The surface of today’s Ljubljansko barje began to sink a long time ago. Over time, it was filled with alluvial deposits. These repeatedly blocked the outfalls of the rivers flowing along it. After the last ice age, a lake was formed that stretched between Ljubljana, Vrhnika and Ig. For more than 2,500 years, its surrounding area was inhabited by the well-known inhabitants of the Ljubljansko barje, the pile dwellers, with several interruptions.
Lakes have interesting lives! Due to sedimentation and the deposition of layers of dead material over the years, they become increasingly shallow and slowly turn into a marsh. Due to constant wetness, the accumulated deposits do not decompose but turn into peat. A unique ecosystem is created, where an acidified environment with few minerals sustains the life of a limited number of species.
Over time, the upper layers of peat completely lose contact with the groundwater, leading to the formation of a so-called raised bog, which eventually dries out. And is then overgrown by the forest. The Goriški mah is a remnant of a raised bog, in whose soil thick layers of peat have been preserved.
Alluvial deposits repeatedly blocked the river outfalls in the Ljubljansko barje. This led to the formation of a large shallow lake. According to scientists, the Ljubljansko barje has experienced 8 cases of ponding in its history.
There are remains of lake deposits under a thick layer of peat. The shells of snails and clams contained within are several thousand years old!
In the bog soil, there are remains of dead plant parts, which did not decompose due to lack of air, but turned into peat.
Every bit of nature slowly changes over many years. This results in an increasingly complex intertwining of species and connections between them. The sequence of changing ecosystems over time is also known as “natural succession”. Turn the prism and check out the life course of a lake!