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Litterfall is a major, yet poorly studied, process within forest ecosystems globally. It is important for carbon dynamics, edaphic communities, and maintaining site fertility. Reliable information on the carbon and nutrient input from litterfall, provided by litter traps, is relevant to a wide audience including policy makers and soil scientists. We used litterfall observations of 320 plots from the pan‐European forest monitoring network of the “International Co‐operative Programme on Assessment and Monitoring of Air Pollution Effects on Forests” to quantify litterfall fluxes. Eight litterfall models were evaluated (four using climate information and four using biomass abundance). We scaled up our results to the total European forest area and quantified the contribution of litterfall to the forest carbon cycle using net primary production aggregated by bioregions (north, central, and south) and by forest types (conifers and broadleaves). The 1,604 analyzed annual litterfall observations indicated an average carbon input of 224 g C · m−2 · year−1 (annual nutrient inputs 4.49 g N, 0.32 g P, and 1.05 g K · m−2), representing a substantial percentage of net primary production from 36% in north Europe to 32% in central Europe. The annual turnover of carbon and nutrient in broadleaf canopies was larger than for conifers. The evaluated models provide large‐scale litterfall predictions with a bias less than 10%. Each year litterfall in European forests transfers 351 Tg C, 8.2 Tg N, 0.6 Tg P, and 1.9 Tg K to the forest floor. The performance of litterfall models may be improved by including foliage biomass and proxies for forest management.

Acid deposition arising from sulphur (S) and nitrogen (N) emissions from fossil fuel combustion and agriculture has contributed to the acidification of terrestrial ecosystems in many regions globally. However, in Europe and North America, S deposition has greatly decreased in recent decades due to emissions controls. In this study, we assessed the response of soil solution chemistry in mineral horizons of European forests to these changes. Trends in pH, acid neutralizing capacity (ANC), major ions, total aluminium (Al ) and dissolved organic carbon were determined for the period 1995-2012. Plots with at least 10 years of observations from the ICP Forests monitoring network were used. Trends were assessed for the upper mineral soil (10-20 cm, 104 plots) and subsoil (40-80 cm, 162 plots). There was a large decrease in the concentration of sulphate (SO42-) in soil solution; over a 10-year period (2000-2010), SO42- decreased by 52% at 10-20 cm and 40% at 40-80 cm. Nitrate was unchanged at 10-20 cm but decreased at 40-80 cm. The decrease in acid anions was accompanied by a large and significant decrease in the concentration of the nutrient base cations: calcium, magnesium and potassium (Bc = Ca + Mg + K ) and Al over the entire dataset. The response of soil solution acidity was nonuniform. At 10-20 cm, ANC increased in acid-sensitive soils (base saturation ≤10%) indicating a recovery, but ANC decreased in soils with base saturation >10%. At 40-80 cm, ANC remained unchanged in acid-sensitive soils (base saturation ≤20%, pHCaCl2 ≤ 4.5) and decreased in better-buffered soils (base saturation >20%, pHCaCl2 > 4.5). In addition, the molar ratio of Bc to Al either did not change or decreased. The results suggest a long-time lag between emission abatement and changes in soil solution acidity and underline the importance of long-term monitoring in evaluating ecosystem response to decreases in deposition.

Restoration efforts in Florida's Everglades focus on preserving and restoring this unique wetland's natural landscape. Because most of the Everglades is a freshwater peatland, it requires surplus rainfall to remain a peatland. Restoration plans generally assume a stable climate, yet projections of altered climate over a 50-year time horizon suggest that this assumption may be inappropriate. Using a legacy regional hydrological model, we simulated combinations of a temperature rise of 1.5 °C, a ± 10% change in rainfall, and a 0.46 m sea level rise relative to base conditions. The scenario of increased evapotranspiration and increased rainfall produced a slight increase in available water. In contrast, the more likely scenario of increased evapotranspiration and decreased rainfall lowered median water depths by 5-114 cm and shortened inundation duration periods by 5-45%. Sea level rise increased stages and inundation duration in southern Everglades National Park. These ecologically significant decreases in water depths and inundation duration periods would greatly alter current ecosystems through severe droughts, peat loss and carbon emissions, wildfires, loss of the unique ridge and slough patterns, large shifts in plant and animal communities, and increased exotic species invasions. These results suggest using adaptive restoration planning, a method that explicitly incorporates large climatic and environmental uncertainties into long-term ecosystem restoration plans, structural design, and management. Anticipated water constraints necessitate alternative approaches to restoration, including maintaining critical landscapes and facilitating transitions in others. Accommodating these uncertainties may improve the likelihood of restoration success.

Integrated Constructed Wetlands (ICWs) constitute an alternative option for the treatment of agricultural wastewater in Ireland. These surface flow systems are formed by interconnected ponds and have the capacity to fit into the landscape and provide habitat for a wide range of biota, including macroinvertebrates that have enormous potential for biodiversity enhancement. For these reasons, five ICW systems were studied. In addition, five natural ponds were investigated to account for the potential of ICW ponds to mimic natural conditions. Nine river sites were also investigated to allow for an evaluation of the catchment biodiversity contribution of the ICW systems. The present study revealed that the last ponds in the chain of these ICW systems are capable of supporting a similar number of taxa as natural ponds. Furthermore, the contribution of the last ponds to the macroinvertebrate diversity at the catchment level was high. ICWs seem to integrate their effluent management and purifying properties with that of biodiversity enhancement and landscape fit. This is the first study to investigate the potential of constructed interconnected ponds, used for wastewater treatment, to enhance biodiversity in agricultural landscapes.