2018年11月18日 星期日
高寒沙区不同生境赖草的生长特征分析
Analyses on growth characteristics of Leymus secalinus in different habitats in alpine sandy area
2018年 第27卷 第3期 页码[87-94]
摘要

对高寒沙区低湿滩地、农田田边、丘间地和固定沙丘4种生境土壤的含水量以及有机质和养分(包括全氮、全磷和全钾)含量进行了测定,并对4种生境中赖草〔Leymus secalinus (Georgi) Tzvel.〕的生长特征进行了比较和分析。结果表明:总体上看,从低湿滩地、农田田边、丘间地到固定沙丘,土壤含水量及有机质、全氮、全磷和全钾含量呈降低的变化趋势,且低湿滩地和农田田边土壤含水量及有机质、全氮、全磷和全钾含量高于丘间地和固定沙丘。不同生境中赖草生长特征差异较大。固定沙丘中赖草的株高和地径均最大,显著大于其他3种生境(P<0.05);低湿滩地和农田田边中赖草的分株密度、根茎直径以及地上部分和根系的生物量较大,总体上显著大于丘间地和固定沙丘;而丘间地和固定沙丘中赖草的间隔子长较长,低湿滩地和农田田边中赖草的间隔子长较短,且前2种生境与后2种生境间差异显著。从低湿滩地、农田田边、丘间地到固定沙丘,赖草根系分布深度逐渐增加,由0~30 cm或0~40 cm增至0~60 cm。随着土层的加深,4种生境中赖草的根系生物量均呈先增加后减少的变化趋势,且10~20 cm土层的根系生物量均最大,显著大于其他土层。研究结果显示:随着生境土壤水分和养分条件的变差,赖草会通过增大间隔子长和根系分布深度以及减小分株密度和根茎直径来积极适应复杂多变的高寒沙区环境。

 

Abstract

Soil moisture, organic matter, and nutrient (including total nitrogen, total phosphorus, and total potassium) contents in four habitats of lowwetland, near farmland, interdune, and fixed dune in alpine sandy area were determined, and growth characteristics of Leymus secalinus (Georgi) Tzvel. in these four habitats were compared and analyzed. The results show that in general, contents of moisture, organic matter, total nitrogen, total phosphorus, and total potassium in soil show a tendency to decrease from lowwetland, near farmland, interdune to fixed dune, and contents of moisture, organic matter, total nitrogen, total phosphorus, and total potassium in soil of lowwetland and near farmland are higher than those of interdune and fixed dune. There are great differences in growth characteristics of L. secalinus in different habitats. Height and ground diameter of L. secalinus are both the largest in fixed dune, which are significantly larger than those of L. secalinus in other three habitats (P<0.05); ramet density, rhizome diameter, and biomass of aboveground part and root of L. secalinus in lowwetland and near farmland is relatively large, which are significantly larger than those of L. secalinus in interdune and fixed dune in general; spacer length of L. secalinus in interdune and fixed dune is relatively long, while that of L. secalinus in lowwetland and near farmland is relatively short, and the difference between the former two habitats and the latter two habitats is significant. Root distribution depth of L. secalinus gradually increases from low-wetland, near farmland, interdune to fixed dune, with an increase from 0-30 cm or 0-40 cm to 0-60 cm. With deepening of soil layer, root biomass of L. secalinus in four habitats shows a tendency to first increase and then decrease, and that in soil layer of 10-20 cm is the largest, which is significantly larger than that in other soil layers. It is suggested that under poor soil moisture and nutrient condition, L. secalinus would actively adapt to the complicated and variable environment in alpine sandy area by increasing spacer length and root distribution depth and decreasing ramet density and rhizome diameter.
 

关键词高寒沙区; 赖草; 根系分布; 根系表型可塑性; 间隔子长; 生物量
Key wordsalpine sandy area; Leymus secalinus (Georgi) Tzvel.; root distribution; root phenotypic plasticity; spacer length; biomass
作者张立恒1,2, 贾志清1, 王学全1, 李清雪1, 陈新均1, 李少华1
所在单位1. 中国林业科学研究院荒漠化研究所, 北京 100091; 2. 甘肃省治沙研究所, 甘肃 兰州 730070
点击量149
基金项目林业公益性行业科研专项经费项目(201504420); 国家自然科学基金资助项目(31600585)