Natural and anthropogenic influences on peat development in Waikato/Hauraki Plains restiad bogs

Domed restiad mires, i.e. restiad bogs, once widespread in the northern part of New Zealand, are today rare. The scarcity of these ecosystems means that understanding the effects of change on the bogs is essential if restiad ecosystems are to be preserved. Of three restiad bogs studied in the North Island of New Zealand, Kopouatai has been little affected by human influence while Moanatuatua and Whangamarino are being subjected to lowered local water tables and are surrounded by farmland. Examination of the physical peat characteristics of the bogs showed patterns of peat degradation within and between the bogs that can be attributed to both natural and anthropogenic influences. Natural influences result in a 'normal' pattern of peat degradation, the degree of degradation decreasing upwards in cores. Differences in sedimentary environment during peat accumulation have resulted in Moanatuatua peat becoming generally more degraded than Kopouatai peat. Recent anthropogenically influenced changes in water table and nutrient content of surface water have resulted in surficial degradation of peat at Moanatuatua and Whangamarino.