Effects of direct seeding of four native species for reclamation of mined land in the cold desert of Xinjiang in northwest China

Abstract

Direct seeding is a more cost-effective method for plant community restoration than transplanting pot-grown plants, but this method is not applicable to all plant species and all regions. To evaluate the effectiveness of direct seeding to restore mined cold desert vegetation without irrigation, Atraphaxis frutescens (L.) Ewersm., Calligonum junceum (Fisch. et Mey.) Litv., Peganum harmala L., and Seriphydium gracilescens (Krasch. et Iljin) Poljak. were directly sown in the bottom of dry furrows and on a flat site in the mined wasteland before the second snowfall in late autumn. Seedling emergence, survival, and growth were monitored for 3 years. For the four species, cumulative seed germination in the furrows ranged from 6.4 to 23.6% and the highest germination was 23.0 and 23.6% for A. frutescens and C. junceum, respectively. Survival at the end of 3 years was 7.0–56.1% for the four species. In the flat area, cumulative seedling emergence for C. junceum, A. frutescens, P. harmala, and S. gracilescens was 0, 0, 0.7, and 1.4%, respectively, and all seedlings died with the onset of drought. Thus, under natural precipitation conditions, the success of direct seeding depends on the microsite and species. We conclude that direct seeding can be an effective method for establishing the shrubs A. frutescens and C. junceum in mined wasteland if seeds are sown in furrows that have been created across the landscape.