Similarity in species composition among different areas plays an essential task in biodiversity management and conservation since it allows the identification of those environmental gradients that functionally operate in determining variation in species composition across spatial scale. The decay of compositional similarity with increasing spatial or environmental distance derives from: 1) the presence of spatial constraints which create a physical separation among habitats, or 2) the decrease in environmental similarity with increasing distance. Even if the distance decay of compositional similarity represents a well known pattern characterising all types of biological communities, few attempts were made to examine this pattern at small spatial scales with respect to both grain and extent. Aim of this work was to test whether the distance decay of similarity 1) can be observed at a local scale in situations where environmental conditions are relatively homogeneous and ecological barriers are absent, and 2) is dependent on the grain size at which plant community data are recorded. We selected two urban brownfields located at Bremen university campus, Germany, of 40 m × 20 m each, systematically divided in nested plots with an increasing spatial scale of 0.25 m2, 1 m2, 4 m2 and 16 m2. Both plant species composition and soil variables were recorded in each cell. Linear and logarithmic least squares regression models were applied in order to examine the decay of similarity due to spatial distance (calculated as the Euclidean distance among pairs of plots) and environmental distance (calculated as the Euclidean distance among PCA-transformed soil variables). A general lack of distance decay was observed, irrespective of the type of distance (spatial or environmental) or the grain size. We argue that this is probably due to a random variation both of the important environmental parameters and of the local distribution patterns of individual species, the latter mainly caused by the high dispersal abilities of the majority of species occurring in the brownfields.
The sports betting market has been growing rapidly over the last years, as have reports of problematic gambling behavior associated with betting. Due to the well-documented gambling problems of famous athletes and the betting supportive nature of many sports-related environments, athletes have been highlighted as a potential group at-risk for problematic sports betting. However, there currently remains a lack of research on individual-level athlete-specific risk-factors or mechanisms that might contribute to the development and perpetuation of betting-related problems. Here, we examine the influence of two potential risk-factors on sports betting behavior and problems: erroneous beliefs and athletes' emotional involvement.
201 athletes with different levels of expertise completed a newly developed scale to assess both factors. Participants were sampled from the general German population, predominantly male (83.08%) and on average 29.52 (SD = 11.05) years old. We use principal components analysis to detect patterns of covariation, potentially due to the proposed underlying latent factors, and regression analyses to test associations of these factors with betting behavior and problems.
We find that athletes' emotional involvement was strongly associated with betting problems whereas erroneous beliefs were not. However, distorted cognitions/beliefs were associated with higher volumes and more frequent betting activities.
Discussion and Conclusions
This might contribute to betting problems in the long run. These results highlight athletes' emotional involvement and erroneous beliefs as potential targets for future intervention and prevention efforts.
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