Study On The Change Of Artemisia Grassland Community And Adaptability Of Seriphidium Transiliens Under Enclosure

Grassland degradation is a problem which was concerned by Xinjiang and even national, as an important means of grassland restoration, enclosure has become an important measure for grassland management. Research on enclosure on varied regularity of grassland community and plant adaptability, which can provide some guidance for understanding of grassland degradation and recovery, and reasonable using enclosed grassland.This experiment designed 2 treatment that was enclosure for 4 years (April 2005 implementation of the fence) and Enclosure for 2 years (April 2008 implementation of the fence) in the Artemisia desert grassland, a full year grazing as a control, the varied regularity of Sagebrush desert grassland community under different enclosure years was researched and the adaptability of Seriphidium transiliens transiliense was researched. The results showed that:1. The total coverage, average height of grassland vegetation in enclosure for 4 years had significantly increased than no enclosure, but the enclosure for 2 years had no significantly increasing Enclosure for 4 years and 2 years had significantly difference with no enclosure (P <0.05). But density and number of species did not change significantly. Meanwhile, the plant above-ground biomass in Artemisia grassland and the biomass of S. transiliense were showed enclosure for 4 years > enclosure for 2 years> no enclosure under the effect of enclosure, but the above-ground biomass showed a decreasing tendency with the change of seasons,while that of S. transiliense indicated the"V"curve.2. With the enclosure time increased, the number of short-lived plants decreased gradually, the Piptatherum kokanicum which adapted to local climatic conditions increased slowly, the importance value of S. transiliense increased rapidly and it was in an absolutely dominant position in the community.3. The enclosure had significant effect on increasing the average plant height,brush of S. transiliens in the Artemisia grassland, and enclosure for 4 years was higher than no enclosure. The average plant height, plant stem bundles of enclosure for 4 years had significantly difference with no enclosure, but the enclosure for 2 years had no significant difference with no enclosure, probably due to relatively short time enclosure.4. Overall, the structure of biomass allocation in S. transiliense was the root> stem> leaf. with the change of seasons, the root, stem and leaf biomass of S. transiliense had a similar variation with the total biomass at different enclosure years, this indicates that seasonal changes had no significant effect on each component biomass, but the enclosure years had some effect, and the variation of each component were greater along with increasing enclosure years. But with the change of seasons, there was not regularity on the biomass allocation of each component enclosure in different enclosure years, but the allocation of root biomass reduced, stem and leaf biomass increased with increasing enclosure years.5. The major reserve was starch that was mainly stored in stubbles, the starch of S. transiliens showed that August was highest (16.67%) and May was lowest (6.29%), it indicates the season had a significant effect on accumulated of NSC, and it presented inverse"V"pattern with changes of time. Enclosure increased significantly the NSC of root and stubbles (p<0.05), but no effect on NSC in leaves. The soluble sugar of S. transiliens of enclosure for 4 years and for 2 years was significantly higher than un-enclosure, but the starch accumulation is not consistent. The NSC of S. transiliens had not significant difference between enclosure for 4 years and for 2 years.