Drip heterogeneity and the impact of decreased flow rates on the vadose zone fauna in Ciur‐Izbuc Cave, NW Romania

Abstract

AbstractThe aim of this study was to better understand the unsaturated zone of a karst massif habitat for aquatic fauna by defining patterns of cave drip flow rates. Dripping was logged over a period of 4 years at three points inside Ciur‐Izbuc Cave (north‐western Romania). Drip rates have been analysed at different scales and also compared with rainfall. The results show the individual behaviour of drips on daily, monthly, and yearly timescales and no significant correlations between the three drip points or between them and rainfall. Yearly differences are statistically significant, showing large changes in drip behaviour over the study period. The results point to two different aspects of the water flow through the vadose zone: (a) a space and time heterogeneity raising questions about related stress for the groundwater invertebrates inhabiting this zone and (b) relative uniformity given by signals at certain time intervals that explain species diversity preservation in such a heterogeneous environment. Conservation concerns, and the need for long‐term monitoring of fauna and hydrological processes, are stressed.