Study Resistance-drough Of Six Shrubs In Tsaidam Basin Assessment

Basesd on the precipitation difference in Tsaidam Basin of Qinghai Province, three sampling areas, including Geremu (extreme arid), Delinghan (arid) and Doulan (semi-arid), were selected, and then three sapmling plots in each sampling area were selected to study the characteristics of plant community which dominated by Ceratoides lateens, Nitraria tangutorum, Tamarix chinensis, Kalidium gracile, Haloxylon ammodendron and Salsola arbuscula respectively. At the same time, the morphological and physiological features of above-mentioned 6 species were measured for probing their drought tolerance. By using the subordinative function method, grey correlative degree analyse and no-weight index comprehensive evaluation method, their drought tolerance were compared as well. The results were showed as follows:The main xeric vegetation types in the desert steppe of Tsaidam Basin were Nitraria tangutorum community, Tamarix chinensis community, Haloxylon ammodendron community, Kalidium gracile+Salsola arbuscula community, Ceratoides lateens+ Haloxylon ammodendron+Kalidium gracile community. The community was characterized with simple structure, low vegetation coverage and saline soil. The drought tolerance of these species was stronger in solely dominant community compared with that in mixed community.The morphological structure of leaf of 6 plants was as follows: Nitraria tangutorum was thickness, Nitraria tangutorum and Ceratoides lateens was coated with hair, Haloxylon ammodendron was degenerated to branch, Kalidium gracile was with tisuues for holding water. All these 6 plants have crystalloid cells.For the physiological index, the highest results were got in Geermu and lowest in Doulan. And the values of Nitraria tangutorum and Tamarix chinensis were higher than other 4 species.Through subordinative function method, the order of drought tolerance was N. tangutorum, T. chinensis, C. lateen, S. arbuscula, H. ammodendron, K gracile. Through grey correlative degree method, the physiology index is near, the soluble sugar, chlorophyll a/b, SOD was the first, and chlorophyll b, CAT ranked the second, praline,chlorophyll a, MDA was the last.