Chronic wind and plant communities in dunes: Total biomass, inter-specific competition, and species abundance

Chronic wind is an important ecological factor, but its direct roles in shaping plant communities remain poorly understood. We hypothesized that chronic wind can modulate community productivity, inter-specific competition, and species abundance in inland dunes. We conducted an experiment with three shrubs (Artemisia ordosica, Caragana intermedia, and Hedysarum laeve) common to semi-arid sandlands, set up seven kinds of plant communities (i.e. Artemisia monoculture, Caragana monoculture, Hedysarum monoculture, Artemisia–Caragana mixture, Artemisia–Hedysarum mixture, Caragana–Hedysarum mixture, and Artemisia–Caragana–Hedysarum mixture), and communities subjected to two levels of wind exposure: shielded (by means of fencing) or exposed (no fencing). We measured total biomass per plot, competitive effects, and relative species abundance. Wind exposure did not significantly affect the total biomass of monocultures but increased their root weight ratio. However, wind exposure enhanced the total biomass of three-species mixtures but not two-species mixtures, and had no effects on root weight ratio of all mixtures. Wind exposed condition increased the competitive ability and relative abundance of Artemisia, decreased the competitive ability of Hedysarum but had no effects on its abundance, and did not affect the competitive ability of Caragana but decreased its abundance. These results suggest that chronic wind, as an environmental filter, can directly modulate plant communities through altering competitive outcomes and thus affect community functioning