Browsing by Subject "relatedness"

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    The Relationship Between Psychological Needs Satisfaction and Professional Commitment of Minnesota School-Based Agricultural Education Teachers
    (2023-03) Rada, Lavyne
    Teachers must be retained in the profession to meet the ever-growing demand for SBAE teachers across the United States. Although the literature has identified several factors which influence SBAE teacher retention, previous research has not examined the psychological needs satisfaction of Minnesota SBAE teachers. While critical to retention, professional commitment remains a needed area within SBAE research. This study viewed psychological needs through the lens of SDT (Ryan & Deci, 2002), recognizing that the psychological needs of autonomy, competence, and relatedness are universal and innate needs essential for psychological functioning (Ryan & Deci, 2020). Given that people are drawn to environments that foster needs satisfaction and that needs satisfaction influences beliefs and behaviors (Collie et al., 2016; Lee & Nie, 2014; Mabekoje et al., 2016), teacher’s psychological needs satisfaction influences a teacher's professional commitment. This study aimed to examine if and to what extent psychological needs satisfaction of autonomy, competence, and relatedness was related to and could predict SBAE teachers’ professional commitment. Hypothesized connections were tested simultaneously with a conceptual model where SBAE teacher’s psychological needs satisfaction and professional commitment was examined. Overall, the results revealed that psychological needs satisfaction of autonomy, competence, and relatedness (independently and collectively) have a significant and negative impact on turnover intention, which was used to measure professional commitment. According to the data, competence and autonomy are the primary predictors of professional commitment. These results align with previous research on teachers that indicated autonomy (Collie et al., 2016) and competence (Palmer, 2020) were indicators of professional commitment. It was concluded that satisfying SBAE teachers' psychological needs, especially the need for autonomy and competence, are an essential component of Minnesota SBAE teacher retention. If leaders in SBAE want to reduce attrition, more must be done to support SBAE teacher’s psychological needs satisfaction of autonomy, competence, and relatedness. Furthermore, special effort should be made to identify the distinctive needs of the majority of current SBAE teachers with up to ten years teaching experience, who tend to have lower psychological needs fulfillment.
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    Species richness, but not phylogenetic diversity, influences community biomass production and temporal stability in a re-examination of 16 grassland biodiversity studies
    (Wiley, 2015) Venail, Patrick; Gross, Kevin; Oakley, Todd H; Narwani, Anita; Allan, Eric; Flombaum, Pedro; Isbell, Forest; Joshi, Jasmin; Reich, Peter B; Tilman, David; van Ruijven, Jasper; Cardinale, Bradley J
    Hundreds of experiments have now manipulated species richness (SR) of various groups of organisms and examined how this aspect of biological diversity influences ecosystem functioning. Ecologists have recently expanded this field to look at whether phylogenetic diversity (PD) among species, often quantified as the sum of branch lengths on a molecular phylogeny leading to all species in a community, also predicts ecological function. Some have hypothesized that phylogenetic divergence should be a superior predictor of ecological function than SR because evolutionary relatedness represents the degree of ecological and functional differentiation among species. But studies to date have provided mixed support for this hypothesis. Here, we reanalyse data from 16 experiments that have manipulated plant SR in grassland ecosystems and examined the impact on above-ground biomass production over multiple time points. Using a new molecular phylogeny of the plant species used in these experiments, we quantified how the PD of plants impacts average community biomass production as well as the stability of community biomass production through time. Using four complementary analyses, we show that, after statistically controlling for variation in SR, PD (the sum of branches in a molecular phylogenetic tree connecting all species in a community) is neither related to mean community biomass nor to the temporal stability of biomass. These results run counter to past claims. However, after controlling for SR, PD was positively related to variation in community biomass over time due to an increase in the variances of individual species, but this relationship was not strong enough to influence community stability. In contrast to the non-significant relationships between PD, biomass and stability, our analyses show that SR per se tends to increase the mean biomass production of plant communities, after controlling for PD. The relationship between SR and temporal variation in community biomass was either positive, non-significant or negative depending on which analysis was used. However, the increases in community biomass with SR, independently of PD, always led to increased stability. These results suggest that PD is no better as a predictor of ecosystem functioning than SR. Synthesis. Our study on grasslands offers a cautionary tale when trying to relate PD to ecosystem functioning suggesting that there may be ecologically important trait and functional variation among species that is not explained by phylogenetic relatedness. Our results fail to support the hypothesis that the conservation of evolutionarily distinct species would be more effective than the conservation of SR as a way to maintain productive and stable communities under changing environmental conditions.