scholarly journals Net Primary Production Predicted by the Proportion of C:N:P Stoichiometric Ratio in the Leaf-Stem and Root of Cynodon Dactylon (Linn.) in the Riparian Zone of the Three Gorges Reservoir

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3279
Author(s):  
Dan Liu ◽  
Liping He ◽  
Zhiguo Yu ◽  
Zhengxue Liu ◽  
Junjie Lin
Keyword(s):  
Primary Production ◽  
Three Gorges Reservoir ◽  
Riparian Zone ◽  
Cynodon Dactylon ◽  
Net Primary Production ◽  
Stoichiometric Ratio ◽  
Three Gorges ◽  
P Content ◽  
C:P Ratio ◽  
Relationship Of

Net primary production (NPP) is closely related to the proportion of carbon (C), nitrogen (N) and phosphorus (P) in the leaf-stem and root of perennial herbs. However, the relationship of NPP with the C:N:P stoichiometric ratio in above- and below-ground plant tissues remains unknown under the periodic flooding stresses in the riparian zone ecosystem. In this study, the leaf-stem and root C, N, P content and biomass of Cynodon dactylon (Linn.) Pers. (C. dactylon) were investigated at the riparian zone altitudes of 145–155, 155–165, and 165–175 m above sea level (masl) of in a Three Gorges Reservoir (TGR) tributary–Pengxi River. The results showed that the NPP and biomass of C. dactylon had a similar decreasing trend with a riparian zone altitudes decrease. The root of C. dactylon showed relatively lower N and P content, but much higher N and P use efficiency with higher C:N and C:P ratio than that of a leaf-stem under N limitation conditions. NPP was positively correlated to C:N in the stem-leaf to root ratio (C:Nstem-leaf/root) and C:P ratio in the root (C:Proot ratio). Hydrological and C:N:P stoichiometric variables could predict 68% of the NPP variance, and thus could be regarded as the main predictor of NPP in the riparian zone of the TGR.

Mulberry trees conserved soil and protected water quality in the riparian zone of the Three Gorges Reservoir, China

2015 ◽  
Vol 23 (6) ◽  
pp. 5288-5295 ◽  
Author(s):  
Yun Liu ◽  
J. H. Martin Willison ◽  
Pan Wan ◽  
Xing-zheng Xiong ◽  
Yang Ou ◽  
...  
Keyword(s):  
Water Quality ◽  
Three Gorges Reservoir ◽  
Riparian Zone ◽  
Three Gorges ◽  
The Three Gorges Reservoir ◽  
The Three Gorges

Strong restrictions on the trait range of co-occurring species in the newly created riparian zone of the Three Gorges Reservoir Area, China

2019 ◽  
Vol 12 (5) ◽  
pp. 825-833 ◽  
Author(s):  
Aiying Zhang ◽  
Will Cornwell ◽  
Zhaojia Li ◽  
Gaoming Xiong ◽  
Dayong Fan ◽  
...  
Keyword(s):  
Leaf Area ◽  
Plant Communities ◽  
Community Assembly ◽  
Three Gorges Reservoir ◽  
Riparian Zone ◽  
Three Gorges Reservoir Area ◽  
Three Gorges ◽  
Unit Leaf ◽  
Altered Hydrology ◽  
The Three Gorges

Abstract Aims Community assembly links plant traits to particular environmental conditions. Numerous studies have adopted a trait-based approach to understand both community assembly processes and changes in plant functional traits along environmental gradients. In most cases these are long-established, natural or semi-natural environments. However, increasingly human activity has created, and continues to create, a range of new environmental conditions, and understanding community assembly in these ‘novel environments’ will be increasingly important. Methods Built in 2006, the Three Gorges Dam, largest hydraulic project in China, created a new riparian area of 384 km2, with massively altered hydrology. This large, newly created ecosystem is an ideal platform for understanding community assembly in a novel environment. We sampled environment variables and plant communities within 103 plots located in both the reservoir riparian zone (RRZ) and adjacent non-flooded and semi-natural upland (Upland) at the Three Gorges Reservoir Area. We measured six traits from 168 plant species in order to calculate community-level distribution of trait values. We expected that the altered hydrology in RRZ would have a profound effect on the community assembly process for the local plants. Important Findings Consistent with previous work on community assembly, the distribution of trait values (range, variance, kurtosis and the standard deviation of the distribution neighbor distances) within all plots was significantly lower than those from random distributions, indicating that both habitat filtering and limiting similarity simultaneously shaped the distributions of traits and the assembly of plant communities. Considering the newly created RRZ relative to nearby sites, community assembly was different in two main ways. First, there was a large shift in the mean trait values. Compared to Upland communities, plant communities in the RRZ had higher mean specific leaf area (SLA), higher nitrogen per unit leaf mass (Nmass), and lower maximum height (MH). Second, in the RRZ compared to the Upland, for the percentage of individual plots whose characteristic of trait values was lower than null distributions, the reductions in the community-level range for SLA, Nmass, nitrogen per unit leaf area (Narea) and phosphorus per unit leaf area (Parea) were much larger, suggesting that the habitat filter in this newly created riparian zone was much stronger compared to longer established semi-natural upland vegetation. This stronger filter, and the restriction to a subset of plants with very similar trait values, has implications for predicting riparian ecosystems’ responses to the hydrological alterations and further understanding for human’s effect on plant diversity and plant floras.

scholarly journals Effects of Rainfall Intensity and Vegetation Cover on Erosion Characteristics of a Soil Containing Rock Fragments Slope

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Bingqin Zhao ◽  
Lun Zhang ◽  
Zhenyao Xia ◽  
Wennian Xu ◽  
Lu Xia ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Vegetation Cover ◽  
Three Gorges Reservoir ◽  
Rainfall Intensity ◽  
Sediment Load ◽  
Cynodon Dactylon ◽  
Three Gorges ◽  
Rock Fragments ◽  
Runoff Volume ◽  
The Three Gorges

Rainfall events coupled with shallow and gravelly sloping farmland have led to serious soil erosion and associated problems in the Three Gorges reservoir. Previous studies have shown that the use of vegetation is an effective way to control soil erosion. Therefore, an artificial, simulated rainfall experiment study is conducted to determine the effect of rainfall intensity and vegetation cover on runoff volume, sediment load, and runoff hydraulics characteristics. The experiment consists of seven vegetation treatments subjected to three rainfall intensities on a soil that contains rock fragments on a slope of 30°. The results indicate that the runoff volume and sediment load of the bare plot were greater than those of vegetation-covered plots under three different rainfall intensities. When Cynodon dactylon and Indigofera amblyantha were applied together, the plot displayed the best performance for soil loss control, with a reduction of 87.88%–99.11%. According to a redundancy analysis, the change in rainfall intensity had the least impact on the Reynolds number and the runoff volume of the herb-shrub mixed plot in this study. These findings suggest that the effect of combining Cynodon dactylon and Indigofera amblyantha and increasing the vegetation coverage is an effective solution for soil and water loss conservation. The application of this method can alleviate environmental stress on the Three Gorges reservoir.

Soil erosion in the riparian zone of the Three Gorges Reservoir, China

2013 ◽  
Vol 46 (2) ◽  
pp. 212-221 ◽  
Author(s):  
Yuhai Bao ◽  
Qiang Tang ◽  
Xiubin He ◽  
Yunhua Hu ◽  
Xinbao Zhang
Keyword(s):  
Soil Erosion ◽  
Surface Runoff ◽  
Water Wave ◽  
Three Gorges Reservoir ◽  
Riparian Zone ◽  
Water Levels ◽  
Three Gorges ◽  
The Three Gorges Reservoir ◽  
The Three Gorges ◽  
Wave Erosion

The riparian zone of the Three Gorges Reservoir (TGR) has experienced substantial erosion that may severely deteriorate the reservoir ecosystem. To calculate soil erosion characteristics, field investigations have been conducted in the TGR area and 12 erosion-monitoring transects have been set in the middle TGR. The results showed that the dominating drive forces are water wave, gravity and surface runoff. In summer when the reservoir ran at lower water levels, wave erosion led to bank instability and bank collapses. Simultaneously, due to a number of heavy storms, surface runoff erosion was also severe. In other seasons when the reservoir ran at relative higher levels reaching the highest level in winter, water wave prevailed due to the wide range of water surface and heavy waterway transportation. Soil erosion was the most severe in the mainstream where higher frequency and intensity of waves occurred. The rates of wave erosion were around 37 mm/year with the highest being 53 mm/year, and surface runoff erosion was up to 15 mm/year in the main stream riparian zone.

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