NATURAL AND ANTHROPOGENIC INFLUENCES ON PEAT DEVELOPMENT IN WAIKATO HAURAKI PLAINS RESTIAD BOGS/

Domed restiad mires, i.e. restiad bogs, once widespread in the norther n part of New Zealand, are today rare. The scarcity of these ecosystem s means that understanding the effects of change on the bogs is essent ial if restiad ecosystems are to be preserved. Of three restiad bogs s tudied in the North Island of New Zealand, Kopouatai has been little a ffected by human influence while Moanatuatua and Whangamarino are bein g subjected to lowered local water tables and are surrounded by farmla nd. Examination of the physical peat characteristics of the bogs showe d patterns of peat degradation within and between the bogs that can be attributed to both natural and anthropogenic influences. Natural infl uences result in a 'normal' pattern of peat degradation, the degree of degradation decreasing upwards in cores. Differences in sedimentary e nvironment during peat accumulation have resulted in Moanatuatua peat becoming generally more degraded than Kopouatai peat. Recent anthropog enically influenced changes in water table and nutrient content of sur face water have resulted in surficial degradation of peat at Moanatuat ua and Whangamarino.