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Penultimate Glacial. The last Glacial Holocene -Transition from open vegetation to deciduous forest -Transformation of forest to open land (heath, shrubs,

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Presentation on theme: "Penultimate Glacial. The last Glacial Holocene -Transition from open vegetation to deciduous forest -Transformation of forest to open land (heath, shrubs,"— Presentation transcript:

1 Penultimate Glacial

2 The last Glacial

3 Holocene -Transition from open vegetation to deciduous forest -Transformation of forest to open land (heath, shrubs, etc.) by early man (burning, grazing, cutting) -From approx BC: agriculture and intensified forest degradation -Late Middle Ages: gradual collapse of agricultural system and degradation (drift sand) -Reforestation from late 19th Century onward (introduction of fertilizers) -Trans

4 Distribution of driftsands

5 The genesis of ‘forten’ and blow-outs

6 Drift sand over Podzol in Coversand

7 Fortresses

8 Geology of the Hoge Veluwe Push moraine Ice melt water fan Snow meltwater valleys Snow meltwater fans Cover sands of eolian origin Snow meltwater fans with thin cover sand layer and later lakes due to water stagnation Driftsand with low relief Driftsand with strong dune relief Active driftsand Road Build-up area

9 The disappearance of drift sands between 1954 and 1960

10 Wind directions and speeds in the NPHV

11 Vegetation types of driftsands and their successional stages

12 Vegetation types of drift sands

13 Regeneration and conservation of drift sands Increase wind speed Remove vegetation Remove litter layer and topsoil Adequate source of sand that can be deflated Low level of atmospheric N-deposition Re

14 The Deelense veld Drift sand over Podzol: stagnation and fens

15 Deelense veld -Accumulative area (drift sand) -Drift sand layer over cover sand and fluvioglacial -Irregular relief with thinner (E) and thicker (W) drift sand over stagnative Placic horizon/Podzol- B horizon -To the West, Podzol eroded and thus infiltration -To the East, no drift sand and thus permeable Podzol at surface

16 Current situation -Strong decline of plant species characteristic for slightly buffered aquatic fen systems -Eutrophication (N) of the fens -Grass encroachment (Molinia) of the moist heath lands Causes Combination of: -No atmospheric input of fine mineral material -No buffering of acidity + increased nutrient level (P, K, etc.) -Atmospheric N-deposition - No atmospheric input es

17 Nature management NPHV - Wildlife and forest development - Fences and zones - Conservation/management at landscape scale - Historical landscapes - Biodiversity and management

18 Excursion 1.The Pollen: regenerated drift sands and their succession 2.Otterlose zand: old drift sand with early successional phases 3.The Deelense veld: fens and wet heathlands through stagnation on Podzol/placic horizon


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