Abstract
This paper presents the results of research relating to the vegetation of the Kulawa River valley and its flow lakes - Głuche Duże, Głuche Małe, and Sieczonek.
Transformations observed in the flora examined were the result of two overlapping factors:
1. anthropogenic factors - among others, a high phosphorus content in the waters of the river and in nutrients accumulating in the lakes;
2. natural factors, such as a reduced level of subsoil waters.
In the protection of river valleys, it is important to diagnose all threats. The diagnosis should be based not only on an evaluation of water quality, but also on the state of the whole environment of the valley.