差不嘎蒿在科尔沁沙地草场植被中的作用

差不嘎蒿是科尔沁沙地草场退化过程中的一个重要缓冲种。在草场退化过程中能够迅速占领退出植物种遗留下来的空间，生物量由８１．６ｇ／ｍ２增加到２８５ｇ／ｍ２；但从半固定沙丘草场到半流动沙丘草场，其生物量减少到了１９０ｇ／ｍ２，占总生物量的７７．２％。差不嘎蒿在半流动沙丘草场中的繁殖力最高，当年生幼苗数和果实生物量分别为５９株／ｍ２和１７．６ｇ／ｍ２。差不嘎蒿以无性繁殖为主，但是，在流动沙丘草场则以种子繁殖为主。

ROLE OF ARTEMISIA HALODENDRON SANDDUNE PASTURE VEGETATION IN HORQIN

Artemisia halodendron is a buffering species in the elementary stage of vegetational degradation in Horqin. It reproduces rapidly, and occupies space that was maintained by eXtinct species in semi-fixed sanddune pasture. Biomass of A. halodendron increases 203. 4 g/m2 from fixed sanddune pasture to semi-fixed sanddune posture, the highest among four pasture types. Its biomass decreases 95 g/m2 from semi-fixed sanddune pasture to semi-drifting sanddune pasture, but relative biomass increases by 16% and it is the highest in four pasture types. Ability of reproduction for A.halodendron is highest in send-drifting senddune pasture. Seedlings and biomass of fruits are 59 unit/m2and 17g/m2 respectively. Except in drifting sanddune pasture, asexual regeneration of A. halodendron is major mode of reproduction. Especially, sprouting from roots and branches buried by sand is the most inportant asexual reproductive means. Shrubby characters of A. halodendron are very evident in semidrifting sandy dune pasture and play an import role.