FILM MULCHED CO-APPLIED WITH COMPOST IMPROVES REVEGETATION IN SAND DUNES FIXED BY CEMENT CHECKERBOARD ALONG THE QINGHAI, TIBET RAILWAY

The ever-increasing sand dunes are destroying alpine ecosystem and threating the Qinghai-Tibet Railway safety. However, sand dunes revegetation gained little success. As a part of the ongoing efforts to exploit practical revegetation techniques, we designed a comparative experiment in the sand dune that over 4560 m above sea level. Four techniques efficiency on the growth conditions (cover, height, tiller and leaf number, total root length, average root diameter, root volume, and root tips) of two indigenous grasses, Elymus breviaristatum and E. sibiricus cv. duoye, and top 30 cm soil nutrients (available potassium, phosphorus, nitrogen, and organic matter) were monitored. Biological measures comprised adding agriculture/forestryô€,± animal manure compost (compost) and sowing grasses, and engineering measures involved nonwoven fabric film (film) mulched in sand dune where established cement checkerboard barriers. Sowing, compost, and film (SCF); sowing, and compost (SC); sowing, and film (SF); and only sowing (CK) were designed in barrier zone. The results showed that SCF and SC improved edaphic and grasses growth conditions considerably, whereas SF and CK improved lightly. The amendment capacity rank was SCF > SC > SF > CK. The E. sibiricus cv. duoye grown were better than E. breviaristatum in fertile habitat while it in turned in poor soil. In conclusion, integrating engineering measures with biological measures is practical in alpine sand dunes revegetation. Plant growth and edaphic conditions are the strong indictors to monitor revegetation efficiency.