Research On The Spread Characteristics Of Achnatherum Inebrians Communities In North Slope Of Tianshan Mountains

Achnatherum inebrians is an gramineous perennial herb. It is mainly distributed in the northwest,northeast and western regions in sichuan, in China; and it is distributed low-mountain steppe in middle andeast of north slope Tianshan mountain in xinjiang. And it is one of the main poisonous weeds.It has tall individual, high percentage of seeds setting and livestock don’t eat. Under the climatechange and grazing disturbance, A. inebrians depend on stronger reproduction, spread and adaptationability already has the strong superiority in the degraded grassland community competition, showed a trendof breeding, lend to the deterioration of the grassland ecological at the same time restricts the developmentof animal husbandry. For this reason in this paper the A. inebrians which in the different altitude and slopeon north slope of Tianshan mountain as the research object to study its community interspecificrelationships, population space distribution, reproductive characteristics, seed germination characteristicsand growth dynamics. To reveal the rule that A. inebrians response to habitat factors and predict thedevelopment trend of A. inebrians species, provide scientific basis for the effective control and herbicide.Through field investigation and eaperimental the essay comes to conclusions as follows:(1) The associations in the communities are significant negative among different plot and A. inebriansshows negative correlation with most of the species. So preliminarily confimed that community was in arelatively unstable condition.(2) From gully bottom to upper part of shady slope the spatial distribution of A. inebrians aregathering distribution-gathering distribution-evenly distribution-gathering distribution but from gullybottom to upper part of sunny slope the spatial distribution are gathering distribution-evenly distribution-evenly distribution-evenly distribution.(3) A. inebrians plant height showed a trend of slow grow-rapid grow-slow reduce. In gully bottomand sunny slope the maximum values of piant height was in Jone but in shady slopes it was in July. Thebranches number and cluster area are increased first, but it gradually decreased after it reach max value,peaked in July.(4) The individudl size, reproductive investment, number of seeding and spike were decreases with theincrease of altitude, but reproductive allocation was increased. This difference is the direct result of altitude,rather than the infuences of plant size.(5) A. inebrians has high percentage of seeds setting. It’s seed has stronger adaption response to stressconditions, germinated fast, germination ability is independent of the altitude and slope in which parentplant may be located and not affected by seed size.(6) The number of A. inebrians seedlings are not affected by altitude in suuny slope but showed anegative correcation with altitude in shady slope, only with a rate of22to29percent to the peaks.