Phenology in a chancing Arctic: Linking trophic interactions across scales
Open Access
- Author:
- Kerby, Jeffrey T
- Graduate Program:
- Ecology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- September 14, 2015
- Committee Members:
- Eric S Post, Dissertation Advisor/Co-Advisor
Eric S Post, Committee Chair/Co-Chair
Erica A H Smithwick, Committee Member
Douglas Miller, Committee Member
Tyler Wagner, Committee Member - Keywords:
- Phenology
mismatch
Arctic
Greenland
Rangifer
Reindeer
Climate Change
Phenocam - Abstract:
- Phenology - the study of the timing of periodic biotic events or processes - is an integrative science that links the phenotypes of individual organisms with forces of global change. In recent decades is has evolved from an obscure pursuit of naturalists into a critical tool for evaluating the ecological consequences of climate change. Beyond simply reflecting climatic variability, phenology acts as a driver of ecological dynamics and a source of insight about an organisms’ evolutionary history. The proximal drivers of phenology vary among species, sometimes resulting in asynchronous phenological responses to shared changes in climate. The match/mismatch hypothesis attributes changes in reproductive success to phenological asynchrony between trophic levels when asynchrony arises during sensitive periods of a consumer/predator life history progression. In chapter 2 I explore the genesis of this concept, review its contemporary relevance, and suggest avenues of future research that I explore in more detail in later chapters. No global region is warming faster than the Arctic, and widespread ecological perturbations have already been documented throughout high latitudes. Combining traditional field observations, novel phenological monitoring techniques, and data from a long-term study of tundra ecology, I examine how phenological dynamics link ecological processes across trophic levels and spatial scales in Arctic West Greenland. In chapter 3 I test predictions about how consumer reproductive strategies and directional changes in resource phenology interact to differentially affect the reproductive performance of two Arctic ungulate species. Sea ice loss is a broad scale abiotic driver of regional warming in the Arctic, but the indirect ecological consequences of these dynamics are poorly studied in terrestrial systems. In chapter 4 I identify a sea ice signal in the terrestrial phenological dynamics of plant phenology and herbivore reproductive performance. These findings suggest sea ice loss may have more wide reaching impacts on terrestrial Arctic ecology than are currently appreciated. Spatial patterns of phenological dynamics are relevant to ecological processes across multiple spatial scales, but often information on plant phenology is derived solely from localized vegetation plots or broad scale satellite derived metrics. In chapter 5 I explore landscape scale variability in plant phenology, its drivers, and evidence for scale dependency within and between years. I do so using a novel quantitative dataset derived from a network of time-lapse cameras distributed across the focal tundra landscape. Scale dependent dynamics were identified in metrics of phenological variability and landscape drivers of this variability, results that suggest traditional data sources may be insufficient to understand landscape-scale consequences of ongoing rapid changes in Arctic plant phenology.