Diaspore bank experiment with the invasive moss Campylopus introflexus: Can peatland restoration suppress its germination?

The spontaneous recovery of the plant cover of extracted peatlands is a long-lasting process, and re-vegetation depends largely on species emerging from the diaspore bank. Restoration also depends on the success of suppressing the expansion of alien species. To evaluate whether the covering of peat by Sphagnum shoots has an effect on the germination of bryophytes, a growth chamber experiment was conducted. Two acrocarpous moss species— Polytrichum strictum , a native moss, and Campylopus introflexus , the invasive moss in the Northern Hemisphere—were chosen for the study. Peat samples from the extracted peat field were taken and grown in a growth chamber for six months. Half of the samples were covered by Sphagnum shoots, and the other half were left bare for control. At the end of the experiment, the number of shoots and the cover of both species were estimated. In the second experiment Sphagnum cover effect was evaluated on shoot elongation where shoots of both species were grown at low and high water levels. Our aims were to compare native and alien species’ germination ability and to test the possibility of suppressing the expansion of alien species by raising the water level and covering the samples with Sphagnum . Our results showed that on extracted peatlands C. introflexus germinated better than P. strictum, but covering with Sphagnum shoots significantly suppressed its emergence. High water level promoted the growth of P. strictum , but not the growth of C. introflexus . Thus, we can conclude that restoration may help to control the expansion of non-native species in disturbed peatlands.