Ellenberg's indicator values (simple ordinal classes of plants with a similar realized ecological niche along a gradient) were tested to describe the changing environment and water resources recharge in the upper plateau of the Jizera Mountains. (Czech Republic). In the 1980s, the acid atmospheric deposition led to the decline and clear-cut of spruce plantations (Picea abies): Junco effusi-Calamagrostietum villosae became a new dominant community there. Ellenberg's indices for light (L), moisture (F), nitrogen (N) and acidity (R) were compared with hydrological parameters of a small catchment (soil water content, evapotranspiration, retention, stream-flow pH and nitrate content) in 1982–2008. Ellenberg's indicators F and L describe well the plant succession related to microclimate and hydrology at clear-cut sites. Also, the indices N and R follow trends in the atmospheric deposition and water quality; however, with lower sensitivity. Ellenberg's indices reflect the observed changes in water phenomena with a lag period of 3–10 years.