Effects of soil water gradient on photosynthesis and root spatial distribution in two Trifolium repens cultivars Biodiversity of shrub community in desert steppe and steppe desert on Erdos plateau Effects of water gradient on soil enzyme activity and active organic carbon composition under Carex lasiocarpa marsh Response of super absorbent polymers under different water gradient on growth characteristics of Parthenocissus quinquefolia seedlings Photosynthetic characteristics of an endangered species Tetrameles nudiflora under different light and water conditions Photosynthetic Physio-response of Taxodium ascendens Seedlings to Different Soil Water Gradients A REVIEW OF GRADIENT CHANGES IN SPECIES DIVERSITY OF LAND PLANT COMMUNITIES Responses of Different Provenances of Nitraria tangutorum Seedlings in Photosynthetic Physiological and Growth Characteristics to Water Gradients