US EPA

3546917 

Journal Article 

Fungi exposed to chronic nitrogen enrichment are less able to decay leaf litter 

van Diepen, LT; Frey, SD; Landis, EA; Morrison, EW; Pringle, A 

2017 

Yes 

Ecology
ISSN: 0012-9658
EISSN: 1920-2005 

98 

1 

5-11 

English 

28052385 

10.1002/ecy.1635 

WOS:000391862900001 

Saprotrophic fungi are the primary decomposers of plant litter in temperate forests, and their activity is critical for carbon (C) and nitrogen (N) cycling. Simulated atmospheric N deposition is associated with reduced fungal biomass, shifts in fungal community structure, slowed litter decay, and soil C accumulation. Although rarely studied, N deposition may also result in novel selective pressures on fungi, affecting evolutionary trajectories. To directly test if long-term N enrichment reshapes fungal responses to N, we isolated decomposer fungi from a long-term (28 yr) N-addition experiment and used a common garden approach to compare growth rates and decay abilities of isolates from control and N-amended plots. Both growth and decay were significantly altered by long-term exposure to N enrichment. Changes in growth rates were idiosyncratic, as different species grew either more quickly or more slowly after exposure to N, but litter decay by N isolates was consistent and generally lower compared to control isolates of the same species, a response not readily reversed when N isolates were grown in control (low N) environments. Changes in fungal responses accompany and perhaps drive previously observed N-induced shifts in fungal diversity, community composition, and litter decay dynamics.