克隆植物扁秆藨草种子库特征及其适应意义  

Seed Bank Characteristic of Clonal Plant Scirpus planiculmis(Cyperaceae)and Its Aadaptive Significance

作　　者：宁宇[1] 张志翔[1] 赵良成[1] 邹畅林 杨佳妮[3] 

机构地区：[1]北京林业大学自然保护区学院,北京100083 [2]吉林莫莫格国家级自然保护区管理局,吉林镇赉137316 [3]北京林业大学林学院,北京100083

出　　处：《湿地科学》2014年第1期55-60,共6页Wetland Science

基　　金：国家"十一五"林业科技支撑计划项目(2006BAD03A19)资助

摘　　要：克隆植物在湿地中普遍存在，其在有性和克隆两种繁殖方式之间的权衡是植物生态学中的热点议题，并具有重要的理论意义。以扁秆蔗草（Scirpus planiculmis）为研究对象，在吉林省莫莫格湿地，对不同环境条件下土壤中的扁秆蔗草种子数量及其分布规律进行了研究，并对影响扁秆蔗草种子数量的环境因素进行了分析。结果表明，①在垂直方向上，扁秆蔗草种子主要集中分布在土壤表层（0～5cm深度）和中层（5-10cm深度）内，在下层土壤（深度〉10cm）中明显减少；表层土壤中的扁秆蔗草种子容易受到干扰而发生变动；这种垂直分布规律不随环境条件的改变而发生变化；②在不同的环境条件下，扁秆蔗草种子的数量存在显著差异；土壤含水率、pH和群落辛普森指数与扁秆蔗草种子数量显著相关，植被中扁秆蔗草的多度则与种子数量不相关。分析发现，因环境因素引发的扁秆蔗草繁殖方式的权衡是存在的，并可以在小的局域范围内实现；扁秆蔗草被重新定义为兼性盐碱植物，其适宜生长条件为弱碱性，在强碱性条件下则会通过大量产生种子而实现对当前生境的逃离；两种繁殖方式的意义不同，有性繁殖主要服务于宏观尺度上种群的扩散与维系，而克隆繁殖的则实现了小尺度内克隆对资源的有效利用和竞争优势的保持。Clonal plant is of ubiquity in the wetlands. Its trade-off between sexual reproduction and clonal prop- agation is a central topic in plant ecology. However, special research for seeds which are the outcome of sexu- al reproduction has not yet been reported. Thus, a field investigation of Scirpus planiculrnis was carried out at Momoge wetlands in Jilin province, aiming to explore the variance of soil seed amount and distribution be- tween different habitats and identify the environmental variables related to it. The result showed that seeds of Scirpus planiculmis had a vertical distribution. Most of the seeds existed in surface layer （0-5 cm） and middle layer （5-10 cm） of the soil. Very few seeds were found in deep layer （more than 10 cm） of the soil. Seeds in surface layer of the soil seemed to be more vulnerable to disturbance and tended to be easily altered. However, the vertical distribution was consistent despite changes in environment. The amount of seeds varied signifi- cantly between habitats. Soil water content, pH and Simpson index were found to correlate with seed amount in the soil significantly, while the abundance of Scirpus planiculmis had no correlation with it. The conclusions were that trade-off in reproductive mode could be intrigued by environmental factors, even in small scale; Scir- pus planiculmis was redefined as facultative salt-alkali plant. Its optimal condition was slight alkali. Great amount of seeds would be produced under high alkali to enable plant to escape from this adversity; these two reproductive modes had different ecological meanings. Sexual reproduction mainly served as way of dispersal and maintenance in large scale while clonal propagation helped clone to utilize resource effectively in small scale and consolidated its superiority in competition.

关 键 词：克隆植物 扁秆藨草 种子 分布规律 繁殖对策 

分 类 号：Q948.1[生物学—植物学]