Thesis
Habitat disturbance has subtle effects on pollinators and pollen quantity in the threatened self-incompatible plant Physaria filiformis (Brassicaceae)
Washington State University
Master of Science (MS), Washington State University
2012
Handle:
https://hdl.handle.net/2376/105404
Abstract
Habitat disturbance is widely considered to be a primary driver of global plant diversity losses. The consequences of habitat disturbance are likely to negatively impact reproductive success via disrupting plant-pollinator interactions, especially in species that are obligately outcrossing and therefore reliant upon pollination to produce offspring. To directly test the effects of plant-pollinator disruption on reproductive success, researchers often quantify pollen limitation (PL) of seed production. Studies quantifying PL have historically relied on hand pollination supplementation experiments, but these may confound estimates of effect sizes in three ways: first, by not accounting for resource reallocation, second, via introducing biases through extensive floral manipulation, and thirdly, by failing to disentangle quantitative and qualitative aspects of pollen limitation. To avoid these potential sources of bias, we described the functional relationship between pollen load and the success of pollen grains using a recently developed regression approach in two populations (Bois D'Arc and Rocky Barrens) with both disturbed and undisturbed habitat in P. filiformis (Brassicaceae), a threatened, self-incompatible plant species. Comparison of open and experimentally bagged flowers revealed low rates of autogamous self-pollination and pollen tube deposition, consistent with the existence of a functional self-incompatibility system. Second, disturbance had simultaneous, negative effects on both pollinator abundance and mean pollen loads in Bois D'Arc, yet these responses were not observed in the Rocky Barrens population. Third, our regression analysis revealed a subtle effect of disturbance on pollen quantity in Rocky Barrens, and there were no differences in pollen quality between disturbed and undisturbed sites in either population. These results add to the growing body of evidence that habitat disturbance negatively impacts plant-pollinator interactions, and illuminates some of the inferential, conceptual, and experimental biases inherent to traditional studies of PL in natural populations
Metrics
6 File views/ downloads
49 Record Views
Details
- Title
- Habitat disturbance has subtle effects on pollinators and pollen quantity in the threatened self-incompatible plant Physaria filiformis (Brassicaceae)
- Creators
- Michael Andrew Joseph
- Contributors
- Jeremiah Busch (Degree Supervisor)
- Awarding Institution
- Washington State University
- Academic Unit
- Biological Sciences, School of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University; [Pullman, Washington] :
- Identifiers
- 99900525104101842
- Language
- English
- Resource Type
- Thesis