Effects of sand burial on seed germination, seedling emergence, survival, and growth of Agropyron psammophilum
Studies were conducted to determine the effects of sand burial on seed germination, seedling emergence, survival, and growth of Agropyron psammophilum. In the field, seedlings of A. psammophilum emerged from burial depths ranging from 0 to 7 cm. The mean depth of seedling emergence was 2.96 ± 1.06 (mean ± SD) cm, with more than 80% individuals emerging from 0 to 4 cm depths of sand burial. In a greenhouse, seeds of A. psammophilum were artificially buried by sand to depths of 0, 2, 4, 8, 10, and 12 cm. Higher emergence percentages were obtained at 2 and 4 cm burial depths and no seedling emerged from depths greater than 8 cm. The percent germination of buried seeds, percent emergence, and emergence rte of seedlings showed negative correlation with burial depth. Burial of young seedlings up to a depth of 6 cm stimulated their growth in height, leaf and tiller production, and overall dry weight. When the burial depth exceeded 6 cm, some seedlings died and if seedlings were buried to 100% of their height (11 cm for 1-week-old and 22 cm for 2-week-old seedlings), all seedlings died.