Restored Agricultural Wetlands in central Iowa: Habitat Quality and Amphibian Response

Amphibians are declining throughout the United States and worldwide due, partly, to habitat loss. Conservation practices on the landscape restore wetlands to denitrify tile drainage effluent and restore ecosystem services. Understanding how water quality, hydroperiod, predation, and disease affect amphibians in restored wetlands is central to maintaining healthy amphibian populations in the region. We examined the quality of amphibian habitat in restored wetlands relative to reference wetlands by comparing species richness, developmental stress, and adult leopard frog (Lithobates pipiens) survival probabilities to a suite of environmental metrics. Although measured habitat variables differed between restored and reference wetlands, differences appeared to have sub-lethal rather than lethal effects on resident amphibian populations. There were few differences in amphibian species richness and no difference in estimated survival probabilities between wetland types. Restored wetlands had more nitrate and alkaline pH, longer hydroperiods, and were deeper, whereas reference wetlands had more amphibian chytrid fungus zoospores in water samples and resident amphibians exhibited increased developmental stress. Restored and reference wetlands are both important components of the landscape in central Iowa and maintaining a complex of fish-free wetlands with a variety of hydroperiods will likely contribute to the persistence of amphibians in this landscape

Groundwater flow systems in turbidites of the Northern Apennines (Italy): natural discharge and high speed railway tunnel drainage

A conceptual model of groundwater flow systems in turbiditic fractured aquifers is proposed, taking into account natural discharge pattern of the hydrogeologic system and the system perturbation induced by tunnel drainage. Silico-clastic and marly calcareous turbidites outcrop extensively in Northern Apeninnes (Italy) and paper deals with the assessment of the aquifer-like behaviour of these units, up to now considered as aquitards, as reflected by the huge amounts of groundwater locally drained by tunnels for the high speed railway (HSR) connection between Bologna and Florence. The study is based on the analysis of a huge amount of hydrological data (springs, streams and tunnels discharge) collected by a monitoring activity performed for a 10 years time-span, integrated by hydrochemical and isotopic analysis on surface and tunnel waters and a stream-tunnel tracer test. In a turbiditic aquifer recession analysis permits to discriminate groundwater flow systems, to calculate recharge relative to the up-stream reach portion and to locate springs more vulnerable to tunnel drainage impacts. Natural discharge is stream-focused and, as the tunnel drainage is for 85% formed by active recharge groundwater, the impact on the stream base-flow is severe with abatement of natural discharge budget component up to 2/3 of natural value