• Open Carboniferous Limestone pavement grike microclimates in Great Britain and Ireland: understanding the present to inform the future

      Burek, Cynthia; Hosie, Lottie; Geary, Matt; York, Peter, J. (University of ChesterUniversity of Chester, 2020-04)
      Limestone pavements are a distinctive and irreplaceable geodiversity feature, in which are found crevices known as grikes. These grikes provide a distinct microclimate conferring a more stable temperature, higher relative humidity, lower light intensity and lower air speed than can be found in the regional climate. This stability of microclimate has resulted in an equally distinctive community of flora and fauna, adapted to a forest floor but found in an often otherwise barren landscape. This thesis documents the long-term study of the properties of the limestone pavement grike in order to identify the extent to which the microclimate may sustain its distinctive biodiversity, to provide recommendations for future research which may lead to more effective management. Over a five-year study, recordings of temperature, relative humidity, light intensity and samples of invertebrate biodiversity were collected from five limestone pavements situated in the Yorkshire Dales and Cumbria in Great Britain, and The Burren in the Republic of Ireland. An extensive description of the grike microclimate was undertaken using the data collected to understand the extent of the microclimate stability of the grike and the conditions for variation in the grike microclimate. Further insights into the grike microclimate were gained through simulation techniques more commonly used in engineering, to explore the effects of air flowing over a grike, the light from the sun entering the grike and regression analysis to simulate the temperature within the grike in the present and projected for the future. This study has indicated that although the whole of the grike confers a degree of microclimatic stability, it is made up of a less stable upper zone and a more stable lower zone. The instability of the upper zone is hypothesised to result from the extent to which the majority of light and external air can enter the grike, whereas the stability of the lower zone may be governed by the thermal stability of the limestone surrounding it. Based on this zonation and the projections for the grike temperature, it is hypothesised that climate change will have the most substantial effects in the upper grike zone where species obligated to this area could be most heavily impacted. This study recommends a range of areas in which research may be employed so that the limestone pavement habitat may be successfully managed in Great Britain and the Republic of Ireland.