| 半干旱区沙地沙蒿生物量及根系分布特征研究 |
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| 引用本文： | 赵明,王文科,王周锋,陈立,马稚桐,宋浩.半干旱区沙地沙蒿生物量及根系分布特征研究[J].干旱区地理,2018,41(4):786-792. |
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| 作者姓名： | 赵明 王文科 王周锋 陈立 马稚桐 宋浩 |
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| 作者单位： | 1. 长安大学环境科学与工程学院, 陕西 西安 710054;
2. 旱区地下水文与生态效应教育部重点实验室, 陕西 西安 710054 |
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| 基金项目： | 国家自然科学基金重点项目（41230314） |
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| 摘 要： | 沙蒿是中国西北半干旱地区主要的固沙植物，其根系分布影响包气带水分运移过程，准确的植被特征和根系密度分布对根系吸水模型的建立十分重要。采用整体挖掘法获取不同层位的根系和根际土壤含水量，引入冠级和龄级的概念对沙蒿根系分布特征进行研究。分析结果表明：沙蒿种群以低龄级沙蒿占优，其根系生物量随龄级呈'S’型增长；根系长度分布和均一化根系密度分布均符合对数正态分布，最大值出现在浅层土壤20 cm处；沙蒿生长不依赖于地下水，其根系主要利用包气带中的水分，持续干旱条件下，为满足蒸腾作用根系出现两种调节方式：（1）横向生长增加根系量，利用横向土壤剖面的水分。（2）浅层根区由于水分胁迫造成的吸水量减少由深部相对湿润的根区补偿。因此沙蒿根系吸水模型中的根系密度分布函数应为对数正态分布，且吸水过程不仅依赖于根系密度分布，同时受土壤水分的影响。
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| 关 键 词： | 半干旱区 沙蒿 龄级 根系分布 |
| 收稿时间： | 2018-02-08 |
Biomass of Artemisia ordosica in sand land and its root system distribution characteristics in the semiarid regions |
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| ZHAO Ming,WANG Wen-ke,WANG Zhou-feng,CHEN Li,MA Zhi-tong,SONG Hao.Biomass of Artemisia ordosica in sand land and its root system distribution characteristics in the semiarid regions[J].Arid Land Geography,2018,41(4):786-792. |
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| Authors: | ZHAO Ming WANG Wen-ke WANG Zhou-feng CHEN Li MA Zhi-tong SONG Hao |
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| Institution: | 1. Environment Technology and Engineering School of Chang'an University, Xi'an 710054, Shaanxi, China;
2. Key Laboratory of Subsurface Hydrology and Ecological Effects in Arid Region, Chang'an University, Ministry of Education, Xi'an 710054, Shaanxi, China |
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| Abstract: | The characteristics of root system distribution play a crucial role in root water uptake simulation and the flow dynamic in vadose zone with vegetation in semiarid regions.The linear and simple nonlinear root density distribution models were adopted frequently in the previous researches and most root water uptake models depended on the root system density distribution closely.In order to depict the real Artemisia ordosica root system density distribution and its relationship with soil water content,the root biomass and rhizospheric soil moisture were obtained by mining Artemisia ordosica roots integrally and were analyzed using the concept of plant crown level and static age level in this study.The results indicated that the Artemisia ordosica roots system is in accordance with lognormal distribution,and the uniform root density distribution can not only ignore the difference among Artemisia ordosica individuals,but also is of universal applicability.When there is a persistent drought,the reduced root water uptake in shallow root zone by water stress could be compensated by the root water uptake in deep root zone where it is relatively moist.Therefore,the complex biophysics indicates that the root water uptake is not only related to the root system density distribution,but also depends on the water state in vadose zone. |
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| Keywords: | semiarid region Artemisia ordosica age class distribution of rootsystem |
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