Plant Ecology of Miranda Wetland: Restoration Options

This study discusses the problems and opportunities associated with restoring Miranda wetland, which forms part of the Firth of Thames, and is an internationally recognised wetland area. Vegetation communities were surveyed for composition, distribution and structure. Basic environmental factors were measured monthly to form community type characteristics and assist in delineating habitat boundaries. Impacts affecting native vegetation types are assessed and specific attention is given to the control of Carex divisa including tests on salinity tolerance to identify potential competitor species. Restoration options include revegetation, continued grazing, and returning the original hydrology. Three options of grazing, mowing and herbicide control are suggested to bring about a more natural and stable wetland vegetation community. Study concluded that full restoration is unlikely as the past state is not fully known. Full discussion of management options in thesis. Purpose: Objectives of the study were to survey the vegetation of the Miranda reserve, relate vegetation patterns and species distributions to ecological forcing functions (e.g. salinity, hydrology, substrate, nutrient, waterlogging), and predict future vegetation devleopment under selected management scenarios. The study also recomends vegetation rehabilitation programmes and provides an experimental basis for monitoring ecological changes at Miranda.

Species distribution maps and environmental variables in Miranda wetland. Full species lists recorded.

Miranda wetland - from south of Kaiaua to Miranda Stream

Plant survey during November-December 1997.

Scott (1965) height-frequency method used. Plots spaced along three line transects (24 plots, 2 m x 2 m). Environmental factors measured at each plot (surveyed elevation, ground water level, water content, bulk density, particle size, conductivity, pH, Climate, soil nitrogen, salinity). Frequency of collection: One off survey.

Gaps in collection: n/a Attribute accuracy: Discussed in detail in thesis.

All data reported in thesis, including printed maps. Digital Format: Unknown

Master of Science Thesis

Thesis available in University of Waikato or Environment Waikato library. Sensitivity/Confidentiality: None

complete