Potassium uptake in the epiphytic lichen Hypogymnia physodes at concentrations and pH conditions as found in stemflow
2003
Hauck, Markus | Gross, Shana
Samples of the foliose epiphytic lichen Hypogymnia physodes were incubated with 0, 100, 500, and 1000 micromolar KCl solution for up to 120 min. K was absorbed by H. physodes only in single replicates of the most highly concentrated solutions. Otherwise a release of K of up to 26 micromol g-1 d. wt. was observed. This can be attributed to the low affinity of K for the cation exchange sites in lichen cell walls. The K concentrations applied with the incubation medium correspond to concentrations found in stemflow from dieback-affected Picea abies forests in the Harz Mountains, northern Germany. The results suggest that stemflow is not a major source of K for H. physodes. The loss of K in the present experiment could be due to changes of the water content in the lichen thalli or due to membrane damage caused by S or heavy metals in the field.
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