[Structural characteristics of Artemisia frigid community at different succession stages in Horqin Sandy Land].

Taking space as a substitute for time, this paper studied the species composition and species diversity of Artemisia frigid community at three succession stages in Horqin Sandy Land. The three succession stages were Periploca sepium-A. frigida community, Periploca sepium-A.

[Identification and characterization of a novel hydrocarbon-degrading Marinobacter sp. PY97S].

Objective: To identify and characterize a hydrocarbon-degrading bacterium isolated from the sediment of the Yellow Sea.

Methods: We used 16S rRNA gene sequences based phylogenetic analysis, physiological and biochemical characterization, DNA G + C content assaying, determination of cellular fatty acids, testing of carbon sources and respiratory lipoquinone and experiment of DNA-DNA relatedness. Its capability of degrading aliphatic hydrocarbons in ONR7a media supplemented with nine n-alkanes, separately, as sole source of carbon and energy was further determined.

[Species diversity of pasture community at different altitude levels in Qilian Mountains].

According to the occurring frequency and life form of plant species at different altitude levels, this paper studied the changing characteristics of the species a diversity of pasture community at the altitude from 2500 m to 3000 m in Qilian Mountains. The results showed that with increasing altitude, the Shannon-Wiener species diversity index increased from 1.432 to 1.

[Functions of different cultivation modes in oasis agriculture on soil wind erosion control and soil moisture conservation].

During 2001-2002, the effects of different cultivation modes including winter irrigation and zero tillage, crop-grass intercropping, and early spring film mulching on sand entrainment, wind velocity gradient and soil moisture conservation were studied in the middle reaches of the Heihe River in the Hexi Corridor region. The results showed that all these modes could reduce soil wind erosion and halt sand entrainment to different degrees. Compared with the bare fields exposed by spring plowing, early spring film mulching could increase soil moisture storage by 35.