For many plants, seedbanking is a cost effective way of conserving vulnerable species outside of their natural habitat but not all species can survive the seedbanking procedure that requires seeds to be tolerant of desiccation.
Seeds that can tolerate drying are 'orthodox'.
Seeds of plants from drier habitats are adapted to being dried out and can therefore be stored in seedbanks at low temperatures for decades without losing viability. Such seeds are termed ‘orthodox’.
Seeds that cannot tolerate drying are 'recalcitrant'.
Of particular concern is the probability that many hundreds of rainforest species have seeds that are sensitive to drying out (desiccation sensitive) and are termed ‘recalcitrant’ to seedbanking, meaning they are killed when dried and frozen. This behaviour has been identified in perhaps as much as 50% of the rainforest species growing in equatorial regions1, however drier rainforests or rainforest which experience a dry season tend to have higher numbers of orthodox species.
As at September 2017, research conducted as part of the Rainforest Seed Conservation Project has identified that of 166 species fully assessed, 80 species are likely to be recalcitrant, 52 species are orthodox, with an additional 34 species likely to have intermediate seed storage behaviour.