This study shows how the feeding behaviour of the increasing number of geese impacts their fragile breeding grounds in the Arctic region of Svalbard and, ultimately, may affect the geese themselves. On arrival in their breeding grounds in spring, pink-footed geese, in common with other goose species, forage for below-ground plant parts. This grubbing behaviour disturbs tundra ecosystems. This thesis investigates the extent and distribution of grubbing on Svalbard, its impact on tundra ecosystems and feedbacks to the goose population in the long term. Grubbing geese reduce the abundance of plants, including moss, in tundra vegetation and cause the loss of substantial quantities of soil carbon. A multi-habitat field manipulation experiment demonstrated that the impact of grubbing varies between communities; wetter communities with high moss cover are less negatively affected, but these are more likely to be grubbed by geese, particularly in valley bases and low lying coastal areas. Using data collected in this project, the long-term effect of geese on tundra was simulated. This resulted in predictions that geese will cause substantial degradation of their habitat if the population increases by another 50% to 75,000. Due to the negative effect of grubbing on vegetation, the long-term sustainable size of the population of pink-footed geese breeding on Svalband is estimated to be 95,000, less than 30% of the number expected based on the tundra’s productivity. Pink-footed geese are therefore “ecosystem engineers” of the tundra, as they affect resource availability and “carrying capacity engineers”, as by degrading their own habitat they reduce the size of the goose population that it can support.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:509136 |
| Date | January 2009 |
| Creators | Speed, James D. M. |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=26470 |
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