TY - JOUR

T1 - Litter decomposition in European coniferous and broadleaf forests under experimentally elevated acidity and nitrogen addition

AU - Růžek, Michal

AU - Tahovská, Karolina

AU - Guggenberger, Georg

AU - Oulehle, Filip

N1 - Funding Information: The authors would like to thank Kateřina Zajícová and Oldřich Myška for their help with the field work and Leopold Sauheitl for providing us access to the CuO oxidation method. We thank Fred Rooks for proofreading. The authors have no relevant financial or non-financial interests to disclose. This study was supported by the Grant Agency of Charles University [GAUK506718] and by the Faculty of Science foundation. Filip Oulehle and Karolina Tahovská acknowledge Czech Science Foundation project 20-19471 S for long-term support of biogeochemical research.

PY - 2021/6

Y1 - 2021/6

N2 - Background: Atmospheric sulfur (S) and nitrogen (N) deposition has impacted many regions across the Northern Hemisphere inducing acidification and eutrophication of terrestrial ecosystems. However, acidification and eutrophication processes may differently impact litter decomposition and thus soil carbon (C) dynamics. Methods: We performed a field soil chemistry manipulation in two mountainous temperate forest stands (Picea abies and Fagus sylvatica) historically affected by acid (S and N) deposition. In each stand, four treatments were established: control, acid addition (H2SO4 – 50 kg S·ha− 1·year− 1), N addition (NH4NO3 – 50 kg N·ha− 1·year− 1) and their combination. In fourth year of manipulation, we established litter decomposition experiment. Litter bags of contrasting quality and origin (green tea, rooibos tea, spruce needles and beech leaves), in total 1536 samples, were buried below the organic layer and left to decompose up to 24 months. Retrieved samples were analysed for mass loss, C/N, and concentration of CuO oxidation lignin. Data were complemented by monitoring soil water pH and soil CO2 efflux. Results: Acid additions decreased soil water pH, soil respiration and suppressed decomposition of the high-quality litter (green tea) in both stands, whereas mass loss of remaining litter was reduced only in the spruce stand. Nitrogen treatments, when coupled with decreasing soil water pH, constrained needle decomposition in the naturally more acidic spruce stand. Conclusions: Our study demonstrates a suppressing effect of soil acidity on decomposition processes and soil C dynamics. The effect of N addition, as a nutrient, was insignificant, likely because of previous ecosystem adaptation to historical N loadings.

AB - Background: Atmospheric sulfur (S) and nitrogen (N) deposition has impacted many regions across the Northern Hemisphere inducing acidification and eutrophication of terrestrial ecosystems. However, acidification and eutrophication processes may differently impact litter decomposition and thus soil carbon (C) dynamics. Methods: We performed a field soil chemistry manipulation in two mountainous temperate forest stands (Picea abies and Fagus sylvatica) historically affected by acid (S and N) deposition. In each stand, four treatments were established: control, acid addition (H2SO4 – 50 kg S·ha− 1·year− 1), N addition (NH4NO3 – 50 kg N·ha− 1·year− 1) and their combination. In fourth year of manipulation, we established litter decomposition experiment. Litter bags of contrasting quality and origin (green tea, rooibos tea, spruce needles and beech leaves), in total 1536 samples, were buried below the organic layer and left to decompose up to 24 months. Retrieved samples were analysed for mass loss, C/N, and concentration of CuO oxidation lignin. Data were complemented by monitoring soil water pH and soil CO2 efflux. Results: Acid additions decreased soil water pH, soil respiration and suppressed decomposition of the high-quality litter (green tea) in both stands, whereas mass loss of remaining litter was reduced only in the spruce stand. Nitrogen treatments, when coupled with decreasing soil water pH, constrained needle decomposition in the naturally more acidic spruce stand. Conclusions: Our study demonstrates a suppressing effect of soil acidity on decomposition processes and soil C dynamics. The effect of N addition, as a nutrient, was insignificant, likely because of previous ecosystem adaptation to historical N loadings.

KW - Acidity

KW - European beech

KW - Litter decomposition

KW - Nitrogen addition

KW - Norway spruce

KW - Tea bag initiative

UR - http://www.scopus.com/inward/record.url?scp=85103394550&partnerID=8YFLogxK

U2 - 10.1007/s11104-021-04926-9

DO - 10.1007/s11104-021-04926-9

M3 - Article

AN - SCOPUS:85103394550

VL - 463

SP - 471

EP - 485

JO - Plant and soil

JF - Plant and soil

SN - 0032-079X

IS - 1-2

ER -