Many places in the world show spectacular landscape changes caused by increasingly rapid alterations of natural phenomena observed in the last 3 to 4 decades. More and more studies reveal the consequences of global climate change strengthened by anthropogenic effects. The cause of rapid changes in the landscape is often due to the alteration of the natural water-cycle. Using moderate resolution imaging spectoradiometer vegetation indices, this study analyzed the relationship between biomass and precipitation, being one of the most important climate elements, over a Hungarian landscape that has been highly affected by the process of groundwater-table sinking in the last decades. Research proved that the reasons for this decrease are mainly the precipitation shortage due to climate change and to a much smaller extent, anthropogenic effects. In the forests of the study area, the annual distribution of precipitation proved to be an important factor, and the biomass produced by forests is influenced by the precipitation over a shorter interval—compared to less sensitive landscapes. Under increasing aridification, further degradation of vegetation can be expected as has already been observed during drier periods in the case of tree species with high water demand.