Large wood was added to regulated and straightened reaches of two third‐order streams in Central Germany; the Jossklein and the Lüder. In the Jossklein, the wood was a by‐product of the forest management in the floodplain and accumulated in the channel during peak floods. In the Lüder, logs were builtin as deflectors in regular intervals and fixed within the stream bank. In the Jossklein, the addition of large wood improved the channel morphology within four years. The variation in channel width and depth was considerably larger than in a regulated section. The extension of the riparian zone, especially of the semi‐aquatic gravel and sand bars was strongly correlated with the amount of large wood that accumulated in the single sections. The number of microhabitats and their patchiness on the stream bottom was higher in restored sections, as well as the density of macroinvertebrates and the species number. In the Lüder, some of the observed trends were similar, but not that clear. This differences can be explained by higher amounts of LWD in the Jossklein, organised in dynamic debris dams situated above the water level at low flow, in contrast to the single stacks of logs at the Lüder, situated as stable deflectors within the low flow water level.
This paper investigates the impact of a 100-year flood in May 1999 on community composition and large woody debris standing stock in an alpine floodplain (Isar, Germany). Detailed pre-flood data sampled from 1993 to 1998 are compared with the situation directly after the flood. In those parts of the Isar floodplain mainly covered with pioneer vegetation prior to flooding, the coverage of unvegetated gravel bars increased by 22% following the flood. However, the flood did not remove larger amounts of older successional vegetation stages (willow thickets, floodplain forest). No significant changes in the benthic invertebrate fauna were recorded. The lowest densities of riparian ground beetles (Carabidae) within the study were recorded one month after the flood. Two months later, the ground beetle densities increased to the highest values ever recorded, indicating the ground beetle's high potential for recolonization. These results highlight the degree of resilience of both the aquatic and the riparian invertebrate fauna. The flood also caused a significant increase in large woody debris standing stock; in one section the number of logs increased tenfold and the volume increased by a factor of 20, leading to the assumption that most woody debris in alluvial flood-plains is provided by catastrophic events.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.