Expansion Dynamics of Monospecific, Temperate Mangroves and Sedimentation in Two Embayments of a Barrier-Enclosed Lagoon, Tauranga Harbour, New Zealand

In recent years, mangrove expansion has become a coastal management issue in the North Island of New Zealand. Little is known about the spatial evolution and forest structure of temperate mangrove forests in New Zealand or about the associated rates of sedimentation. The extent of mangrove colonization in both a large (Waikareao Estuary) and small (Welcome Bay) embayment within Tauranga Harbour were documented. Forest structure and growth rates were described using tree height, stem density, pneumatophore density, and seedling establishment. Surface elevation changes within mangrove habitat were determined from erosion pin measurements and, on bare intertidal flats, using buried baseplates. Sediment texture and availability was also assessed using sediment traps. Results show that in 1943, mangrove vegetation covered