Simultaneously reducing the intensity and increasing the frequency of sand movements promotes the performance of Artemisia ordosica seedlings in dune environments

Windblown sand movements, i.e., wind denudation and sand burial, pose a strong selective pressure on dune vegetation. Dune plants commonly receive repeated wind denudation or sand burial. Therefore, simultaneously examining the role of sand movement intensity and frequency in shaping dune vegetation is critical for dune biodiversity conservation and ecological restoration. However, studies of this nature are rare.

We studied the integrated effects of sand movement intensity and frequency on the seedling performance of a dominant semi-shrub, Artemisia ordosica, in the Mu Us sandland. We subjected A. ordosica seedlings to a total intensity of 10 cm wind denudation or sand burial treatments conducted once, twice or four times.

We found, given that the total intensity of sand movement remains the same, increasing frequency and decreasing intensity per time largely improved seedling survival. Furthermore, increasing frequency and decreasing intensity per time significantly alleviated the negative effects of wind denudation, although such alleviation effect was not detected for sand burial. Seedlings of A. ordosica increased specific leaf area, root length, and biomass allocation to root to adapt to wind denudation, while they developed adventitious roots to adapt to sand burial.

Our results demonstrate that a single heavy sand movement is more detrimental than multiple light ones to the performance of A. ordosica seedlings. Our findings suggest that windproof measures to prevent severe sand movements is necessary to allow the establishment of A. ordosica during the dune restoration process.