Patrick CHIROIU, Adrian C. ARDELEAN, Alexandru ONACA, Mircea VOICULESCU & Florina ARDELEAN
West University of Timişoara, Department of Geography, Bdul Vasile Pârvan, 4, 300223-Timişoara, ROMANIA
p.chiroiu@gmail.com, adrian.ardelean86@e-uvt.ro, ducuonaca@yahoo.com, voicu@cbg.uvt.ro, florina.ardelean@cbg.uvt.ro

ASSESSING THE ANTHROPOGENIC IMPACT ON GEOMORPHIC PROCESSES USING TREE-RINGS: A CASE STUDY IN THE FĂGĂRAȘ MOUNTAINS (ROMANIAN CARPATHIANS)

Full text

In mountain environments, geomorphic slope processes such as rockfall, debris-flows and snow avalanches are common and widespread, their natural occurrence being controlled by topographic, geological and climatic parameters. Instead, in regions where human activities are present, the slope equilibrium and the natural dynamics of geomorphic processes can be significantly altered. For instance, the construction of the alpine Transfăgărășan Highway, which crosses the Făgăraș Mountains in the Romanian Carpathians, affected the morphogenetic potential of the Bâlea and Capra valleys, influencing slope stability and present-day geomorphic process dynamics. Anthropogenic disturbance may induce cascading environmental changes, posing a growing threat to human lives and activities, thus urging for the initiation of logical research approaches in this direction. Dendrogeomorphology has been used since the 1970s in the study of slope processes, becoming a well established reconstruction and analysis method. In our study, we employed tree-ring based techniques to examine the anthropogenic impact on geomorphic processes on a scree slope located right beneath the runway of the Transfăgărășan road. A total number of 33 Picea abies trees were sampled in the lower part of the scree to reconstruct the rockfall and snow avalanches activity by the analysis of geomorphic-induced growth disturbances in tree-rings. Another 20 Picea abies trees were selected from an undisturbed stand located north of the investigated area to build a reference chronology. The relative ages of the two stands were then compared to evaluate the impact of human activities in natural forest and landscape dynamics. The results of our study indicate that the investigated scree was initiated by the time of road construction activities in the early 1970s and is nowadays shaped by various geomorphic slope processes. Rockfall rates are most probably amplified by road traffic, whereas snow avalanches seem to follow a natural regime in the cold season, when the alpine road is closed.