The responses of seed germination, seedling emergence and seedling growth in Agropyron cristatum to sand water content in Otindag Sandland, China
浑善达克沙地冰草种子萌发、出苗和幼苗生长对土壤水分的反应

Agropyron cristatum (L.) Gaertn is a dominant perennial grass in Otindag Sandland, China. The survival and distribution of A. cristatum mainly depends on the mechanisms ensuring germination and seedling development at the right time and in a suitable place. We investigated the sand water content from April to October in Otindag Sandland and the responses of seed germination, seedling emergence and seedling growth in A. cristatum to sand water content (1, 2, 3, 4, 6, 8, 12, 16 and 20%). Results showed that the sand water content from the last ten-day of April to the first twenty-day of May was critical to seed germination, seedling emergence and seedling settlement in A. cristatum. The optimal sand water content for seed germination and seedling emergence in A. cristatum was 12 to 20%. The optimal sand water content for A. cristatum's seedling development was 12%. When sand water content was under 3%, seed could not germinate; when sand water content was under 6%, seedling could not emerge and settle. When sand water was 16 and 20%, biomass decreased a little. At 6 to 8%, seedling allocated more biomass to root.