LAUSR

Abstract Assessing ecosystem states quantitatively or qualitatively is important for ecosystem management. Currently, Traditional Comprehensive Assessment (TCA), including ecosystem health, risk, and service assessment is used most often. Ecosystem stability theory (EST) and ecosystem regime shift theory (RST) from mathematical ecology have not been widely used. In this paper, we compare TCA and EST and RST result using two lakes, Onondaga Lake and Poyang Lake, as case studies. We find that biological oxygen demand (BOD) could be a suitable variable to calculate temporal stability and variance indexes in EST and RST, and trend in general. The result could replace TCA when the key lake driver is not too extreme. This recommendation is preliminary, needing validated with data.