4 research outputs found

    Determining basic forest stand characteristics using airborne laser scanning in mixed forest stands of Central Europe

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    This study focused on the derivation of basic stand characteristics from airborne laser scanning (ALS) data, aiming to elucidate which characteristics (mean height and diameter, dominant height and diameter) are best approximated by the variables obtained using ALS data. The height of trees of different species in four permanent plots located in the Slovak Republic was derived from the normalised digital surface model (nDSM) representing the canopy surface, using an automatic approach to identify local maxima (individual treetops). Tree identification was carried out using four different spatial resolutions of the nDSM (0.5 m, 1.0 m, 1.5 m, and 2.0 m) and the number of trees identified was compared with reference data obtained from field measurements. The highest percentage of tree detection (69-75%) was observed at the spatial resolutions of 1.0 and 1.5 m. Absolute differences of tree height between reference and ALS datasets ranged from 0 to 36% at all spatial resolutions. The smallest difference in mean height was obtained using the higher spatial resolution (0.5 m), while the smallest difference in the dominant height of the relative number of thickest trees (h10% and h20%) was observed using the lower spatial resolution (2 m). The same trends also apply to diameters. The average errors at resolution of 1.0 and 1.5 m was 8.7%, 5.9% and 9.7% for mean height, h20% and h10%, respectively. ALS-derived diameters (obtained using regression models from reference data and ALS-derived individual height as predictor) showed absolute errors in the range 0-48% at all spatial resolutions. The deviation in mean diameter at a resolution of 0.5 m ranged from -12.1% to 15.3%

    The role of the perception of family environment in relation to body dissatisfaction, disordered eating and difficulties in close relationships

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    Purpose Invalidating childhood environments have been characterised as those in which caregivers do not validate a child's personal experiences and the communication of emotions is considered inappropriate, being either ignored or punished. The current study assessed the relationships among invalidating childhood environments, body dissatisfaction, disordered eating and difficulties in close relationships in a sample of college students. Methods In this study, 362 non-clinical participants with ages ranging from 17 to 25 years (M = 20.02, SD = 1.51) completed self-report measures. Results Difficulties in close relationships, body dissatisfaction and disordered eating were significantly higher in invalidating families than in validating families. Invalidating childhood environments were associated with higher body dissatisfaction and disordered eating, and both associations were mediated by difficulties in close relationships. Finally, body dissatisfaction mediates the effects of BMI and difficulties in close relationships on eating disorder symptoms. Conclusions Perceived experiences of invalidation in childhood may be associated with eating disorder symptomatology. In addition, difficulties in close relationships during adulthood possibly contribute to the emergence of eating disorder symptoms.- (undefined
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