W pracy przedstawiono wyniki badań przeprowadzonych w latach hydrologicznych 2002/2003 i 2007/2008 w zlewniach śródleśnych oczek wodnych nr 1, 3, 5 i 6, usytuowanych w leśnictwach Wielisławice i Laski na terenie Leśnego Zakładu Doświadczalnego Siemianice Uniwersytetu Przyrodniczego w Poznaniu (rys. 1). Lasy tych leśnictw leżą w zasięgu Niziny Południowo-Wielkopolskiej, na Wysoczyźnie Wieruszowskiej, będącej zdenudowaną równiną morenową przeciętą biegiem górnej Prosny [6]. Omawiane tereny leżą w zlewni Niesobu i Pomianki, które są lewobrzeżnymi dopływami Prosny. Przeważającym typem siedliskowym lasu, w zlewniach analizowanych oczek, jest las mieszany świeży (LMśw), który zajmuje około 95% powierzchni, a dominującym gatunkiem drzewostanu jest sosna w wieku około 95 lat. W omawianych zlewniach, w terenach położonych najbliżej badanych oczek, występują w przewadze gleby bielicowo-rdzawe, o uziarnieniu piasku gliniastego, z wkładkami utworów mocniejszych.
The paper presents the results of the research carried out in 2002/2003 and 2007/2008 hydrological years. Hydrological year 2002/2003 was a middledry year in terms of rainfall - 56 mm lower than multi-year, when the air temperature was 1,0°C lower than multi-year average air temperature. The second analyzed year, 2007/2008 was a dry year - the rainfall total was 103 mm lower than multi-year and the air temperature was 0,8°C lower than average. The research was carried out in catchments of ponds No. 1, 3, 5 and 6, lo-cated in Wielisławice and Laski forestries - area of Siemianice Experimental Forest Farm of Poznan University of Life Sciences. The forests of mentioned forestries are within range of Południowo-Wielkopolska Lowland, on Wysoczyzna Wieruszowska, which is differential morainic plain, cut with the river Prosna headwaters. Discussed areas are located in catchment of Niesob and Pomianka rivers, which are left-bank tributaries of Prosna river. Fresh mixed forest is predominating in analyzed ponds' catchments - it takes about 95% of the area, and pine in age of ab. 95 years is predominating species of the tree stand. In areas situated closest to the ponds in analyzed catchments, there is a predominance of proper podzol soils with grain size of loamy sand. The ponds, discussed in this paper, have features typical for water reservoirs, from which essential are: the presence of water table, the presence of clearly outlined recess of the area, presence of vegetation affiliated with wet areas. The ponds No. 1 and 6, which have gentle slope, are typical natural melt ponds, ponds no. 3 and 5 are the results of human activities, as evidence by their unnatural shapes. The ponds No. 1 and 3 have no outflow. The pond No. 5 situated at the foot of morainic slope - is intensively supplied by spring waters from adjacent areas and it has constant outflow. According to the information from the local residents, the pond no 5 used to be a fish pond, and pond no. 6 in XIX century used to have an outflow through the ditch - today there's only left 60 m long section. Drainage occurred only at high states, mostly during the spring thaws. Currently discussed pond does not have any drainage, which is mainly attributable to the incidence of lower water levels and silting of the ditch. Two wetlands having their own microcatchments, located in south-eastern and eastern part of the catchment, has an important role in the water management of pond's no 6 catchment. Results of the research confirm that in most of analyzed ponds meteorological conditions (precipitation and air temperature) had a significant impact on the change of the water level. The only exception was pond no. 5, where the changes of the water level were caused by intensive supply by the spring waters. Studies have also shown that an important element in the characteristics of forest ponds, in addition to their morphometric features, is the variability of water levels in these ponds. A key determinant of changes in water levels in analyzed ponds, was the course of meteorological conditions, as well as the nature and size. In the research period most variable were ponds no. 1 and 3, characterized by small size and outflow, and the smallest variability had pond no. 5, supplied by the spring waters. Basing on the results of research and analysis it was also found, that in ponds of small size and with no outflow, with the highest variability of water levels, water table may disappear completely. Disappearance of the water table falls in these ponds mostly during the summer half-years.
