Ecological restoration of rich fens in Europe and North America: from trial and error to an evidence-based approach

Fens represent a large array of ecosystem services, including the highest biodiversity found among wetlands, hydrological services, water purification and carbon sequestration. Land use change and strong drainage has severely damaged or annihilated these services in many parts of North America and Europe, which urges the need of restoration plans at the landscape level. We review the major constraints for the restoration of rich fens and fen water bodies in agricultural areas in Europe and disturbed landscapes in North America: 1) habitat quality problems: drought, eutrophication, acidification, and toxicity, 2) recolonization problems: species pools, ecosystem fragmentation and connectivity, genetic variability, invasive species, and provide possible solutions. We discuss both positive and negative consequences of restoration measures, and their causes. The restoration of wetland ecosystem functioning and services has, for a long time, been based on a trial and error approach. By presenting research and practice on the restoration of rich fen ecosystems within agricultural areas, we demonstrate the importance of biogeochemical and ecological knowledge at different spatial scales for the management and restoration of biodiversity, water quality, carbon sequestration and other ecosystem services, especially in a changing climate. We define target processes that enable scientists, nature managers, water managers and policy makers to choose between different measures and to predict restoration prospects for different types of deteriorated fens and their starting conditions

Waterkwaliteit en biodiversiteit in het laagveenlandschap

As a result of altered land use, water shortage and eutrophication, aquatic and semi-aquatic biodiversity in minerotrophic peatlands has severely declined in The Netherlands. After the improvement of surface water quality following hydrological and other measures, biodiversity is now increasing again in many reserves including former peat extraction areas, but not in all. In large peatland meadow areas, eutrophication is still a major problem and tightly linked to land subsidence. This paper reviews the current state of fen waters in relation to different restoration measures based on applied research, including projects sponsored by the Knowledge Network for Restoration and Management of Nature in The Netherlands. We also plead for more sustainable future land use and management of Dutch peatland areas, including marsh restoration and paludiculture, aimed at stopping land subsidence or at the regrowth of peat, and improvement of water quality

Waterkwaliteit en biodiversiteit in het laagveenlandschap

As a result of altered land use, water shortage and eutrophication, aquatic and semi-aquatic biodiversity in minerotrophic peatlands has severely declined in The Netherlands. After the improvement of surface water quality following hydrological and other measures, biodiversity is now increasing again in many reserves including former peat extraction areas, but not in all. In large peatland meadow areas, eutrophication is still a major problem and tightly linked to land subsidence. This paper reviews the current state of fen waters in relation to different restoration measures based on applied research, including projects sponsored by the Knowledge Network for Restoration and Management of Nature in The Netherlands. We also plead for more sustainable future land use and management of Dutch peatland areas, including marsh restoration and paludiculture, aimed at stopping land subsidence or at the regrowth of peat, and improvement of water quality

Spatial self-organized patterning in seagrasses along a depth gradient of an intertidal ecosystem

The spatial structure of seagrass landscapes is typically ascribed to the direct influence of physical factors such as hydrodynamics, light, and sediment transport. We studied regularly interspaced banded patterns, formed by elongated patches of seagrass, in a small-scale intertidal ecosystem. We investigated (1) whether the observed spatial patterns may arise from feedback interactions between seagrass and its abiotic environment and (2) whether changes in abiotic conditions may lead to predictable changes in these spatial patterns. Field measurements, experiments, and a spatially explicit computer model identified a ‘‘scale-dependent feedback’’ (a mechanism for spatial self-organization) as a possible cause for the banded patterns. Increased protection from uprooting by improved anchoring with increasing seagrass density caused a local positive feedback. Sediment erosion around seagrass shoots increased with distance through the seagrass bands, hence causing a long-range negative feedback. Measurements across the depth gradient of the intertidal, together with model simulations, demonstrated that seagrass cover and mean patch size were predictably influenced by additional external stress caused by light limitation and desiccation. Thus, our study provides direct empirical evidence for a consistent response of spatial self-organized patterns to changing abiotic conditions, suggesting a potential use for self-organized spatial patterns as stress indicators in ecosystems.

Attention, spatial integration, and the tail of response time distributions in Stroop task performance

Item does not contain fulltextA few studies have examined selective attention in Stroop task performance through ex-Gaussian analyses of response time (RT) distributions. It has remained unclear whether the tail of the RT distribution in vocal responding reflects spatial integration of relevant and irrelevant attributes, as suggested by Spieler, Balota, and Faust (200027. Spieler , D. H. , Balota , D. A. and Faust , M. E. 2000 . Levels of selective attention revealed through analyses of reaction time distributions . Journal of Experimental Psychology: Human Perception and Performance , 26 : 506 – 526 . [CrossRef], [PubMed], [Web of Science ®], [CSA] View all references). Here, two colour–word Stroop experiments with vocal responding are reported in which the spatial relation between colour and word was manipulated. Participants named colours (e.g., green; say “green”) while trying to ignore distractors that were incongruent or congruent words (e.g., red or green), or neutral series of Xs. The vocal RT was measured. Colour words in colour, white words superimposed onto colour rectangles (Experiment 1), and colour rectangles combined with auditory words (Experiment 2) yielded Stroop effects in both the leading edge and the tail of the RT distributions. These results indicate that spatial integration is not necessary for effects in the tail to occur in vocal responding. It is argued that the findings are compatible with an association of the tail effects with task conflict

Self-facilitation and negative species interactions could drive microscale vegetation mosaic in a floating fen

Aim: The formation of a local vegetation mosaic may be attributed to local variation in abiotic environmental conditions. Recent research, however, indicates that self-facilitating organisms and negative species interactions may be a driving factor. In this study, we explore whether heterogeneous geohydrological conditions or vegetation feedbacks and interactions could be responsible for a vegetation mosaic of rich and poor fen species. Location: Lake Aturtaun, Roundstone Bog, Ireland. Methods: In a floating fen, transects were set out to analyze the relation between vegetation type and rock–peat distance and porewater electrical conductivity. Furthermore, three distinct vegetation types were studied: rich fen, poor fen and patches of poor fen within rich fen vegetation. Biogeochemical measurements were conducted in a vertical profile to distinguish abiotic conditions of distinct vegetation types. Results: Geohydrological conditions may drive the distribution of poor and rich fen species at a larger scale in the floating fen, due to the supply of minerotrophic groundwater. Interestingly, both rich and poor fen vegetation occurred in a mosaic, when electrical conductivity values at 50 cm depth were between 300 µS/cm and 450 µS/cm. Although environmental conditions were homogeneous at 50 cm, they differed markedly between rich and poor fen vegetation at 10 cm depth. Specifically, our measurements indicate that poor fen vegetation lowered porewater alkalinity, bicarbonate concentrations and pH. No effects of rich fen vegetation at 10 cm depth on biogeochemistry was measured. However, rich fen litter had a higher mineralization rate than poor fen litter, which increases the influence of minerotrophic water in rich fen habitat. Conclusions: These results strengthen our hypothesis that species can drive formation of vegetation mosaics under environmentally homogeneous conditions in a floating fen. Positive intraspecific self-facilitating mechanisms and negative species interactions could be responsible for a stable coexistence of species, even leading to local ecosystem engineering by the species, explaining the local vegetation mosaic at the microscale level in a floating fen

How bird droppings can affect the vegetation composition of ombrotrophic bogs

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