Ecohydrological Changes and Resilience of a Shallow Lake Ecosystem under Intense Human Pressure and Recent Climate Change

In this work we present the complicated situation of a faunistically and floristically valuable ecosystem of the Rakutowskie Lake wetlands complex, which is part of the Special Protection Area for Birds of “Błota Rakutowskie” (PLB40001) and “Błota Kłócieńskie” Habitats Directive Sites (PLH040031) included in the Natura 2000 network. Numerous ornithological observations have drawn our attention to the problem of rapidly progressing overgrowth of the lake and significant fluctuations in its water surface area. These fluctuations, especially in the spring period, significantly limit safe reproduction possibilities of very rare species of water–marsh birds. A multidirectional and comprehensive spectrum of research works allowed us to determine the genesis of the ecosystem and show that the shallow lake is undergoing the final stage in its evolution. The economic aspect of human activity (changes in land use and land development works) has contributed to serious degradation of the ecosystem. Climate changes observed in recent years (increased air temperature and, consequently, higher evaporation) additionally deepen and accelerate this process. The research made it possible to determine how the ecosystem functions today, but it is also an attempt to determine our predictions about its future