Effects of nitrogen addition and mowing on nitrogen- and water-use efficiency of <i>Artemisia frigida</i> in a grassland restored from an abandoned cropland

Abstract Aims Competition among plants in a community usually depends on their nitrogen (N)-use efficiency (NUE) and water-use (WUE) arid semi-arid regions. Artemisia frigida is an indicator species heavily degraded grassland, however, how its NUE WUE respond to N addition different successional stages still unclear, especially with mowing, common management practice grasslands. Methods Based long-term controlled experiment mowing abandoned cropland from 2006 2013, we investigated the of A. two patches (i.e. grass herb patches) 2013 which represented potential communities. The coverage was higher (about 50%) patch than 10%). Stable isotopic C (δ 13C) 15N) as well pools were measured soils. calculated leaf C/N, δ 13C values used proxy for WUE. Important Findings did not affect frigida, but significantly decreased by 42.9% 26.6% patches, respectively. response related altering utilization sources (NH4+vs. NO3−) according changed relationship between 15N/soil 15N NUE. Mowing had no effect regardless addition, increased 2.3% without patch. reduced positive Our results suggested that and/or under could reduce competition, further accelerate restoration succession natural grassland region.