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在松嫩草原应用红外线增温和人工施氮的方法对羊草群落模拟全球变暖和氮沉降,提取羊草中的植硅体,分析探讨植硅体的形态及数量变化规律.羊草中的植硅体可以划分为4个大类和12个亚类,以及较小的植硅体碎片,其中帽型植硅体含量高达70%.尖顶帽型和平顶帽型植硅体与刺帽型植硅体可能有不同的发育机制,并且尖型植硅体对施氮更为敏感;与对照相比,增温处理对羊草植硅体的发育有促进作用(长宽增加0.1～2.6μm),而施氮处理则有一定的抑制作用(长宽减小0.1～1.4μm),增温和施氮交叉作用,则施氮对羊草植硅体发育表现出的抑制作用明显减弱;施氮处理中出现其他处理中未见到的空心棒型(占棒型总量的46%),而且除棒型、帽型、尖型以外的植硅体含量增加到10%,从而推测,对于以羊草为优势植物的松嫩草原,施氮的影响可能要强于增温,如果两者同时作用,增温能在一定程度上缓解施氮的影响.实验中的羊草植硅体对模拟全球变化很敏感,说明植硅体对环境因子的改变很敏感,其作为古环境的代用指标应是可靠的.
In Songnen grassland, the methods of infrared warming and artificial nitrogen application were used to simulate global warming and nitrogen deposition in the Leymus chinensis community, and the phytoliths in Leymus chinensis were extracted, and the morphological and quantitative changes of phytoliths were analyzed. Phytoliths can be divided into four broad categories and 12 sub-categories, as well as smaller phytolith fragments, including capped phytoliths as high as 70%. Steep cap and top cap type phytoliths and barbed cap type The phytoliths may have different developmental mechanisms, and the apical phyllosilicate is more sensitive to nitrogen application. Compared with the control, the warming treatment can promote the development of phyllostachys chinensis (0.1 ~ 2.6μm in length and width) ), While nitrogen application (0.1-1.4 μm in length and width) could inhibit the growth of L. chinensis significantly; Hollow rods (46% of total rods) not seen in other treatments appeared in the nitrogen treatment, and the content of phytoliths other than rods, caps and pointers increased to 10%, suggesting that for the The Leymus chinensis grassland dominated Songnen prairie, the impact of nitrogen may be stronger than warming, if both at the same time, the warming can be in a The extent of nitrogen application was alleviated to some extent.The phytoremediation of Leymus chinensis in the experiment is very sensitive to global changes in simulation, indicating that phytoliths are sensitive to the change of environmental factors and should be reliable as a surrogate indicator of paleoenvironment.