Studies on the characteristics of ecosystem using soil seed banks

Abstract

We used the seedling emergent method using the soil sample to study the vegetation change and regeneration strategy after flooding in river ecosystem, and the effect of prescribed burning and grazing on wetland vegetation in Blanket Bog moorlands, UK, and the spread of alien invasive plants during road constructions. In the river ecosystem, above-ground vegetation and soil seed banks have a low similarity. However, there are species found only in soil seed banks without above-ground vegetation. Therefore, the soil seed banks are regarded to support biodiversity. In addition, the formation of soil seed banks and ground-level vegetation in the stream has been simplified after the flood, but it has been studied that the flood functions to maintain the native vegetation of the stream as the number of aquatic plants has increased. The Blanket Bog moorlands in the UK are well-developed peat layers that play an important role in controlling the global carbon concentration. In the second study, we proposed the appropriate intervals of prescribed burning to maintain Sphagnum species, the main species forming peat layers, and the Calluna vulgaris community, which provides essential ecosystem services. Finally, the dispersal trend of alien invasive plants along the road was studied using the hand sorting seed count method. The alien invasive plants are introduced during the road construction and they tend to spread according to the movement of the vehicle and the road conditions. We found that the unique 'tubular' structure of the road enables the long-distance dispersal in a relatively short time. As such, the study of seed banks in the soil can be applied in various ways, providing a clue to the solution of phenomena occurring in the ecosystem. There are considerations, such as the inability to identify all seeds in the soil samples and the fact that the dominant above-vegetation species may differ from the soil seed bank in an ecosystem. However, there are advantages, such as providing information for predicting potential vegetation, and it takes relatively short time with less than four months, in common, to evaluate.