REGULAR ARTICLE The legacy of climate change effects: previous drought increases short-term litter decomposition rates in a temperate mixed grass- and shrubland Merian Skouw Haugwitz & Anders Michelsen & Anders Priemé Received: 7 August 2015 /Accepted: 3 May 2016 # Springer International Publishing Switzerland 2016 Abstract Aims Fungi play a central role in litter decomposition, a key process controlling the terrestrial carbon cycle and nutrient availability for plants and microorganisms. Climate change and elevated CO 2 affect soil fungi, but the relative importance of the global change variables for litter decomposition is still uncertain. The main objective was therefore to assess the short-term litter decomposition and associated fungal community in a global change manipulated temperate heath ecosystem. Methods The heath had been exposed to 6 years of warming, elevated atmospheric CO 2 and an extended pre-summer drought. Litterbags with litter from heather (Calluna vulgaris) and wavy-hair grass (Deschampsia flexuosa) were incubated in the litter layer for 6 months, where after we analyzed the litter-associated fungal community, litter loss, CO 2 respiration, and total content of carbon, nitrogen and phosphorus. Results Elevated temperature tended to increase litter decomposition rates, whereas elevated CO 2 had no ef- fect on the process. The pre-summer drought treatment had a positive impact on litter decomposition, CO 2 respiration and fungal abundance in the litterbags, al- though we observed no major changes in fungal com- munity composition. Conclusions The drought treatment during pre-summer had a legacy effect on litter decomposition as decompo- sition rates were positively affected later in the year. The community structure of litter-decomposing fungi was not affected by the drought treatment. Hence, the legacy effect was not mediated by a change in the fungal community structure. Keywords Drought . Elevated atmospheric CO 2 . Increasedtemperature . Fungal community composition . Litter degradation . Litter mass loss Introduction Litter decomposition is a key process in the terrestrial ecosystem carbon cycle and controls nutrient availabil- ity for plants and microorganisms. In terrestrial ecosys- tems, fungi play a central role in litter decomposition Plant Soil DOI 10.1007/s11104-016-2913-2 Responsible Editor: Duncan D. Cameron. Electronic supplementary material The online version of this article (doi:10.1007/s11104-016-2913-2) contains supplementary material, which is available to authorized users. M. S. Haugwitz : A. Michelsen Terrestrial Ecology Section, Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark M. S. Haugwitz : A. Priemé (*) Section of Microbiology, Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen Ø, Denmark e-mail: aprieme@bio.ku.dk Present Address: M. S. Haugwitz Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, 1350 Copenhagen K, Denmark