Abstract: Photovoltaic power station mainly changes soil temperature and moisture and illumination condition, with consequences on vegetation growth and distribution. We investigated the height and density of seven plant species in different microhabitat areas and their relationship with environmental factors at a small experimental photovoltaic power station in Xining. Plant height between the interval areas of photovoltaic arrays and the areas was higher than that below photovoltaic arrays (P<0.05). From the front end of the photovoltaic array to the front end of the other, plant height changed periodically, which first decreased and then increased, and the lowest was between the front end and the middle end of the arrays. Bryophytes were only distributed in the middle of the arrays. Medicago sativa L. was distributed only in the interval of the arrays. Elsholtzia ciliata(Thunb.) Hyland. was distributed only in the five areas below the arrays. The plant density at the front end and the back end of the arrays was significantly lower than that of other areas (P<0.05). Soil moisture and temperature in the photovoltaic power station were the main positive factors affecting plant density, while the illumination intensity was the main positive factor affecting plant height. The photovoltaic arrays made plant growth and distribution in the station area tend to be regular, by reducing soil moisture and increasing soil temperature, reducing plant height and density and improving species richness.

Key words: photovoltaic array, plant height, distribution density, soil temperature, soil moisture.