Abstract:To understand the effects of frequent gusts of wind on the rates of photosynthesis and transpiration in Pinus sylvestris var. mongolica seedlings, a field wind-blowing experiment using a wind speed gradient of 0 (CK), 6, 9, 12, 15, and 18 m/s and four episodes of wind blowing was conducted in the spring of 2013 in the Horqin Sand Land of Inner Mongolia. The results showed that:1) Frequent wind blowing did not change the diurnal variation in the rates of photosynthesis and transpiration in seedlings, but resulted in in an extension of midday depression and a higher degree of dormancy in photosynthesis and transpiration. 2) Increasing the wind strength led to a significant decrease in the average daily rates of photosynthesis and transpiration, with a decrease of 27.6% and 22.3% in the 18 m/s-treated seedlings compared to the CK, respectively. With an increase in wind strength, stomatal conductance and intercellular CO2 concentrations first increased and then decreased, and were significant lower in all treatment groups as compared with the CK group, with the exception of intercellular CO2 concentration, which was higher in the 18 m/s group. 3) Increasing the wind-sand flow strength led to a significant increase in water-use efficiency, except for a significant decrease in the 18 m/s treatment group as compared with the CK group. In addition, the efficiency of sunlight energy use tended to decrease except for a significant increase in the 6 m/s-treatment group as compared with the CK group. 4) Decreases in the average daily rates of photosynthesis and transpiration resulted from a decrease in stomatal conductance, and changes in water-use efficiency and sunlight energy-use efficiency resulted from changes in the rates of photosynthesis and transpiration.