Abstract
Key note lectures 11th Arctic Ungulate Conference (AUC), Saariselkä, Finland, 24-28 August 2003
Highlights
One of the established ecological principles is the Intermediate Disturbance Hypothesis (IDH), stating that for each habitat, there is an optimum level of disturbance, leading to highest plant species diversity by allowing the coexistence of both disturbance-adapted plants and plants adapted to various durations of transient dynamics initiated by the disturbance (Grime, 1973; 1979; Connell, 1978)
The reindeer pellet abundance indices reveal that there is a clear gradient of grazing pressure between the eight study sites, with the lowest reindeer density, as expected, on Pikku-Malla and Iso-Malla, and the highest grazing pressure on Jávrioaivit (Table 1)
There was no significant correlation between reindeer density and any of the conventional indices of biodiversity
Summary
One of the established ecological principles is the Intermediate Disturbance Hypothesis (IDH), stating that for each habitat, there is an optimum level of disturbance, leading to highest plant species diversity by allowing the coexistence of both disturbance-adapted plants and plants adapted to various durations of transient dynamics initiated by the disturbance (Grime, 1973; 1979; Connell, 1978). Growth and production of offspring are of key importance for every animal species In arctic species, such as reindeer, these basic physiological functions are modulated by the seasonal changes in the availability and quality of food, wide changes in the temperature and photoperiod. In contrast to the unicellular parasitic organisms (bacteria, protozoa), which are capable of very rapid replication within the host (hours), the metazoan parasites (helminths: nematodes, trematodes, cestodes) must remain in their hosts for a much longer period of time before they can successfully complete their life cycle, which generally takes several weeks These long-lived helminth parasites are highly accomplished practitioners of immune evasion and manipulation, using strategies honed during their long co-evolutionary interaction with the immune system of their mammalian hosts (Behnke et al, 1992; Allen & Maizels, 1996). Not until 2000, did the state provide significant funding to enable aerial surveys of reindeer to be conducted
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