Effects of sand burial on survival and growth of Artemisiahalodendron and its physiological response

There is a great deal of literature on the effects of sand burial upon the survival and growth of desert plants, but thephysiological adaption mechanisms of desert plants to sand burial have as yet rarely been studied. Artemisia halodendronis widely distributed in the semi-arid deserts of China and is a dominant species in semi-moving dune vegetation. Thegrowth and physiological properties of A. halodendron seedlings under different sand burial depths were studied in 2010and 2011 in the Horqin Sand Land, Inner Mongolia, to better understand the ability and physiological mechanism by whichdesert plants withstand sand burial. The results showed that A. halodendron as a prammophyte species had a strongerability to withstand sand burial compared to non-prammophytes, with some plants still surviving even if buried to a depthreaching 225% of seedling height. Although seedling growth was inhibited significantly once the depth of sand burialreached 50% of the seedling height, seedling survival did not decrease significantly until the burial depth exceeded 100%of the seedling height. Sand burial did not result in significant water stress or MDA (Malondialdehyde) accumulation in theseedlings, but membrane permeability increased significantly when the burial depth exceeded 100% of the seedling height.After being subjected to sand burial stress, POD (Peroxidase) activity and proline content increased significantly, but SOD(Superoxide Dismutase) and POD activities and soluble sugar content did not. The primary mechanism resulting in increasedmortality and growth inhibition were that cell membranes were damaged and photosynthetic area decreased whensubjected to the severe stress of sand burial, while proline and POD played key roles in osmotic adjustment and protectingcell membranes from damage, respectively.