On the Relationship between Shade Tolerance and Shade Avoidance Strategies in Woodland Plants

Oikos ◽  
1997 ◽  
Vol 80 (3) ◽  
pp. 575 ◽  
Author(s):  
Hugh A. L. Henry ◽  
Lonnie W. Aarssen
Keyword(s):  
Shade Tolerance ◽  
Shade Avoidance ◽  
Avoidance Strategies ◽  
The Relationship

Thinking in terms of law and mortality

1998 ◽  
Vol 7 (1) ◽  
pp. 7-20 ◽  
Author(s):  
K Greenawalt
Keyword(s):  
Country Of Origin ◽  
Cultural Property ◽  
Avoidance Strategies ◽  
Standards Of Conduct ◽  
Moral Rules ◽  
Moral Behaviors ◽  
National Governments ◽  
The Relationship

The author lays a blueprint for distinctions between legal and moral rules and socially accepted behavior, situations in which these distinctions set different standards of conduct, and the relationship among them. Several of the more common paradigms of cultural property disputes are then fit into the patterns of legal and moral rules and obligations, thus establishing a framework for the discussion of how to evaluate ethical or moral behaviors in varying circumstances. The author also considers the relevance of deontological and consequentialist arguments for the return of cultural property, as well as avoidance strategies by which a country of origin can make a claim for restitution while ignoring the long-term questions of the legitimacy, power, and responsibilities of national governments. The author concludes by emphasizing the difficulties in basing arguments concerning cultural property on moral evaluations and conclusions.

Tree growth prediction using size and exposed crown area

2005 ◽  
Vol 35 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Peter H Wyckoff ◽  
James S Clark
Keyword(s):  
Growth Rate ◽  
Tree Growth ◽  
Shade Tolerance ◽  
Strong Predictor ◽  
Tree Size ◽  
Crown Area ◽  
Long Term Ecological Research ◽  
Size Growth ◽  
The Relationship

We address the relationships between tree growth rate and growing environment for 21 co-occurring species. Tree growth rates are obtained from mapped plots at the Coweeta Long-Term Ecological Research site in the southern Appalachian Mountains. We employ high-resolution aerial photography to assess the light environment for trees growing in these plots, using exposed crown area (ECA) as a surrogate for light interception. The relationship between growth and ECA is compared with two other growth predictors: tree size and shade-tolerance classification. We find that ECA is an excellent predictor of tree growth (average R2 = 0.69 for nine species). When ECA is combined with tree size, growth rate prediction is improved (average R2 = 0.76). Tree size alone is also a strong predictor of tree growth (average R2 = 0.68). Shade-tolerance classification, by contrast, is a poor predictor of tree growth.

scholarly journals Avoidance and overgeneral memory

2021 ◽  
Author(s):  
◽  
Tim Ganly
Keyword(s):  
Autobiographical Memory ◽  
Clinical Sample ◽  
Memory Performance ◽  
Memory Test ◽  
Self Report ◽  
Clinical Samples ◽  
Overgeneral Memory ◽  
Significant Relationships ◽  
Avoidance Strategies ◽  
The Relationship

<p>Overgeneral memory is a phenomenon that occurs in depression in which people tend to remember temporally non-specific autobiographical memories. Overgeneral memory may be functional; by avoiding specific memories, potentially distressing emotions can avoided. This “functional avoidance” may be part of a repertoire of avoidance strategies people use when they are under stress. The question of the relationship between avoidance, stress, and overgeneral memory has been investigated using only laboratory-based stressors, and no previous research has examined the relationships in both non-clinical and clinical samples. Across four studies, this thesis investigated the relationships between avoidance and overgeneral memory in clinical and non-clinical samples and whether every-day stress moderates this relationship.  Studies 1, 2, and 4 engaged undergraduate samples in which mean depression scores were low (non-clinical samples). Study 3 engaged a sample from a university counselling service in which the mean depression score was high (clinical sample). Participants completed self-report measures of avoidance and stress. They were also asked to remember specific events to a series of emotion cue words on the Autobiographical Memory Test (AMT). This thesis also investigated the possibility that avoidance may be associated with a reduction in memory performance on other tests of autobiographical memory besides the AMT, perhaps because other types of memories, not just specific, can be distressing. Thus, in Study 1, participants also completed the Autobiographical Memory Test-Reversed (AMT-R) in which they were asked to retrieve general memories. In addition, across studies, the pleasantness of events remembered to positive and negative cues was examined. In Study 4, the possible moderating role of rating pleasantness on the relationship between avoidance and overgeneral memory was examined.  Results from the non-clinical samples indicated higher avoidance was associated with less overgeneral remembering on the AMT. In the clinical sample, there were no significant relationships between avoidance and overgeneral memory. There were no significant relationships between avoidance and AMT-R performance. Overall, stress did not moderate the relationship between avoidance and overgeneral memory. Mean pleasantness ratings for events remembered to positive and negative cues were congruent with cue valence. However, individual positive and negative cues did not always elicit memories for pleasant and unpleasant events, respectively. Rating (vs. not rating) the pleasantness of remembered events did not moderate the relationship between avoidance and overgeneral memory. Overall, findings suggested that functional avoidance is not part of a repertoire of avoidance strategies. Ironic process theory is discussed as an explanation for why higher avoidance was associated with a lower proportion of overgeneral memories in the non-clinical samples.</p>

Characterizing shade tolerance by the relationship between mortality and growth in tree saplings in a southeastern Texas forest

2001 ◽  
Vol 31 (2) ◽  
pp. 345-349
Author(s):  
Jie Lin ◽  
Paul A Harcombe ◽  
Mark R Fulton
Keyword(s):  
Survival Analysis ◽  
Mortality Risk ◽  
Shade Tolerance ◽  
Mesic Forest ◽  
Tolerant Species ◽  
Shade Tolerant Species ◽  
Zero Growth ◽  
Using Data ◽  
Species Specific ◽  
The Relationship

We investigated the relationship between shade tolerance and sapling mortality using data collected over 15 years in a mesic forest in southeastern Texas. Seven species representing a range of shade-tolerance classes were included in the study. We used survival analysis to estimate species-specific sapling mortality risk (hazard) as a function of recent growth. We found that shade-intolerant species had higher mortality risk at zero growth than shade-tolerant species. The results strongly support the point that shade tolerance can be characterized by the relationship between sapling mortality and growth.

scholarly journals Understanding the Shade Tolerance Responses Through Hints From Phytochrome A-Mediated Negative Feedback Regulation in Shade Avoiding Plants

2021 ◽  
Vol 12 ◽  
Author(s):  
Huiying Xu ◽  
Peirui Chen ◽  
Yi Tao
Keyword(s):  
Negative Feedback ◽  
Shade Tolerance ◽  
Dynamic Properties ◽  
Survival Rates ◽  
Feedback Regulation ◽  
Shade Avoidance ◽  
Phytochrome A ◽  
Negative Feedback Regulation ◽  
Signaling Components

Based on how plants respond to shade, we typically classify them into two groups: shade avoiding and shade tolerance plants. Under vegetative shade, the shade avoiding species induce a series of shade avoidance responses (SARs) to outgrow their competitors, while the shade tolerance species induce shade tolerance responses (STRs) to increase their survival rates under dense canopy. The molecular mechanism underlying the SARs has been extensively studied using the shade avoiding model plant Arabidopsis thaliana, while little is known about STRs. In Aarabidopsis, there is a PHYA-mediated negative feedback regulation that suppresses exaggerated SARs. Recent studies revealed that in shade tolerance Cardamine hirsuta plants, a hyperactive PHYA was responsible for suppressing shade-induced elongation growth. We propose that similar signaling components may be used by shade avoiding and shade tolerance plants, and different phenotypic outputs may result from differential regulation or altered dynamic properties of these signaling components. In this review, we summarized the role of PHYA and its downstream components in shade responses, which may provide insights into understanding how both types of plants respond to shade.

Body Recovery After the “First 48”: Implications for Sexual Homicide Investigations

2018 ◽  
Vol 23 (2) ◽  
pp. 126-144 ◽  
Author(s):  
Kylie Reale ◽  
Eric Beauregard
Keyword(s):  
Forensic Evidence ◽  
Sexual Homicide ◽  
Crime Commission ◽  
Factors Influencing ◽  
Offender Characteristics ◽  
Avoidance Strategies ◽  
Recovery Times ◽  
The Relationship

There is a lack of research examining the relationship between body recovery times and the “first 48,” despite the risk of forensic evidence deteriorating and the difficulty in forming leads without a body. The study explores factors influencing body recovery—both during and after the critical 48-hr investigative window—in sexual homicide cases. Offender characteristics, victimology, contact scene and body recovery locations, and forensic awareness strategies are used to predict body recovery after the “first 48.” Findings suggest that certain offenders can delay body recovery past the first 48 because they utilized detection avoidance strategies during the crime-commission process.

scholarly journals Avoidance and overgeneral memory

2021 ◽  
Author(s):  
◽  
Tim Ganly
Keyword(s):  
Autobiographical Memory ◽  
Clinical Sample ◽  
Memory Performance ◽  
Memory Test ◽  
Self Report ◽  
Clinical Samples ◽  
Overgeneral Memory ◽  
Significant Relationships ◽  
Avoidance Strategies ◽  
The Relationship

<p>Overgeneral memory is a phenomenon that occurs in depression in which people tend to remember temporally non-specific autobiographical memories. Overgeneral memory may be functional; by avoiding specific memories, potentially distressing emotions can avoided. This “functional avoidance” may be part of a repertoire of avoidance strategies people use when they are under stress. The question of the relationship between avoidance, stress, and overgeneral memory has been investigated using only laboratory-based stressors, and no previous research has examined the relationships in both non-clinical and clinical samples. Across four studies, this thesis investigated the relationships between avoidance and overgeneral memory in clinical and non-clinical samples and whether every-day stress moderates this relationship.  Studies 1, 2, and 4 engaged undergraduate samples in which mean depression scores were low (non-clinical samples). Study 3 engaged a sample from a university counselling service in which the mean depression score was high (clinical sample). Participants completed self-report measures of avoidance and stress. They were also asked to remember specific events to a series of emotion cue words on the Autobiographical Memory Test (AMT). This thesis also investigated the possibility that avoidance may be associated with a reduction in memory performance on other tests of autobiographical memory besides the AMT, perhaps because other types of memories, not just specific, can be distressing. Thus, in Study 1, participants also completed the Autobiographical Memory Test-Reversed (AMT-R) in which they were asked to retrieve general memories. In addition, across studies, the pleasantness of events remembered to positive and negative cues was examined. In Study 4, the possible moderating role of rating pleasantness on the relationship between avoidance and overgeneral memory was examined.  Results from the non-clinical samples indicated higher avoidance was associated with less overgeneral remembering on the AMT. In the clinical sample, there were no significant relationships between avoidance and overgeneral memory. There were no significant relationships between avoidance and AMT-R performance. Overall, stress did not moderate the relationship between avoidance and overgeneral memory. Mean pleasantness ratings for events remembered to positive and negative cues were congruent with cue valence. However, individual positive and negative cues did not always elicit memories for pleasant and unpleasant events, respectively. Rating (vs. not rating) the pleasantness of remembered events did not moderate the relationship between avoidance and overgeneral memory. Overall, findings suggested that functional avoidance is not part of a repertoire of avoidance strategies. Ironic process theory is discussed as an explanation for why higher avoidance was associated with a lower proportion of overgeneral memories in the non-clinical samples.</p>

scholarly journals Low light intensity delays vegetative phase change in Arabidopsis thaliana

2021 ◽  
Author(s):  
Mingli Xu ◽  
Tieqiang Hu ◽  
R. Scott Poethig
Keyword(s):  
Arabidopsis Thaliana ◽  
Light Intensity ◽  
Phase Change ◽  
Shade Tolerance ◽  
Light Quality ◽  
Shade Avoidance ◽  
Low Light ◽  
Vegetative Phase ◽  
Master Regulators ◽  
Vegetative Phase Change

Plants that develop under low intensity light (LL) often display a phenotype known as the "shade tolerance syndrome (STS)". This syndrome is similar to the phenotype of plants in the juvenile phase of shoot development, but the basis for this similarity is unknown. We tested the hypothesis that the STS is regulated by the same mechanism that regulates the juvenile vegetative phase by examining the effect of LL on rosette development in Arabidopsis thaliana. We found that LL prolonged the juvenile vegetative phase and that this was associated with an increase the expression of the master regulators of vegetative phase change, miR156 and miR157, and a decrease in the expression of their SPL targets. Exogenous sucrose partially corrected the effect of LL on seedling development and miR156 expression. Our results suggest that the response of Arabidopsis to LL is mediated by an increase in miR156/miR157 expression and by factors that repress SPL gene expression independently of miR156/miR157, and is caused in part by a decrease in carbohydrate production. The effect of LL on vegetative phase change does not require the photoreceptors and transcription factors responsible for the shade avoidance syndrome, implying that light intensity and light quality regulate rosette development by different pathways.

scholarly journals Shade suppresses wound-induced leaf repositioning through a mechanism involving PHYTOCHROME KINASE SUBSTRATE (PKS) genes

2021 ◽  
Author(s):  
Anne-Sophie Fiorucci ◽  
Olivier Michaud ◽  
Emanuel Schmid-Siegert ◽  
Martine Trevisan ◽  
Laure Allenbach Petrolati ◽  
...  
Keyword(s):  
Leaf Growth ◽  
Expression Patterns ◽  
Defense Responses ◽  
Potential Interaction ◽  
Shade Avoidance ◽  
Mechanical Wounding ◽  
Kinase Substrate ◽  
Wound Signal ◽  
The Relationship

Shaded plants challenged with herbivores or pathogens prioritize growth over defense. However, most experiments have focused on the effect of shading light cues on defense responses. To investigate the potential interaction between shade-avoidance and wounding-induced Jasmonate (JA)-mediated signaling on leaf growth and movement, we used repetitive mechanical wounding of leaf blades to mimic herbivore attacks. Phenotyping experiments with combined treatments on Arabidopsis thaliana rosettes revealed that shade strongly inhibits the wound effect on leaf elevation. By contrast, petiole length is reduced by wounding both in the sun and in the shade. Thus, the relationship between the shade and wounding/JA pathways varies depending on the physiological response, implying that leaf growth and movement can be uncoupled. Using RNA-sequencing, we identified genes with expression patterns matching the hyponastic response (opposite regulation by both stimuli, interaction between treatments with shade dominating the wound signal). Among them were genes from the PKS (Phytochrome Kinase Substrate) family, which was previously studied for its role in phototropism and leaf positioning. Interestingly, we observed reduced shade suppression of the wounding effect in pks2pks4 double mutants while a PKS4 overexpressing line showed constitutively elevated leaves and was less sensitive to wounding. Our results indicate a trait-specific interrelationship between shade and wounding cues on Arabidopsis leaf growth and positioning. Moreover, we identify PKS genes as integrators of external cues in the control of leaf hyponasty further emphasizing the role of these genes in aerial organ positioning.

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