Líffræðifélag Íslands
Líffræðiráðstefnan 2015

Erindi/veggspjald / Talk/poster E24

The ecological role of large vertebrate grazers in high-latitude ecosystems – is it different between livestock and wild populations?

Ingibjörg Svala Jónsdóttir (1,2) and Isabel C. Barrio (1)

1. University of Iceland 2. University Centre in Svalbard

Kynnir / Presenter: Ingibjörg Svala Jónsdóttir

Tengiliður / Corresponding author: Ingibjörg Svala Jónsdóttir (isj@hi.is)

Large vertebrate grazers play a central role in the structuring and functioning of many terrestrial ecosystems at high latitudes through selective grazing, consumption of large quantities of the primary production, increased rate of nutrient turnover and mechanical disturbances such as trampling. In general, those ecosystems tend to have relatively high abundance of grasses and other grazing tolerant graminoids and low abundance of woody species, bryophytes and lichens. Wild populations are regulated through birth and death rates that are controlled by environmental factors, both biotic density dependent factors such as predation, food availability and deceases and by stochastic abiotic factors such as weather. In contrast, the regulation of livestock populations has to a large extent been based on decisions made by individual farmers. These two situations can be viewed as two extremes on a spectrum of herbivore population regulation. Along that spectrum we find situations such as wild populations heavily managed by hunting and well-managed livestock grazing. In this talk I will discuss different ecological consequences of wild herbivore and livestock grazing for ecosystem structuring and functioning at northern latitudes.