Coupling of landscape pattern and water use efficiency with different amplitudes: a case study of Qianyanzhou in eastern China

The landscape pattern, which could exert critical impacts on the carbon and water distribution and their coupling in the ecosystem, is the product of integrated actions of ecological processes on a time-spaced scale.

ObjectiveThe objective of this study is to explore the interaction law between landscape pattern and water use efficiency at multiple scales, and to provide a theoretical basis for studies of the coupling relationship between landscape pattern and ecological process, and regional ecological planning.

MethodWe used the Biome-BGC model optimized by the PEST model to simulate water use efficiency (WUE) of Qianyanzhou forest ecosystem from 2000 to 2014, and analyzed the correlations between landscape pattern index (LPI) and WUE, landscape pattern and total primary productivity (GPP), and their trends.

ResultThe results showed that: (1) the landscape fragmentation index (NP and PD) and WUE had a significantly negative correlation in the buffer range of 10−80, while there was a significantly positive correlation between AREA-MN and WUE in this range; (2) The landscape shape index (SHAPE and FRAC) was significantly positive correlated with WUE in the range of 50−100; (3) The positive correlation between landscape polymerization index (PLADJ and AI) and WUE was significant in the range of 10−50; (4) Both landscape diversity and uniformity index (SIDI and SIEI) showed a significantly negative correlation with WUE when the buffer was between 10 to 20, while a significantly positive correlation in the buffer range of 70−100; (5) The correlation between landscape pattern index and water use efficiency showed a conspicuous scale effect; (6) The change law of the correlation between GPP and LPI was consistent with the correlation between WUE and LPI.

ConclusionThis indicates that the coupling of landscape pattern and ecological process is affected by the scale effect. We suggest that the scale effect should be fully considered into regional ecological planning so that the coupling effect of landscape pattern and ecological process could be maximized.