摘要
根系构型反映植物对资源的吸收能力和利用情况,可揭示沙地植被更新生长与适应机制。本研究以腾格里沙漠东南缘不同地表条件下[流沙地,藻结皮地(半固定沙地),藓结皮地(固定沙地)]的猪毛菜(Salsola collina)为研究对象,采用传统挖掘法收集植物根系,基于量化的根系形态指标,利用几何拓扑学及分形理论分析了根系构型特征,探讨了地表演变对猪毛菜根系构型特征的影响及其适应机制。结果表明:从流沙地、藻结皮地到藓结皮地,猪毛菜根深宽比、根冠比、比根长和比表面积逐次显著降低,根系水平幅则显著增加;根系拓扑指数TI分别为0.8125(流沙地)、0.7107(藻结皮地)、0.6313(藓结皮地),根系结构趋向于从鱼尾形分支结构转变为叉状分支结构;根系分形维数显著提高,但根系分形丰度显著降低。总之,伴随沙地固定程度的增加以及地表结皮覆盖条件的演变,猪毛菜根系生长投入下降,空间拓展能力退化,同时根系的整体结构进一步复杂化,根系生长对策从数量型向质量型转变,资源利用对策向高竞争力方向转变。本研究可为荒漠地区植被恢复和物种选择、配置提供参考依据。
Root architecture reflects the absorptive capacity and utilization of plant resources,and is an important aspect to reveal the mechanism of vegetation regeneration,growth and adaptation in sandy land.In this study,Salsola collina under different surface conditions(quicksand,algal crusts(semi fixed sand),moss crusts(fixed sand))in the southeast edge of Tengger Desert was selected as the research object.The traditional mining method was used to collect plant roots.Based on the quantitative root morphology index,the geometric topology and fractal theory were used to analyze the root configuration characteristics,The effects of land surface evolution on the root architecture of Salsola collina and its adaptation mechanism were discussed.The results showed that the ratio of root depth to width,the ratio of root to shoot,the specific root length and the specific surface area of Salsola collina decreased significantly from quicksand,algae crusts to moss crusts,while the horizontal range of root system increased significantly;The root topological index TI was 0.8125(quicksand),0.7107(algal crusts),0.6313(moss crusts),which decreased gradually,and the root structure tended to change from fishtail branching structure to fork branching structure;The fractal dimension of roots increased significantly,but the fractal abundance of roots decreased significantly.In a word,with the increase of sand fixation degree and the evolution of surface crusting and covering conditions,the investment in root growth of Salsola collina decreased,and the spatial expansion ability degenerated.At the same time,the overall structure of the root system was further complicated.The root growth strategy changed from quantity to quality,and the resource utilization strategy changed to high competitiveness.This study can provide reference for vegetation restoration,species selection and allocation in desert areas.
作者
楼科尔
曲文杰
王磊
王兴
郜永贵
杨新国
Keer Lou;Wenjie Qu;Lei Wang;Xing Wang;Yonggui Gao;Xinguo Yang(MOE Key Laboratory of Northwest Degraded Ecosystem Restoration and Reconstruction/Cultivation Base of State Key Laboratory of Northwest Land Degradation and Ecological Restoration/College of Ecological Environment,Ningxia University,Yinchuan 750021,China;Zhongwei Gusha Forest Farm,Zhongwei Public Works Section of China Railway Lanzhou Bureau Group Co.,Ltd.,Zhongwei 755000,Ningxia,China)
出处
《中国沙漠》
CSCD
北大核心
2024年第4期193-201,共9页
Journal of Desert Research
基金
国家自然科学基金项目(32060313)
宁夏重点研发计划课题(2021BEG03008)。
