Identifying pollinator communities visiting berry-producing plants on coastal barrens By Lyndsey M. Burrell A Thesis Submitted to Saint Mary’s University, Halifax, Nova Scotia in Partial Fulfillment of the Requirements for the Degree of Bachelor of Science with Honours © Lyndsey M. Burrell, 2019 Approved: Dr. Jeremy Lundholm Supervisor Approved: Dr. David Richardson Examiner Approved: Dr. Erin Cameron Examiner Date Submitted: March 20, 2019 Identifying pollinator communities visiting berry-producing plants on coastal barrens By Lyndsey M. Burrell Abstract There is a lack of research on the pollinator communities of flowering plant species within coastal barren habitats. This study examined four closely related plant species in the Ericaceae that have a similar flower structure: Vaccinium angustifolium, Gaylussacia baccata, Gaylussacia bigeloviana, and Gaultheria procumbens. They were studied at four coastal barren sites within Halifax County, Nova Scotia. At each site, pollinator collection and observations were carried out, as well as vegetation surveys to identify available foraging resources. Pollinators were identified down to morphospecies. A total of 145 insect pollinators, comprised of 32 morphospecies were collected. Results identified pollinator assemblages. There were significant correlations between all pollinator variables (catches, visits, richness) and the number of flowers on the target species. G. baccata and G. bigeloviana displayed higher pollinator diversity and had significantly more flowers than the other two target plant species. This study is one of the first to document and record pollinator communities of berry-producing plant species and underlines the importance of understanding plant-pollinator interactions. Date submitted: March 20, 2019 Table of Contents 1 Introduction .................................................................................................................... 1 1.1 Coastal Barrens .......................................................................................................... 1 1.2 Pollinator Communities ............................................................................................. 2 1.3 Plant-Pollinator Interactions ....................................................................................... 3 1.3.1 Mutualism ........................................................................................................... 3 1.3.2 Co-Flowering Species ......................................................................................... 4 1.3.3 Climate Change Influences ................................................................................ 4 1.4 Objectives .................................................................................................................. 5 2 Methods ........................................................................................................................... 6 2.1 Study Site .................................................................................................................. 6 Figure 1 ........................................................................................................................ 7 Figure 2 ....................................................................................................................... 8 Figure 3 ....................................................................................................................... 9 Figure 4 ..................................................................................................................... 10 2.2 Target Species ......................................................................................................... 11 Figure 5 ...................................................................................................................... 12 2.3 Experimental Design ............................................................................................... 13 2.3.1 Plot Selection .................................................................................................... 13 2.3.2 Pollinator Collection ......................................................................................... 13 Figure 6 ...................................................................................................................... 14 2.3.3 Vegetation Surveys ........................................................................................... 15 2.4 Pollinator Preparation and Identification ................................................................ 15 2.5 Foraging Conditions ................................................................................................ 15 2.6 Statistical Analysis .................................................................................................. 16 3 Results ........................................................................................................................... 18 3.1 Pollinator Assemblage ............................................................................................. 18 Figure 7 ...................................................................................................................... 18 Figure 8 ...................................................................................................................... 20 Figure 9 ...................................................................................................................... 20 Figure 10 .................................................................................................................... 21 3.2 Pollinator Richness .................................................................................................. 22 Figure 11 .................................................................................................................... 23 Figure 12 .................................................................................................................... 24 Table 2 ....................................................................................................................... 25 Table 3 ....................................................................................................................... 26 3.3 Vegetation Survey ................................................................................................... 26 Table 4 ....................................................................................................................... 27 Figure 13 .................................................................................................................... 28 Figure 14 .................................................................................................................... 30 Figure 15 .................................................................................................................... 30 Figure 16 .................................................................................................................... 31 Table 5 ....................................................................................................................... 32 3.4 Environmental Factors ............................................................................................ 32 Table 6 ....................................................................................................................... 33 Table 7 ....................................................................................................................... 34 Table 1 ....................................................................................................................... 35 4 Discussion ...................................................................................................................... 36 4.1 Pollinator Assemblage ............................................................................................. 36 4.2 Morphospecies ......................................................................................................... 38 4.3 Richness ................................................................................................................... 40 4.4 Vegetation ............................................................................................................... 41 4.5 Environmental Relevance ........................................................................................ 42 4.6 Limitations ............................................................................................................... 42 5 Conclusion .................................................................................................................... 44 6 Acknowledgements ...................................................................................................... 45 7 References ..................................................................................................................... 46 Page: 1 1 Introduction 1.1 Coastal Barrens Coastal barrens are classified as heathland ecosystems neighbouring marine environments that are dominated by ericaceous vegetation, sparse tree cover, acidic soils, exposed bedrock, and stressful conditions (Oberndorfer & Lundholm, 2009; Balsdon et al., 2011; Porter, 2013). Barren vegetation is heavily influenced by these extreme conditions, resulting in stunted, slow growing plant species that have adapted to live in this ecosystem type (Oberndorfer, 2006; Porter, 2013). Gaylussacia baccata, Vaccinium angustifolium, Juniperus communis, and Empetrum nigrum