Regional Mountain Conference

The study of long-term ecosystem dynamics is essential for understanding the resistance and resilience of alpine biodiversity to climatic and anthropogenic pressures. The Alpine region, particularly the Central and Eastern Alps, is known for its abundance of glacial lakes. Numerous paleoecological studies have provided key insights into postglacial environmental change. In contrast, little is known from environmental history of the Gesäuse National Park (Ennstaler Alpen, Styria, Austria), an area that has been glaciated only locally.

In this study, we analysed a 573 cm long sedimentary record from Lake Sulzkarsee, representing 14,000 years of the lake’s history and its surrounding environment. A multi-proxy analysis including litho- and chemostratigraphy, diatoms, pollen, macro-remains, and sedimentary ancient DNA of plants and vertebrates has been conducted on the lake sediments. In addition, archaeological surveys and dendrochronological analyses were performed.

The results indicate that the lake was formed during the latest glacial advance. Oligotrophic conditions prevailed during this period, evidenced by diatoms, vertebrates, and macro-remains of plants. Around 3,500 years before present, the first signs of human impact appeared, marked by elevated soil erosion, the appearance of domesticated vertebrates, and a rise in pastoral plant indicators. In the modern era, an intensification of human activity has led to a major ecological shift, reflected by the appearance of eutraphentic diatoms.

Today, the lake is considered ecologically degraded and strongly affected by both human activities and environmental pressures. Yet its complete sedimentary record offers a valuable foundation for future lake restoration efforts.