Responses of leaf functional traits of different grassland plants to desertification and their adaptation strategies.

We examined the responses of leaf functional traits and their adaptation strategies of four dominant species (Lespedeza davurica, Carex duriuscula, Potentilla chinensis, and Cleistogenes chinensis) to desertification in the Zhanggutai desertified grassland, Liaoning Province. We measured the morphological and chemical functional traits under five desertification levels (0%, 10%, 30%, 50%, and 70% of sand addition by mass). The results showed that desertification significantly affected leaf functional traits in the natural grasslands of northwestern Liao-ning, but with significant species-specific difference. With the increases of desertification intensity, specific leaf area of C. duriuscula and P. chinensis increased initially and then decreased, peaking at 30% and 10% sand addition levels, respectively. Leaf dry matter content of the four species all showed a decreasing trend with aggravated desertification, but the changes were not statistically significant. Desertification significantly increased leaf N and P contents of C. duriuscula and C. chinensis, with N content being increased by 45.8% and 28.2%, and P content being increased by 87.1% and 50.3%, respectively under 70% sand addition treatment. The four species adapted to desertification through trade-offs among morphological and chemical traits. P. chinensis exhibited a "low-input, high-benefit" resource-conservative strategy. L. davurica maintained relatively stable leaf nutrient content. Both species exhibited a relatively strong adaptability to desertification.