title: Mean reproductive traits of fungal assemblages are correlated with resource availability.
abstract: Organisms have evolved a fascinating variety of strategies and organs for successful reproduction. Fruit bodies are the reproductive organ of fungi and vary considerably in size and shape among species. Our understanding of the mechanisms underlying the differences in fruit body size among species is still limited. Fruit bodies of saprotrophic fungi are smaller than those of mutualistic ectomycorrhizal fungi. If differences in fruit body size are determined by carbon acquisition, then mean reproductive traits of saprotrophic and ectomycorrhizal fungi assemblages should vary differently along gradients of resource availability as carbon acquisition seems more unpredictable and costly for saprotrophs than for ectomycorrhizal fungi. Here, we used 48 local inventories of fungal fruit bodies (plot size: 0.02 ha each) sampled along a gradient of resource availability (growing stock) across 3 years in the Bavarian Forest National Park in Germany to investigate regional and local factors that might influence the distribution of species with different reproductive traits, particularly fruit body size. As predicted, mean fruit body size of local assemblages of saprotrophic fungi was smaller than expected from the distribution of traits of the regional species pool across central and northern Europe, whereas that of ectomycorrhizal fungi did not differ from random expectation. Furthermore and also as expected, mean fruit body size of assemblages of saprotrophic fungi was significantly smaller than for assemblages of ectomycorrhizal species. However, mean fruit body sizes of not only saprotrophic species but also ectomycorrhizal species increased with resource availability, and the mean number of fruit bodies of both assemblages decreased. Our results indicate that the differences in carbon acquisition between saprotrophs and ectomycorrhizal species lead to differences in basic reproductive strategies, with implications for the breadth of their distribution. However, the differences in resource acquisition cannot explain detailed species distribution patterns at a finer, local scale based on their reproductive traits.
authors: Bavarian Forest National Park Freyunger Str. 2 94481 Grafenau Germany.
authors: Claus
authors: C
authors: Bässler
authors: German Mycological Society Danziger Str. 20 63916 Amorbach Germany.
authors: Hans
authors: H
authors: Halbwachs
authors: Bavarian Mycological Society Section Bavarian Forest Ablegweg 9 94227 Rabenstein Germany.
authors: Peter
authors: P
authors: Karasch
authors: Bavarian Mycological Society Section Bavarian Forest Ablegweg 9 94227 Rabenstein Germany.
authors: Heinrich
authors: H
authors: Holzer
authors: German Mycological Society Dorfstrasse 27 07751 Jenaprießnitz Germany.
authors: Andreas
authors: A
authors: Gminder
authors: German Mycological Society Konrad-Adenauer-Str. 32 73529 Schwäbisch Gmünd Germany.
authors: Lothar
authors: L
authors: Krieglsteiner
authors: Chair of Remote Sensing and Landscape Information Systems University of Freiburg 79106 Freiburg Germany.
authors: Ramiro Silveyra
authors: RS
authors: Gonzalez
authors: Bavarian Forest National Park Freyunger Str. 2 94481 Grafenau Germany.
authors: Jörg
authors: J
authors: Müller
authors: Animal Ecology Department of Ecology Faculty of Biology Philipps-Universität Marburg 35037 Marburg Germany.
authors: Roland
authors: R
authors: Brandl
keywords: Assemblage composition; elevation gradient; fruit body; null model; sporocarp