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根-土界面水分再分配研究对于干旱、半干旱地区退化植被的恢复与重建具有重要意义,同时也是国际植物生理生态学和生态水文学界十分关注的研究领域之一。为了探明科尔沁沙地优势乔木树种樟子松(Pinus sylvestris var.mongolica)、小叶杨(Populus simonii Carr.)、榆树(Ulmus pumila)是否具有根-土界面水分再分配的现象,我们利用时域反射仪(TDR)每隔2h连续测定植株根际土壤水分,同时应用干沙瓶分根法对3种乔木根-土界面水分再分配作了测定,结果表明:三种常见乔木树种樟子松、小叶杨、榆树均具有根-土界面水分再分配的潜力;并且榆树的水分再分配能力较樟子松和小叶杨强;三种常见乔木根-土界面水分再分配现象一般发生在14:00之后,而分配水量最大的时间多是出现在次日凌晨4:00左右,即4:00-14:00为植物的蒸腾耗水时段,而14:00至次日4:00为植物的水分再分配时段。
The research on water redistribution at root-soil interface is of great significance to the restoration and reconstruction of degraded vegetation in arid and semi-arid regions. It is also one of the research fields that is of great concern in the world of plant physiological ecology and ecohydrology. In order to find out whether Pinus sylvestris var. Mongolica, Populus simonii Carr. And Ulmus pumila in the Horqin sandy land have the phenomenon of water redistribution at the root-soil interface, The rhizosphere soil moisture of the plant was measured continuously by reflectometer (TDR) every 2h, and the redistribution of water and moisture at the root-soil interface of the three tree species was determined by dry sand bottle rooting method. The results showed that the three common tree species Pinus sylvestris , Populus euphratica and Ulmus had the potential of water redistribution at the root-soil interface. The water redistribution ability of Elm was stronger than that of Pinus sylvestris var. Mongolica and Populus simonii. The redistribution of water content of the three common tree root-soil interfaces generally occurred at 14: After 00:00, and the distribution of the maximum amount of time the water is mostly appeared around 4:00 the next day or so, 4: 00-14: 00 for the plant’s transpiration water consumption period, and 14:00 to 4:00 the next day for the plant Moisture redistribution period.