Abstract: Wild plants can be served as potential sources of bio-fuel production. We determined the caloric values, ash contents, concentrations of C, N and mineral elements of 14 plant species in Hunshadake Sandy Land of Inner Mongolia. We also examined the relationship between caloric value and ash content and the contents of other mineral elements. The results showed that the caloric value ranged from 16.18 to 20.23 MJ·kg^-1 across all species, with a mean value of 18.80 MJ·kg^-1, which is higher than that of worldwide terrestrial plants. The caloric values of the 14 species were in order of Caragana microphylla>Artemisia desertorum>Cynanchum thesioides>Artemisia sievrsiana>Hedysarum fruticosum>Trigonella ruthenica>Cleistogenes squarrosa>Psammochloa villosa>Agropyron mongolicum>Polygonum divaricatum>Agropyron cristatum>Iris tenuifolia>Kochia prostrate> Salsola collina. The ash contents of the 14 species ranged from 3.98% to 12.18%, with the order of S. collina>K. prostrate>C. thesioides>I. tenuifolia>P. divaricatum>C. microphylla>A. desertorum>A. cristatum>T. ruthenica>A. mongolicum>A. sievrsiana>H. fruticosum>C. squarrosa>P. villosa. Across the 14 species, the caloric value was negatively correlated with ash content (P<0.01) and positively correlated with both C and N concentrations (all P<0.01). Moreover, the caloric value was negatively correlated with the concentrations of metal elements, and positively correlated with the concentrations of nonmetal elements (P>0.05). Our results indicated that these wild plants could be served as an important source of bio-energy, as their caloric values were much higher than that of the commonly used biomass for bio-energy (such as switch grass, corn stalk and king grass) in this region.

Key words: red soil dryland, grey relational analysis, multiple cropping pattern