Dead frond “skirts” as tree fern defence: what is the evidence?

Many tree fern taxa have a skirt, an encircling structure of persistent dead fronds or stipes around the growing crown at the top of the trunk. Page and Brownsey (1986) hypothesised that the function of these skirts was to protect tree ferns against damage from large epiphytes, hemiepiphytes, and climbing plants. Tree fern trunks provide both suitable establishment surfaces for a range of woody epiphytes and hemiepiphytes in New Zealand, as well as attachment surfaces for climbing rātā (Metrosideros spp.).

A lowland vegetation sequence in South Westland: Pakihi bog to mixed beech-podocarp forest Part 2: Ground and epiphytic vegetation.

The quantitative composition of ground and epiphytic vegetation, consisting predominantly of bryophytes, is recorded from a lowland stand of climax beech-podocarp forest at Jacksons Bay, South Westland, together with briefer accounts from five pre-climax transitional stands. A survey of epiphylls, indicators of very high humidity, is included and comparisons are made with stands on Secretary Island and Stewart Island