干旱区生态环境知识资源中心(Arid): 阿拉善沙漠植物钙质根管:形态特征、分类及其环境指示意义

Arid

	阿拉善沙漠植物钙质根管:形态特征、分类及其环境指示意义
其他题名	Calcareous Root Tubes in the Alashan Deserts: morphological characteristics, classification and environmental significance
	高有红; 李卓仑; 韩朗; 李若兰
来源期刊	沉积学报
ISSN	1000-0550
出版年	2017
卷号	35 期号:1 页码:75-84
中文摘要	在系统总结前人对植物钙质根管定义及形成机制的基础上,采用形态学方法对阿拉善沙漠26组不同形态的植物钙质根管进行了分类,初步统一了我国植物钙质根管的定义及其分类;通过统计阿拉善沙漠不同类型植物钙质根管在全新世的数量分布,探讨了其分布特征可能蕴含的古环境意义。结果表明,植物钙质根管是陆生植物形成的次生碳酸盐结壳,包括钙质根套、绕根结核、根模具、根导管和根状结核五种类型。其中钙质根套和绕根结核的形成受到植物生长及其根围微生物活动的影响,而根模具、根导管和根状结核的形成则不受上述作用的影响。据此将阿拉善沙漠植物钙质根管分为钙质根套和绕根结核两种类型。这两类植物钙质根管在不同时期的相对数量百分比能够指示植物钙质根管形成时期有效湿度的高低,绕根结核数量百分比较高能够指示较高的有效湿度,而钙质根套数量百分比较高则指示了较低的有效湿度。因此,从植物钙质根管中能够提取丰富的古环境信号,并将其运用于沙漠地区的古环境研究中。
英文摘要	The definition and classification of calcareous root tubes which have been used in different studies are still unified. However, it remains uncertain that whether different definitions of calcareous root tubes indicated the same morphology or not. At the same time, there were disagreements over the formation mechanism and paleoenvironment significance of calcareous root tubes. Some research results suggested that the formation of calcareous root tubes in this area indicated relatively humid climate conditions, while others argued that they were formed by recrystallization of calcium carbonate required the presence of underground water. In this study, 26 calcareous root tubes samples collected from the Alashan Desert are classified using morphological method, which was based on previous studies about the definition and formation mechanism of calcareous root tubes. Then the paleoenvironment significance for different types of calcareous root tubes was discussed. The results showed that calcareous root tubes were products of terricolous plants and were formed by encrustation of plant roots by secondary carbonates, including five subclasses, namely calcareous sheath, rhizocretion, root mould, root tubule, and root cast. Calcareous sheath and root tubule have hollow tubes in morphology, and then rhizocretion and root cast have structure of double layer cemented by calcium carbonate or solid construction filled with coarse gravel or sediment. Root mould is simply tubular voids left after roots decayed. According to whether the formation process is under the influence of plant growth and rhizosphere microorganism activity or not, the formation process can be divided into two patterns. Calcareous sheath and rhizocretion were formed by the influence of plant growth and rhizosphere microorganism activity, while the formation of root mould, root tubule, and root cast were not influenced by them. Thus, the classification of the above five subclasses can be distinguished by morphology character clearly. Results from n-alkanes indicated that abundant short chain alkanes which indicate the influence of plant growth and rhizosphere microorganism activity occurred in calcareous root tubes. Therefore, calcareous root tubes can be divided into calcareous sheath and rhizocretion in the Alashan Desert. Both of them occurred at the same sampling point. However, the quantity percentage of rhizocretion was variates in the Holocene. During the middle-Holocene, the quantity percentage of rhizocretion is significantly higher than that in the late Holocene. The formation of rhizocretion were jointly controlled by calcium solution leaching, CO_2 produced by the rot of root, and rhizosphere becoming alkaline. Calcium solution leaching could be resulted in higher effective humidity. Therefore, changes in the quantity percentage of rhizocretion could indicate levels of effective humidity, higher quantity percentage of rhizocretion could be interpreted as a humid environment, and vice versa.
中文关键词	阿拉善高原 ; 植物钙质根管 ; 钙质根套 ; 绕根结核 ; 次生碳酸盐 ; 沙漠
英文关键词	Alashan Plateau calcareous root tubes calcareous sheath rhizocretion secondary carbonate desert
语种	中文
国家	中国
收录类别	CSCD
WOS类目	PLANT SCIENCES
WOS研究方向	Plant Sciences
CSCD记录号	CSCD:5928186
来源机构	兰州大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/235721
作者单位	兰州大学资源环境学院/干旱区与沙漠研究中心, 兰州, 甘肃 730000, 中国
推荐引用方式 GB/T 7714	高有红,李卓仑,韩朗,等. 阿拉善沙漠植物钙质根管:形态特征、分类及其环境指示意义[J]. 兰州大学,2017,35(1):75-84.
APA	高有红,李卓仑,韩朗,&李若兰.(2017).阿拉善沙漠植物钙质根管:形态特征、分类及其环境指示意义.沉积学报,35(1),75-84.
MLA	高有红,et al."阿拉善沙漠植物钙质根管:形态特征、分类及其环境指示意义".沉积学报 35.1(2017):75-84.