Developmental phenology of Persoonia longifolia (Proteaceae) and the impact of fire on these events

Abstract

Persoonia longifolia R.Br. is a common understorey tree that is difficult to re-establish following bauxite extraction and land restoration in parts of the jarrah forest of south-western Western Australia. To improve restoration outcomes for P. longifolia, understanding its phenology is vital for developing methods for returning this plant to rehabilitated areas. The present study investigated in detail different aspects of the phenology of P. longifolia over a 3-year-period. Most vegetative growth occurred during the summer months and flowering and fruiting occurred concurrently. Fruit matured from July through to September, at which time these dropped to the forest floor. Germination occurred in late winter-early spring from fruit that was at least 1-year old, with poor seedling survival in natural bush (<10%) during the first 12 months. Following fire, P. longifolia plants resprouted prolifically in the next growing season, although there was very little fruit production in the first year following fire. Fruit was not produced until at least the second year following a fire, and when dispersed, required at least another year in the soil seed bank before germination commenced (i.e. 3 years post-fire). Results from the present study will improve restoration outcomes for this species, by providing guidance on better seed-collection strategies and baseline information concerning growth rates under natural conditions that can then be used to assess performance of this species in restored environments.