Coarse Woody Debris Quantity and Distribution in Central European Streams

Abstract

Summarized here are ten investigations concerning the volume of coarse woody debris (CWD) in Central European streams. Altogether, 69 stream sections were examined ranging from Northern German lowland streams to brooks in alpine regions. Most of the study streams are according to Central European standards quasi-natural and are bordered by deciduous forest.The geometric mean of CWD volume related to stream length is 1.44 m 3 /100 meter reach. Related to stream bottom area, the geometric mean of CWD volume is 0.202 m 3 /100 m 2 . The mean number of logs (≥ 10 cm diameter) is 12.5 logs/100 meter reach, and 3.01/100 m 2 bottom area (geometric means). Regarding only quasi-natural stream sections (riparian forest currently unmanaged and no removal of CWD for at least 10 years), the geometric mean of CWD standing stock is 0.45 m 3 /100 m 2 for lowland streams, 0.38 m 3 /100 m 2 for streams in lower mountainous areas and 0.02 m 3 /100 m 2 for alpine floodplains.From the distribution of size classes and comparison with other studies it is likely, that the current CWD standing stock is considerably less than the potential amount of CWD. For centuries all of the streams have been influenced by man. Historic alterations of the stream, its floodplain and the riparian vegetation may still affect CWD supply and standing stock. We conclude that virtually all streams in Central Europe are highly altered with respect to the amount of CWD, and that the importance of CWD is under-represented in recent assessment principles for streams in Germany.

Wood placement in river restoration: fact, fiction, and future direction

“…Natural wood loading in streams ranged from ϳ10 m 3 ·m −2 of channel area in deciduous-softwoods (willows) to well over 1000 m 3 ·m −2 in conifer forests (Gurnell 2003). Examples include low loadings of 0.021-222 m 3 ·m −2 in high-elevation and drier environments (Berg et al 1998;Dunkerley 2014;Hering et al 2000;Lester et al 2006), moderate loadings of 227-638 m 3 ·m −2 in dense forests (e.g., Baillie et al 2008;Carlson et al 1990), and high loadings of over 1000 m 3 ·m −2 in California redwood forests (MacDonald et al 1982).…”

A review of habitat thresholds for dead wood: a baseline for management recommendations in European forests

“…Other, less dominant groups include mollusks (Kappes 2005;Müller et al 2005b;Kappes et al 2009), flat bugs (Jonsell et al 2005;Möller 2005;Goßner 2006), syrphids (Speight 1989;Reemer 2005;Dziock 2006), and parasitic diptera of woodinhabiting beetles (Hövemeyer and Schauermann 2003;Hilszczanski et al 2005). The role of the vertical and horizontal distribution of dead wood as habitat in forests has been considered (Schiegg 2000;Goßner 2004;Müller 2004;Vodka et al 2009), including underground (Schulz and Ammer 1997) and in rivers and lakes (Hering et al 2000). Most of the numerous reviews on the relationship of various organisms and dead-wood point to the necessity of an increase in the amount of dead wood in forests, but mostly provide only more or less vague suggestions (Speight 1989;Kirby et al 1998;Siitonen 2001;Grove 2002c;Grove and Meggs 2003;Christensen et al 2005;Davies et al 2008).…”

In the mood for wood-habitat specific colonization patterns of benthic invertebrate communities along the longitudinal gradient of an Austrian river

“…The importance of LW has mainly been studied in North America (e.g., Anderson et al, 1978;Harmon et al, 1986;Maser & Sedell, 1994;Abbe & Montgomery, 1996;Bilby & Bisson, 1998) as only few pristine river stretches with intact riparian vegetation and LW dynamics remain in Central Europe (Hering & Reich, 1997;Hering et al, 2000;Tockner et al, 2009). Most studies focused on specific river sections.…”