Aquatic hyphomycete diversity and identity affect leaf litter decomposition in microcosms

Abstract

We conducted a microcosm experiment with monocultures and all possible combinations of four aquatic hyphomycete species, Articulospora tetracladia, Flagellospora curta, Geniculospora grandis and Heliscus submersus, to examine the potential effects of species richness on three functional aspects: leaf litter decomposition (leaf mass loss), fungal production (ergosterol buildup) and reproductive effort (released spores). Both species richness and identity significantly affected fungal biomass and conidial production (number and biomass of released spores), whereas only species identity had a significant effect on leaf mass loss. In mixed cultures, all measures of fungal functions were greater than expected from the weighted performances of participating species in monoculture. Mixed cultures outperformed the most active monoculture for biomass accumulation but not for leaf mass loss and conidial production. The three examined aspects of aquatic hyphomycete activity tended to increase with species richness, and a complementary effect was unequivocally demonstrated for fungal biomass. Our results also suggest that specific traits of certain species may have a greater influence on ecosystem functioning than species number.

Changes in dominance among species in aquatic hyphomycete assemblages do not affect litter decomposition rates

“…individual degradative capabilities that may compensate each other in species assemblages) and environmental variables. Conversely, some indication for non-redundancy among aquatic hypho mycete communities comes from studies where the effect of species richness on litter decomposition and fungal variables was examined in several distinct communities within each diversity level (Bärlocher & Corkum 2003, Dang et al 2005, Duarte et al 2006. Despite the conflicting results regarding the effect of species richness among the latter studies, a closer look at the (sometimes high) variation of effect size among communities within a given diversity level indicates the importance of species composition.…”

Fungal diversity on fallen leaves of Ficus in northern Thailand

“…Fungi are chemoheterotrophic organisms that play an important role as decomposers in natural ecosystems (Duarte et al, 2006;Gadd, 2007). Fungi have additional economic importance as biocontrol agents, chemical producers of bioactive compounds used in the pharmaceutical and many other industries (Yuen et al, 1999;Bucher et al, 2004;Duarte et al, 2006).…”

“…Fungi have additional economic importance as biocontrol agents, chemical producers of bioactive compounds used in the pharmaceutical and many other industries (Yuen et al, 1999;Bucher et al, 2004;Duarte et al, 2006). The economic impact of fungi in the environment is likely related to the total fungal species pool (Hyde, 2001;Piepenbring, 2007).…”

Litter quality and temperature modulate microbial diversity effects on decomposition in model experiments

“…However, many studies used over-simplified systems with a low species number (usually less than 10 species) with respect to natural systems (e.g., Frankland 1966, Dilly et al 2004, and a short time frame compared to the majority of the decomposition experiments (Berg and McClaugherty 2008). In addition, a large fraction of such studies were done in freshwater systems using hyphomycete fungi (Bärlocher and Corkum 2003, Dang et al 2005, Duarte et al 2006, Costantini and Rossi 2010, while relatively few studies were carried-out in terrestrial ecosystems using both fungi and bacteria (Setälä and McLean 2004).…”