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A study of soil morphological, physical and chemical properties was performed in woodland of different ages, in which spruce (Picea abies), aspen (Populus tremula) and birch (Betula pendula) growing stocks have colonized former agricultural land. The aim of the study was to clarify changes in soil genesis, morphology and properties due to the afforestation of abandoned agricultural land in glacial till deposits. The research showed that soil in these deposits (loamy sand, loam, clay) retains the morphological properties of agricultural land for up to 100 years. Secondary podzolization features in the soil profiles were observed within 100 years of the start of afforestation, whereas the diagnostic properties of Albic and Spodic horizons had not developed in the soil profile after 200 years. This study demonstrated that the morphological and physico-chemical properties of forest litter horizons, including the accumulation of organic substances, are dependent on forest age; however, changes in the properties of mineral soil horizons are mainly related to woodland age. Following the afforestation of agricultural lands, changes in soil pHKCl, organic matter content and extractable Al and Fe concentrations occur more rapidly than changes in soil diagnostic properties and profile formation. 相似文献
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AVHRR remote sensing data for sea surface temperature during the first successful satellite track of a basking shark, Cetorhinus maximus on 6 July 1982 is analysed using the new composite front map technique. The shark is shown to have been swimming, presumed to be filter-feeding zooplankton, in warm coastal water off the west coast of Scotland parallel to the line of a thermal front. 相似文献
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