Interactions between pH and nutrients on benthic algae in streams and consequences for ecological status assessment and species richness patterns

Eutrophication and acidification are among the major stressors on freshwater ecosystems in northern Europe and North America, but possible consequences of interactions between pH and nutrients on ecological status assessment and species richness patterns have not previously been assessed. Using data from 52 river sites throughout Norway, we investigated the combined effects of pH and nutrients on benthic algae assemblages, specifically 1) taxa-specific couplings between nutrient and acidity traits, 2) the degree of consistency between different biotic indices, separately for nutrients and acid conditions, 3) the impact of pH on nutrient indices and phosphorus on indices of acid conditions, and 4) the impact of pH and phosphorus supply on diatom and non-diatom taxon richness. We found that 1) acid-tolerant taxa are generally associated with nutrient-poor conditions, with only a few exceptions; this is probably more a consequence of habitat availability than reflecting true ecological niches; 2) correlation coefficients between nutrient indices and TP, as well as acid conditions indices and pH were barely affected when the confounding factor was removed; 3) the association of acid-tolerant taxa with nutrient-poor conditions means that the lowest possible nutrient index at a site, as indicated by benthic algae, is lower at acid than at circumneutral sites. Although this may be an artifact of the datasets from which taxa-specific indicator values were derived, it could lead to a drift in nutrient indices with recovery from acidification; 4) the response of non-diatom taxon richness follows a complex pattern with a synergistic interaction between nutrient supply and pH. In contrast, diatom richness follows a simple additive pattern; this suggests structural differences between diatoms and non-diatom benthic algae in their response to nutrient supply and pH; diatom taxon richness tended to increase with nutrient supply, while non-diatom richness decreased. (C) 2012 Elsevier B.V. All rights reserved

Is forest landscape restoration socially desirable? A discrete choice experiment applied to the Scandinavian transboundary Fulufjället National Park Area

Using an economic valuation approach, we assessed people's stated preferences for policy aimed at enhancing restoration of functional networks of naturally dynamic boreal forest habitats as a public good. Active landscape restoration can improve the functionality of boreal forest habitats as green infrastructure, which is essential for biodiversity conservation and delivery of multiple ecosystem services that production forests are poor at providing. In contrast, so far designation of protected areas in Fennoscandia has focused on remnant patches of near‐natural forests, and not on forest landscape restoration. We assessed citizens' preferences for forest landscape restoration in a transboundary region primarily managed for sustained‐yield wood production for the forest industry, and which hosts the transboundary Fulufjället National Parks in Sweden and Norway. We conducted a discrete choice experiment by asking Swedish and Norwegian citizens to choose among two options for the Fulufjället area, including (1) extension of passive protection on one side or both sides of the border, by additional area protection and restoration of forest naturalness, and (2) a status quo option. The scenario assumed that extension of the protected forest area would imply a compulsory tax administered bilaterally by the two countries. Just over half of the sample, in both countries expressed willingness to pay for forest landscape restoration. Alternatives that contemplated larger extensions of forest landscape restoration were assigned higher willingness‐to‐pay. Public awareness and support, combined with spatial planning, are necessary for forest landscape restoration to become a viable tool for biodiversity conservation in Scandinavia