As a creeping process, salinisation represents a significant long-term environmental risk in coastal and deltaic environments. Excess soil salinity may exacerbate existing risks of food insecurity in densely populated tropical deltas, which is likely to have a negative effect on human and ecological sustainability of these regions and beyond. This study focuses on the coastal regions of the Ganges–Brahmaputra delta in Bangladesh, and uses data from the 2010 Household Income and Expenditure Survey and the Soil Resource Development Institute to investigate the effect of soil salinity and wealth on household food security. The outcome variables are two widely used measures of food security: calorie availability and household expenditure on food items. The main explanatory variables tested include indicators of soil salinity and household-level socio-economic characteristics. The results of logistic regression show that in unadjusted models, soil salinisation has a significant negative effect on household food security. However, this impact becomes statistically insignificant when households’ wealth is taken into account. The results further suggest that education and remittance flows, but not gender or working status of the household head, are significant predictors of food insecurity in the study area. The findings indicate the need to focus scholarly and policy attention on reducing wealth inequalities in tropical deltas in the context of the global sustainable deltas initiative and the proposed Sustainable Development Goals.

Of all terrestrial ecosystems, peatlands store carbon most effectively in long-term scales of millennia. However, many peatlands have been drained for peat extraction or agricultural use. This converts peatlands from sinks to sources of carbon, causing approx. 5% of the anthropogenic greenhouse effect and additional negative effects on other ecosystem services. Rewetting peatlands can mitigate climate change and may be combined with management in the form of paludiculture. Rewetted peatlands, however, do not equal their pristine ancestors and their ecological functioning is not understood. This holds true especially for groundwater-fed fens. Their functioning results from manifold interactions and can only be understood following an integrative approach of many relevant fields of science, which we merge in the interdisciplinary project WETSCAPES. Here, we address interactions among water transport and chemistry, primary production, peat formation, matter transformation and transport, microbial community, and greenhouse gas exchange using state of the art methods. We record data on six study sites spread across three common fen types (Alder forest, percolation fen, and coastal fen), each in drained and rewetted states. First results revealed that indicators reflecting more long-term effects like vegetation and soil chemistry showed a stronger differentiation between drained and rewetted states than variables with a more immediate reaction to environmental change, like greenhouse gas (GHG) emissions. Variations in microbial community composition explained differences in soil chemical data as well as vegetation composition and GHG exchange. We show the importance of developing an integrative understanding of managed fen peatlands and their ecosystem functioning.

Precipitation is a key factor affecting shallow water table fluctuations. Although the literature on shallow aquifers is vast, groundwater response to precipitation in peatlands has received little attention so far. Characterizing groundwater response to precipitation events in differently managed peatlands can give insight into ecohydrological processes. In this study we determined the groundwater table response rate following precipitation events at a drained and a rewetted fen to characterize the effect of rewetting on hydrological buffer capacity. Multiple regression analysis revealed that the groundwater table at the rewetted fen has more than two times lower rate of response to precipitation events than that of the drained fen, even after adjusting for antecedent groundwater levels. Thus, the rewetted fen delivers a better hydrological buffer function against heavy precipitation events than the drained fen. We found that for the depths at which the groundwater interacts with incoming precipitation, the peat of the rewetted fen has a higher specific yield causing groundwater to rise slower compared to the response at the drained fen. A period of 20 years of rewetting was sufficient to form a new layer of organic material with a significant fraction of macropores providing storage capacity. Long-term rewetting has the potential to create favorable conditions for new peat accumulation, thereby altering water table response. Our study has implications for evaluating the success of restoration measures with respect to hydrological functions of percolation fens.

While the benefits humans gain from ecosystem functions and processes are critical in natural resource-dependent societies with persistent poverty, ecosystem services as a pathway out of poverty remain an elusive goal, contingent on the ecosystem and mediated by social processes. Here, we investigate three emerging dimensions of the ecosystem service-poverty relationship: economic contribution of provisioning ecosystem services to the household livelihood mix, social-ecological systems producing different bundles of ecosystem services and material wealth versus reported life satisfaction. We analyse these relationships in Bangladesh, using data from a bespoke 1586-household survey, stratified by seven social-ecological systems in the delta coastal region. We create poverty lines to ensure comparability with traditional poverty measures that overlook environmental factors and subjective measurements of well-being. We find that any contribution of ecosystem service-based income to the livelihood mix decreases the likelihood of the incidence of poverty, and of individuals reporting dissatisfaction. We find no relationship between the incidence of material poverty and the specific social-ecological systems, from agriculture to fishery-dominated systems. However, the probability of the household head being dissatisfied was significantly associated with social-ecological system. Individuals living in areas dominated by export-oriented shrimp aquaculture reported lower levels of life satisfaction as an element of their perceived well-being. These results highlight the need for social policy on poverty that accounts for the diversity of outcomes across social-ecological systems, including subjective as well as material dimensions of well-being. National poverty reduction that degrades ecosystem services can have negative implications for the subjective well-being of local populations.

Fens belong to the most threatened ecosystems in Europe. Maintaining a high water table through rewetting is an effective measure to rehabilitate many of their ecosystem functions. However, the impact of meteorological conditions such as vapor pressure deficit (VPD) and precipitation on water tables is still unclear for rewetted fens. Here, we compare the impact of meteorological factors on water table dynamics in a drained and a rewetted fen, using multiple regression with data from continuous high-resolution (temporal) water level monitoring and weather stations. We find that an increase in the daily mean VPD causes a higher drop in the water table at the drained and degraded fen compared to the rewetted fen. Precipitation contributes to recharge, causing the water table to rise higher at the drained site than at the rewetted site. We attribute the differential influence of meteorological conditions on water table dynamics to different soil specific yield values (i.e., water storage capacity) largely driven by lower water table position at the drained site. Our study underlines the importance of understanding how and why water tables in peatlands vary in response to meteorological factors for management decisions (e.g., rewetting). Continuous monitoring of water table and vegetation development in rewetted fen peatlands is advisable to ensure long-term success especially under climate change conditions and associated drought events.