【摘要】 通过对栽培条件下尖叶胡枝子地下不同直径根系组分和生物量的测定及模拟分析,结果表明:尖叶胡枝子的根系垂直空间分布为典型的表层聚积型,根系主要集中在0~20 cm,根系垂直分布特征参数β的值较小;生长1080 d(生长3年)的尖叶胡枝子根系入土深度可达100 cm,其中在0~40 cm的土层中,以粗根为主,占总根量的81.54%,40 cm之下以细根为主;根系密度随着尖叶胡枝子生长期的延长呈明显增大的趋势。更多还原

【Abstract】 In this study,the components of roots with different diameters and the underground biomass of Lespedez hedysaroide plants growing for different days are measured and analyzed.The study area(900 m a.s.l.) is located in Linxi County,Inner Mongolia,where it belongs to the arid continental monsoon climate,the annual air temperature and the monthly temperature in July and January vary in ranges of 4~5 ℃,20~22 ℃ and-13~-17 ℃,the extremely maximum and minimum temperatures are 40.4 ℃ and-32.2℃,respectively,and the accumulated temperature ≥10 ℃ is 2 600 ℃;the annual precipitation varies in a range of 320~380 mm and occurs mainly during the period from June to August,and the annual evaporation is over 1 800 mm;the frost-free period varies in a range of 125~130 days;the soil is chestnut soil.The results reveal that the vertical distribution of root ecological niche of L.hedysaroides is characterized by root accumulation in surface soil layer.The roots distribute mainly in soil layer of 0~20 cm in depth,and the characteristic parameter of root vertical distribution(β) is low.The roots of L.hedysaroides plants growing for 1 080 days(three years) can grow deep into soil layer of 100 cm in depth.Thick roots distribute mainly in soil layer of 0~40 cm in depth,their proportion is as high as 81.25% of the total,and the thin roots distribute manly in soil layer deeper than 40 cm.Root density increases significantly with prolonging the growing time of L.hedysaroides plants.更多还原