PenultimateGlacial
The last Glacial
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. 2500 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
Distribution of driftsands
The genesis of ‘forten’ and blow-outs
Drift sand over Podzol in Coversand
Fortresses
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
The disappearance of drift sands between
1954 and 1960
Wind directions and speeds in the NPHV
Vegetation types of
driftsands and their
successional stages
Vegetation types of drift sands
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
The Deelense
veld
Drift sand over Podzol: stagnation and fens
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
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
CausesCombination 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
Nature managementNPHV
- Wildlife and forest development
- Fences and zones
- Conservation/management at landscape scale
- Historical landscapes
- Biodiversity and management
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