A total of 52 pairs of nests on agricultural land, with each pair consisting of one marked nest and one unmarked reference counterpart nest, were monitored for 2004 nest-days until hatching, agricultural operations or failure. The results proved that marking itself does not result in increased nest predation. The nests found in the early incubation stage were under higher threat of depredation, irrespective of the presence of marking. Our results show that it is possible to find a finely-tuned trade-off in nest marking of ground-nesting birds between risk of damage by agricultural machinery and risk of increased nest predation. Our positive experience with Northern Lapwing, and episodically with three other wader species in the Czech Republic, suggests that this direct nest protection could be used effectively for a wider variety of ground-nesting birds.

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