Mountain laurel (Kalmia latifolia L.) is relatively difficult to establish in landscapes. One experiment tested the effect of container size on the water relations of pinebark substrate embedded in field soil. Two other experiments tested the effects of transplant season and container size on landscape establishment of nursery-produced mountain laurel. Experiment one compared volumetric water content of embedded substrate of five sizes (4-L to 100-L) to adjacent field soil at two depths with time domain reflectometry (TDR) during a dry down cycle. Available water was calculated by subtracting unavailable water (estimated with pressure plates) from volumetric water content (TDR measurements). Adjacent soil contained more available water than embedded substrate. The middle depth held more water than the top. Larger pinebark substrate volumes retained higher volumetric water content than smaller volumes. The second experiment consisted of 7.6- and 19-L containers of Kalmia latifolia L. ‘Olympic Wedding’, transplanted into field soil in October or May. Larger container plants generally had lower xylem potential than smaller plants, but better visual ratings. Root growth into surrounding soil was negligible for all treatments. Leaf area was higher for spring transplants than fall transplants. Experiment three was a rhizotron study with 19-L plants, transplanted in October or May. Canopy growth of spring transplants was greater than fall transplants, but fall transplants had longer roots into the backfill. Overall, our data suggest that fall transplanting will potentially allow faster plant establishment than spring transplanting. The effect of container size on plant establishment could not be determined. / Master of Science

The effect of portion size on food intake is a well-documented phenomenon: when served larger portions, individuals significantly increase their food intake. Insofar authors have limited their research on presenting the potential outcomes, while identifying several conditions favorable to this phenomenon. Indeed, the mechanisms of this effect are poorly understood and no research has insofar provided conclusive evidence regarding the underlying mechanism that could help explain the portion size effect. The first part of this dissertation aimed to fill this gap. We argue that the anchoring and adjustment heuristic accounts for most of the favoring conditions evidenced in earlier research and present it as a possible mechanism underlying the portion size effect. In this view, the portion size served is used as an anchor whereas other influences (i.e. economical, metabolic, regulatory, physiological, sensory, social and environmental) may further contribute to adjust total amount of food consumed. Moreover, we argue that prevention strategies based on this decision making literature may be similarly effective to limit excess food intake from enlarged portions. <p><p>The second and third chapter of this dissertation focus on two other factors related to the portion size of foods, namely the container size and the structure of the portion (i.e. food item size). The discussion of this dissertation reviews the facilitating conditions put forward previously to understand the portion size effect, as well as those reinforcing this effect, and how they may be integrated in an anchoring and adjustment perspective of eating. Finally, it aims to provide a food intake model that may accommodate for most environmental influences, with a special focus on the three influences mentioned above. / Doctorat en Sciences Psychologiques et de l'éducation / info:eu-repo/semantics/nonPublished