How plant production in the Mongolian grasslands is affected by wind-eroded coarse-textured topsoil

Wind erosion results in soil redistribution and textural changes on topsoil. There is little information about how these changes affect plant production. Here, we compared simulations of vegetation growth between a wind-eroded scenario and an actual condition at two sites in Mongolian grasslands (steppe and desert steppe) using an ecosystem model. The wind-eroded scenario, topsoil (0–0.1 m depth) with 1% clay and 99% sand, was designed to represent an extremely wind-eroded soil surface that had permanently lost the fine particles and gained sand particles. Effects of temperature, nutrient, and water stresses on vegetation were quantitatively estimated. The model gave reasonably good simulations of the vegetation and soil water dynamics. Results show that water had more effect on plant production than nitrogen and temperature. In the wind-eroded scenario, stresses because of a lack of water and nutrients affected plant production. For the wind-eroded topsoil, plant production decreased (20.2%) in the desert steppe with increasing water stress, but it was slightly increased (5.0%) in the wetter steppe because of an inverse texture effect, where water infiltrates from the coarse topsoil to the deeper root-zone due to lower soil evapotranspiration and facilitates growth. Plant growth was, therefore, affected by the nitrogen supply.