Ecological studies of Hieracium pilosella and H. praealtum
Degree GrantorUniversity of Canterbury
Degree NameDoctor of Philosophy
The ecology of Hieracium pilosella and H. prealtum in short tussock (Festuca novae-zelandiae) grasslands was investigated using a multifactorial approach. H. pilosella is an invasive species of grazed, moderate to sparsely vegetated habitats, while H. praealtum is an opportunist coloniser of vegetation gaps. Although H. prealtum co-existed with other pasture species, H. pilosella expanded into adjoining vegetation and eliminated most species. H. pilosella has considerable interference potential (competition and allelopathy) and regenerative advantages (vegetative reproduction) over H. praealtum and other resident species. Although the ecological behaviour, seasonal growth pattern, and dry matter production of H. pilosella are deleterious to short tussock grasslands, the presence of H. praealtum is of some agronomic value in them.