Biocrust-induced partitioning of soil water between grass and shrub in a desert steppe of Northwest China

Maintaining the stability of exotic sand-binding shrub has become a large challenge in arid and semi-arid grassland ecosystems northern China. We investigated two kinds shrublands with different BSCs (biological soil crusts) cover desert steppe Northwest China to characterize water sources (Caragana intermedia Kuang et H. C. Fu) grass (Artemisia scoparia Waldst. Kit.) by stable 18O isotopic. Our results showed that both were subject persistent deficiency from 2012 2017, minimum depth CV (coefficient variation) <15% SWC (soil content) <6% was 1.4 m shrubland open areas lacking obvious BSC cover, 0.8 covered mature BSCs. For intermedia, considerable proportion pointed surface soil. Water contributed averages 22.9% 17.6% total for A. scoparia, respectively. might use more rainy season than dry season, contrast scoparia. The relationship between (or grass) δ18O shown significant differences months, which partly verified potential trends relations high variability source at seasonal scale. More fine roots 0–5 cm layer could be found (8000 cm/m3) without (3200 cm/m3), ensured possibility using intermedia. result implies even under serious deficiency, can water, leading coexistence Different areas, natural withdrawal artificial will long-term process, highly competitive shrubs grasses also determines its habitat maintained drought state long time.