Effects of sand burial disturbance on establishment of three desert shrub species in the margin of oasis in northwestern China

Abstract

AbstractSand burial is an important environmental disturbance which determines seed germination, plant establishment, and plant fitness in sand dune ecosystems. But the critical importance of sand burial for seedling establishment of desert shrubs is rarely explored. We investigated the effects of sand burial at different regimes (0, 1, 2, 3, 4 and 5 cm, the main depths of soil seed bank) on the seedling emergence, growth and survival rate of three dominant desert shrubs (Calligonum mongolicum, Nitraria sphaerocarpa and Haloxylon ammodendron) for ecosystem restoration in sand dunes of northwestern China. The results indicated that shallow burial improved the seedling emergence and the subsequent seedling survival rate for the initial establishment period. The optimal burial depths were 2, 4 and 5 cm for H. ammodendron, N. sphaerocarpa and C. mongolicum, respectively; this difference in optimal burial depth may account for observed decreased regeneration of H. ammodendron as compared to the other two species. Beyond the optimal depths, we found that sand burial prevented seedling emergence for H. ammodendron and N. sphaerocarpa. Only a small proportion of seedlings can emerged from deep burial depth by increasing seedling biomass allocation to blow‐ground stem. However, after emergence deep sand burial stimulated growth rate of emerged seedlings, increased the seedling vigor and promoted the seedling establishment. We suggest that sand burial could affect plant regeneration and potentially leaded to shift in species composition. Choice of suitable species for ecosystem restoration needs to account for its ability in term of seed germination and plant establishment/regeneration to adapt to disturbance of sand burial.