Water heterogeneous affects water storage in two rhizomatous clonal plants Leymus secalinus and Calamagrostis pseudophragmites

Abstract

Aims Essential resources for plant growth are heterogeneously distributed in natural systems, and clonal plants can efficiently use heterogeneously distributed resources. Many studies have addressed effects of heterogeneous water supply on the growth, morphology and physiology of clonal plants, but few have tested effects of water heterogeneity on the ability of clonal plants to store water. Methods We grew ramets of two rhizomatous clonal plants Leymus secalinus and Calamagrostis pseudophrag- mites under both homogeneous and heterogeneous water supply. The experiment was conducted from 15 August to 14 October 2010 under a rain shelter at Ordos Sandland Ecological Station (39°29′ N, 110°11′ E). Water content and biomass of roots, shoots, spacers (rhizomes) and buds were measured. Important findings Spacer water content, shoot water content and root water content were significantly higher under the heterogeneous water condition than under the homogeneous water condition in both species, suggesting that clonal plants could increase the ability to store water when growing in heterogeneous water conditions. Leymus secalinus decreased single ramet biomass and increased bud number to adapt to water heterogeneity, while C. pseudophragmites increased belowground biomass, including rhizome biomass, root biomass and bud biomass, to deal with water heterogeneity. Increasing water storage may increase the ability of clonal plants to adapt to unpredictable water conditions.