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Geology and pedology

The NMM Hadce u Želivky lies on massive serpentinite body located east of Sedlice and north of Bernartice. It is elongated in the direction E-W (up NW) and approximately 3.5 km long and 1 km wide. The serpentinite body is quite large, about 275 km2. Two streams interrupt the area: Sedlický potok (Sedlický stream) on the west and Želivka on the east. Serpentine rocks form steep slopes falling down to the streams. Originally compact site was extensively fragmented by the construction of the Želivka dam. At least half of the serpentine rocks area was permanently flooded on both sides of the Sedlický stream and more than two thirds of the rocks on the left bank of Želivka (20-50 m water height). Furthermore, the rest of the site was divided by highway D1. On the edge of the area, there is a functional eclogite quarry. Despite all these negative impacts, NNM Hadce u Želivky is one of the most significant serpentine sites in Czech Republic.

The local serpentine is interesting due to occurrence of magnesite, eclogite and amphibolite. The serpentine also contains abundant olivine, tremolite and fragments of opal. Serpentine (serpentinite) is a rock that is very unfavourable for plant growth because of its properties. Serpentine soils (classified as rendzina) contain high proportion of magnesium and heavy metals, but are poor in essential nutrients. Serpentine weathering is very slow, that’s why serpentine areas are characterized by steep slopes and sharp jagged rocks. Thus the soil erosion is very easy and the water run-off is rapid. Another stress factor is very shallow and drought soil layer. These extreme conditions have led to the fact that these sites are inhabited by specific vegetation, which is very rich in species.