Presentation on theme: "; Soils = soilscape = geopedological setting. OUTLINE INTRODUCTION THEORETICAL BACKGROUND AND ILLUSTRATIVE EXAMPLES CONCLUSION."— Presentation transcript:
; Soils = soilscape = geopedological setting
OUTLINE INTRODUCTION THEORETICAL BACKGROUND AND ILLUSTRATIVE EXAMPLES CONCLUSION
INTRODUCTION: Soil definition A natural body consisting of layers (or horizons) of mineral (and/or organic constituents) of variable thickness, which differ from the parent material in their morphological, physical, chemical, and mineralogical properties and their biological characteristics S = f (Cl, O, R, P, T,……M)
Definition : A soil = pedon is the smallest volume with a surface extent which varies from about 1 to 10 m² Soil samplePedons/ polypedons in soilscape
Definition: Pedon / polypedon For mapping purposes, similar pedons are pooled together, forming a polypedon, obviously associated with variability, depending on scale
Functions: What does soil do? 1- Soil provides the required setting for water, nutrient, air, and heat exchange for living organisms. 2- Soil controls the water distribution;affects the movement of soluble materials. 3- Soil regulates biological activity and molecular exchanges among solid, liquid, and gaseous phases. 4- Soil acts as a filter to protect the quality of water, air, and other resources.
What does soil do? 5- Soil provides mechanical support for living organisms and their structures. People and wildlife depend on this function. 6- Soils act: - as an archive (=history book of the landscape), - as a guide, and - as a predictor
Soils speak out; an account of the past, present, and future THEORETICAL BACKGROUND AND ILLUSTRATIVE EXAMPLES
An account of the past, present, and future Past Paleoecology Present Soil Management Future Soil Degradation/ Conservation
History book of the landscape (archive) Examples of features revealing paleoecology: 1.Pedogenic (horizons): * Anthropic, * Plaggen, etc * Argillic, *Agric, etc 2. Geomorphic (features): * Glacis formation:Tunisia, Morocco * Travertine (karstic): Iran
1. Pedogenic (horizons)
2. Geomorphic; glacis formation 2.1 Tunisian example: Pedimentation/ planation : in practice, erosional glacis – adjacent to the mountain front is followed by an accumulation glacis. A fan distinguishes itself from the glacis by being associated with a distributary (dichotomic) drainage pattern.
2. Geomorphic features Karstic springs; Travertine Karst spring (dried out) Travertine in scattered patches
Microgram of travertine speciman
Iran: A wetter climate, karstic springs where travertine is spread out; Once upon a time (27000 yr BP yr BP) the study area was subject to cycles of erosion and sedimention, also approved by the occurrence of Argillic and Petrocalcic horizon ; Aridification has never been as degrading as it is today Morocco: Occurrence of Ultisols and Plinthite implies a wetter and hotter climatic condition Different vegetation cover
When well managed Traditional wooden device for plowing; pulled by oxen
Future: PredictionA soil survey describes the characteristics of the soils in a given area, classifies the soils according to a standard system of classification, plots the boundaries of the soils on a map, and makes predictions about the behavior of soils.(SSM, 1993)
Change of erosion base-level: gully formation and landslide Landslide Bushes hold soils together The gully Gully running perpendicular Landslide It is clearly seen that the gully in the bottom of the vale (fig c) is triggering; landslide has occurred once the slope has been de-bushed (cleared) Fig. c
Gullies formed Bush land Cereals Ploughed for Vine tree plantation Gully Boundary between 2 soil series
Incision (gully) occurs in a joint, the weakest line between two pedons
If you want to conserve the environment Listen to what soils say Prevention is better than cure CONCLUSION:
Is check-dam solving the problem?! Slump Check- dam does not help The first check dam Second trial Water goes like this; neglecting the dam
Rferences Rosa M.Poch (editor- in- Chief) and Kovda, Irnia and Curtis Monger (Guest editors) st volume of the proceedings of the 14th IWMSM. Departament de Medi Ambient i Ciències del Sòl Universitat de Lleida Av. Rovira Roure 191, Lleida (Catalonia) Buol, S.W., Hole, F.D., and R.J. McCracken Soil Genesis and Classification. The Iowa State University Press, Ames. Farshad, A Introduction to Applied Geomorphology for Soil Scientists (Geopedologists). Lecture-notes, Department of Earth System Analysis (ESA), ITC, Enschede, The Netherlands. USDA, Soil Taxonomy, A Basic System of Soil Classification for Making Interpreting Soil Surveys. Soil Survey Staff. Agricultural Handbook No Zinck, G.A. 1988/89. Physiography and soils; soil survey courses (Lecture-notes), ITC, Enschede, The Netherlands.