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Water use efficiency of China's terrestrial ecosystems and responses to drought.

Liu Y, Xiao J, Ju W, Zhou Y, Wang S, Wu X - Sci Rep (2015)

Bottom Line: Droughts usually increased annual WUE in Northeast China and central Inner Mongolia but decreased annual WUE in central China. "Turning-points" were observed for southern China where moderate and extreme droughts reduced annual WUE and severe drought slightly increased annual WUE.The cumulative lagged effect of drought on monthly WUE varied by region.WUE is expected to continue to change under future climate change particularly as drought is projected to increase in both frequency and severity.

View Article: PubMed Central - PubMed

Affiliation: Jiangsu Key Laboratory of Agricultural Meteorology, School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, 210044, China.

ABSTRACT
Water use efficiency (WUE) measures the trade-off between carbon gain and water loss of terrestrial ecosystems, and better understanding its dynamics and controlling factors is essential for predicting ecosystem responses to climate change. We assessed the magnitude, spatial patterns, and trends of WUE of China's terrestrial ecosystems and its responses to drought using a process-based ecosystem model. During the period from 2000 to 2011, the national average annual WUE (net primary productivity (NPP)/evapotranspiration (ET)) of China was 0.79 g C kg(-1) H2O. Annual WUE decreased in the southern regions because of the decrease in NPP and the increase in ET and increased in most northern regions mainly because of the increase in NPP. Droughts usually increased annual WUE in Northeast China and central Inner Mongolia but decreased annual WUE in central China. "Turning-points" were observed for southern China where moderate and extreme droughts reduced annual WUE and severe drought slightly increased annual WUE. The cumulative lagged effect of drought on monthly WUE varied by region. Our findings have implications for ecosystem management and climate policy making. WUE is expected to continue to change under future climate change particularly as drought is projected to increase in both frequency and severity.

No MeSH data available.


The correlation coefficients of annual mean LAI with annual WUE for terrestrial ecosystems of China during the period 2000–2011.Correlation coefficients of 0.497, 0.576, and 0.708 indicate respective significant levels of 0.10, 0.05, and 0.01. This figure was produced using ArcGIS 10.0.
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f3: The correlation coefficients of annual mean LAI with annual WUE for terrestrial ecosystems of China during the period 2000–2011.Correlation coefficients of 0.497, 0.576, and 0.708 indicate respective significant levels of 0.10, 0.05, and 0.01. This figure was produced using ArcGIS 10.0.

Mentions: LAI was partly responsible for the interannual variation of WUE. Figure 3 shows the correlation between the mean annual LAI and mean WUE during the period from 2000 to 2011. Annual LAI exhibited positive relationship with WUE in most regions. In sparsely vegetated regions, the ratio of transpiration to evaporation increases with the increase in LAI, and water is more effectively consumed for carbon uptake, leading to increases in WUE. During the 12-year period, LAI increased in northeastern and northern China24, and annual WUE also significantly increased (Fig. 2); LAI decreased in Qinghai-Tibet Plateau and the eastern part of Southwest China24, and annual WUE also significantly declined (Fig. 2).


Water use efficiency of China's terrestrial ecosystems and responses to drought.

Liu Y, Xiao J, Ju W, Zhou Y, Wang S, Wu X - Sci Rep (2015)

The correlation coefficients of annual mean LAI with annual WUE for terrestrial ecosystems of China during the period 2000–2011.Correlation coefficients of 0.497, 0.576, and 0.708 indicate respective significant levels of 0.10, 0.05, and 0.01. This figure was produced using ArcGIS 10.0.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4562296&req=5

f3: The correlation coefficients of annual mean LAI with annual WUE for terrestrial ecosystems of China during the period 2000–2011.Correlation coefficients of 0.497, 0.576, and 0.708 indicate respective significant levels of 0.10, 0.05, and 0.01. This figure was produced using ArcGIS 10.0.
Mentions: LAI was partly responsible for the interannual variation of WUE. Figure 3 shows the correlation between the mean annual LAI and mean WUE during the period from 2000 to 2011. Annual LAI exhibited positive relationship with WUE in most regions. In sparsely vegetated regions, the ratio of transpiration to evaporation increases with the increase in LAI, and water is more effectively consumed for carbon uptake, leading to increases in WUE. During the 12-year period, LAI increased in northeastern and northern China24, and annual WUE also significantly increased (Fig. 2); LAI decreased in Qinghai-Tibet Plateau and the eastern part of Southwest China24, and annual WUE also significantly declined (Fig. 2).

Bottom Line: Droughts usually increased annual WUE in Northeast China and central Inner Mongolia but decreased annual WUE in central China. "Turning-points" were observed for southern China where moderate and extreme droughts reduced annual WUE and severe drought slightly increased annual WUE.The cumulative lagged effect of drought on monthly WUE varied by region.WUE is expected to continue to change under future climate change particularly as drought is projected to increase in both frequency and severity.

View Article: PubMed Central - PubMed

Affiliation: Jiangsu Key Laboratory of Agricultural Meteorology, School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, 210044, China.

ABSTRACT
Water use efficiency (WUE) measures the trade-off between carbon gain and water loss of terrestrial ecosystems, and better understanding its dynamics and controlling factors is essential for predicting ecosystem responses to climate change. We assessed the magnitude, spatial patterns, and trends of WUE of China's terrestrial ecosystems and its responses to drought using a process-based ecosystem model. During the period from 2000 to 2011, the national average annual WUE (net primary productivity (NPP)/evapotranspiration (ET)) of China was 0.79 g C kg(-1) H2O. Annual WUE decreased in the southern regions because of the decrease in NPP and the increase in ET and increased in most northern regions mainly because of the increase in NPP. Droughts usually increased annual WUE in Northeast China and central Inner Mongolia but decreased annual WUE in central China. "Turning-points" were observed for southern China where moderate and extreme droughts reduced annual WUE and severe drought slightly increased annual WUE. The cumulative lagged effect of drought on monthly WUE varied by region. Our findings have implications for ecosystem management and climate policy making. WUE is expected to continue to change under future climate change particularly as drought is projected to increase in both frequency and severity.

No MeSH data available.