Effects of soil biodiversity on nutrients and water used by plants Tufted Hairgrass (Deschampsia caespitosa) Exhibits a Lower Photosynthetic Plasticity than Antarctic Hairgrass (D. antarctica) The changes of water-use efficiency and stoma density of Leymus chinensis along Northeast China Transect EFFECT OF GROWTH IRRADIANCE ON STABLE CARBON ISOTOPE RATIO, INTERCELLULAR COsub>2 CONCENTRATION AND WATER-USE EFFICIENCY OF TWO WOODY PLANT IN SUBTROPICAL NATURAL FOREST Relationship between temperature and δ13C values of C3 herbaceous plants and its implications of WUE in farming-pastoral zone in North China