Effects of water level fluctuations on root architectural and morphological traits of plants in lakeshore areas of three subtropical floodplain lakes in China
Effects of water level fluctuations on root architectural and morphological traits of plants in lakeshore areas of three subtropical floodplain lakes in China
复制标题
水位波动对我国三个亚热带洪泛区湖岸区植物根系结构和形态特征的影响
DOI：
10.1007/s11356-018-3429-5
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发表时间：
2018
影响因子：
5.8
通讯作者：
Guanhua Liu
中科院分区：
文献类型：
--
作者：
Xiaoke Zhang;Haiming Qin;Huili Wang;An Wan;Guanhua Liu
湖滨带植物根系的大小直接决定着植物地上部分的存活。然而，目前的研究主要集中在地上部，而对根系的功能研究较少。为研究水位波动对湖滨带植物根系构型和形态特征的影响，对3个不同类型水位波动的亚热带洪泛区湖泊进行了季节性的实地调查。结果表明：3个湖泊土壤pH值和含水量在所有季节均存在显著差异，而土壤全氮和全磷仅在某些季节存在显著差异。两个结构特征参数（根长密度和根分枝数）和三个形态特征参数（根组织密度、根表面积和根体积）也存在显著差异，除根组织密度外，其余参数均以间歇性WLF的大湖池最高，而以类似沼泽的WLF的巢湖最低。随着湖岸海拔梯度的增加，三个湖泊的根长密度、根分枝数、根表面积和根体积均发生显著变化，且均呈现先增加后减小的趋势。不同季节三个湖泊的上述4个根系性状差异不显著。斯皮尔曼相关分析表明，水文和理化因子与根系构型和形态性状参数均存在较强的相关性，其中淹水时间（duration）对根系构型和形态性状参数的影响最大。多元逐步回归分析结果进一步表明，生育期是影响根系性状的关键因子。根据研究结果，我们建议应改变湖泊的WLF，以改善湖岸的生态功能。
Plant roots in lakeshore areas can directly determine the survival of the aboveground plant parts. However, most current studies are focused on the aerial shoots, and less attention has been paid to the functions of the roots. In order to evaluate the effects of water level fluctuations (WLFs) on root architectural and morphological traits of plants in lakeshore areas, field investigations were conducted seasonally in three subtropical floodplain lakes with different types of WLFs. The results showed that both the pH and moisture contents of the soils were significantly different in all seasons among the three lakes, while the total nitrogen and total phosphorus in the soils only showed significant differences in certain seasons. Significant differences were also found in the two architectural trait parameters (root length density and root branching number) and three morphological trait parameters (root tissue density, root surface area, and root volume), all of which (except for root tissue density) were highest in the Dahuchi lake that experiences intermittent WLFs, and lowest in the Chaohu Lake with reservoir-like WLFs. With increasing lakeshore elevation gradients, we found that root length density, root branching number, root surface area, and root volume in the three lakes changed significantly, and all these root trait parameters increased first and then decreased. However, no significant differences were found for the above four root traits in the three lakes over the different seasons. Spearman correlation analyses indicated that both the hydrological and physicochemical factors were strongly correlated with the architectural and morphological root trait parameters, and the duration of submergence (duration) was the most important factor, judging from the correlation coefficients (R). The results of stepwise multiple regression further indicated the duration was the key factor affecting plant root traits. Based on the results of this study, we suggest that the WLFs in reservoir-like lakes should be changed in order to improve the ecological functions of the lakeshore.