Aim of the investigation is to monitor the long-term trends and changes in soil solution chemistry in connection to stress factors of the environment (e.g. input of acidifying substances, air pollution, climate changes), and to state relationships between the forest health state and these stress factors, study nutrient cycling (inputs and outputs) in the forest ecosystem, in connection to deposition and forest management. Besides direct effect of the stress factors, the forest stands are affected also indirectly via soil environment. Investigation of soil solution chemistry makes possible to state nutrient availability and/or lower input due to potentially toxic Al and other stressors affecting roots of plants and mycorrhizae, and, in the long-term perspective, also prediction of the development of the soil environment.
Soil solution chemistry is studied in 11 plots of intensive monitoring – level II (Benešovice, Březka, Medlovice, Klepačka, Lazy, Luisino údolí, Mísečky, Nová Brtnice, Lásenice, Všeteč, Želivka), in two depths – under the organic horizon (humus horizon FH) and in mineral soil, in 30 cm.
Gravitational lysimeters are used for sampling of the soil water; they are placed in three repetitions, in each depth. Lysimeters are made of poly-ethylene, rectangular shaped, collecting area of 0.06 m2. Water is conducted to storing barrels, placed in covered soil pit, to prevent allae growth. In three of the plots also suction lysimeters are installed (Prenart), in the same depths as the gravitational lysimeters.
Soil solution samples are taken in ten day intervals, together with precipitation water (deposition). After taking, the samples are frozen, and before analyzing mixed monthly samples are prepared. Chemical analyses are done in the FGMRI accredited laboratory, following parameters are stated: pH, alkalinity, conductivity in 25°C, S-SO42- anions, N- NO3-, Cl-, F- P-PO43-, and N-NH4+cations, Al, Ca, Cu, Fe, K, Mg, Mn, Na, Zn, total nitrogen (TN), and dissolved organic carbon (DOC). The laboratory is regularly participating in the national and international ring tests on water analyses.