Contrast of Pattern Characters in Two Different Natural Nitraria tangutorum Communnities in Half Fixed Dunes Outside Oases under Different Irrigating Systems
Abstract: Making use of the methods of multi-scale ordination(Ver Hoef Glenn-Lewin,1989),the pattern intense and pattern consistence index(Dale Zbigniewicz)and the moving weight average quadrat scores(Noy-Meir Anderson),the paper analyzed the vegetation pattern characters of the natural Nitraria tangutorum communities in half fixed dunes outside the Huanghe River irrigating oasis and the well water irrigating oasis including pattern scale,species combination at different scale,behavior of the vegetation along the transect,pattern intense and pattern consistence.The results showed that both the two half fixed Nitraria tanguiorum communities were shrub patterns controlled by single species.The association of same species were different at different scale and under different environment condition.The average number of pattern scale was more,pattern scale was larger,the corresponding pattern intense was lower,and the pattern consistence was smaller in Nitraria tangutorum communities of half fixed dunes outside the Huanghe River irrigating oasis,contrasting with that outside the well water irrigating oasis.