Assessing the Impacts of Land Use and Land Cover Changes 1984-2020 on Wetland Habitats in the Gediz Delta (Turkey)

Introduction

Wetlands are an essential part of human well-being and play an integral role for many organisms to complete their life cycles (Mitsch and Gosselink, 2000; Ramsar Convention Secretariat, 2016). They provide valuable ecosystem services to people such as provisioning water and food, flood regulation, erosion prevention, groundwater discharge, water purification, nutrient recycling, carbon storage, and recreational activities (Ramsar Convention Secretariat 2016). Despite their vital importance, wetlands have been one of the most transformed ecosystems over the last hundred years, with a loss of 87% of the world’s wetlands since the 1700s. This trend increased four-fold in the 19^th century (Davidson, 2014; Ramsar Convention on Wetlands, 2018). Agricultural extension, creation of artificial wetlands and urban development have been the main drivers of natural wetland loss and degradation over the last 200 years and continue to threaten the remaining 12.1 million km² worldwide (Zedler and Kercher, 2005; Hu et al., 2017; Ramsar Convention on Wetlands, 2018). It is estimated that approximately 35% of wetlands have been disturbed or irreversibly destroyed after the 1970s (Ramsar Convention on Wetlands, 2018). On the other hand, human-made wetlands (such as dams and reservoirs, salinas, rice fields, etc.) have increased since the 1970s (and earlier) and as of 2018 they constitute 12% of existing wetlands around the world (Ramsar Convention on Wetlands, 2018). In the Mediterranean Basin, natural wetlands have decreased by 48% since the 1970s, mainly through the conversion into agricultural lands, human-made wetlands and built-up areas (MWO, 2018). The human-made wetlands have been shown to host an important biodiversity and play a key role for waterbirds, but the changes in water supplies and management for these new wetlands are often a detriment to natural wetlands (Ramsar Convention on Wetlands, 2018; MWO, 2018).