Comparative Size, Fecundity and Ecophysiology of Roadside Plants of Banksia hookeriana

• Published in: The Journal of applied ecology 1994-02, Vol.31 (1), p.137-144
• Main Authors: Lamont, Byron B., Rees, Rosemarie G., Witkowski, E. T. F., Whitten, Victoria A.
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Conservation, protection and management of environment and wildlife; Environmental degradation: ecosystems survey and restoration; Follicles; Fundamental and applied biological sciences. Psychology; Plant growth; Plant nutrition; Plants; Roadside plants; Seed banks; Seedlings; Vegetation; Xylem
• ISSN: 0021-8901; 1365-2664
• DOI: 10.2307/2404606

1. The crowns of roadside plants of Banksia hookeriana were on average 2.34 times larger than their non-edge counterparts for a range of ages at five sites. Roadside plants produced 2.51 times more flower heads. 2. Mass of the cones was 32% greater than those of non-roadside plants and they contained 27% more follicles and seeds. The fractions of seeds released and eaten/decayed were similar at both positions. 3. Increased cone production, follicles per cone and seed viability per follicle resulted in a 4.74 times larger seed store in the roadside plants. 4. This greater fecundity was apparently due to greater access to water (non-significantly different or higher transpiration rates, lower pre-dawn xylem tensions and diurnal leaf temperatures) and mineral nutrients (including higher concentrations of N, K and Ca), leading to higher photosynthetic and growth rates. 5. Variable access to resources was confirmed by a bioassay using B. hookeriana seedlings: there was a decreasing gradient in survival and size from the road drain beside the roadside plants through to the non-edge positions.