Temporal changes in soil temperature at the Hilton Experimental Site, Shropshire, UK (1982-2006): Evidence of a warming trend?

Abstract

Soil temperature variations at different depths at a research site over a 25-year period (1982-2006) are discussed. Based on a database of 11,498 individual soil temperature measurements in loamy sand (Bridgnorth series) soils, soil temperature at the Hilton Experimental Site in Shropshire, UK, significantly increased between 1982 and 2006. The surface soil (0 cm) warmed twice as fast (∼0.1°C year-1) as soil at 100 cm depth (∼0.05°C year-1) and thus implies progressively steeper thermal gradients with soil depth through time. The trend of increase in soil temperatures at 0 cm was generally greater in winter. These observations contribute to the growing corpus of evidence of global warming.