Freshwater wetlands restoration: An ecosystem under pressure from pastoral agriculture and recreational uses : A dissertation submitted in partial fulfilment of the requirements for the Degree of Master of Landscape Architecture at Lincoln University

Abstract

Freshwater wetlands are one of most valuable ecosystems which support protecting biodiversity, regulate water cycles, and store carbon. Even though their ecological importance is known, they are increasingly pressured by pastoral agriculture and recreational land uses. Landscape architecture attempts to bridge the gap between landscape ecology, conservation, agriculture and recreational uses. This dissertation investigates how design-based scenario analysis can contribute to wetland restoration while balancing ecological, agricultural, and recreation. It explores the potential for coexistence for major stakeholders – the wetland itself, wildlife, pastoral farming, and recreational users – using two case studies in New Zealand and Switzerland. The research examines the Wairewa (Lake Forsyth) wetland on Banks Peninsula, Aotearoa New Zealand, and the Schmerikoner Allmeind wetland in the Linth Plain, Switzerland. Both sites represent freshwater wetlands which have been modified through drainage, agricultural intensification and recreational uses. However, they also provide opportunities to explore restoration strategies using a theoretical approach for land allocation. Using mixed-methods, the study combines spatial mapping, field observation, and design-based scenario modelling to evaluate whole-of-catchment dynamics and potential restoration strategies. Spatial analysis identified significant land-cover change and reduction in wetland extent. The impacts of pastoral agriculture vary between countries. In New Zealand, the sheep grazing in riverbeds and the wetland has led to problematic soil compaction, sedimentation, and nutrient input, while in Switzerland, highly controlled seasonal mowing has maintained certain fen types and supported biodiversity but also suffers from nutrient input of the adjacent agriculture. Switzerland enforces strong national laws to protect fens and bogs, whereas New Zealand relies on regional planning and voluntary engagement of landowners. Recreational use adds further complexity. By focusing on the major land uses - wetland restoration, wildlife conservation, farming, recreation and tourism - four single-factor based scenarios are created. First two wetlands are selected and then patterns are described. The study highlights where in the catchment riparian plantings are needed to improve water quality. In the wetlands the soil saturation and current vegetation in relation to stakeholders are mapped and analysed to describe the potential extent for restoration and clarify the current land allocation. After, the wetlands are mapped according to four single-factor scenarios, each reflecting the priority of one stakeholder, the scenarios show which stakeholders have synergies and adverse effects. The scenarios also illustrate that, although wetlands share many ecological functions, their responses to land-use pressures and restoration strategies are still dependent on context. The study defines four landscapes which focus on two stakeholders each, which are shown in two factor-based scenarios. The study also proposes to focus on ‘Experience Nature’ to use major synergies between all stakeholders. Based on the scenarios recommendations for land allocation changes are defined and tested on both wetlands, which uses three factor-based scenarios. This demonstrated that expanding and restoring wetland areas enhances wildlife habitat but also recreational opportunities, while reducing agricultural land. However, this trade-off ultimately benefits farming in the long term by strengthening ecosystem services. The findings suggest that coexistence between agriculture, recreation, and conservation requires spatial compromises to create coexistence in freshwater wetlands. It promotes the need for site-specific and design-led approaches through recognising wetlands as dynamic cultural and ecological systems which provide important services. It focuses on restoration strategies that sustain biodiversity, support local livelihoods, and rich recreational experience. These findings can contribute to planning improvements among planners, decision-makers, and stakeholders.