scholarly journals Effects of water level and competition pattern on ecological stoichiometry characteristics of a typical wetland plant Polygonum hydropiper in Lake Dongting

2019 ◽  
Vol 31 (6) ◽  
pp. 1651-1661
Author(s):  
LI Xu ◽  
◽  
YU Jie ◽  
LI Feng ◽  
HU Cong ◽  
...  
2018 ◽  
Vol 5 (12) ◽  
pp. 180729 ◽  
Author(s):  
Yong Ji ◽  
Zhidong Yao ◽  
Jie Zhang ◽  
Xueru Wang ◽  
Jixiang Luo ◽  
...  

Vallisneria spiralis , a widely distributed wetland plant, was used to reveal how the light intensity at the top of the plant, plant morphology and antioxidant enzyme activity respond to different hydrologic conditions from Lake Poyang, China. By designing a laboratory experiment simulating historical water levels of low, normal and high wetland plant submersion, this study aimed to elucidate the effects of different levels of flooding on growth and antioxidant enzyme activity for V. spiralis . The results showed that the plant crown light intensity of the treated group and control group (CG) first decreased and then increased along with the seasonal variation of the water level. The maximum and minimum values of the plant crown light intensity were observed in April and July, respectively. Similar to the CG, V. spiralis from the normal and low water level (LWL) groups was measured and had higher plant height growth in the flooding period from May to June, and the entire plant biomass also showed a steady growth trend in the same period. However, the plant growth of the high water level (HWL) group was lower during the whole simulation period, with negative growth in July. Antioxidant enzyme activities changed with the seasonal temperature, and the activity of the CG showed a rising trend. Compared with those of the CG, the antioxidant enzyme activities of the HWL group showed a ‘bell shaped’ trend, which was first significantly induced and then significantly inhibited. In addition, the peroxidase (POD) and catalase (CAT) activities from the LWL group in April were also significantly induced. The integrated biomarker response (IBR) index showed that a comprehensive biological index could well reflect the effects of seasonal water levels in Poyang Lake on the growth of the wetland plant V. spiralis . This study indicated that high flooding levels had the strongest negative effect on the growth and enzyme activity of the submerged plant V. spiralis .


1999 ◽  
Vol 64 (2) ◽  
pp. 151-165 ◽  
Author(s):  
John P.M. Lenssen ◽  
Frank B.J. Menting ◽  
Wim H. van der Putten ◽  
Cornelis W.P.M. Blom

Author(s):  
D.S. Rakisheva ◽  
◽  
B.G. Mukanova ◽  
I.N. Modin ◽  
◽  
...  

Numerical modeling of the problem of dam monitoring by the Electrical Resistivity Tomography method is carried out. The mathematical model is based on integral equations with a partial Fourier transform with respect to one spatial variable. It is assumed that the measurement line is located across the dam longitude. To approximate the shape of the dam surface, the Radial Basic Functions method is applied. The influence of locations of the water-dam, dam-basement, basement-leakage boundaries with respect to the sounding installation, which is partially placed under the headwater, is studied. Numerical modeling is carried out for the following varied parameters: 1) water level at the headwater; 2) the height of the leak; 3) the depth of the leak; 4) position of the supply electrode; 5) water level and leaks positions are changing simultaneously. Modeling results are presented in the form of apparent resistivity curves, as it is customary in geophysical practice.


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