Root features related to plant growth and nutrient removal of 35 wetland plants.
Root features related to plant growth and nutrient removal of 35 wetland plants.
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DOI：
10.1016/j.watres.2011.05.002
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发表时间：
2011-07
期刊：
影响因子：
12.8
通讯作者：
Wen-Ling Lai;Shu-Qiang Wang;C. Peng;Zhang-he Chen
中科院分区：
文献类型：
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作者：
Wen-Ling Lai;Shu-Qiang Wang;C. Peng;Zhang-he Chen
为进一步探讨两种类型湿地植物根系假说，对35种小型湿地挺水植物根系的形态、结构、生理生态特征、养分去除以及指标间的相关性进行了比较研究（Chen et al.，2004年）。35种植物的根系形态、结构和生理生态特征存在显著差异。它们分为两种类型：纤维根植物和粗根植物。纤维根植株的大部分或全部根的直径（D）≤ 1 mm。D> 1 mm的根也有许多D ≤ 1 mm的细而长的侧根。这些植物的根长，表皮薄，木质化程度低。粗根植物的根几乎都粗于1 mm，并且通常没有进一步的细侧根。根短，光滑，肉质，表皮厚。纤维根植物的根孔隙度高于厚根植物（p= 0.001）。纤维根植物的通气组织由许多小腔形成的大腔组成，呈放射状分布在外皮层和维管组织之间。粗根植物的通气组织中有大量的小腔，分布在中脐部。与粗根植物相比，纤维根植物的根系生物量、地上生物量、总生物量和根系长度显著增加（p= 0.003，0.018，0.020，0.032，0.042，0.001），但根系寿命显著缩短（p= 0.003，0.018，0.020，0.032，0.042，0.001）。纤维根植物的径向氧损失（ROL），根系活力，光合速率，蒸腾速率，总氮和总磷的去除率也显着高于粗根植物（p= 0.001，0.008，0.010，0.004，0.020，0.002）。结果表明，不同湿地植物根系形态结构特征存在显著差异，这些特征与植物对营养盐的去除能力密切相关。
Morphological, structural, and eco-physiological features of roots, nutrient removal, and correlation between the indices were comparatively studied for 35 emergent wetland plants in small-scale wetlands for further investigation into the hypothesis of two types of wetland plant roots (Chen et al., 2004). Significant differences in root morphological, structural, and eco-physiological features were found among the 35 species. They were divided into two types: fibrous-root plants and thick-root plants. The fibrous-root plants had most or all roots of diameter (D) ≤ 1 mm. Roots ofD> 1 mm also had many fine and long lateral roots ofD≤ 1 mm. The roots of these plants were long and had a thin epidermis and a low degree of lignification. The roots of the thick-root plants were almost all thicker than 1 mm, and generally had no further fine lateral roots. The roots were short, smooth, and fleshy, and had a thick epidermis. Root porosity of the fibrous-root plants was higher than that of the thick-root plants (p= 0.001). The aerenchyma of the fibrous-root plants was composed of large cavities which were formed from many small cavities, and distributed radially between the exodermis and vascular tissues. The aerenchyma of the thick-root plants had a large number of small cavities which were distributed in the mediopellis. The fibrous-root plants had a significantly larger root biomass ofD≤ 1 mm, of 1 mm <D< 3 mm, above-ground biomass, total biomass, and longer root system, but shorter root longevity than those of the thick-root plants (p= 0.003, 0.018, 0.020, 0.032, 0.042, 0.001). The fibrous-root plants also had significantly higher radial oxygen loss (ROL), root activity, photosynthetic rate, transpiration rate, and removal rates of total nitrogen and total phosphorus than the thick-root plants (p= 0.001, 0.008, 0.010, 0.004, 0.020, 0.002). The results indicate that significantly different root morphological and structural features existed among different wetland plants, and these features had a close relationship to nutrient removal capacity.