Chapter 34 - Future climate scenario impacts on peatland and constructed wetland water quality under water level management

Abstract

This new chapter highlights that water purification is one of the most essential services provided by wetlands. A lot of concerns regarding wetlands subjected to climate change relate to their susceptibility to hydrological change and the increase in temperature as a result of global warming. A warmer condition may accelerate the rate of decomposition and release of nutrients, which can be exported downstream and cause serious ecological challenges; e.g., eutrophication and acidification. The aim of this chapter is to investigate the effect of climate change on water quality in peatland and constructed wetland ecosystems subject to water level management. For this purpose, the authors simulated the current climate scenario base on the database from Malmö station (Scania, Sweden) for 2016 and 2017 as well as the future climate scenarios for the last 30years of the century based on the Representative Concentration Pathway (RCP) and different regional climate models (RCM) for a region wider than Scania County. For future climate change, low (RCP 2.6), moderate (RCP 4.5), and extreme (RCP 8.5) climate scenarios were simulated. All simulations were conducted within climate chambers for experimental peatland and constructed wetland mesocosms. The results demonstrate that the effect of climate scenario is significantly different for peatlands and constructed wetlands (interactive effect) for the combined chemical variables. The warmest climate scenario RCP 8.5 is linked to a higher water purification function for constructed wetlands, but to a lower water purification function and a subsequent deterioration of peatland water qualities, even if subjected to water level management. The explanation for the different responses of constructed wetlands and peatlands to climate change could be due to the substrate in the constructed wetland mesocosms and peatlands to be different in terms of the organic matter quality and quantity. Readers will learn that the utilization of nutrients by plants and microbial community readily exceeds the mineralization under a limited nutrient content (as observed in the constructed wetlands) when the temperature rises. However, concerning the extreme scenario RCP 8.5, the peatlands have shown a tendency to have reverse processes.