Summary of NPS results from 2007

In late spring of 2007 the National Pollination Survey was initiated. Of the 26 returned surveys: four were from the North Island, one from D’Urville Island and the rest from the South Island (see maps below). The results indicate that flowers on hermaphrodite plants get more pollen than those on female plants, probably because hermaphrodites can at least partially self-pollinate whereas females cannot. Hence, females probably give a clearer picture of how much pollen is being moved around by birds.

Overall, the results for females show that pollination is not working very effectively at most studied sites. At only one site (Kaikoura) did female flowers get enough pollen to be classed as “good”, using the detailed studies of Robertson et al. (2008) on Fuchsia as a yardstick. The next healthiest pollination sites were Waitutu and the two sites in the middle of the North Island. Consistently poor pollination was recorded from the mid Canterbury and lower West Coast of the South Island sites.

While 26 is a relatively small number, we have been able to show regional differences, and that at many sites pollination is a cause of concern. More importantly we have shown that the survey can be a highly useful resource for measuring plant-bird interactions (especially as it is quick and easy to do).

Maps of the average pollen load on flowers for female (left) and hermaphrodite (right) tree fuchsia plants, from the 26 surveys carried out in 2007. “Good” flowers have enough pollen to allow high levels of seed set, whereas “poor” flowers have low levels of pollination which is associated with low seed set (Robertson et al. 2008,
NZ J Botany).