Some research on Bulbil Watsonia

At last we understand the life cycle whose manifestations we have been witnessing since May 2018 throughout the manuka forest margin, and it confirms the suppression of native regeneration through dense soil occupation by corms, despite the failure of the weed to flower in this partial shade: http://www.herbiguide.com.au/Descriptions/hg_Bulbil_Watsonia.htm

On initially observing this forest margin, juvenile and seedling manuka, kunzea and native broadleaf or podocarps were rare in the 6 to 8m H dense manuka canopy, with an understorey only of dead manuka. We feared the forest succession from manuka to kanuka and then forest trees might not occur, and instead the pampas, gorse, Watsonia, Aristea and other weeds might take over this 150 x 10m of land, which had been dedicated to the extension of existing podocarp/rawirinui forest regeneration by the cessation of mowing several decades ago..

If the intended natural forest succession does take place, it may never be possible to determine what would have happened without control of the Watsonia and pampas, since the entire area has now been at least partially hand weeded for 1-2 years, and leptospermeae are germinating and developing in released areas, often seen directly alongside the annually winter-growing Watsonia leaves during their control.

But we may be able to learn the effect of the method and timing being used in the control of Watsonia, both in the filtered light of a broken manuka canopy, and in the partial shade of the outer manuka and rawirinui margin, in previously-mown grass where in 2018 it was flowering and reproducing through cormils.

Posted on September 8, 2020 10:30 PM by kaipatiki_naturewatch