Impacts of forest loss in the eastern Carpathian Mountains: linking remote sensing and sediment changes in a mid-altitude catchment (Red Lake, Romania)

摘要

Worldwide accelerated forest loss and the associated environmental impacts are important environmental concerns. In this study, we integrate evidence from historical maps and a Landsat-derived time series of catchment-scale forest cover changes with a multi-proxy, palaeolimnological reconstruction spanning the last 150years from Red Lake (Eastern Carpathians, Romania) to better understand the impact of long-term forest changes on catchment erosion and sediment accumulation. We are able to consider two time windows. Firstly, we show that during the traditional (1840-1948) and socialist (1948-1989) periods, catchment changes and sediment responses, as reflected in the sediment accumulation rate, detrital input and grain size were moderate and likely reflect the combined result of known periods of excessive precipitation and local-scale forest disturbances. Secondly, and in contrast, rapid responses in catchment-scale geomorphological processes to forest loss are evident during the post-socialist land use period (1987-2010). We found that the first land restitution period (1987-1999) and the first part of the second land restitution period (2000-2002) had a greater impact on forest loss and subsequent catchment processes with sediment accumulation rates increasing from 0.5cmyear(-1) to 1.2cmyear(-1). Finally, environmental impacts of forest changes were strongly dependent on the size of the area deforested, its location within the catchment, susceptibility to erosion and geomorphological thresholds. In a region noted for accelerated recent forest loss, our study highlights the potential of combining historical maps, satellite images and sediment proxies for documenting such changes and highlights the need for more strategic and sustainable environmental management planning.