不同生境中差不嘎蒿(Artemisia halodendron)生长特征及地下生物量分布

Growth Character and Belowground Biomass Distribution of Artemisia halodendronin Different Positions of Sand Dune

植物根系活动是植物-土壤系统物质周转的关键环节。为研究不同坡位差不嘎蒿(Artemisia halodendron)根系生长特征,用土钻法调查了科尔沁沙地半固定沙丘不同坡位0~60cm深度差不嘎蒿活根与杂质(包括死根与根表脱落物)的生物量。结果表明:不同坡位间差不嘎蒿活根与杂质生物量均存在显著差异;差不嘎蒿活根的垂直分布特征在各坡位不同,在坡中和坡顶,主要分布在0~20cm层,而在坡底和背风坡,垂直分布较均匀;总生物量和杂质生物量在各坡位的垂直分布随土壤深度增加而下降;差不嘎蒿群落特征与植株生长特征在不同坡位间存在显著差异,坡底盖度及物种数高于其他部位,坡底和背风坡差不嘎蒿植株密度减小,单株高度增加。差不嘎蒿活根生物量与自身密度呈显著的正相关关系(p【0.05),但与自身高度呈显著的负相关关系(p【0.05)。差不嘎蒿根生长和分配是其在不同沙丘生境生长策略变化的重要反映。

Plant root activity plays important role in material turnover in plant-soil systems.In order to investigate the distribution of Artemisia halodendron's root,vegetation character,live root and necromass(dead root and cell sloughing of epidermal root tissues)during the growing season were investigated in4 different positions(bottom,mid-slope,top and leeward)of dunes in the Horqin Sandy Land.The result showed that:Both live root mass and necromass were significantly different among slop positions in semifixed dune.In terms of live root mass distribution,there were different characters in these 4 positions,most of the live-root biomass was allocated at the depth of 0-20 cm in middle-slope and top of the dune,while in bottom and leeward,the variations were slight.Vertical distribution of the total mass and necromass all significantly declined among soil depth in all the 4 positions.Meanwhile,ecological index of plant community and growth character of A.halodendronamong slop positions showed significantly difference:coverage and richness in bottom were significantly higher than others,and both in bottom and leeward,density of A.halodendrondecreased while its height increased.Live root mass of A.halodendronplayed significant relationship positively with its density while negatively with its height(p<0.05).In conclusion,allocation and growth character of A.halodendronshowed an important reflection of growing strategy variation among habitats in sand land.