【摘要】 【目的】欧李是干旱、半干旱地区防风阻沙、保持水土、城市绿化及生态建设的优良灌木树种。其根系分布状况及形态结构特征能够反映植物对环境的生态适应性,不仅会影响植物的水分和养分吸收效率,还会影响欧李对风沙的抵抗能力,为进一步了解欧李适应干旱生境的机理,促进欧李在乌兰布和沙漠地区进一步的推广与应用。【方法】采用全挖掘法研究了乌兰布和沙漠不同林龄引种欧李的各径级根长、表面积、体积和生物量特征。【结果】栽植3 a内的欧李根系垂直分布较浅,主要呈水平分布,当根系垂向生长至40 cm后,则开始大量横向生长,根系主要分布在0～30 cm范围内。细根总根长较中根和粗根长,生长3 a后细根总根长达7 049.70 cm,为栽植苗的20.14倍。欧李根系的根长、表面积、体积、生物量均随林龄增大呈逐渐增加趋势。根系在第2 a时,中根根长、表面积、体积及生物量较小,分别为497.46 cm、377.41 cm~2、22.96 cm~3、9.89 g,此时的中根正快速增粗生长,向粗根发展。当欧李生长3 a时,总根系生物量达611.35 g,分别较栽植年、生长1 a、生长2 a增加了610.22 g、572.39 g、373.75 g。3种径级的根系中,细根占总根的比例最低;生长1 a时,中根生物量占比最高;生长2 a后,粗根占总根的比例最大。【结论】综上可得,欧李根系能够吸收水平范围较广的水分和养分,且具有较强的抵抗风沙能力的根系。更多还原

【Abstract】 【Objective】 Cerasus humilis is an excellent shrub tree for wind and sand control,soil and water conservation,urban greening and ecological construction in arid and semi-arid areas. Its root system distribution and morphology characteristics can reflect the plant ecological adaptability to the environment,not only affects the water and nutrient absorption efficiency of plants,can also affect Cerasus humilis resistance of sand,in order to further understand the mechanism of Cerasus humilis adaptation to arid habitats,promote Cerasus humilis in UlanBuh Desert areas further popularization and application. 【Method】Using the excavation method,the different forest ages of Cerasus humilis in UlanBuh Desert were investigated,the changes of root length,surface area,volume and biomass were analyzed,it is helpful to clearly understand the adaptation mechanism of eucalyptus in desert area. 【Result】The vertical distribution of plum root was shallower in 3 years,it is mainly distributed horizontally. When the root grew to 40 cm,the roots began to multiply laterally,mainly distributed in the range of 0-30 cm. The total root length of the fine roots was longer than that of the medium and rough roots. After growth of 3 a,the total root length of fine root reached 7 049.70 cm,it was 20.14 times higher than when it was planted. The root length,surface area,volume and biomass of Cerasus humilis increased with the growth of forest age. At 2 a,the root length,surface area,volume and biomass of the middle root were small,which were 497.46 cm,377.41 cm~2,22.96 cm~3 and 9.89 g,respectively. At this time,the middle root was growing rapidly and developing towards the thick root. When Cerasus humilis grew 3 a,the total root biomass reached 611.35 g,which was increased by 610.22 g,572.39 g and 373.75 g,respectively,compared with the planting year,growth 1 a and growth 2 a. Among the roots of the three diameters,the proportion of fine roots to total roots was the lowest. When growth 1 a,the proportion of medium root biomass was the highest. After growth 2 a,the proportion of coarse roots to the total roots was the largest. 【Conclusion】To sum up,the root system of Cerasus humilis could absorb a wide range of water and nutrients,and had a strong ability to resist wind and sand.更多还原