Wardle DA (1992) A comparative assessment of factors which influence microbial biomass carbon
and nitrogen levels in soil. Biol Rev 67:321–358
Wardle DA, Walker LR, Bardgett RD (2004) Ecosystem properties and forest decline in contrasting
long-term chronosequences. Science 305:509–513
Weintraub S, Wieder W, Cleveland C et al (2013) Organic matter inputs shift soil enzyme activity
and allocation patterns in a wet tropical forest. Biogeochemistry 114:313–326
Wright RF, Rasmussen L (1998) Introduction to the NITREX and EXMAN projects. For Ecol
Manag 101:1–7
Wu J, Liu W, Fan H et al (2013) Asynchronous responses of soil microbial community and
understory plant community to simulated nitrogen deposition in a subtropical forest. Ecol
Evol 3(11):3895–3905
Wu J, Duan H, Liu W et al (2017) Individual size but not additional nitrogen regulates tree carbon
sequestration in a subtropical forest. Sci Rep 7:46293
Xu M, Cheng S, Fang H et al (2013) Low-level nitrogen addition promotes net methane uptake in a
boreal forest across the great Xing’an mountain region, China. For Sci 60(5):973–981
Xu Z, Yu G, Zhang X et al (2017) Soil enzyme activity and stoichiometry in forest ecosystems
along the North-South Transect in eastern China (NSTEC). Soil Biol Biochem 104:152–163
Yan G, Xing Y, Wang J et al (2018) Sequestration of atmospheric CO 2 in boreal forest carbon pools
in Northeastern China: effects of nitrogen deposition. Agric For Meteorol 248:70–81
Yang K, Zhu J, Gu J et al (2015) Changes in soil phosphorus fractions after 9 years of continuous
nitrogen addition in a Larix gmelinii plantation. Ann For Sci 72:435–442
Yang X, Wang C, Xu K (2017) Response of soil CH fluxes to stimulated nitrogen deposition in a
temperate deciduous forest in northern China: a 5-year nitrogen addition experiment. Eur J Soil
Biol 82:43–49
Yao F, Chen Y, Yan Z et al (2015) Biogeographic patterns of structural traits and C: N: P
stoichiometry of tree twigs in China’s forests. PLoS One 10:e0116391
Yu Q, Zhang T, Cheng Z et al (2017) Is surface water acidification a serious regional issue in China?
Sci Total Environ 584:783–790
Zhang W, Mo J, Zhou G et al (2008) Methane uptake responses to nitrogen deposition in three
tropical forests in southern China. J Geophys Res-Atmos 113:D11116
Zhang J, Zhu T, Cai Z et al (2011a) Nitrogen cycling in forest soils across climate gradients in
Eastern China. Plant Soil 342:419–432
Zhang T, Zhu W, Mo J et al (2011b) Increased phosphorus availability mitigates the inhibition of
nitrogen deposition on CH 4 uptake in an old-growth tropical forest, southern China.
Biogeosciences 8:2805–2813
Zhang J, Cai Z, Zhu T et al (2013) Mechanisms for the retention of inorganic N in acidic forest soils
of southern China. Sci Rep 3:2342
Zhang W, Zhu X, Luo Y et al (2014) Responses of nitrous oxide emissions to nitrogen and
phosphorus additions in two tropical plantations with N-fixing vs non-N-fixing tree species.
Biogeosciences 11:4941–4951
Zhang W, Shen W, Zhu S et al (2015) Can canopy addition of nitrogen better illustrate the effect of
atmospheric nitrogen deposition on forest ecosystem? Sci Rep 5:11245
Zhao D, Sun B (1986) Air-pollution and acid-rain in China. Ambio 15:2–5
Zhao Y, Duan L, Xing J et al (2009) Soil acidification in China: is controlling SO 2 emissions
enough? Environ Sci Technol 43:8021–8026
Zhao C, Zhu L, Liang J et al (2014) Effects of experimental warming and nitrogen fertilization on
soil microbial communities and processes of two subalpine coniferous species in Eastern
Tibetan Plateau, China. Plant Soil 382:189–201
Zheng M, Zhang T, Liu L et al (2016) Effects of nitrogen and phosphorus additions on nitrous oxide
emission in a nitrogen-rich and two nitrogen-limited tropical forests. Biogeosciences
13:3503–3517
Zhou W, Ji H, Zhu J et al (2016) The effects of nitrogen fertilization on N 2 O emissions from a
rubber plantation. Sci Rep 6:28230
212
E. Du et al.
and nitrogen levels in soil. Biol Rev 67:321–358
Wardle DA, Walker LR, Bardgett RD (2004) Ecosystem properties and forest decline in contrasting
long-term chronosequences. Science 305:509–513
Weintraub S, Wieder W, Cleveland C et al (2013) Organic matter inputs shift soil enzyme activity
and allocation patterns in a wet tropical forest. Biogeochemistry 114:313–326
Wright RF, Rasmussen L (1998) Introduction to the NITREX and EXMAN projects. For Ecol
Manag 101:1–7
Wu J, Liu W, Fan H et al (2013) Asynchronous responses of soil microbial community and
understory plant community to simulated nitrogen deposition in a subtropical forest. Ecol
Evol 3(11):3895–3905
Wu J, Duan H, Liu W et al (2017) Individual size but not additional nitrogen regulates tree carbon
sequestration in a subtropical forest. Sci Rep 7:46293
Xu M, Cheng S, Fang H et al (2013) Low-level nitrogen addition promotes net methane uptake in a
boreal forest across the great Xing’an mountain region, China. For Sci 60(5):973–981
Xu Z, Yu G, Zhang X et al (2017) Soil enzyme activity and stoichiometry in forest ecosystems
along the North-South Transect in eastern China (NSTEC). Soil Biol Biochem 104:152–163
Yan G, Xing Y, Wang J et al (2018) Sequestration of atmospheric CO 2 in boreal forest carbon pools
in Northeastern China: effects of nitrogen deposition. Agric For Meteorol 248:70–81
Yang K, Zhu J, Gu J et al (2015) Changes in soil phosphorus fractions after 9 years of continuous
nitrogen addition in a Larix gmelinii plantation. Ann For Sci 72:435–442
Yang X, Wang C, Xu K (2017) Response of soil CH fluxes to stimulated nitrogen deposition in a
temperate deciduous forest in northern China: a 5-year nitrogen addition experiment. Eur J Soil
Biol 82:43–49
Yao F, Chen Y, Yan Z et al (2015) Biogeographic patterns of structural traits and C: N: P
stoichiometry of tree twigs in China’s forests. PLoS One 10:e0116391
Yu Q, Zhang T, Cheng Z et al (2017) Is surface water acidification a serious regional issue in China?
Sci Total Environ 584:783–790
Zhang W, Mo J, Zhou G et al (2008) Methane uptake responses to nitrogen deposition in three
tropical forests in southern China. J Geophys Res-Atmos 113:D11116
Zhang J, Zhu T, Cai Z et al (2011a) Nitrogen cycling in forest soils across climate gradients in
Eastern China. Plant Soil 342:419–432
Zhang T, Zhu W, Mo J et al (2011b) Increased phosphorus availability mitigates the inhibition of
nitrogen deposition on CH 4 uptake in an old-growth tropical forest, southern China.
Biogeosciences 8:2805–2813
Zhang J, Cai Z, Zhu T et al (2013) Mechanisms for the retention of inorganic N in acidic forest soils
of southern China. Sci Rep 3:2342
Zhang W, Zhu X, Luo Y et al (2014) Responses of nitrous oxide emissions to nitrogen and
phosphorus additions in two tropical plantations with N-fixing vs non-N-fixing tree species.
Biogeosciences 11:4941–4951
Zhang W, Shen W, Zhu S et al (2015) Can canopy addition of nitrogen better illustrate the effect of
atmospheric nitrogen deposition on forest ecosystem? Sci Rep 5:11245
Zhao D, Sun B (1986) Air-pollution and acid-rain in China. Ambio 15:2–5
Zhao Y, Duan L, Xing J et al (2009) Soil acidification in China: is controlling SO 2 emissions
enough? Environ Sci Technol 43:8021–8026
Zhao C, Zhu L, Liang J et al (2014) Effects of experimental warming and nitrogen fertilization on
soil microbial communities and processes of two subalpine coniferous species in Eastern
Tibetan Plateau, China. Plant Soil 382:189–201
Zheng M, Zhang T, Liu L et al (2016) Effects of nitrogen and phosphorus additions on nitrous oxide
emission in a nitrogen-rich and two nitrogen-limited tropical forests. Biogeosciences
13:3503–3517
Zhou W, Ji H, Zhu J et al (2016) The effects of nitrogen fertilization on N 2 O emissions from a
rubber plantation. Sci Rep 6:28230
212
E. Du et al.