Mowing exacerbates the loss of ecosystem stability under nitrogen enrichment in a temperate grassland
作 者：Zhang, YH; Loreau, M; He, NP; Zhang, GM; Han, XG
卷 期 号：31(8)
1. Global reactive nitrogen (N) is projected to further increase in the coming years. Previous
studies have demonstrated that N enrichment weakens the temporal stability of the ecosystem
and the primary productivity through decreased biodiversity and species asynchrony. Mowing
is a globally common practise in grasslands; and infrequent mowing can maintain or increase
plant diversity under N enrichment conditions. However, it is unclear how infrequent mowing
affects ecosystem stability in the face of N enrichment.
2. By independently manipulating the frequency (twice vs. monthly additions per year) and
rate (i.e. 0, 1, 2, 3, 5, 10, 15, 20, and 50 g N m2 year1) of NH4NO3 inputs and mowing
(unmown vs. mown) over 3 years (2011–2013) in a temperate grassland of northern China, we
aimed to examine the interactive effects of N enrichment and mowing on ecosystem stability.
3. The results show that mowing maintained a positive relationship between species richness
and ecosystem stability despite N addition, but that it exacerbated the negative effects of N
addition on ecosystem stability. Mowing increased mean primary productivity and plant
species richness, but it also increased the synchrony of population fluctuations and the variability
of primary productivity under N enrichment, thereby contributing to a decline in the
4. Thus, our study reveals that infrequent mowing can buffer the negative effects of N enrichment
on biodiversity to some extent and further increase the primary productivity, but it exacerbates
the loss of ecosystem stability with N enrichment, thereby threatening local and/or
semiarid regional food security.