Vegetation recovery following fire in two Waikato peatlands at Whangamarino and Moanatuatua, New Zealand

Abstract

After fires in 1984 and 1989 at Whangamarino wetland, and in 1972 at Moanatuatua Bog, peatland flora and vegetation were monitored to determine rates and patterns of recovery. Species with rhizomes that survived the fires were able to resprout and grow rapidly in the initial post-fire period. Species that were eliminated had to re-establish from seed and so recovered more slowly. The vegetation at Moanatuatua took almost 12 years to recover to pre-fire condition, twice as long as at Whangamarino. Adventive and early colonising native species were prominent only in the first 1-2 post-fire years, probably because of temporarily increased availability of nutrients and/or open habitat. Ordination techniques arranged the plots and species in a sequence from shrub-sedgeland (Whangamarino), through Empodisma minus restiad rushland (Whangamarino), to Sporadanthus traversii/ Empodisma restiad rushland (Moanatuatua) following a gradient of decreasing fertility with time. Fires reset the bog development process but generally do not alter the recovery pathways. In the absence of future major disturbance, including invasion by troublesome adventive species, the younger Whangamarino peatlands are expected to develop eventually into floristically poor, oligotrophic raised bogs similar to those at Moanatuatua and elsewhere in the Waikato district.

Keywords:

• vegetation recovery
• fire
• peatland
• Whangamarino wetland
• Moanatuatua Bog
• Restionaceae
• Empodisma minus
• Sporadanthus traversii