Dante S.K.,Queens University |
Schamp B.S.,Algoma University |
Aarssen L.W.,Queens University
Functional Ecology | Year: 2013
Theory has produced contrasting predictions related to flowering time overlap among coexisting plant species largely because of the diversity of potential influences on flowering time. In this study, we use a trait-based null modelling approach to test for evidence of deterministic assembly of species according to flowering time in an old-field plant community. Plant species coexisting in one-metre-square plots overlapped in flowering time significantly more than expected. This flowering synchrony was more pronounced when analyses focused on bee-pollinated species. Flowering synchrony was also observed for wind-pollinated species, although for only one of our two null model tests, highlighting the sensitivity of some results to different randomization methods. In general, these patterns suggest that relationships between pollinators and plants can influence community assembly processes. Because our study community is composed of approximately 43% native plant species and 57% exotic species, and because the arrival of new species may complicate plant-pollinator interactions, we tested whether flowering time overlap was altered by introduced species. Flowering synchrony was greater in plots with a higher proportion of introduced species. This pattern held for both null model tests, but was slightly stronger when analyses focused on bee-pollinated species. These results indicate that introduced species alter community flowering distributions and in so doing will inevitably affect pollinator-plant interactions. Finally, we tested whether our results were influenced by variation among study plots in above-ground biomass production, which some theory predicts will be related to the importance of competition. Our results were not influenced by this variation, suggesting that resource variation among our plots did not contribute to observed patterns. Synthesis: Our results provide support for predictions that coexisting species should display flowering synchrony, and provide no support for species coexistence via temporal niche partitioning at this scale in this study community. Our results also indicate that introduced species significantly alter the community assembly process such that flowering synchrony is more pronounced in plots with a greater proportion of introduced plant species. © 2013 British Ecological Society.
Terrion J.L.,University of Ottawa |
Aceti V.,Algoma University
Research in Learning Technology | Year: 2012
While technology - in the form of laptops and cellphones - may be the cause of much of the distraction in university and college classrooms, some, including the personal or classroom response system (PRS/CRS) or clicker, also present pedagogical opportunities to enhance student engagement. The current study explored the reactions of students to clicker implementation in a large, introductory chemistry class. During the final class of the semester, 200 students in an introductory chemistry class responded to an attitudinal and informational student survey using both Likert-type and non-Likert type questions to evaluate their perception of the implementation of the clickers and their impact on student learning and engagement. The results demonstrated that, when implemented effectively, clickers contribute to greater student engagement and, ultimately, an opportunity for professors to enact best practices in higher education pedagogy. This study points to the importance of effective pedagogy in making clickers worthwhile. © 2012 J. Lennox Terrion and V. Aceti.
Hornstein H.A.,Algoma University
International Journal of Project Management | Year: 2015
Project management processes and the training of new project managers (PM) must consider the impact of organizational change on the success and failure of project implementations. The case for requiring project managers to be conversant with organizational change management (OCM) is made by the author by reviewing supportive literature. In addition, PM certifying agencies like PMI and IPMA are strongly encouraged to include education on OCM to the certification process for new PMs. © 2014 Elsevier Ltd and Association for Project Management and the International Project Management Association.
Schamp B.,Algoma University |
Horsak M.,Masaryk University |
Hajek M.,Masaryk University
Journal of Animal Ecology | Year: 2010
1. We investigated whether coexisting snail species in 145 treeless fen communities in the Western Carpathian Mountains differed more in size and diet than would be expected by chance, as predicted for traits commonly associated with competition and differential resource acquisition under limiting similarity theory. 2. Contrary to expectations, coexisting snail species were no more different in body size than expected by chance under a null model. However, variation in body size played a significant role in structuring snail communities: coexisting snail species were significantly more similar with respect to body size. 3. We developed two new test statistics to expand our investigation of limiting similarity to include diet, a nominal trait. We tested whether communities of snails were characterized by a greater richness of diet, and whether different diets were represented more or less evenly within communities. Communities of snails were significantly less evenly distributed than expected by chance, with detritivores being over-represented relative to predatory strategies. 4. We also examined the effect of water pH and conductivity, herbaceous cover, and bryophyte and vascular plant richness, on these trends by examining how the effect size of our tests varied across these gradients. Convergence in species size increased with increasing habitat pH. Specifically, smaller snail species were over-represented in fen communities in general, and this effect was accentuated in increasingly calcareous fens. 5. Theory predicts that traits related strongly to environmental conditions are more likely to be convergent. Our findings support this suggestion, as small snail species have an advantage in tolerating freezing conditions over winter when refuges are limited. 6. These results add to the growing body of literature demonstrating that variation in body size and diet play a strong role in structuring communities, although frequently in ways not predicted by limiting similarity theory. Finally, our results increase our understanding of how species are assembled non-randomly into communities with respect to important traits. © 2010 The Authors. Journal compilation © 2010 British Ecological Society.
Schamp B.S.,Algoma University |
Aarssen L.W.,Queens University
Journal of Vegetation Science | Year: 2014
Question: Experimental evidence suggests that competition among plant species is generally hierarchical and that relatively large species are at a competitive advantage when competition is predominantly above-ground. However, regional species pools are dominated numerically by relatively small plant species, and small species generally have higher local densities of resident plants within natural communities. One explanation is that larger plant species suffer disproportionately more under effects of intra-specific competition (i.e. greater density dependence). We tested this prediction using ten herbaceous plant species in a competition experiment. Location: Kingston, Ontario, Canada, glasshouse. Methods: Using a glasshouse experiment, we tested whether relatively large species suffer disproportionately more in monoculture relative to mixtures of all ten herbaceous plant species. We measured the effects of competition on biomass production and survival by monitoring both in monocultures and mixtures of our species. Results: Larger plant species suffered more under intra-specific relative to diffuse inter-specific competition in terms of survival; however, the slope of this relationship was not significantly greater than one, indicating that larger species did not suffer disproportionate density-dependent suppression. Conclusions: Our results support a role for size in plant competition, but also indicate that this role is reduced because relatively larger species suffer greater density-dependent mortality when competing with other, equally large plants. As such, size-based competitive hierarchies may not function as clearly in natural systems because the increased negative density dependence for larger species contributes to balancing out competition across size hierarchies. © 2013 International Association for Vegetation Science.