内蒙古阿拉善荒漠灌木果实类型多样性研究

本文对分布于内蒙古阿拉善荒漠的21科44属82种灌木果实类型、形态、大小及扩散器进行了计测。结果显示,阿拉善荒漠灌木果实中,干果占果实类型的91.5%,居优势地位;肉果仅占果实类型的8.5%。干果中,裂果占34.1%,闭果占65.9%。阿拉善荒漠灌木中果实形态以卵形、倒卵形、椭圆形、近球形和矩圆形为主,分别占果实形态的28.05%、9.75%、10.97%、8.54%、8.54%。阿拉善荒漠灌木果实中,36.58%的果实千粒重小于3g,且其形状近球形,67.1%的果实具有扩散器。以上结果表明:一方面,阿拉善荒漠灌木果实类型对荒漠环境的适应具有趋同性,表现为果实类型以干果为主,而且大部分果实具有扩散器,这有利于果实在风力作用下传播;另一方面,阿拉善荒漠灌木果实类型又表现出对荒漠环境适应的多样性,传播方式的多样性,果实类型、果实形态、果实大小的多样性。不同的果实类型对阿拉善荒漠植被的更新起不同的生态作用,保证了阿拉善荒漠植被的多样性,从而为荒漠灌木生态位的分异奠定了基础。

STUDY ON ADAPTATION DIVERSITY OF SHRUB FRUIT TYPE IN ALASHAN DESERT

The morphological features of fruit and fruit size of the shrub in Alashan were measured. The result indicated: All of the shrub fruits in Alashan ,most of the fruit types were dry fruits, it's number percentage were 91.5%. In dry fruit, dehiscent fruits were 34.1% and indehiscent fruits were 65.9%.The important shape of fruit proportion were: oviform 28.05%, obovate 9.75%, ellipse 10.97%, almost sphericity 8.54%, oblonga 8.54%, In these fruits, 1 000-seed weight of 36.58% fruits was smaller than 3mg 67.1 % seeds had appendage. The results of the analysis were:the fruits type, shape, size and appendage of Alashan shrub tend to be seasoned with leanness, aridity and windy environment of the hungriness area. Their fruits diffused in anemophilous form and tend to coherence in the form and motivity of diffusion. The diversiform type of fruits provide a basement for distinguish the hungriness shrub niche.