title: Theoretical consequences of trait-based environmental filtering for the breadth and shape of the niche: New testable hypotheses generated by the Traitspace model

authors: Laughlin, Daniel C.

subjects: Community assembly

abstract: Every species on Earth fills a unique environmental niche that is driven, in part, by the process of environmental filtering, where the adaptive value of the functional traits of individuals determine their fitness within the given environmental conditions. Despite its long-standing importance in ecology, theoretical investigations of environmental filtering have lagged behind studies of species interactions and neutral dynamics. A new statistical model of trait-based environmental filtering can be a useful tool for exploring the logical consequences of this process while holding all other processes constant. The model uses the logic of objective Bayesian inference to compute the probabilities of species within different environments using two sources of information: the location and dispersion of species within functional trait space, and the statistical relationship between traits and environmental gradients. By varying key parameters in the model, we highlight several testable hypotheses for trait-based ecology. First, niche breadth decreases as intraspecific trait variation decreases, as the strength of the environmental filter increases, and if the trait values do not enhance fitness in any environmental condition in the landscape. Second, niche shape is determined by the form of the trait-environment relationships, where species with extreme trait values are predicted to dominate at the environmental extremes when traits are linearly related to the environment, species with intermediate trait values generally have a selective advantage across a broader environmental range, and bimodal species response curves can occur independently from negative species interactions. The generality of these modelling results can be tested using empirical data from any ecosystem.

text: Theoretical consequences of trait-based environmental filtering for the breadth and shape of the niche: New testable hypotheses generated by the Traitspace model Every species on Earth fills a unique environmental niche that is driven, in part, by the process of environmental filtering, where the adaptive value of the functional traits of individuals determine their fitness within the given environmental conditions. Despite its long-standing importance in ecology, theoretical investigations of environmental filtering have lagged behind studies of species interactions and neutral dynamics. A new statistical model of trait-based environmental filtering can be a useful tool for exploring the logical consequences of this process while holding all other processes constant. The model uses the logic of objective Bayesian inference to compute the probabilities of species within different environments using two sources of information: the location and dispersion of species within functional trait space, and the statistical relationship between traits and environmental gradients. By varying key parameters in the model, we highlight several testable hypotheses for trait-based ecology. First, niche breadth decreases as intraspecific trait variation decreases, as the strength of the environmental filter increases, and if the trait values do not enhance fitness in any environmental condition in the landscape. Second, niche shape is determined by the form of the trait-environment relationships, where species with extreme trait values are predicted to dominate at the environmental extremes when traits are linearly related to the environment, species with intermediate trait values generally have a selective advantage across a broader environmental range, and bimodal species response curves can occur independently from negative species interactions. The generality of these modelling results can be tested using empirical data from any ecosystem.

year: 2015-07-01

title: Organisational Justice, Individual Differences and Counterproductive Work Behaviour: A Longitudinal Study in New Zealand and Thailand

authors: Jarunratanakul, Prapimpa

subjects: organisational justice

abstract: Although extensive research has investigated the effects of perceptions of organisational justice and personality traits on counterproductive work behaviour (CWB), few studies have examined the overall process in which justice perceptions mediate the relationships of outcome satisfaction, opportunity to voice, leader-member exchange (LMX) and communication quality with CWB, and the moderating effects of individual differences (agreeableness, conscientiousness, self-control, collectivism and power distance). Additionally, cultural differences may alter individuals’ justice perceptions and their responses to those perceptions. The primary purpose of this research was to examine whether the justice antecedent-justice-CWB model and the moderating influence of the above individual differences would be generalizable to New Zealand and Thailand. A two-wave longitudinal design was employed for main effect, mediation and moderation analyses in this research. Respondents representing a wide variety of organisations in New Zealand (N = 624 at Time 1, N = 276 at Time 2) and Thailand (N = 480 at Time 1, N = 242 at Time 2) completed self-report questionnaires, with two data collection points separated by a six-month time interval.

Mediation analyses showed that the justice antecedent-justice-CWB model was applicable to both samples, indicating that the four forms of perceived justice (distributive, procedural, interpersonal and informational justice) functioned as mediators. In addition, justice antecedents (outcome satisfaction, opportunity to voice, LMX and communication quality) had specific effects on each form of perceived justice, and justice perceptions had differential effects on two forms of CWB - CWB directed toward the organisation (CWBO) and CWB directed toward other individuals (CWBI). The full mediating effects of justice perceptions were observed more in the short-term for the New Zealand sample, but in a longer-term for the Thai sample. That is, New Zealand respondents tended to have a more immediate response to injustice than did their Thai counterparts. This may suggest that differences in cultural values should be taken into consideration to understand the antecedent-justice-outcome linkages.

Even though both samples had similar antecedents (outcome satisfaction predicted distributive justice, opportunity to voice predicted procedural justice, three LMX dimensions - affect, loyalty and professional respect - predicted interpersonal and informational justice, and communication quality predicted informational justice), communication and leadership can have different effects on employees, depending on their cultural values. Among the four forms of justice, interpersonal justice was the most consistent predictor of CWB in both countries, indicating that interpersonal concerns may be more important for individuals than specific outcomes received from work or organisational practices.

The main effects of individual differences were more substantial than their moderating effects. Confirmatory factor analysis (CFA) results found two factors (positive and negative factors) for each of the agreeableness and conscientiousness constructs. Of all the personality variables, agreeableness (for the Thai sample) and disagreeableness (for the New Zealand sample) significantly predicted the four forms of justice. Disagreeableness (the negative factor of agreeableness) consistently predicted CWBI, while negligence (the negative factor of conscientiousness) consistently predicted CWBO in both samples. However, the effects of personality variables on CWB were not stable across time, and the effects of collectivism and power distance on CWB were observed only in the Thai sample.

The current research not just replicated the model of justice, personality and CWB, which was developed mainly in the USA, but also provided both global and local level comparisons. The research findings provide additional knowledge in relation to the impact of justice perceptions on CWB in different cultural contexts. On the practical side, the findings help practitioners better understand the formation of employees’ justice perceptions and significant factors leading to CWB, which may aid them in devising organisational policies of justice enhancement.

text: Organisational Justice, Individual Differences and Counterproductive Work Behaviour: A Longitudinal Study in New Zealand and Thailand Although extensive research has investigated the effects of perceptions of organisational justice and personality traits on counterproductive work behaviour (CWB), few studies have examined the overall process in which justice perceptions mediate the relationships of outcome satisfaction, opportunity to voice, leader-member exchange (LMX) and communication quality with CWB, and the moderating effects of individual differences (agreeableness, conscientiousness, self-control, collectivism and power distance). Additionally, cultural differences may alter individuals’ justice perceptions and their responses to those perceptions. The primary purpose of this research was to examine whether the justice antecedent-justice-CWB model and the moderating influence of the above individual differences would be generalizable to New Zealand and Thailand. A two-wave longitudinal design was employed for main effect, mediation and moderation analyses in this research. Respondents representing a wide variety of organisations in New Zealand (N = 624 at Time 1, N = 276 at Time 2) and Thailand (N = 480 at Time 1, N = 242 at Time 2) completed self-report questionnaires, with two data collection points separated by a six-month time interval.

Mediation analyses showed that the justice antecedent-justice-CWB model was applicable to both samples, indicating that the four forms of perceived justice (distributive, procedural, interpersonal and informational justice) functioned as mediators. In addition, justice antecedents (outcome satisfaction, opportunity to voice, LMX and communication quality) had specific effects on each form of perceived justice, and justice perceptions had differential effects on two forms of CWB - CWB directed toward the organisation (CWBO) and CWB directed toward other individuals (CWBI). The full mediating effects of justice perceptions were observed more in the short-term for the New Zealand sample, but in a longer-term for the Thai sample. That is, New Zealand respondents tended to have a more immediate response to injustice than did their Thai counterparts. This may suggest that differences in cultural values should be taken into consideration to understand the antecedent-justice-outcome linkages.

Even though both samples had similar antecedents (outcome satisfaction predicted distributive justice, opportunity to voice predicted procedural justice, three LMX dimensions - affect, loyalty and professional respect - predicted interpersonal and informational justice, and communication quality predicted informational justice), communication and leadership can have different effects on employees, depending on their cultural values. Among the four forms of justice, interpersonal justice was the most consistent predictor of CWB in both countries, indicating that interpersonal concerns may be more important for individuals than specific outcomes received from work or organisational practices.

The main effects of individual differences were more substantial than their moderating effects. Confirmatory factor analysis (CFA) results found two factors (positive and negative factors) for each of the agreeableness and conscientiousness constructs. Of all the personality variables, agreeableness (for the Thai sample) and disagreeableness (for the New Zealand sample) significantly predicted the four forms of justice. Disagreeableness (the negative factor of agreeableness) consistently predicted CWBI, while negligence (the negative factor of conscientiousness) consistently predicted CWBO in both samples. However, the effects of personality variables on CWB were not stable across time, and the effects of collectivism and power distance on CWB were observed only in the Thai sample.

The current research not just replicated the model of justice, personality and CWB, which was developed mainly in the USA, but also provided both global and local level comparisons. The research findings provide additional knowledge in relation to the impact of justice perceptions on CWB in different cultural contexts. On the practical side, the findings help practitioners better understand the formation of employees’ justice perceptions and significant factors leading to CWB, which may aid them in devising organisational policies of justice enhancement.

year: 2013

title: Maori perspectives of the environment: Summary document

authors: Whangapirita, Laura

subjects: Maori

abstract: The Community and Economy Programme at Environment Waikato has developed a partnership with the Maori and Psychology Research Unit of the University of Waikato to further assist in strengthening its commitment to cultural research and information work. This relationship facilitated the development of the Maori and Environment project, which was conducted in two stages and produced a number of significant research reports throughout 2003. This is the summary document.

text: Maori perspectives of the environment: Summary document The Community and Economy Programme at Environment Waikato has developed a partnership with the Maori and Psychology Research Unit of the University of Waikato to further assist in strengthening its commitment to cultural research and information work. This relationship facilitated the development of the Maori and Environment project, which was conducted in two stages and produced a number of significant research reports throughout 2003. This is the summary document.

year: 2003-12