Divergence of Water Yield and Gross Ecosystem Productivity Under the Changing Vegetation Cover and Climate in the Poyang Lake Watershed

2019 ◽  
Author(s):  
LinLing Tang ◽  
Xiaobin Cai ◽  
Xiaoling Chen ◽  
Jialin Wang
Keyword(s):  
Vegetation Cover ◽  
Poyang Lake ◽  
Water Yield ◽  
Ecosystem Productivity ◽  
Gross Ecosystem Productivity

Ecological responses of Stipa steppe in Inner Mongolia to experimentally increased temperature and precipitation. 4. Carbon exchange

2018 ◽  
Vol 40 (2) ◽  
pp. 159 ◽  
Author(s):  
Luomeng Chao ◽  
Zhiqiang Wan ◽  
Yulong Yan ◽  
Rui Gu ◽  
Yali Chen ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Air Temperature ◽  
Inner Mongolia ◽  
Ecosystem Respiration ◽  
Block Design ◽  
Net Ecosystem Exchange ◽  
Carbon Exchange ◽  
Ecosystem Productivity ◽  
Temperature And Precipitation ◽  
Gross Ecosystem Productivity

Aspects of carbon exchange were investigated in typical steppe east of Xilinhot city in Inner Mongolia. Four treatments with four replicates were imposed in a randomised block design: Control (C), warming (T), increased precipitation (P) and combined warming and increased precipitation (TP). Increased precipitation significantly increased both ecosystem respiration (ER) and soil respiration (SR) rates. Warming significantly reduced the ER rate but not the SR rate. The combination of increased precipitation and warming produced an intermediate response. The sensitivity of ER and SR to soil temperature and air temperature was assessed by calculating Q10 values: the increase in respiration for a 10°C increase in temperature. Q10 was lowest under T and TP, and highest under P. Both ER and SR all had significantly positive correlation with soil moisture. Increased precipitation increased net ecosystem exchange and gross ecosystem productivity, whereas warming reduced them. The combination of warming and increased precipitation had an intermediate effect. Both net ecosystem exchange and gross ecosystem productivity were positively related to soil moisture and negatively related to soil and air temperature. These findings suggest that predicted climate change in this region, involving both increased precipitation and warmer temperatures, will increase the net ecosystem exchange in the Stipa steppe meaning that the ecosystem will fix more carbon.

scholarly journals Stream flow simulation and verification in ungauged zones by coupling hydrological and hydrodynamic models: a case study of the Poyang Lake ungauged zone

2017 ◽  
Vol 21 (11) ◽  
pp. 5847-5861 ◽  
Author(s):  
Ling Zhang ◽  
Jianzhong Lu ◽  
Xiaoling Chen ◽  
Dong Liang ◽  
Xiaokang Fu ◽  
...  
Keyword(s):  
Water Resource ◽  
Stream Flow ◽  
Assessment Tool ◽  
Poyang Lake ◽  
Swat Model ◽  
Water Yield ◽  
Lake Basin ◽  
Observation Data ◽  
Wet Season ◽  
Annual Water

Abstract. To solve the problem of estimating and verifying stream flow without direct observation data, we estimated stream flow in ungauged zones by coupling a hydrological model with a hydrodynamic model, using the Poyang Lake basin as a test case. To simulate the stream flow of the ungauged zone, we built a soil and water assessment tool (SWAT) model for the entire catchment area covering the upstream gauged area and ungauged zone, and then calibrated the SWAT model using the data in the gauged area. To verify the results, we built two hydrodynamic scenarios (the original and adjusted scenarios) for Poyang Lake using the Delft3D model. In the original scenario, the upstream boundary condition is the observed stream flow from the upstream gauged area, while, in the adjusted scenario, it is the sum of the observed stream flow from the gauged area and the simulated stream flow from the ungauged zone. The experimental results showed that there is a stronger correlation and lower bias (R2 = 0.81, PBIAS  =  10.00 %) between the observed and simulated stream flow in the adjusted scenario compared to that (R2 = 0.77, PBIAS  =  20.10 %) in the original scenario, suggesting the simulated stream flow of the ungauged zone is reasonable. Using this method, we estimated the stream flow of the Poyang Lake ungauged zone as 16.4 ± 6.2 billion m3 a−1, representing ∼ 11.24 % of the annual total water yield of the entire watershed. Of the annual water yield, 70 % (11.48 billion m3 a−1) is concentrated in the wet season, while 30 % (4.92 billion m3 a−1) comes from the dry season. The ungauged stream flow significantly improves the water balance with the closing error decreased by 13.48 billion m3 a−1 (10.10 % of the total annual water resource) from 30.20 ± 9.1 billion m3 a−1 (20.10 % of the total annual water resource) to 16.72 ± 8.53 billion m3 a−1 (10.00 % of the total annual water resource). The method can be extended to other lake, river, or ocean basins where observation data is unavailable.

scholarly journals Soil respiration of a Moso bamboo forest significantly affected by gross ecosystem productivity and leaf area index in an extreme drought event

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5747 ◽  
Author(s):  
Yuli Liu ◽  
Guomo Zhou ◽  
Huaqiang Du ◽  
Frank Berninger ◽  
Fangjie Mao ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Respiration ◽  
Soil Temperature ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Moso Bamboo ◽  
Drought Event ◽  
Ecosystem Productivity ◽  
Area Index ◽  
Gross Ecosystem Productivity

Moso bamboo has large potential to alleviate global warming through carbon sequestration. Since soil respiration (Rs) is a major source of CO2 emissions, we analyzed the dynamics of soil respiration (Rs) and its relation to environmental factors in a Moso bamboo (Phllostachys heterocycla cv. pubescens) forest to identify the relative importance of biotic and abiotic drivers of respiration. Annual average Rs was 44.07 t CO2 ha−1 a−1. Rs correlated significantly with soil temperature (P < 0.01), which explained 69.7% of the variation in Rs at a diurnal scale. Soil moisture was correlated significantly with Rs on a daily scale except not during winter, indicating it affected Rs. A model including both soil temperature and soil moisture explained 93.6% of seasonal variations in Rs. The relationship between Rs and soil temperature during a day showed a clear hysteresis. Rs was significantly and positively (P < 0.01) related to gross ecosystem productivity and leaf area index, demonstrating the significance of biotic factors as crucial drivers of Rs.

scholarly journals Water balance assessment of an ungauged area in Poyang Lake watershed using a spatially distributed runoff coefficient model

2018 ◽  
Vol 20 (5) ◽  
pp. 1009-1024 ◽  
Author(s):  
Jianzhong Lu ◽  
Xiaoling Chen ◽  
Ling Zhang ◽  
Sabine Sauvage ◽  
José-Miguel Sánchez-Pérez
Keyword(s):  
Water Balance ◽  
Water Flow ◽  
Poyang Lake ◽  
Reanalysis Data ◽  
Water Yield ◽  
Runoff Coefficient ◽  
Plain Area ◽  
Proposed Model ◽  
Spatially Distributed ◽  
Relative Errors

Abstract The Poyang Lake ungauged area (PLUA) is an essential hydrology buffer surrounding Poyang Lake. For such a data-scarce area, a novel spatially distributed runoff coefficient model (SDRCM) was developed based on the underlying surface properties using remotely sensed precipitation and reanalysis data after their validation. The runoff simulated by the SDRCM based on both sets of gridded precipitation data were validated in a subbasin where R2 and ENS are larger than 0.87. In addition, a hydrodynamic model was applied to validate the proposed model further by considering the estimated water yield for PLUA that involves boundary inputs, in which the result more closely aligns to the monthly observed discharge. On an annual basis, the PLUA water flow accounted for 12%–19% of the total annual water flow within the watershed, which was approximately equal to the proportion of the area of PLUA in relation to the entire watershed. Finally, the water balance between inflow and outflow of Poyang Lake was investigated, with relative errors observed at the Hukou gauging station all being less than 10% from 1998 to 2009. The proposed model will be helpful in understanding the significance of water yields of such ungauged plain area when evaluating the water balance.

Sign in / Sign up

Export Citation Format

Share Document