seed predation

Recent work has shown that resource accumulation is important in allowing mast-seeding plants to display occasional intense reproductive efforts. Anecdotal reports suggest that Chionochloa tussocks (bunchgrasses) on patch edges flower more frequently, and it has been proposed that this is due to greater resource availability. This study aimed to quantify any edge effect in flowering effort in Chionochloa populations at Mt Hutt in the Southern Alps of New Zealand, and to look for correlations with available soil nutrients.

Norway rats (Rattus norvegicus) were eradicated from Ulva Island, Rakiura National Park, in 1996. The aim of our work was to determine if seedlings and saplings increased in density and/or species richness following this eradication. In 2003, we took advantage of eight permanent plots (5 × 5 m) that had been established on Ulva Island in 1991, by counting seedlings and saplings of woody species, including tree ferns. Over this period, total numbers of woody seedlings (< 30 cm tall), and saplings (30 cm – 2 m tall) did not increase significantly (P > 0.05).