vegetation dynamics

Cyathea medullaris (Cyatheaceae) is a frequent pioneer of disturbed areas (e.g. landslides) or edge environments, sometimes forming near continuous canopies. We test the hypothesis that colonisation by this species as a pioneer alters the seedling assemblage to favour more shade-tolerant broadleaved trees than that beneath another common native pioneer (Kunzea robusta, Myrtaceae) in the same landscapes. We compared vegetation and abiotic characteristics of 166 sites across the Auckland region where C. medullaris or K.

Fire has been a major driver of forest loss in New Zealand. A conceptual model has been proposed in which positive feedbacks between vegetation, fire and soils can arrest regeneration of recurrently burned wet forest landscapes. We used vegetation data collected across three topographically similar landscapes – Awana, Glenfern and Windy Hill – on Great Barrier Island to (1) describe current vegetation composition and structure and predict future change in composition and (2) assess evidence for interactions between fire and soils slowing regeneration in these landscapes.