In the agricultural landscape of southern Wielkopolska (Krotoszyn area) common ecological niches such as field tree and shrub lots, boundary strips between cultivated land, paths and ponds are accompanied by small bodies of water, which often are distributed geometrically. These are remnants of marl mining in the second half of the 19th century. Currently these reservoirs disappear: they dry up or are filled by farmers. The author discusses their existence in the ecosystem.