Vegetation patterns generated by a wind driven sand-vegetation system in arid and semi-arid areas

摘要

Wind has been proposed as a driving factor in determining vegetation patterns, but there are few dynamic models that include both vegetation and wind. In this paper, we present a dynamic model to investigate how a vegetation pattern is generated and affected by wind. In the model, the effects of prevailing wind and non-prevailing wind on sand and vegetation are modeled respectively as advection terms and diffusion terms. With these considerations and proper parameter values that satisfy Turing bifurcation conditions, labyrinth and banded vegetation patterns are obtained in two situations of wind. By changing wind transportation capacity, we simulate the adaptation process from one vegetation pattern to another. With environmental changes of large amplitude, the width of vegetationbands varies while the wavelength can increase but does not decrease in our simulation. Then we describe the difference between simulated patterns and real patterns. And in the discussion, we explain the mechanism that forming patterns and the consistency of this research with other studies. (C) 2017 Elsevier B.V. All rights reserved.