Abstract:

Ulanbuhe desert is one of the sites that supply much material for dust storms in north China. Ammopiptanthus mongolicus is endangered which is the only evergreen broadleaf species in sand area of north west China and is also good fixing sand plant. This paper contrasts two natural A. mongolicus communities outside the oases on the north west of Ulanbuhe desert that are irrigated by Huanghe River and well water respectively, using the methods of multi-scale ordination which Ver Hoef et al.(1989) have revised and the pattern intensity and pattern consistency index which Dale et al.(1995) put forward. The aim of this paper is to explore the vegetation structure characters and species relations on different scales outside the oases and provide the basis data for combating desertification and vegetation restoration in the area. The results showed, the pattern scale of A. mongolicus community outside the oasis irrigated by the Yellow River is much smaller than that outside the oasis irrigated by well water. Most patterns of the two communities are multi-species shrub patterns. And what more, the pattern intensity is larger and the pattern consistency index is smaller in the community outside the oasis irrigated by the Yellow River than that outside the oasis irrigated by well water.

Key words: Ammopiptanthus mongolicus, community, multi-species and multi-scale pattern, contribution, species relations