The interactions between ornamental flowering plants and pollinator communities
Open Access
- Author:
- Erickson, Emily
- Graduate Program:
- Entomology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- May 17, 2021
- Committee Members:
- Jared Ali, Major Field Member
Harland Patch, Major Field Member
Christina Grozinger, Chair & Dissertation Advisor
John Tooker, Major Field Member
Claude Depamphilis, Outside Unit & Field Member
Gary Felton, Program Head/Chair
Jared Ali, Major Field Member - Keywords:
- Pollinators
Ornamental Flowers
Plant-Pollinator
Floral Traits
Plant-Pollinator Networks - Abstract:
- Insect pollinators, which play an integral role in supporting biodiversity and agricultural productivity, have been experiencing global population declines. These losses are attributed to several interacting factors, including habitat degradation and a reduction in high-quality foraging resources due to human land-use. There has been a significant rise in public interest in planting and managing gardens to mitigate pollinator declines, particularly in urban and suburban landscapes. However, a large portion of plant taxa used in these anthropogenic environments are cultivated ornamental varieties, and their capacity to provide resources to ecological communities is not well known. Thus, an understanding of the interactions between ornamental flowers and insect pollinators is crucial to supporting biodiversity in human managed environments. I observed pollinator visitation to commercially popular annual and perennial cultivars across multiples years and sites within a biodiverse and semi-natural landscape. I used statistical modeling analyses to explore the overall and relative attractiveness of cultivars to bee, fly, beetle, wasp, and butterfly taxa and to understand how community and landscape dynamics shape pollinator visitation to ornamental plants. Additionally, I applied ecological network theory to describe the role of these cultivars in the context of a diverse and species rich plant-pollinator community. To determine how artificial selection and plant breeding has affected cultivar attractiveness and utility to pollinators, I employed analytical methods such as GC-MS, UHPLC, and spectrometry to collect detailed data of cultivar visual, chemical, and nutritional traits. I then used multivariate statistics, including regression and NMDS Ordination analyses, to correlate visitation by pollinator taxonomic groups and bee species to multimodal cultivar phenotypic traits. Ultimately, my studies revealed that (1) annual ornamental taxa had limited contribution to ecological community stability, while naturalistic perennial cultivars were overall more capable of supporting a complex and diverse pollinator community. Furthermore, (2) ornamental cultivars exhibited significant variation within and across plant genera in attractiveness to pollinators which is shaped by complex factors including (3) landscape and community context and (4) artificial selection on floral phenotypic traits. I conclude that ornamental plant taxa may be used in managed landscapes to boost overall floral resource availability, provide season-long foraging resources, and increase habitat connectivity. Additionally, certain ornamental taxa may contribute to building more resilient and stable ecological communities in human modified environments. However, gardeners, landscape managers, and plant breeders should consider the effects of artificial breeding and cultivar selection on the utility of ornamental plants to pollinators.