Relative importance of coarse and ﬁne woody debris for the
diversity of wood-inhabiting fungi in temperate broadleaf forests
*, Martin Ryberg
, Frank Go
, Bettina Olausson
Department of Systematic Botany, Botanical Institute, Go
teborg University, Box 461, SE-405 30 Go
Department of Zoology, Animal Ecology, Go
teborg University, Box 463, SE-405 30 Go
Received 15 November 2002; received in revised form 24 May 2003; accepted 9 June 2003
Dead wood is considered important in forest conservation, but patterns of fungal diversity on dead wood have rarely been
quantiﬁed. We investigated the relative importance of coarse (diameter >10 cm) and ﬁne woody debris (1–10 cm) for fungi in
broadleaf forests in southern Sweden. The numbers of species per unit wood volume and per forest area were signiﬁcantly higher
for ﬁne than for coarse woody debris for both ascomycetes and basidiomycetes. When the number of species was plotted against the
number of records, coarse woody debris was more species rich than ﬁne woody debris for a given number of basidiomycete records.
Of the ascomycetes, 75% were found exclusively on ﬁne woody debris (the corresponding proportion for basidiomycetes is 30%),
2% were found exclusively on coarse woody debris (basidiomycetes 26%), and 23% of the species were found on both diameter
classes (basidiomycetes 44%). We conclude that ﬁne woody debris is important for diversity of wood-inhabiting fungi, especially
ascomycetes, in this forest type. However, coarse woody debris must also be provided to insure the occurrence of many species of
# 2003 Elsevier Ltd. All rights reserved.
Keywords: Fungi; Coarse woody debris; Fine woody debris; Species richness; Species density
A very large number of organisms are dependent on
decaying wood for nutrients or habitat (Samuelsson et
al., 1994; Ohlson et al., 1997; McComb and Linden-
mayer, 1999; Boddy, 2001; Siitonen, 2001). Fungi are a
crucial part of this biodiversity, and one of the main
groups decomposing wood on dead or living trees
world-wide (Dix and Webster, 1995). They also play a
key role for the diversity of other organisms associated
with dead wood, e.g. saproxylic insects (Batra, 1967;
Wheeler and Blackwell, 1984; Wilding et al., 1989;
Blackwell and Jones, 1997). Wood-inhabiting fungi are
here deﬁned as all fungi with fruitbodies on decaying
wood. They are not necessarily wood decayers and may
have other (primary) ecological roles as parasites or
symbionts (Dix and Webster, 1995; Norde
n et al., 1999).
The amount of dead wood has decreased drastically
in Swedish forests since the middle of the 19th century
following intense forestry (Linder and O
Nilsson et al., 2001), and its associated biota has there-
fore become threatened (Berg et al., 1994; Ga
2000) especially in the temperate broadleaf forest of
southern Sweden (Berg et al., 1994; Rydin et al., 1997).
Temperate broadleaf forest is one of the most severely
disturbed and endangered biomes world-wide (Hannah
et al., 1995), and has declined considerably in Sweden
fgren and Andersson, 2000; Nilsson et al., 2001).
Most work on the importance of dead wood for fungi
has been performed in boreal, coniferous forest (Jons-
son and Kruys, 2001). In this study, we investigated the
importance of dead wood for fungal diversity in the
more southerly distributed broadleaf forest. We chose
woodland dominated by the oaks Quercus robur L. and
Q. petraea Liebl., since these have been reported to play
key roles for biodiversity in the temperate broadleaf
forests of Europe (Berg et al., 1994; Nilsson et al., 2001,
Butler et al., 2001).
Several studies suggest that the occurrence of coarse
woody debris (CWD, diameter > 10 cm) is critical for
diversity of wood-inhabiting fungi (Samuelsson et al.,
0006-3207/03/$ - see front matter # 2003 Elsevier Ltd. All rights reserved.
Biological Conservation 117 (2004) 1–10
* Corresponding author. Fax: +46-31-773-2677.
E-mail address: firstname.lastname@example.org (B. Norde