Plant functional traits of Dasiphora fruticosa shrub have a stronger response to soil properties in Qinghai-Tibet Plateau, China

Dasiphora fruticosa widely distributes in subalpine and alpine regions in the world, and is originated from Qinghai-Tibet Plateau. Further exploration of influence of environmental factors on plant functional traits of Dasiphora fruticosa in Qinghai-Tibet Plateau is essential to predict the growth and distribution under climate change more accurately. The Dasiphora fruticosa shrub on 24 plots were sampled at the altitude gradient of 2550-5200 meters above sea level on Qinghai-Tibet Plateau. Totally 13 plant functional traits of Dasiphora fruticosa were measured, including morphological traits (plant height, crown width, specific leaf area and leaf dry matter content) and stoichiometric traits (carbon, nitrogen and phosphorus content in leaves, flowers and stems). The results showed that morphological traits of Dasiphora fruticosa changed significantly along altitude. With the increase of altitude, plant height and crown width tended to be shorter. Leaf dry matter content also decreased along altitude. The stoichiometric traits varied along altitude, and were different in organs. Specifically, the phosphorus content in organs increased significantly along altitude. The morphological traits had large coefficient of variation. Soil properties were the main drivers of most of plant functional traits. Soil properties significantly directly affected the morphological traits and carbon and phosphorus contents while mean annual precipitation significantly indirectly affected them by affecting soil nutrients. Dasiphora fruticosa adapts to diverse habitats by adjusting its morphological traits and phosphorus content in organs. Soil properties have a stronger influence and act as a direct filter on plant functional traits of Dasiphora fruticosa in alpine regions.