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|Michalzik, B; Stadler, B: Effects of phytophagous insects on soil solution chemistry: herbivores as switches for the nutrient dynamics in the soil., Basic and Applied Ecology, 1, 117-123 (2000)|
In a column irrigation experiment the effects of different amounts of honeydew on the dynamics of soil respiration, dissolved organic carbon and nitrogen (DOC and DON, respectively) and inorganic nitrogen species in the organic layer of a forest soil were investigated.
On the base of hourly and daily sampling, the application of different field-relevant amounts of honeydew-DOC caused short-time effects on the chemical composition of the gas and solution phase in the forest floor. Within one hour, the micro-organisms of the forest floor responded to the input of easily decomposable carbon compounds producing significantly higher rates of CO2 than the control. In the forest floor solution the concentrations of inorganic nitrogen were reduced in the presence of high amounts of honeydew-DOC. The input of honeydew-DOC also slightly affected the DON dynamics causing reduced concentrations compared to the control. In case of DOC concentrations, differences between the treatments disappeared three days after the application of honeydew DOC has stopped.
The column experiment showed that high temporal resolution measurements are necessary to achieve a better understanding of processes concerning the effects of phytophagous insects in the canopy on the solution chemistry of the forest floor.