The role of soil in bioclimatology - a review

Soil's part in bioclimatology is not defined and formulated yet. We interpret soil together with its plant cover as primary climate modifier for organisms living on, and within it. At the same time evaporating soil together with its transpiring vegetation is affecting the climate, and functioning as secondary climate modifier in context of bioclimatology. Selected Hungarian studies are used to highlight four primary and three secondary soil modifier actions connected to bioclimatology. Both primary and secondary soil modifier roles coupled mainly to soil hydro-physical properties. The first primary soil climate modifier action is the dew formation in the surface of sandy soils. As dew 80 mm of water can annually be transported from the subsoil to soil surface. Positive water resource value of dew is still not completely accepted. The second primary soil climate modifier example presents different amounts of usable soil moisture resource in two oak forest habitats with different species composition of herbs. In the third primary soil example the microclimate of the wetter habitat with deeper soil and denser herb vegetation of the oak forest - estimated by inverse modelling - showed higher shading, air moisture content and lower soil coverage than that of dry one. In the fourth primary soil modifier example forest hydrology is quantified for a Scots pine forest. Amount of transpiration, evaporation, interception, and change in the soil water storage were quantified and modelled. As secondary soil climate modifier role CO2 emitting of different plant production forms and land-uses is shown. Estimated CO2 production burning fuels for soil and plant cultivation is one to threefold of the organic extensive and intensive plant production farm consecutively in 2001. For the estimative calculations cost data of the farms are used. Amount of CO2 fixed in the crop biomass is also one to threefold as estimated with the regional scale formula of CEEMA (Canadian Economic and Emission Model for Agriculture). Two secondary soil modifier examples of soil texture and land use pattern's influence on local weather phenomena and near surface atmospheric processes as storm move and development are presented yet. Both studies demonstrate the significance of site-specific soil hydraulic parameters - as field capacity, usable and actual water storage - in formation of the local weather through the soil evaporation and plant transpiration in modelling studies. Of course variety of soil's role is much wider as the examples show and even it is not known completely at present. Soil's role in bioclimatology as new discipline will expectably be formulated in the future.