[Spatial pattern of sand-mound of Nitraria in different habitat at the southeastern fringe of the Tengger desert].

Based on the geo-statistics and quantitative ecology method, the spatial pattern of sand-mound of Nitraria was been analyzed in different habitat at the southeastern fringe of the Tengger desert in order to keep the natural mounds stability and ecological efficiency. The results showed that the different groundwater level and plant growth condition resulted in difference of Nitraria population at capacity of withstanding sand bury and the effect of sand-binding. The coverage, density and biomass of Nitraria population at the lacustrine basin lowland were significant higher than those of the alluvial fan (p < 0.01). Although the height of Nitraria population at the lacustrine basin lowland was lower than that of the alluvial fan, there was no significant difference between two habitat (p > 0.05). The height and volume of sand-mound was 1.20 m and 88.19 m3 at the lacustrine basin lowland, 1.14 m and 33.16 m3 at the alluvial fan, respectively. The size and distribution of sand-mound was significant difference at different habitat (p < 0.01). The mound of the lacustrine basin lowland has the tendency of large patch and low density, developed longer scale pattern in auto-correlated distance, and those of the alluvial fan just the reverse. The spatial heterogeneity of mound size and volume of accumulation sand in the lacustrine basin lowland can be controlled by auto-correlated factors at 1.2-84 m scale, and the random factors at under 100 m controlled the spatial heterogeneity in the alluvial fan. Especially, the size and volume of sand-mound has constant variation at under the 100 m scale in the alluvial fan, and has random spatial pattern without law.