2015 INTERNATIONAL SYMPOSIUM ON FOREST SOILS
Alpine meadow restorations by non-dominant species increased
soil nitrogen transformation rates but decreased
their sensitivity to warming
Received: 1 December 2015 /Accepted: 17 June 2016 /Published online: 29 June 2016
Purpose Alpine meadow soils are large carbon (C) and nitro-
gen (N) pools correlated significantly with global C and N
cycling. Soil N transformations, including nitrification and N
mineralization, are key processes controlling N availability.
Alpine meadow degradations are common worldwide, and
vegetation restorations have been widely implemented.
However, grass species used for restorations may alter
soil N transformations or their response to warming and
N deposition due to divergent plant traits and their different
effects on soil characteristic. To understand the effects of
meadow restorations by non-historically dominant species
on N transformations, we measured N transformation rates
in restored soils and control soils under the context of
warming and N deposition.
Materials and methods We collected soils from plots restored
by dominant (Miscanthus floridulus) and non-dominant spe-
cies (including Carex chinensis and Fimbristylis dichotoma)
and non-restored plots in alpine meadows of Wugong
Mountain, China. We measured nitrification and N minerali-
zation rates when soils were incubated at different temperature
(15 or 25 °C) and N additions (control vs. 4 g m
their responses to restoration species, warming, and N.
Results and discussion Vegetation restored soils differed sub-
stantially from non-restored bare soils. Total N, total organic
C, pH, and dissolved organic C contributed the most to the
separation. Restoration altered soil N transformations substan-
tially, even though the effects varied among restoration spe-
cies. Specifically, non-historically dominant species accelerat-
ed N transformations, while the originally dominant species
decreased N transformations. In addition, sensitivity of nitri-
fication to warming in restored soils was decreased by resto-
rations. Soils restored by originally dominant species were
higher in sensitivity of N transformations to warming than
those restored by the other two species. Warming increased
nitrification rates by 45.5 and 17.4 % in bare soils and restored
soils, respectively. Meanwhile, N mineralization rates were
increased by 52.8 and 21.9 %, respectively.
Conclusions Vegetation restoration of the degraded meadows
impacted N transformations and their sensitivity to warming.
The effects varied with identity of the restoration species, sug-
gesting that grass species should be considered in future res-
torations of degraded meadows in terms of their divergent
effects on N transformations and sensitivity to warming.
Keywords Alpine meadow degradation
Vege ta tion
Grassland ecosystems are important components of the global
terrestrial ecosystems (Adams et al. 1990), covering
Responsible editor: Chris E. Johnson
Electronic supplementary material The online version of this article
(doi:10.1007/s11368-016-1488-0) contains supplementary material,
which is available to authorized users.
* Ling Zhang
Jiangxi Key Laboratory of Silviculture, Co-Innovation Center of
Jiangxi Typical Trees Cultivation and Utilization, College of
Forestry, Jiangxi Agricultural University, Nanchang 330045, China
Environmental Futures Research Institute, School of Natural
Sciences, Griffith University, Nathan, Brisbane, QLD 4111, Australia
College of Land Resources and Environment, Jiangxi Agricultural
University, Nanchang 330045, China
J Soils Sediments (2017) 17:2329–2337
Springer-Verlag Berlin Heidelberg 2016