Can seed banking assist in conserving the highly endemic New Zealand indigenous flora?

Abstract

Context Globally, plant species are facing numerous threats; an issue particularly acute for island floras, which often exhibit high levels of endemism. Ex situ conservation in seed banks is an important tool for plant conservation. However not all species’ seeds can be stored in conventional seed banks. Data on seed storage behaviour are therefore vital for conservation decision making. Aims To review available seed storage information for the New Zealand (NZ) indigenous seed plant flora, 86% of which are endemic. Methods We compiled seed storage information for the NZ flora from databases and existing literature, and used boosted regression trees models to investigate predictors of seed storage behaviour for NZ woody plants. We used existing global models to predict the likely storage behaviour for the NZ woody flora where this was unknown, to examine the overall contribution that conventional seed banking could make towards NZ plant conservation. Key results Data were available for 412 of 1823 seed plants, of which 83% produced orthodox seeds that can be stored in a conventional seed bank. Of the woody flora, the incidence of non-orthodox seeds was positively correlated with seed mass, plant height, biotic dispersal, and habitat diurnal temperature range. Eighty-one percent of the woody flora are predicted to produce orthodox seeds. Conclusions and implications Conventional seed banking is likely to be suitable for a high proportion of the NZ flora. However, work is required to gain further seed storage behaviour data for NZ species, and to develop protocols for alternative ex situ conservation strategies for non-orthodox species, especially those facing in situ conservation threats.