Grassland gap effects on Elymus dahuricus Turcz. seedling emergence, survival and growth

The influence of gaps in degraded semi-arid steppe grassland in northern China on the establishment of Elymus dahuricus seeds sown for the restoration purpose was investigated. There were seven treatments: no gap (control; CK), shoot and shoot + root gaps each with diameters of 10, 20 and 40 cm. Shoot gaps were formed by removing above- and below-ground biomasses without restricting the re-growth of roots and rhizomes back into the gap, and shoot + root gaps were formed by barriers restricting root and rhizomes extension back into the gaps. Seedling emergence, survival and growth after 85 days of seed sowing were recorded. Increase in the size of gaps increased soil temperature and moisture especially for the shoot + root gaps. Survival and size of seedlings followed a similar response pattern. It was concluded that creating gaps, particularly larger root gaps, would assist seedling establishment to restore degraded grassland.

► Increasing the size of gaps increased soil temperature and moisture especially for the shoot + root gaps.
► The survival percentage and size of seedlings followed a similar response pattern.
► In degraded grassland restoration process, creating appropriate gaps would assist successful seedling establishment.