“Keeping the wet in wetlands”: A case study of wetland response to projected changes in climate at Mathews Lagoon, Boggy Pond and Wairio Wetlands

Wetlands are some of the most biodiverse ecosystems on the planet. They are critical for global, regional and local ecosystems, and provide considerable social and economic value for human populations (Findlayson, et. al., 2011). Wetlands have been extensively destroyed in many developed countries, establishing a growing concern and greater awareness of the importance of wetlands in the global hydrological cycle - for climate regulation, and for ecological migration (Pfadenhauer & Grootjans, 1999). Changes in climate, driven by increases in atmospheric concentrations of greenhouse gasses are predicted to cause significant changes to the spatial and temporal distributions in rainfall. Since water is the dominant forcing component in the structural development of wetland systems, they are particularly susceptible to changes in climate. While considerable work is now being conducted globally to better understand how wetlands will respond to changes in climate, little work has been conducted in New Zealand to identify the vulnerability of New Zealand wetland systems.  Recent projection by NIWA (2016a) on regional changes in climate have been used to assess how three wetland systems (Wairio Stage 1, Boggy Pond, and Mathews Lagoon), located in the Lower Wairarapa Valley may respond to changes in climate. This study identifies relationships between ground and surface water, examines the interactions and connections between the three wetlands, and explores the sensitivity of the wetlands to climate-induced changes in evapotranspiration, temperature, humidity, wind speed, and rainfall. Wairio stage 1 has been identified as the most susceptible wetland of the three due to a lack of recharge source, while Boggy Pond is the least susceptible due to its interaction/connection with the local groundwater system.