Can wind pollination provide a selective benefit to mast seeding inChionochloa macra(Poaceae) at Mt Hutt, New Zealand?

Abstract

Mast seeding, which is very pronounced in Chionochloa (Poaceae) in New Zealand, could provide selective advantages through reduced seed predation or through more efficient wind pollination. The importance of wind pollination in favouring masting was tested experimentally by measuring the pollination success of Chionochloa macro individuals in 10 m x 10 m plots subject to a range of experimentally altered flowering densities within a single season. Very low local flowering densities produced a moderate but non‐significant increase in the proportion of unfilled seeds (assumed to represent unsuccessful pollination). This result is consistent with the conclusions from between‐year observational studies on Chionochloa pollens that wind pollination makes only a small contribution to any present selective benefit of masting in Chionochloa. However, masting may provide larger benefits from higher seed quality (reduced inbreeding depression) than from seed quantity.