scholarly journals Willow tree shoot module length and the attack and survival pattern of a shoot-galling sawfly, Euura atra (Hymenoptera: Tenthredinidae)

1997 ◽  
Vol 8 (2) ◽  
pp. 113-119 ◽  
Author(s):  
Peter Price ◽  
Heikki Roininen ◽  
Jorma Tahvanainen
Keyword(s):  
Explanatory Power ◽  
Small Population ◽  
Pattern Generation ◽  
Shoot Length ◽  
Length Class ◽  
Salix Alba ◽  
Ovipositional Preference ◽  
Long Shoots ◽  
Survival Pattern ◽  
The Mean

A small population of the shoot-galling sawfly , Euura atra (Jurine), attacking the willow, Salix alba L. (Salicaceae) in Joensuu, Finland, showed strong preference-performance linkage between female ovipositional choices and survival of progeny. Although shoot lengths on trees were most common in the classes 200-400 mm, the probability of attack increased with shoot length until rare long shoots over 400 mm had a 50-80% probability of attack. The regression of attack probability on shoot length class accounted for 91% of the variance in attack. Attack was significantly greater on longer shoot length classes than that predicted by random attack based on total shoot length available per class, or total number of shoots per class. As shoot length increased the mean number of galls per shoot increased from 0 to 3 per shoot, and establishment and survival of progeny increased from 0 to over 60%. Shoot length class accounted for 70% and 50% of the variance in larval establishment and ultimate survival respectively, while attack by carnivores showed no pattern and had no explanatory power. The results are consistent with those from studies on seven other Euura species showing attack on rapidly growing plants, an ovipositional preference for longer shoots, higher survival on longer shoots, and no detectable effects of carnivores on pattern generation. The study aids in the development of a strong comparative ecology of galling sawflies and the eventual development of empirically based factual theory on their population dynamics.

Explanation Plus Prediction—The Logical Focus of Project Management Research

2021 ◽  
pp. 875697282199994
Author(s):  
Joseph F. Hair ◽  
Marko Sarstedt
Keyword(s):  
Project Management ◽  
Statistical Models ◽  
Predictive Power ◽  
Mean Absolute Error ◽  
Explanatory Power ◽  
Absolute Error ◽  
Model Parameters ◽  
Mean Square ◽  
Management Research ◽  
The Mean

Most project management research focuses almost exclusively on explanatory analyses. Evaluation of the explanatory power of statistical models is generally based on F-type statistics and the R 2 metric, followed by an assessment of the model parameters (e.g., beta coefficients) in terms of their significance, size, and direction. However, these measures are not indicative of a model’s predictive power, which is central for deriving managerial recommendations. We recommend that project management researchers routinely use additional metrics, such as the mean absolute error or the root mean square error, to accurately quantify their statistical models’ predictive power.

scholarly journals Mediating Effect of Acceptance Action in relationship between Diabetes Self-Stigma and Quality of Life in People with Diabetes in Korea

2021 ◽  
Vol 28 (3) ◽  
pp. 384-394
Author(s):  
Kawoun Seo
Keyword(s):  
Quality Of Life ◽  
Explanatory Power ◽  
Mediating Effect ◽  
Research Approach ◽  
Mediating Effects ◽  
Descriptive Research ◽  
Patients With Diabetes ◽  
The Mean ◽  
The Relationship

Purpose: This study was done to investigate the mediating effects of acceptance action on the relationship between diabetes self-stigma and quality of life in diabetes patients.Methods: For this study a descriptive research approach was used. Patients (237) with a diagnosis of diabetes mellitus from a doctor of endocrinology were included. Data collection was done from March 26, to March 28, 2020. Data were analyzed using descriptive statistics, t-test, one-way ANOVA, Pearson’s correlation coefficient analysis, and hierarchecal multiple regression.Results: The mean scores for diabetes self-stigma, acceptance action and quality of life were 2.67±0.71, 4.12±0.38, and 3.26±0.48, respectively. Acceptance action was found to partial mediate the relationship between diabetes self-stigma and quality of life (z=-4.20, p<.001), and its explanatory power was 17.6%.Conclusion: To improve the quality of life among patients with diabetes in diabetes self-stigma situations, it is necessary to improve their acceptance action and develop step-by-step and differentiated acceptance action enhancement programs through multidisciplinary collaboration.

Breeding Ecology of the Western Long-billed Corella, Cacatua pastinator pastinator

1991 ◽  
Vol 18 (1) ◽  
pp. 91 ◽  
Author(s):  
GT Smith
Keyword(s):  
Clutch Size ◽  
Western Australia ◽  
Divorce Rate ◽  
Small Population ◽  
Breeding Ecology ◽  
Pair Bonds ◽  
The Mean ◽  
Wing Growth ◽  
First Time ◽  
Older Siblings

The breeding ecology of a small population of the western long-billed corella, Cacatua p. pastinator, was investigated for 6 years in the central wheatbelt of Western Australia. Pair-bonds tended to be long-lasting; however, the divorce rate for birds breeding for the first time was 25% with an overall rate of 15%. Females formed stable pair-bonds by age 2, and bred for the first time between 3 and 5 years old; males started breeding when 5 years old. Clutches (range from one to four, mode three) were started in early August; 78% are started in the last 3 weeks of the month. Mean clutch size, brood size and number fledged were 2.7 , 1.9 and 1.6 respectively; there were no significant differences in these parameters among the six years of the study. Hatching was asynchronous and was followed by the death of the young nestlings when they were significantly smaller (77%) than their older siblings. Nestlings fledged when they were about 60 days old; neither their mass or degree of wing growth influenced fledging age. Mean mass of fledglings from broods of three was significantly greater than that of broods of two or one. Productivity was assessed by the numbers of young fledging, surviving the post-fledging period, and reaching independence. Neither mass nor condition at fledging influenced any of these measures; productivity in all three increased with clutch size. Rainfall and temperature had no influence on the numbers fledged, but the number reaching independence was significantly and positively correlated with the mean maximum summer temperature. The results are discussed in relation to the results from studies of other species of cockatoos living in the wheatbelt of Western Australia.

scholarly journals Patterns, determinants and models of woody plant diversity in China

2010 ◽  
Vol 278 (1715) ◽  
pp. 2122-2132 ◽  
Author(s):  
Zhiheng Wang ◽  
Jingyun Fang ◽  
Zhiyao Tang ◽  
Xin Lin
Keyword(s):  
Species Richness ◽  
Woody Plants ◽  
Large Scale ◽  
Explanatory Power ◽  
Woody Species ◽  
Tropical Species ◽  
Controversial Issues ◽  
Strongly Correlated ◽  
Distribution Maps ◽  
The Mean

What determines large-scale patterns of species richness remains one of the most controversial issues in ecology. Using the distribution maps of 11 405 woody species in China, we compared the effects of habitat heterogeneity, human activities and different aspects of climate, particularly environmental energy, water–energy dynamics and winter frost, and explored how biogeographic affinities (tropical versus temperate) influence richness–climate relationships. We found that the species richness of trees, shrubs, lianas and all woody plants strongly correlated with each other, and more strongly correlated with the species richness of tropical affinity than with that of temperate affinity. The mean temperature of the coldest quarter was the strongest predictor of species richness, and its explanatory power for species richness was significantly higher for tropical affinity than for temperate affinity. These results suggest that the patterns of woody species richness mainly result from the increasing intensity of frost filtering for tropical species from the equator/lowlands towards the poles/highlands, and hence support the freezing-tolerance hypothesis. A model based on these results was developed, which explained 76–85% of species richness variation in China, and reasonably predicted the species richness of woody plants in North America and the Northern Hemisphere.

scholarly journals Effects of dominance and size of population on response to mass selection

1961 ◽  
Vol 2 (2) ◽  
pp. 177-188 ◽  
Author(s):  
Ken-Ichi Kojima
Keyword(s):  
Gene Frequency ◽  
Finite Size ◽  
Prediction Equation ◽  
Small Population ◽  
Mass Selection ◽  
Gene Frequencies ◽  
Random Drift ◽  
Expected Gain ◽  
The Mean ◽  
Frequency Changes

A theory of mass selection in a small population was developed, and the mean change in gene frequencies, the variance of gene frequency changes and the expected gain in the mean phenotypic value of an offspring population were formulated in terms of a generalized selection differential and the additive and dominance effects of genes.The magnitude of the variance of changes in gene frequency was compared with the magnitude of the variance expected from the genetic random drift in a population with the same gene frequency and of the same size in absence of selection. The former was found to be usually smaller than the latter when the gene frequency ranged from intermediate to high and when selection was directed for a high performance.The usual prediction equation for gain from selection in an infinite population was compared with the expected gain formula derived for a small population. The size of the population did not cause a serious difference between the two expected gains when there was no dominance effect of genes. Dominance alone could cause the usual prediction to be slightly more biased. The joint effects of the finite size of population and dominance gene action could amount to a considerable bias in the usual prediction equation. Such a bias can be, in the main, accounted for by the inbreeding depression.

Influence of plant-hardiness zone, shoot length, and crown class on the incidence of gouting by the balsam woolly adelgid on balsam fir

2010 ◽  
Vol 142 (5) ◽  
pp. 466-472
Author(s):  
Bertrand Guillet ◽  
Andrew Morrison ◽  
Drew Carleton ◽  
Don Ostaff ◽  
Dan Quiring
Keyword(s):  
Growth Rate ◽  
New Brunswick ◽  
Abies Balsamea ◽  
Shoot Length ◽  
Balsam Fir ◽  
Parabolic Relationship ◽  
Balsam Woolly Adelgid ◽  
Shoot Size ◽  
The Mean ◽  
Plant Hardiness

AbstractWe collected midcrown branches of balsam fir, Abies balsamea (L.) Mill. (Pinaceae), at six different sites located in five different plant-hardiness zones, along a north–south transect in New Brunswick, Canada, to evaluate the effect of plant-hardiness zone, crown class (overstory versus understory), and shoot length during the previous 10 years on the annual incidence of gouting by the balsam woolly adelgid, Adelges piceae (Ratzeburg) (Homoptera: Adelgidae). Site, crown class, and their interaction, along with the square of shoot length, explained 78% of the variation in gouting. Variations in gouting attributed to plant-hardiness zone were probably primarily due to variation in mean January temperature: at each site, the mean January temperature was positively and closely related to the mean level of gouting. The level of gouting was consistently higher on trees in the understory than on those in the overstory. Shoot length was parabolically related to the proportion of shoots with gout. The parabolic relationship between shoot size and the level of gouting is similar to that previously reported for galling adelgids, and suggests that gouting by A. piceae may be greatest on trees with an intermediate growth rate.

Crown architecture of Larix laricina saplings: an analysis of higher order branching

1987 ◽  
Vol 65 (2) ◽  
pp. 268-279 ◽  
Author(s):  
W. R. Remphrey ◽  
G. R. Powell
Keyword(s):  
Simulation Modelling ◽  
Shoot Length ◽  
Larix Laricina ◽  
Structural Development ◽  
Short Shoot ◽  
Lateral Buds ◽  
Architectural Patterns ◽  
Long Shoots ◽  
Short Shoots ◽  
Terminal Shoot

Quantitative analysis and simulation modelling of Larix laricina (Du Roi) K. Koch branches revealed a complex system of architectural patterns and correlations. Numbers of lateral buds and long shoots were positively correlated with parent-shoot length, but the relationships varied among shoot orders and for sylleptic shoots. For order 2 and sylleptic shoots, numbers of lateral long shoots were also correlated with associated terminal-shoot lengths. Sylleptic shoots produced more lateral long shoots than equivalent proleptic shoots. Lateral long-shoot lengths decreased basipetally and were correlated with terminal-shoot lengths. Lengths of order 2 lateral long shoots also varied independently with crown position. Generally, the degree of apical control decreased and the proportion of short shoots increased with positions of less vigour in the crown. Terminal long-shoot lengths varied with parent-shoot length, location, and to some extent parent-axis leader length. Terminal short-shoot production was associated with shorter parent shoots. Shorter order 2 shoots (<60 mm) and most order 3 shoots produced no lateral long shoots. The net result was that branch structural development ceased in less vigorous crown positions. The spatial disposition of shoots, as defined by elevation and divergence angles, varied with position of origin around and along parent shoots. Although variable, elevation angles decreased and divergence angles increased basipetally.

Long-shoot bud development, shoot growth, and foliage production in provenances of lodgepole pine

1987 ◽  
Vol 17 (11) ◽  
pp. 1421-1433 ◽  
Author(s):  
Conor O'Reilly ◽  
John N. Owens
Keyword(s):  
British Columbia ◽  
Mitotic Activity ◽  
Shoot Growth ◽  
Shoot Length ◽  
Apical Growth ◽  
Axillary Buds ◽  
Provenance Trial ◽  
Bud Development ◽  
Shoot Bud ◽  
Long Shoots

Long-shoot bud development, shoot growth, and foliage production were studied in seven provenances of Pinuscontorta Dougl. ssp. latifolia Engelm. from the major sites in British Columbia and one Yukon source growing in a provenance trial at Prince George, B.C. Branch terminal apical mitotic activity began in early March and continued until late September. Initiation of axillary buds began in May, about 2 weeks after the initiation of the subtending cataphyll. Differentiation of dwarf shoots began in early July to mid-August and continued until late October in some sources. Distal axillary buds had not always differentiated by late October in the southern sources. The duration of the period of apical growth and apical size during activity were related to final cataphyll numbers. Provenances with the widest, flattest, dormant apices produced the most cataphylls. The two northern provenances had more terminal sterile cataphylls but fewer sterile cataphylls lower in the long-shoot bud and shorter mean stem unit lengths than the others. Differences among provenances in shoot length were due mostly to variation in stem unit numbers. The large proportion of polycyclic long shoots in some provenances contributed to variation in dwarf shoot numbers.

scholarly journals Shoot-foliage relationships in deciduous, semideciduous, and evergreen cerrado tree species

2009 ◽  
Vol 21 (1) ◽  
pp. 76-86 ◽  
Author(s):  
João Paulo Souza ◽  
Carlos Henrique B. A. Prado ◽  
Ana Lúcia S. Albino ◽  
Maria A. Damascos
Keyword(s):  
Leaf Area ◽  
Biomass Allocation ◽  
Tree Species ◽  
Shoot Length ◽  
Leaf Number ◽  
Deciduous Tree ◽  
Structural Differentiation ◽  
Evergreen Species ◽  
Leaf Production ◽  
Long Shoots

The morphology and the biomass allocation in shoots and leaves were investigated in 15 cerrado tree species with distinct leaf phenology growing under natural conditions. Higher values of leaf/shoot ratio on mass base, individual leaf area, leaf area per shoot, leaf display index, and leaf number per shoot length were found in deciduous than in evergreen species. The differences about shoot-foliage relationship across leaf phenological groups could be explained by plagiotropic shoots on deciduous and by erect shoots in semideciduous and evergreen species. Plagiotropic shoots allow similar irradiance along shoots and high biomass allocation in favor of leaves without foliage self-shading in deciduous tree species. The structural differentiation between short and long shoots was indicated by an exponential relationship between leaf display index and shoot length in all deciduous, in three semideciduous, and in two evergreen species. Therefore, especially in deciduous, the short shoots had higher leaf area per unit of length than the long shoots. The differentiation between short and long shoots depends on the shoot length in deciduous because of the leaf number on shoot is predetermined in buds. Contrastingly, the leaf neo-formation in semideciduous and in evergreen tree species keeps the shoot-leaf relationship per shoot length more constant, because of the foliage being produced according to the shoot growth during the year. In conclusion, the foliage persistence, the shoot inclination, the type of leaf production and the resources allocation between autotrophic and heterotrophic vegetative canopy parts are interdependent in cerrado tree species across different leaf phenological groups.

scholarly journals Effect of some botanical fungicide and chemicals as forest seed dressing  on the quality of the seeds: تأثير بعض مبيدات الفطريات والكيمياويات النباتية في تلبيس بذور الغابات  على جودة البذور

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Shler Hassan Mahmood, Jalal Hama Salih Ismael
Keyword(s):  
Seed Germination ◽  
Root Length ◽  
Germination Percentage ◽  
Shoot Length ◽  
Salix Alba ◽  
Seed Dressing ◽  
Number Of Leaves ◽  
Petri Plate ◽  
Local Plants ◽  
The University

An experiment was conducted to study the antifungal activity of different concentrations aqueous extracts from three local plants, Hypericum triquetrifolium, Salix alba, Salvia rosmarinus and also different concentrations of fungicide (Captan) and Salicylic acid were evaluated for their efficacy as seed dressing on Catalpa and Albizia that seeds were soaked separately for 30 mints in various concentrations of aqueous extract and fungicide. Forest seeds were grown in pots which were inoculated by Sclerotinia sclerotiorum and Fusarium oxysporum that one petri plate/ pot in 2018 in a greenhouse at the University of Sulaimani–College of Agricultural Sciences Engineering. The results showed that seed germination percentage, shoot length, root length and number of leaves was significantly (p≤0.05) increased with both the treatments. Captan (0.5%) was more effective in comparison with Captan (0.3%) and seed germination, shoot length, root length and number of leaves was gradually increased with increase of the doses of fungicides. It can be suggested that fungicide Captan have antifungal effect and can be used to treat seed against seed borne pathogens of forest, increase seed germination and shoot length, root length and number of leaves.

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