不同增温方式下芦苇植硅体大小变化特征的对比研究

Change characteristics of the phytolith size in Phragmites communis under different warming treatments

在松嫩草原分别采用开顶式气室(Open Top Chamber,OTC)和红外线辐射器(Infrared Radiator,IR)两种不同的增温方式模拟增温,分别设置3个不同温度梯度的增温处理和一个对照处理,提取芦苇中的植硅体,对比分析了不同增温方式下芦苇植硅体大小对增温的响应规律,研究了芦苇植硅体大小与温度因子之间的关系.结果表明:OTC增温方式下芦苇植硅体大小普遍比IR的大,且芦苇植硅体大小主要受控于土壤有效硅的含量;在不同增温方式下,增温对不同类型植硅体大小的影响存在差异,对于鞍型植硅体来说,在OTC增温方式下,增温后导致鞍型植硅体的各个参数均变小,在IR增温方式下,增温后鞍型植硅体的长变小而宽变大;对于尖型植硅体来说,不同增温方式下增温均导致尖型植硅体的长变大,但宽减小;对于硅化气孔来说,在不同增温方式下,增温后硅化气孔的长和宽均变大.不同类型植硅体的大小对温度升高的响应比较敏感,两种增温方式下增温后同种类型植硅体大小的变化规律也存在差异.

As warming continues,it is necessary to know how to response of the terrestrial ecosystems on warming.In this paper,used Open Top Chamber(OTC)and Infrared Radiator(IR)to simulate warming on Phragmites communis in the Songnen Grassland(123°44′~123°47′E,44°30′~44°45′N).There were three warming treatments and a control for OTC and IR,respectively to study the responses of the P.communis phytolith size to warming.And tried to investigate the differences and similarities of phytoliths size to warming between OTC and IR warming treatment.Phytolith were extracted by wet oxidation method.Canada balsam was used to prepare slides and at least 300 grain phytoliths were observed and identified in every sample.The results showed that the phytolith sizes were different under the two warming facilities.Specifically,the phytolith size of the P.communis under the OTC was the larger,under the IR was the smaller.And the phytoliths size was controlled by the available soil silicon.In addition,the responses of phytolith size to warming between the two warming facilities were different.For the saddle size,under the treatment of OTC,warming decreased the size of saddle,whereas warming caused the length decreased while the width increased under the treatment of IR.For the lanceolate size,warming increased the length but decreased the width of lanceolate under the two warming treatments.For the silicified stomata,warming caused the length and width become bigger both under the warming treatments OTC and IR.On the whole,the different types of phytoliths sizes were different under the warming treatment of OTC and IR and the effects of warming on different types of phytoliths sizes were different.