Impact of Wetland Development and Degradation on the Livelihoods of Wetland-Dependent Communities: A Case Study from the Lower Gangetic Floodplains

Wetland ecosystem services exceed those provided by terrestrial ecosystems and their ‘wise use’ has implications for achieving sustainable development goals. Yet we have lost almost 87% of wetlands since pre-industrial times with losses projected to be much higher by 2050 in developing economies, particularly in Asia. Little is known about how this loss impacts people’s dependency at local scales in human-dominated landscapes. We identified 18 ecosystem services of Dankuni wetlands located in the Lower Gangetic Floodplains by analysing oral testimonies of wetland-dependent villagers. The ecosystem services include 12 provisioning services and two each of regulatory, cultural and supporting services. Farming and use of wetland products including molluscs, fuelwood, fodder, fibre and fish was found to subsidize living costs and provide diverse livelihood options to local residents. Encroachment of wetlands by factories and blockage of its riverine connection was reportedly degrading the wetland’s quality and eroding its ecosystem services since the last 20 years and especially since the last three years. In years of excessive and unseasonal rainfall such as during the study year, post-monsoon farming was severely impacted. We portray the human costs of wetland development which will affect vulnerable sections the most, especially landless widows and older residents. Respondents believed that it was possible to rejuvenate the wetland by restoring its riverine connections but stressed that local politicians had vested interests in supporting its degradation. We strongly assert the need to increase government accountability for protection of wetlands amidst a determined pursuit of development at the cost of sustainability.

Flooding and ecological restoration promote wetland microbial communities and soil functions on former cranberry farmland

Microbial communities are early responders to wetland degradation, and instrumental players in the reversal of this degradation. However, our understanding of soil microbial community structure and function throughout wetland development remains incomplete. We conducted a survey across cranberry farms, young retired farms, old retired farms, flooded former farms, ecologically restored former farms, and natural reference wetlands with no history of cranberry farming. We investigated the relationship between the microbial community and soil characteristics that restoration intends to maximize, such as soil organic matter, cation exchange capacity and denitrification potential. Among the five treatments considered, flooded and restored sites had the highest prokaryote and microeukaryote community similarity to natural wetlands. In contrast, young retired sites had similar communities to farms, and old retired sites failed to develop wetland microbial communities or functions. Canonical analysis of principal coordinates revealed that soil variables, in particular potassium base saturation, sodium, and denitrification potential, explained 45% of the variation in prokaryote communities and 44% of the variation in microeukaryote communities, segregating soil samples into two clouds in ordination space: farm, old retired and young retired sites on one side and restored, flooded, and natural sites on the other. Heat trees revealed possible prokaryotic (Gemmatimonadetes) and microeukaryotic (Rhizaria) indicators of wetland development, along with a drop in the dominance of Nucletmycea in restored sites, a class that includes suspected mycorrhizal symbionts of the cranberry crop. Flooded sites showed the strongest evidence of wetland development, with triple the soil organic matter accumulation, double the cation exchange capacity, and seventy times the denitrification potential compared to farms. However, given that flooding does not promote any of the watershed or habitat benefits as ecological restoration, we suggest that flooding can be used to stimulate beneficial microbial communities and soil functions during the restoration waiting period, or when restoration is not an option.