Assessment of seedling recruitment under manuka (Leptospermum scoparium) and kanuka (Kunzea ericoides) plantings at Shakespear and Wenderholm regional parks

• Main Author: Quadling, Diane Patricia
• Other Authors: Ussher, Graham, Lovegrove, Tim, Gillman, Len
• Format: Thesis
• Language: unknown
• Published: Auckland University of Technology 2007
• Subjects: Seedling regeneration; Seed bank; Revegetation; Auckland Regional Council; Regional parks; Rattus rattus
• Online Access: https://hdl.handle.net/10292/320

Exclosure plots were monitored to investigate the impact of browsing on seedling recruitment by Trichosurus vulpecula, Oryctolagus cuniculus and Rattus rattus on seedlings under Leptospermum scoparium and Kunzea ericoides plantings in two Auckland Regional Council Parks (ARC), Shakespear and Wenderholm. The number of woody seedlings that established over a 17-month period was recorded. Gaps within the same Leptospermum scoparium and Kunzea ericoides canopy were created to investigate the influence of the canopy on seedling recruitment. Soil samples were taken to investigate the existing seed bank beneath the same Leptospermum scoparium and Kunzea ericoides canopies.At Wenderholm, net change in seedling density differed among treatments (P=0.014). Seedling density increased within the plots that excluded Trichosurus vulpecula and Oryctolagus cuniculus and within plots that additionally excluded Rattus rattus, but declined in the control plots. In contrast at Shakespear, although seedling density increased more within both the exclosure plots than in the control plots, this result was not statistically significant (P=0.728). At Wenderholm, the average seedling height increased within both types of exclosure plots, but declined in the control plots. However, these differences among treatments were not statistically significant (P=0.204). At Shakespear, seedlings increased in height within the Trichosurus vulpecula, Oryctolagus cuniculus and Rattus rattus exclosures and declined marginally in the other two treatments. Again, differences in height change among treatments were not statistically significant (P=0.202).At both regional parks, the greatest cause of mortality within the exclosures excluding Trichosurus vulpecula and Oryctolagus cuniculus was desiccation. All of the mortalities within the Trichosurus vulpecula, Oryctolagus cuniculus and Rattus rattus exclosures was unidentifiable. However, within the control plots, at Wenderholm, the greatest identified cause of mortality was browsing and at Shakespear, the ...