Spatial and temporal fluxes of plant-nutrients in turlough soils

Abstract

Turloughs are annually flooding karstic depressions which constitute ecologically important and geographically restricted ground-water dependent ecosystems, identified as priority habitats under the EU Habitats Directive. Turlough conservation is also driven by the EU Water Framework Directive and recent developments have attempted to characterise the karst aquifers associated with turloughs, which are generally of a conduit or shallow epikarst nature. Different types of karst aquifers are thought to account for ecological diversity among turloughs and influence turlough trophic status, which is currently assessed using qualitative assessments of the proportional area of nutrient-sensitive plant communities. The natural trophic status of turloughs is also thought to be influenced by the soil types present, however the relationships between turlough karst aquifers, soil types and soil nutrient status are poorly understood. Eutrophication constitutes one of the main threats to the quality of the turlough habitat and soil nutrient assessments are required as part of the current drive to generate quantitative information on turlough trophic ranges. Soil property variability is well recognised, however information on the spatial and temporal variations of soil nutrient related properties, and how these might influence plant community structure and sampling strategies for conservation assessment, is lacking. The primary aim of this project is to contribute to a better understanding of turlough spatial and temporal soil nutrient dynamics and their associations with soil types, vegetation types, karst aquifer types and current turlough trophic assessments at both catchment and within-turlough scales. At the catchment scale, focus was placed on determining whether turloughs located within different types of karstic flow systems have contrasting soil nutrient properties.