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Plants that grow in dune ecosystems always suffer from sand burial. Shrubs play implications on the healthy functioning of dune ecosystems due to control blowing sand. However, the survival and growth responses of shrubs to sand burial remain poorly understood. The survival rate and seedling height of two shrubs (Artemisia halodendron and Lespedeza davurica) along with the soil properties under different burial depths were examined in order to reveal the causing ecophysiological attributes of sand burial on shrubs in the desertified region. It was found that A. halodendron can survive a burial depth of 6 cm greater than its seedling height, which is a dominant shrub in mobile dunes with intense burial, whereas a burial depth equivalent to three fourths of its seedling height is detrimental to L. davurica, which is dominant in fixed dunes with less burial. The reasons for the shrub death under sand burial were associated with the physical barrier to vertical growth and the reduction in photosynthetic area. In conclusion, A. halodendron can facilitate the stabilization of mobile dunes because of their high tolerance to the frequent and intensive sand burial, while L. davurica can be beneficial for the recovery process because of their higher survival rates under shallow burial following restoration of mobile dunes.

Invasive species are a global threat to biodiversity and the functioning of natural ecosystems. Here, we report on a two-year experiment aimed at elucidating the combined and relative effects of three key controls on plant invasions: propagule supply, soil nitrogen (N) availability, and herbivory by native insects. We focus on the exotic species Lespedeza cuneata, a Rank 1 invasive species. Propagule supply and soil N-availability interacted to control the density and foliar cover of L. cuneata. In low N plots, density and foliar cover of L. cuneata were higher in the propagule addition plots than in the plots to which propagules were not added. Surprisingly, this interaction was significant only when the abundance of herbivores was experimentally reduced. This experiment provides evidence that native insect herbivores mediate the interactive effects of propagule supply and resources on invasion by a widespread invasive plant species.

The water physio-ecological index and photosynthetic rate of four plant species, Caragana microphylla, Amorpha fruticosa, Artemish halodendron, and Lespedeza bicolor, in kerqin sandy land were determined. The results showed that C. microphylla has the lowest leaf water potential and the highest water-maintainance, bound water/free water ratio, and water utilization efficiency. Its drought-resistance is the strongest. Amorpha fruticosa was contrary to Caragana microphylla, and its drought-resistance was the weakest. Artemish halodendrona had a high leaf water potential, but its water-maintainance, bound water/free water ratio, and water utilization efficiency were very high. Its drought-resistance was stronger. Lespedeza bicolar had a lower leaf water potential and water-maintainance, and a usual bound water/free water ratio, and water utilization efficiency. Its drought-resistance was stronger than Amorpha fruticosa's, but weaker than Artemish halodendron's.