Vegetation Succession on River Sediments along the Nakdong River, South Korea

Abstract

We investigated successional vegetation on river sediments along the Nakdong River in South Korea at the time when a river regulation project, named the Four River Project, was launched. We sampled differently aged stages of succession in 63 plots of 10 × 10 m in 2010 using species cover estimations. To explain the observed species composition, we considered the following environmental variables: successional age, distance from the estuary, altitude, elevation above the river water line, texture of the substrate (silt, sand and gravel content) and cover of forest around each site within a radius of 1 km. We used ordination techniques to relate plant community characteristics to environmental variables. We distinguished three main successional vegetation types based on their floristic composition, which included especially a variety of willow species. Besides the cover of forest and certain components of substrate texture, all the variables exhibited significant effects on species composition of the vegetation over the course of succession. The most important factors determining the seral vegetation were the altitudinal gradient and successional age. Environmental factors in the riverine landscape together form a complex riverine environment and determine the vegetation pattern. Unfortunately, this environment has been largely destroyed by the massive river regulation project, but our results indicate that, under certain conditions, the riverine vegetation has a potential to at least partly recover even after such a large-scale disturbance.