Physio-ecological Adaptability Of Artemisia Sphaerocephalla In Aerial Seeding Area Of Horqin Sandy Land

In this paper, the adaptive changes of the Artemisia sphaerocephallaafter the long-range aerial seeding were studied. The chosen origin located inDalate County of Kubuqi Desert in central Inner Mongolia, and the aerialseeding area was selected in Wengniute County of Horqin Sandy Land ineastern Inner Mongolia.The morphological characteristics, growth andcommunity characteristics, physiological characteristics, and droughtresistance of A.sphaerocephalla were researched. So the results were asfollows:（1）From the soil differences of the two regions, the soil water contentin different periods had otherness between the two areas. The soil bulk densityand soil compaction of the aerial seeding area were higher than the origin.The soil pH was lower in the aerial seeding area. No significant differencewas found in content of soil organic matter and total nitrogen in the tworegions, while the total phosphorus content of origin was higher than aerialseeding area. For soil available nutrients, available phosphorus content ofaerial seeding area in different periods were significantly higher than those oforigin.（2）From the anthodium size of A.sphaerocephalla, the diameter andlength of anthodium in the aerial seeding area were significantly lower thanorigin,and the diameter/length was smaller. The result showed the trend ofanthodium of A.sphaerocephalla in Horqin Sandy Land changed small andspherical. For the leaves, the length and width of central stem and leaves-fidin aerial seeding area were significantly smaller than origin（p﹤0.01）.However the leaves on stem base changed little.（3）Plant compositions between the two places were simple. The plantspecies of the aerial seeding area per square meter was0.173species/m², andit was only0.053species/m²in origin. The similarity of the plant composition between the two areas was low and the K_jaccard was0.13. As the aerial seedingarea located at eastern Inner Mongolia and more abundant annual rainfall,there were a large number of annual herbaceous in the community.The annualherbaceous took69.2%, and the mesophyte took53.8%; while the annualherbaceous took25%and there were only xerophyte and extreme xerophytein origin.（4）A.sphaerocephalla growed well after aerial seeding. No significantdifference existed in plant height of the two regions, but there were certainchanges of plant height due to diverse habitat conditions of differentcommunities. BuRiDun was the highest, XiangShui was the lowest andZhanDanZhao was in the middle. However, the density was contrary. For thecoverage of A.sphaerocephalla, XiangShui was the highest, BuRiDun andZhanDanZhao were similar. The density and coverage were high that theheight was low. A.sphaerocephalla in two regions could grow up to age6, butthe age6plants were rare. In addition to age6, both the biomass of currentannual reproductive shoots and total biomass in the two regions increasedwith age, the proportion for reproduction gradually increased; at the age offive the proportion could achieve80%above. At the age of2A.sphaerocephalla started to reproduce in aerial seeding area while the originbegan in age3.（5）In different periods, all the physiological parameters of A.sphaerocephalla from two areas had significant differences. In the threeperiods of investigation the contents of chlorophyll and proline inZhanDanZhao were higher than XiangShui. The diversification related totemperatures, sunshine hours and soil moisture content. In the flowering andfruiting periods of autumn, the content of POD was significantly high, but itmarkedly decreased during the summer vegetative period, and these haddirect relationships with temperature and precipitation. However cause theinfluence of temperature the contents of CAT only significantly increased inSeptember, and no obvious difference existed in the other two periods. Owingto the temperature change, the soluble sugar and soluble protein of ZhanDanZhao were lower than XiangShui for the autumn. As the result of thetemperature drop, Malondialdehyde and SOD only distinctly declined inSeptember. After aerial seeding, the diversification of physiological indicatorsrelated to the temperature. A. sphaerocephalla subjected to the lowtemperature stress in aerial seeding area especially in September, but throughthe physiological regulation it could adapt to the range of temperaturebetween the two areas.（6）Through PEG-6000（polyethylene glycol） simulated drought stressenvironment four indicators were selected to analyze drought resistance ofA.sphaerocephalla seeds, they were relatively germination rate, relativegermination potential, relative germination index and drought index. Theresult was that the drought resistance of origin was better than aerial seedingarea. The result also showed that cause better moisture conditions and yearsof adaptation the seeds drought resistance of A.sphaerocephalla in aerialseeding area had decreased.