Ecosystem health assessment on the hill and gully area of Loess Plateau in Inner Mongolia,China

Maintenance of ecosystem health is the primary focus of a sound ecological restoration.Yet methods in-volved in quantifying and assessing the health level remain a challenge to the ecological community.In this study,we selected the hill and gully area of Loess Plateau,Inner Mongolia,China,as our study area.The soil and water ero-sions in this area continue to be responsible for many environmental problems in northern China because of its fragility and long disturbance history.In this study,we de-veloped an assessment method of indicator system(AMIS)based on analytical hierarchy process(AHP),fuzzy mathe-matics,and the theory of net-hierarchy.At ecosystem or catchment scale,three sample areas,that is(1)intact vege-tation(i.e.,Aguimiao Natural Reserve,110°45′E,39°28′N),(2)reconstructed vegetation(Wufendigou Soil and Water Conservation Experimental Area,111°07′E,39°45′N),and(3)severely degraded vegetation(Yangquangou Catchment,111°06′E,39°45′N)in the hill and gully area of Loess Pla-teau in Inner Mongolia,China,were selected to examine ecosystem vigor,organizational structure,service function,and soil health.We applied the AMIS for all three land-scapes by categorizing each ecosystem into five health levels.We found that the health index for reconstructed vegetation were at levels of IV,II,IV,and III,while those of degraded vegetation were ranked at V,IV,V,and IV.Overall,the comprehensive ecosystem health index of re-constructed vegetation was lower than that of intact vegetation but higher than that of degraded vegetation.The health index for reconstructed vegetation was at level III,and that of degraded vegetation was still at level IV.The contributing values were:organization structure>soil health>vigor>service function.Based on our results and assessments,we proposed several management recommen-dations and methods for restoring the regional ecosystems.