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Understanding the transient dynamics of interlinked social-ecological systems (SES) is imperative for assessing sustainability in the Anthropocene. However, how to identify critical transitions in real-world SES remains a formidable challenge. In this study, we present an evolutionary framework to characterize these dynamics over an extended historical timeline. Our approach leverages multidecadal rates of change in socioeconomic data, paleoenvironmental, and cutting-edge sedimentary ancient DNA records from China's Yangtze River Delta, one of the most densely populated and intensively modified landscapes on Earth. Our analysis reveals two significant social-ecological transitions characterized by contrasting interactions and feedback spanning several centuries. Initially, the regional SES exhibited a loosely connected and ecologically sustainable regime. Nevertheless, starting in the 1950s, an increasingly interconnected regime emerged, ultimately resulting in the crossing of tipping points and an unprecedented acceleration in soil erosion, water eutrophication, and ecosystem degradation. Remarkably, the second transition occurring around the 2000s, featured a notable decoupling of socioeconomic development from ecoenvironmental degradation. This decoupling phenomenon signifies a more desirable reconfiguration of the regional SES, furnishing essential insights not only for the Yangtze River Basin but also for regions worldwide grappling with similar sustainability challenges. Our extensive multidecadal empirical investigation underscores the value of coevolutionary approaches in understanding and addressing social-ecological system dynamics. [ABSTRACT FROM AUTHOR]

The 10Be record in laminated travertines is a potential proxy for reconstructing past solar activity down to the annual scale; however, correcting for the potential influence of climatic or environmental variations remains challenging. Here, we present an annually resolved 10Be record using travertines from Baishuitai, China, covering the period from 1510 to 1701 CE, along with environmental proxies, to evaluate climatic influences and implement corrections to accurately reconstruct solar activity. We demonstrate that the 10Be deposition in travertines exhibits two environmental impacts: the transport efficiency of atmospheric 10Be into travertine and the additional 10Be inflow from overland flow associated with rainfall. We show that these impacts can be corrected based on iron and potassium contents. The resulting corrected record agrees with ice‐core and tree‐ring records, demonstrating the feasibility of using such carbonate sediment 10Be records to reconstruct past solar activity. Plain Language Summary: The travertine 10Be record has great potential as a proxy for high‐resolution reconstruction of past solar activity; however, the methodology for correcting the potential influence of climatic or environmental variations has not been fully established. This study presents a new high‐precision annual 10Be record using travertines from Baishuitai, China, covering the period 1510–1701 CE, together with records of environmental proxies, allowing us to evaluate the climatic influences and establish a methodology for correcting them to facilitate accurate solar activity reconstruction. We find that there are two environmental impacts on the deposition of 10Be in travertine: one is the transport efficiency of atmospheric 10Be into travertine, and the other is the additional 10Be inflow from the runoff following rainfall events, and we use iron (Fe) and potassium (K) contents to correct these impacts. The corrected travertine 10Be record exhibits good agreement with ice‐core 10Be and tree‐ring 14C records, supporting that the 10Be record in Baishuitai travertine reliably reflects the atmospheric radionuclide production rate as regulated by solar activity. This result demonstrates the feasibility of using such carbonate sediment 10Be records to reconstruct annual solar activity and suggests the possibility of extending the annual records further back in time than previously obtained. Key Points: A high‐precision annual record of travertine 10Be from 1510 to 1701 CE was obtained to assess its potential as a proxy for solar activityClimatological and environmental impacts on 10Be deposition were found to be correctable based on the content of trace elementsThe travertine 10Be record corrected for climatological impacts reasonably preserves the decadal and centennial‐scale solar cycles [ABSTRACT FROM AUTHOR]

Dynamics of the terrestrial water surface impact hydrological connectivity. Compared with traditionally deployed water surface parameters, changes in the water-boundary more effectively account for the dynamics of water surface and depth resulting from hydrological variations. However, previous studies of hydrological connectivity generally applied only connectivity length or width parameters using the center line of the water body and therefore fail to fully capture the impact of water boundary dynamics. In this study, optimized water body extraction indices based on data obtained from remote sensing imagery are used to develop a novel metric that indicates water surface boundary dynamics and reveal surface hydrological connectivity changes in the Yangtze River Delta from 1990 to 2020. Detailed inter-annual and seasonal changes in the evolution of water body boundaries from a water surface perspective indicate an overall decline in hydrological connectivity against the background of climate change, increased urbanization, and dam construction. The declining trend in connectivity occurs in three phases, viz. from 1990 to 2003, a gradual decline is exhibited but with a very marked degree of inter-seasonal variability; between 2003 and 2012, connectivity remains relatively constant but with a reduced amplitude between seasons; further reductions in the magnitude of seasonal variations characterize the third phase, to 2020. Meanwhile, the stability of hydrological connectivity, indicated by the coefficient of variation, also exhibits marked spatial heterogeneity. Parts of the delta with more tributaries, including the Huaihe and southeastern basins, have lower stability (7.33 and 6.59, respectively) than the Yangtze basin (6.22). This study presents a novel metric to achieve greater precision in the monitoring of hydrological connectivity. Such information can be harnessed to improve regional ecological and water resource management. [ABSTRACT FROM AUTHOR]