Trade-offs between growth and cold and drought hardiness in submaritime Douglas-fir

2012 ◽  
Vol 42 (8) ◽  
pp. 1530-1541 ◽  
Author(s):  
N. Darychuk ◽  
B.J. Hawkins ◽  
M. Stoehr
Keyword(s):  
Stress Tolerance ◽  
Water Conservation ◽  
Cold Hardiness ◽  
Seed Orchard ◽  
Tree Breeding ◽  
Douglas Fir ◽  
Controlled Environment ◽  
Abiotic Stress Response ◽  
Trade Off ◽  
Trade Offs

Trade-offs between growth and stress tolerance in plants may limit the possible phenotypes that can evolve or be selected. Such limits would have important implications for tree breeding. We examined evidence for trade-offs between growth and stress tolerance, particularly cold and drought tolerance, in 56 families of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) from wild stand and seed orchard seed with a range of predicted growth rates. Families were assessed in field and controlled-environment experiments for growth and key physiological traits related to abiotic stress response. In the field, family growth was negatively correlated with fall and spring cold hardiness, indicating a trade-off between growth and cold hardiness. Combined results from field and controlled-environment experiments showed lower stomatal conductance and higher water potential in fast-growing families, indicating greater water conservation; thus no evidence existed for a growth – drought hardiness trade-off. Multivariate regression trees of normalized family means of growth and physiological parameters in the field split the families primarily by an index of continentality. Continental families had greater growth, survival, and fall hardiness than coastal families. We conclude that selection pressures in Douglas-fir have resulted in a trade-off between cold hardiness and high vigour, but little evidence exists for a trade-off between growth and drought hardiness.

scholarly journals HEAT STRESS TOLERANCE AND SEASONAL DEVELOPMENT IN CONIFER SEEDLINGS

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1085c-1085
Author(s):  
Karen E. Burr ◽  
Stephen J. Wanner ◽  
Richard W. Tinus
Keyword(s):  
Heat Stress ◽  
Stress Tolerance ◽  
Ponderosa Pine ◽  
Cold Hardiness ◽  
Douglas Fir ◽  
Bud Dormancy ◽  
Bud Break ◽  
Conifer Seedlings ◽  
Engelmann Spruce ◽  
Heat Stress Tolerance

It is not known when changes in primary direct heat stress tolerance of conifer seedlings occur in relation to other seasonally changing physiological parameters. This information should be incorporated into nursery practices and the matching of genotypes to landscape sites. Greenhouse-cultured, container-grown Douglas-fir, Engelmann spruce, and ponderosa pine. were cold acclimated and reacclimated in growth chambers over 19 weeks. Direct heat stress tolerance of needles, cold hardiness, and bud dormancy were measured weekly. Douglas-fir and Engelmann spruce heat stress tolerance increased with the development of new growth through one complete growth cycle, i.e., bud break, maturation, cold hardening, dehardening, and bud break the following growing season. Ponderosa pine differed in that new needles had intermediate tolerance, and fully cold hardy needles were the most intolerant. In none of the species did the timing of changes in heat stress tolerance coincide consistently with changes in cold hardiness or bud dormancy.

Prediction of cold hardiness in Douglas fir seedlings by index of injury and conductivity methods

1976 ◽  
Vol 6 (4) ◽  
pp. 511-515 ◽  
Author(s):  
R. van den Driessche
Keyword(s):  
Cold Hardiness ◽  
Douglas Fir ◽  
Critical Values ◽  
Promising Method ◽  
Controlled Environment ◽  
Electrical Conductivities ◽  
Freezing Temperatures ◽  
Environment Experiment ◽  
Whole Plants ◽  
Stem Segments

Electrical conductivities of diffusate from stem segments of Douglas fir (Pseudotsugamenziesii (Mirb.) Franco) were measured after exposing segments to various freezing temperatures and after heat killing. These data were expressed as conductivity percentage (conductivity after freezing as a percentage of conductivity after heat killing) or as index of injury (It, equivalent to conductivity percentage corrected for conductivity of unfrozen sample). Conductivity percentage, meaned over six test temperatures, predicted the temperature lethal to subsamples of whole plants exposed to different freezing temperatures reasonably well (R2 = 0.77, SEE = ±3.3 °C). However, 'critical' values of It associated with the temperature lethal to 50% of whole plants (T50) could only be determined for the three lowest test temperatures, and they varied from 32 to 40. In a controlled-environment experiment, levels of hardiness predicted by mean conductivity percentage, which seemed the most promising method, did not fully agree with survival results obtained from whole plants after freezing tests.

The triangular space of abiotic stress tolerance in woody species: a unified trade-off model

2020 ◽  
Author(s):  
GIACOMO PUGLIELLI ◽  
Michael J. Hutchings ◽  
Lauri Laanisto
Keyword(s):  
Abiotic Stress ◽  
Stress Tolerance ◽  
Woody Plants ◽  
Shade Tolerance ◽  
Abiotic Stress Tolerance ◽  
Woody Species ◽  
Trade Off ◽  
Considerable Uncertainty ◽  
Trade Offs ◽  
The Relationship

Tolerance of abiotic stress in woody plants is known to be constrained by biological trade-offs between different forms of stress, shade and drought in particular. However, there is still considerable uncertainty about the relationship between tolerances, and the limits on tolerance combinations. Using the most extensive database available on tolerance of shade, drought, waterlogging and cold in woody species, we demonstrate that stress tolerance combinations can be summarized by two PCA dimensions defining a triangular stress tolerance space (STS). The first dimension reflects segregation between drought- and waterlogging-tolerant species. The second reflects shade tolerance, which is independent of the other tolerances. The shape of the STS was compared with theoretical surfaces generated from several prominent theories that assume different interdependence relationships between stress tolerances. This allowed us to define the limits of shade, drought, waterlogging and cold tolerance combinations across the 799 woody species in the database. The STS reconciles all major theories about trade-offs between abiotic stress tolerances. It provides a unified trade-off model and a set of coordinates that can be used to examine how other aspects of plant biology, such as plant functional traits, change within the limits of abiotic stress tolerance.

scholarly journals 333 Evaluation of New Elms from China for Stress Tolerance

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 500D-500
Author(s):  
A.M. Shirazi ◽  
G.H. Ware
Keyword(s):  
Stress Tolerance ◽  
Heat Tolerance ◽  
Cold Hardiness ◽  
Urban Landscape ◽  
Tree Breeding ◽  
Breeding Program ◽  
Dutch Elm Disease ◽  
Leaf Beetles ◽  
Tree Breeding Program ◽  
And Performance

The high resistance of Chinese elms to Dutch elm disease and elm leaf beetles makes them excellent trees for the urban landscape. There are many new Chinese elms being developed through the tree breeding program at The Morton Arboretum. Many new elms are already on the market or will be available soon from nurseries. There is little known about the stress tolerance, e.g., cold, heat, drought, etc., of new elms from China. The objectives of this study were 1) to determine the midwinter cold hardiness of new Chinese elms and 2) to determine the leaf heat tolerance and stem cold hardiness of new elms from the nursery. The stem cold hardiness of nine new elms from China was evaluated in Feb. 1998 and 1999 from the elm breeding program at The Morton Arboretum by using an artificial freezing test. The LT50 (the temperature at which 50% of the tissues were killed) of the most to least hardy genuses for Feb. 1998 were Ulmus macrocarpa (> -36 °C), U. wilsoniana # 673 (-34 °C), U. parvifolia R-89-120 (-34 °C), U. wilsoniana # 669 (-34 °C), U. wilsoniana # 997 (-33.8 °C), U. szechuanica (-30 °C), U. gaussenii R-94-85D (-30.7 °C), U. bergmanniana var. lasiophylla R-9422SD (-27.7 °C), and U. castaneifolia #R-9411-11-SD (-25.9 °C). Four new elms from Schmidt Nursery, Boring, Ore., were also evaluated for leaf heat tolerance in August and cold hardiness in Dec. 1998 and Feb. 1999. The LT50 of cold hardiness of stem tissues of cultivars in December were U. parvifolia `Emer 1' P.P. 7551, Athena® elm (-23.5 °C), U. parvifolia `Emer 1' P.P. 7552 Allee® (-26.5 °C), U. Accolade™ (-33.5 °C), and U. Danada Charm™ elm (-31 °C). The LT50 of the most to least heat-tolerant cultivars were U. parvifolia `Emer 1' P.P. 7551, Athena® elm (53.8 °C), U. parvifolia `Emer 1' P.P. 7552 Allee® (52.1 °C), U. Accolade™ (50.8 °C), and U. Danada Charm™ elm (50.6 °C). Growth, dormancy development, spring budbreak, and performance of these cultivars will be compared.

Dual Goals for Speed and Accuracy on the Same Performance Task

2012 ◽  
Vol 11 (3) ◽  
pp. 118-126 ◽  
Author(s):  
Olive Emil Wetter ◽  
Jürgen Wegge ◽  
Klaus Jonas ◽  
Klaus-Helmut Schmidt
Keyword(s):  
Memory Scanning ◽  
Performance Task ◽  
Performance Tasks ◽  
Trade Off ◽  
Test Experiment ◽  
Trade Offs ◽  
New Finding ◽  
Sternberg Paradigm ◽  
Speed Accuracy ◽  
Speed And Accuracy

In most work contexts, several performance goals coexist, and conflicts between them and trade-offs can occur. Our paper is the first to contrast a dual goal for speed and accuracy with a single goal for speed on the same task. The Sternberg paradigm (Experiment 1, n = 57) and the d2 test (Experiment 2, n = 19) were used as performance tasks. Speed measures and errors revealed in both experiments that dual as well as single goals increase performance by enhancing memory scanning. However, the single speed goal triggered a speed-accuracy trade-off, favoring speed over accuracy, whereas this was not the case with the dual goal. In difficult trials, dual goals slowed down scanning processes again so that errors could be prevented. This new finding is particularly relevant for security domains, where both aspects have to be managed simultaneously.

The Effects of Decision Time on Perceptions of Decisions and Decision Makers in (Moral) Trade-Off Scenarios

2019 ◽  
Author(s):  
Anna Katharina Spälti ◽  
Mark John Brandt ◽  
Marcel Zeelenberg
Keyword(s):  
Decision Process ◽  
Decision Time ◽  
Decision Makers ◽  
Process Information ◽  
Total N ◽  
Trade Off ◽  
Financial Gain ◽  
Trade Offs ◽  
Sacred Values ◽  
Moral Context

People often have to make trade-offs. We study three types of trade-offs: 1) "secular trade-offs" where no moral or sacred values are at stake, 2) "taboo trade-offs" where sacred values are pitted against financial gain, and 3) "tragic trade-offs" where sacred values are pitted against other sacred values. Previous research (Critcher et al., 2011; Tetlock et al., 2000) demonstrated that tragic and taboo trade-offs are not only evaluated by their outcomes, but are also evaluated based on the time it took to make the choice. We investigate two outstanding questions: 1) whether the effect of decision time differs for evaluations of decisions compared to decision makers and 2) whether moral contexts are unique in their ability to influence character evaluations through decision process information. In two experiments (total N = 1434) we find that decision time affects character evaluations, but not evaluations of the decision itself. There were no significant differences between tragic trade-offs and secular trade-offs, suggesting that the decisions structure may be more important in evaluations than moral context. Additionally, the magnitude of the effect of decision time shows us that decision time, may be of less practical use than expected. We thus urge, to take a closer examination of the processes underlying decision time and its perception.

Predicting Undesired Treatment Outcome in Mental Healthcare: Machine Learning Study (Preprint)

2019 ◽  
Author(s):  
Kasper Van Mens ◽  
Joran Lokkerbol ◽  
Richard Janssen ◽  
Robert de Lange ◽  
Bea Tiemens
Keyword(s):  
Machine Learning ◽  
Treatment Outcome ◽  
Mental Health Treatment ◽  
Mental Healthcare ◽  
Machine Learning Algorithms ◽  
Gradient Boosting ◽  
Trade Off ◽  
Trade Offs ◽  
Outcome Monitoring ◽  
Extreme Gradient Boosting

BACKGROUND It remains a challenge to predict which treatment will work for which patient in mental healthcare. OBJECTIVE In this study we compare machine algorithms to predict during treatment which patients will not benefit from brief mental health treatment and present trade-offs that must be considered before an algorithm can be used in clinical practice. METHODS Using an anonymized dataset containing routine outcome monitoring data from a mental healthcare organization in the Netherlands (n = 2,655), we applied three machine learning algorithms to predict treatment outcome. The algorithms were internally validated with cross-validation on a training sample (n = 1,860) and externally validated on an unseen test sample (n = 795). RESULTS The performance of the three algorithms did not significantly differ on the test set. With a default classification cut-off at 0.5 predicted probability, the extreme gradient boosting algorithm showed the highest positive predictive value (ppv) of 0.71(0.61 – 0.77) with a sensitivity of 0.35 (0.29 – 0.41) and area under the curve of 0.78. A trade-off can be made between ppv and sensitivity by choosing different cut-off probabilities. With a cut-off at 0.63, the ppv increased to 0.87 and the sensitivity dropped to 0.17. With a cut-off of at 0.38, the ppv decreased to 0.61 and the sensitivity increased to 0.57. CONCLUSIONS Machine learning can be used to predict treatment outcomes based on routine monitoring data.This allows practitioners to choose their own trade-off between being selective and more certain versus inclusive and less certain.

Challenges in the Empirical Study of Global Governance Legitimacy

2018 ◽  
Author(s):  
Steven Bernstein
Keyword(s):  
Empirical Study ◽  
Global Governance ◽  
Research Agenda ◽  
Cultural Factors ◽  
Theory Building ◽  
Trade Off ◽  
Trade Offs ◽  
Different Types ◽  
Political Communities

This commentary discusses three challenges for the promising and ambitious research agenda outlined in the volume. First, it interrogates the volume’s attempts to differentiate political communities of legitimation, which may vary widely in composition, power, and relevance across institutions and geographies, with important implications not only for who matters, but also for what gets legitimated, and with what consequences. Second, it examines avenues to overcome possible trade-offs from gains in empirical tractability achieved through the volume’s focus on actor beliefs and strategies. One such trade-off is less attention to evolving norms and cultural factors that may underpin actors’ expectations about what legitimacy requires. Third, it addresses the challenge of theory building that can link legitimacy sources, (de)legitimation practices, audiences, and consequences of legitimacy across different types of institutions.

scholarly journals Toward Inclusive Landscape Governance in Contested Landscapes: Exploring the Contribution of Participatory Tools in the Upper Suriname River Basin

2021 ◽  
Author(s):  
Lisa Best ◽  
Kimberley Fung-Loy ◽  
Nafiesa Ilahibaks ◽  
Sara O. I. Ramirez-Gomez ◽  
Erika N. Speelman
Keyword(s):  
Land Use ◽  
River Basin ◽  
Scenario Planning ◽  
Community Members ◽  
Trade Off ◽  
3 Dimensional ◽  
Landscape Governance ◽  
Information Tools ◽  
Tribal Communities ◽  
Trade Offs

AbstractNowadays, tropical forest landscapes are commonly characterized by a multitude of interacting institutions and actors with competing land-use interests. In these settings, indigenous and tribal communities are often marginalized in landscape-level decision making. Inclusive landscape governance inherently integrates diverse knowledge systems, including those of indigenous and tribal communities. Increasingly, geo-information tools are recognized as appropriate tools to integrate diverse interests and legitimize the voices, values, and knowledge of indigenous and tribal communities in landscape governance. In this paper, we present the contribution of the integrated application of three participatory geo-information tools to inclusive landscape governance in the Upper Suriname River Basin in Suriname: (i) Participatory 3-Dimensional Modelling, (ii) the Trade-off! game, and (iii) participatory scenario planning. The participatory 3-dimensional modelling enabled easy participation of community members, documentation of traditional, tacit knowledge and social learning. The Trade-off! game stimulated capacity building and understanding of land-use trade-offs. The participatory scenario planning exercise helped landscape actors to reflect on their own and others’ desired futures while building consensus. Our results emphasize the importance of systematically considering tool attributes and key factors, such as facilitation, for participatory geo-information tools to be optimally used and fit with local contexts. The results also show how combining the tools helped to build momentum and led to diverse yet complementary insights, thereby demonstrating the benefits of integrating multiple tools to address inclusive landscape governance issues.

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