Grazing and the absence of fire promote the dominance of an unpalatable shrub in a patch mosaic cyclic successional system

2016 ◽  
Vol 64 (1) ◽  
pp. 45 ◽  
Author(s):  
Jamie B. Kirkpatrick ◽  
Kerry L. Bridle
Keyword(s):  
Grazing Pressure ◽  
Lower Proportion ◽  
Interactive Effects ◽  
Strong Reduction ◽  
Shrub Layer ◽  
Grazing Exclusion ◽  
Low Intensity ◽  
Patch Mosaic ◽  
Dead Material ◽  
Preferential Location

We experimentally determined how an apparently unpalatable and fire-sensitive shrub, Richea acerosa (Lindley) F.Muell., responded to the single and interactive effects of grazing and burning over 3–24 years at two subalpine sites in Tasmania. At the Middlesex Plains site, a low-intensity burn killed most individuals of the species 3 years after fire and fencing. At the Lake Botsford site, total grazing exclusion for 24 years resulted in a strong reduction of the number of small shrubs of the species, and in a lower proportion of dead material in plants of any given size. An open shrub layer results from the absence of R. acerosa seedlings in the open centres of senescing plants and their preferential location along the margins of the foliage of mature and senescing plants. Thus, the persistence of R. acerosa appears to require an absence of frequent fire and the presence of sufficient grazing pressure from vertebrate herbivores to produce lawn between shrubs. Richea acerosa is, thus, an unpalatable shrub that depends on grazing.

Patch mosaic cyclic succession associated with the growth and senescence of an alpine shrub

2016 ◽  
Vol 64 (2) ◽  
pp. 111 ◽  
Author(s):  
Danielle C. McPhail ◽  
Jamie B. Kirkpatrick
Keyword(s):  
Vegetation Change ◽  
Root Competition ◽  
Shrub Species ◽  
Central Plateau ◽  
Clear Sky ◽  
Patch Mosaic ◽  
Dead Material ◽  
Alpine Shrub ◽  
Floristic Variation ◽  
Sky Conditions

Endogenously-induced cyclic vegetation change has been associated with the life cycle of shrub species, resulting in mosaic or linear patterning in vegetation. We investigated whether mosaic cyclic succession was taking place in Richea acerosa (Lindley) F.Muell. alpine heath on the Central Plateau of Tasmania, Australia by determining the variation in species composition associated with different growth characteristics of the shrub and by monitoring shrubs in plots over 11 years. Temperatures below and adjacent to shrubs were measured in clear sky conditions to determine if microclimatic variation was associated with structural and floristic variation. Species richness was higher outside than inside the shrubs, and was further depressed by an increasing proportion of dead material in the shrub. However, Poa saxicola R.Br. appeared to be protected by the prickly foliage of R. acerosa and also preferentially occurred among the mass of dead stems that characterised the centre of older plants. There was a strong floristic shift associated with the development of the shrub. The live cover of individual shrubs remained constant in all plots over the 11 years, while plots initially dominated by senescent plants contained young plants and vice-versa. The live part of the shrubs moderated temperatures. However, root competition and protection from grazing seem likely to have made a major contribution to the shifting conditions associated with the mosaic cyclic succession.

Vegetation state change and consequent carbon dynamics in savanna woodlands of Australia in response to grazing, drought and fire: a scenario approach using 113 years of synthetic annual fire and grassland growth

2005 ◽  
Vol 53 (7) ◽  
pp. 715 ◽  
Author(s):  
Michael J. Hill ◽  
Stephen H. Roxburgh ◽  
John O. Carter ◽  
Gregory M. McKeon
Keyword(s):  
Carbon Dynamics ◽  
Grazing Pressure ◽  
Carbon Accumulation ◽  
Interactive Effects ◽  
Sensitivity Analyses ◽  
Annual Rainfall ◽  
Transition Model ◽  
Model Framework ◽  
Time Step ◽  
State And Transition Model

A spatially explicit state and transition model for assessing the interactive effects of grazing, fire and climate on carbon dynamics in Australian savannas is described. The model runs on a yearly time step. It is based on a sequential treatment of events within each year, involving, in order, growth of biomass, consumption of biomass by livestock and burning of the remaining fuel (growth minus consumption). The major drivers are 113 years of annual rainfall data, annual modelled rangeland growth, synthetic fire incidence and timing data, and data describing stocking rates in dry sheep equivalents. Baseline carbon stocks are derived from pre-settlement estimates from the VAST steady-state carbon model. State and transition models for nine vegetation zones define vegetation condition and consequent carbon stock. Change is mediated by key indices of driver variables such as grazing, growth and fire, a series of parameters and default thresholds, and a set of rules. The model is run for three 113-year spin-up cycles to establish a set of initial condition grids that represent a plausible synthetic current state. Sensitivity analyses on selected parameters and index thresholds showed that fire and growth thresholds were most important for woodland zones, and utilisation rates and degradation and recovery periods were most important for grassland zones. The model was used to examine a series of scenarios involving changes to grazing pressure and suppression of fire for different climate sequences. Changes to a few parameters enabled simulation of low and high levels of encroachment of woody weeds, and hence carbon accumulation, in the Astrebla (Mitchell) grasslands; and effective capture of the climate-induced variation in grassland condition, and hence potential for soil carbon loss, within Heteropogon spp.-dominated grasslands in northern Queensland. The scenario results suggest that this simple state and transition model with an annual time step provides a potentially useful and flexible scenario model framework for exploration of vegetation and consequent carbon dynamics of the Australian tropical savanna region.

Interactive effects of shade and surface orientation on the recruitment of spirorbid polychaetes

2001 ◽  
Vol 26 (1) ◽  
pp. 109-115 ◽  
Author(s):  
R. J. Saunders ◽  
S. D. Connell
Keyword(s):  
Surface Orientation ◽  
Interactive Effects

Low-Intensity Cognitive Behavioral Therapy

2017 ◽  
Vol 2 (1) ◽  
pp. 31-36
Author(s):  
Pascal Wabnitz ◽  
Michael Schulz ◽  
Michael Löhr ◽  
André Nienaber
Keyword(s):  
Cognitive Behavioral Therapy ◽  
Behavioral Therapy ◽  
Cognitive Behavioral ◽  
Low Intensity

Investigation of the Effect of Mode and Tempo on Emotional Responses to Music Using EEG Power Asymmetry

2013 ◽  
Vol 27 (3) ◽  
pp. 142-148 ◽  
Author(s):  
Konstantinos Trochidis ◽  
Emmanuel Bigand
Keyword(s):  
Left Hemisphere ◽  
Right Hemisphere ◽  
Emotional Responses ◽  
Interactive Effects ◽  
Eeg Activity ◽  
Musical Excerpt ◽  
Major Mode ◽  
Musical Modes ◽  
Slow Tempo ◽  
The Right

The combined interactions of mode and tempo on emotional responses to music were investigated using both self-reports and electroencephalogram (EEG) activity. A musical excerpt was performed in three different modes and tempi. Participants rated the emotional content of the resulting nine stimuli and their EEG activity was recorded. Musical modes influence the valence of emotion with major mode being evaluated happier and more serene, than minor and locrian modes. In EEG frontal activity, major mode was associated with an increased alpha activation in the left hemisphere compared to minor and locrian modes, which, in turn, induced increased activation in the right hemisphere. The tempo modulates the arousal value of emotion with faster tempi associated with stronger feeling of happiness and anger and this effect is associated in EEG with an increase of frontal activation in the left hemisphere. By contrast, slow tempo induced decreased frontal activation in the left hemisphere. Some interactive effects were found between mode and tempo: An increase of tempo modulated the emotion differently depending on the mode of the piece.

Interactive Effects of Acute Suicidal Affective Disturbance and Pain Persistence on Suicide Attempt Frequency and Lethality

Crisis ◽  
2019 ◽  
Vol 40 (6) ◽  
pp. 413-421 ◽  
Author(s):  
Megan L. Rogers ◽  
Thomas E. Joiner
Keyword(s):  
Suicide Attempt ◽  
Suicidal Behavior ◽  
Pain Perception ◽  
Suicide Attempts ◽  
Pain Tolerance ◽  
Self Report ◽  
Interactive Effects ◽  
Physical Pain ◽  
Affective Disturbance ◽  
The Relationship

Abstract. Background: Acute suicidal affective disturbance (ASAD) has been proposed as a suicide-specific entity that confers risk for imminent suicidal behavior. Preliminary evidence suggests that ASAD is associated with suicidal behavior beyond a number of factors; however, no study to date has examined potential moderating variables.  Aims: The present study tested the hypotheses that physical pain persistence would moderate the relationship between ASAD and (1) lifetime suicide attempts and (2) attempt lethality. Method: Students ( N = 167) with a history of suicidality completed self-report measures assessing the lifetime worst-point ASAD episode and the presence of a lifetime suicide attempt, a clinical interview about attempt lethality, and a physical pain tolerance task. Results: Physical pain persistence was a significant moderator of the association between ASAD and lifetime suicide attempts ( B = 0.00001, SE = 0.000004, p = .032), such that the relationship between ASAD and suicide attempts strengthened at increasing levels of pain persistence. The interaction between ASAD and pain persistence in relation to attempt lethality was nonsignificant ( B = 0.000004, SE = 0.00001, p = .765). Limitations: This study included a cross-sectional/retrospective analysis of worst-point ASAD symptoms, current physical pain perception, and lifetime suicide attempts. Conclusion: ASAD may confer risk for suicidal behavior most strongly at higher levels of pain persistence, whereas ASAD and pain perception do not influence attempt lethality.

Parenting Behaviors and Anxiety in Young Adults

2015 ◽  
Vol 36 (3) ◽  
pp. 170-176 ◽  
Author(s):  
Erin N. Stevens ◽  
Joseph R. Bardeen ◽  
Kyle W. Murdock
Keyword(s):  
Effortful Control ◽  
Parenting Behaviors ◽  
Protective Role ◽  
Anxiety Symptoms ◽  
Interactive Effects ◽  
Parental Overprotection ◽  
High Control ◽  
Development Of Anxiety ◽  
The Relationship

Parenting behaviors – specifically behaviors characterized by high control, intrusiveness, rejection, and overprotection – and effortful control have each been implicated in the development of anxiety pathology. However, little research has examined the protective role of effortful control in the relation between parenting and anxiety symptoms, specifically among adults. Thus, we sought to explore the unique and interactive effects of parenting and effortful control on anxiety among adults (N = 162). Results suggest that effortful control uniquely contributes to anxiety symptoms above and beyond that of any parenting behavior. Furthermore, effortful control acted as a moderator of the relationship between parental overprotection and anxiety, such that overprotection is associated with anxiety only in individuals with lower levels of effortful control. Implications for potential prevention and intervention efforts which specifically target effortful control are discussed. These findings underscore the importance of considering individual differences in self-regulatory abilities when examining associations between putative early-life risk factors, such as parenting, and anxiety symptoms.

Differences in the Way to Conceive Happiness Relate to Different Reactions to Negative Events

2018 ◽  
Vol 39 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Giulia Fuochi ◽  
Chiara A. Veneziani ◽  
Alberto Voci
Keyword(s):  
Positive Emotions ◽  
Satisfaction With Life ◽  
Well Being ◽  
Protective Role ◽  
Stressful Events ◽  
Interactive Effects ◽  
Negative Events ◽  
Orientations To Happiness ◽  
Specific Reactions ◽  
The Way

Abstract. This paper aimed to assess whether differences in the way to conceive happiness, measured by the Orientations to Happiness measure, were associated with specific reactions to negative events. We hypothesized that among orientations to pleasure (portraying hedonism), to meaning (representing a eudaimonic approach to life), and to engagement (derived from the experience of flow), orientation to meaning would have displayed a stronger protective role against recent negative and potentially stressful events. After providing a validation of the Italian version of the Orientations to Happiness measure (Study 1), we performed regression analyses of the three orientations on positive and negative emotions linked to a self-relevant negative event (Study 2), and moderation analyses assessing the interactive effects of orientations to happiness and stressful events on well-being indicators (Study 3). Our findings supported the hypotheses. In Study 2, meaning was associated with positive emotions characterized by a lower activation (contentment and interest) compared to the positive emotions associated with pleasure (amusement, eagerness, and happiness). In Study 3, only meaning buffered the effect of recent potentially stressful events on satisfaction with life and positive affect. Results suggest that orientation to meaning might help individuals to better react to negative events.

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