Considering this place is called U Hájů, have you ever wondered what “háj” means? It means grove. This natural monument U Hájů is a treasure. It lies in Prague’s Stodůlky district.
U Hájů is nestled between the former Háj farmstead and the Prague Semmering railway embankment. The area spans 6.59 hectares. It was declared a natural monument in 1982.
Imagine this area 7,000 years ago. The first agricultural activities began here. The most intensive farming happened in the 18th and 19th centuries. Most of the area was pasture for farm animals from the nearby Háj farm. Forests were cleared or grazed. Only small groups of trees remained near watercourses.
The most valuable part of U Hájů is a meadow. It is located in the northeastern part. Several springs with lime-rich water emerge here. Water quality is vital because it supports unique wetland meadow communities. Protected species thrive here.
Geologically U Hájů tells a very old story. The shallow valley is carved into rocks. These rocks are about 470 million years old. They are sediments from a deep sea. Shales are common here.
Horotvorné processes lifted the area above sea level. This happened between 370 and 320 million years ago. The area was flooded again during the Cretaceous period. This was roughly 96 to 87 million years ago. The Cretaceous sea left sandstones and claystones.
Plant life is diverse at U Hájů. Besides common wetland species rare ones exist here too. You might spot the broad-leaved marsh orchid. Also look for the sea medick. In the vicinity of calcareous springs rare sedges grow.
The forest is variable. Along the Bvětvený Brook, you’ll find stands of black alder. Other flora include rowan. Fauna includes endangered amphibians. Listen for the European fire-bellied toad. Also watch for the green toad. You might see the slow worm a legless lizard. Many forest and songbirds live here.
The Brouček retention reservoir is home to koi carp. Red-eared sliders also reside there. Originally a pond it was rebuilt in the 1970s. It was meant to capture rainwater. However sediment quickly filled it. In 2007 it was dredged. They installed Prague’s first wooden drain.
U Hájů was never farmed intensively. After grazing stopped in the 1960s and 70s part of the area was poorly reforested. Spruce and larch were planted. Some alder stands were likely planted then too.
The long-term goal is to preserve the main features. This includes protecting biodiversity. Management practices are needed. These practices replace former farming. They stabilize non-forest habitats.
The unsuited forests must change. The goal is to create near-natural forests. This means removing non-native trees. It also means thinning stands. U Hájů is a testament to nature’s resilience. It also shows the importance of conservation. Take a moment to appreciate this unique space.