| Abstract: | Banksia serrata and Isopogon anemonifolius are serotinous resprouters (single-stemmed tree, multi-stemmed shrub, respectively) found in forests within the Sydney region. Studies were conducted to predict the population dynamics of these species. Seed production and survival and the accumulation of seed-bank within cones were estimated in relation to time since fire. Emergence, survival and development of lignotubers were measured in young juveniles and the time taken to reach adulthood was estimated. This information and published data on survival were used to estimate the amount of recruitment of adults and juveniles necessary for stands to remain in a stable state under frequent (<16 years), high and low intensity fire regimes. The effects of longer intervals (up to 80 years) between fires were also estimated. It was predicted that B. serrata populations will decline in numbers when the interval between high intensity fires is <9 years, while under low intensity fires the critical interval was 12–13 years. In I. anemonifolius the predicted intervals were 14 and 16 years, respectively. When fires are timed so that maximum seed-bank is available (about 30 year interval), it is unlikely that resprouters will dominate communities because the seed-banks and rates of growth of seedlings of obligate seeder shrubs are greater than these resprouters. Populations of these resprouters may be more able to persist than obligate seeders when the fire frequency is either very high (<6 years) or low (>50years), though the density of resprouter populations may slowly decline under such fire regimes. |
