Regime Shifts and Resilience of the Lake Taihu Social‐Ecological System Under Long‐term External Disturbance (1960s–2000s)

Abstract

The assessment of regime shifts and resilience variations are powerful analytical approaches for understanding the dynamics of social‐ecological systems (SESs) over time. Here, we used a sequential t‐test algorithm for analyzing regime shifts and system resilience coefficient (SRC) to assess the state of Lake Taihu, a shallow lake in China that has experienced long‐term external disturbances. The results showed that the Lake Taihu SES underwent a regime shift in the early of 1990s, and the development states of Lake Taihu SES can be divided into four stages: normal development stage (1960 to the late 1960s), preliminary degradation stage (the late 1960s to the late 1980s), disorder stage (the late1980s to the late 1990s), and reorganization stage (the late 1990s to the 2000s). The SRC declined gradually from 1960, reached its lowest point in 1990, and then slowly began to improve. Our results implied that the loss of system resilience resulted in the regime shift of the Lake Taihu SES essentially. Adaptive management that focuses on the gradual and fundamental variations should be adopted to prevent SESs from shifting to undesirable states.

Spatial heterogeneity of food web structure in a large shallow eutrophic lake (Lake Taihu, China): implications for eutrophication process and management

“…In the algae-dominated zone, the small zooplankton-preferring carnivorous fishes appeared to play an important trophic role in the food web. Their proportion in the total catches of Lake Taihu have especially increased remarkably since 1980s (Xu et al 2015). Considering their abundance and diet, small zooplankton-preferring carnivorous fishes exhibited strong predation pressure on zooplankton, and then had a trophic cascade effect on phytoplankton.…”

Coupled impacts of climate and land use change across a river–lake continuum: insights from an integrated assessment model of Lake Champlain’s Missisquoi Basin, 2000–2040

“…Regime shifts in SESs can result in rapid state transitions in a variety of natural ecosystems, including coral reefs and fisheries [10][11][12], tropical forests and rangelands [13][14][15][16][17] among others. Of particular interest to the current study are welldocumented state changes in freshwater lakes resulting from shifting land-use practices in lake catchments [18][19][20][21][22][23][24][25][26][27][28]. In the Lake Champlain Basin of Vermont, New York and Quebec, changes in agricultural activity resulting from evolving socio-economic pressures have resulted in increased nutrient loads to the lake, promoting a rapid shift to eutrophic conditions within significant portions of the lake [29].…”

A blooming business : Identifying limits to Lake Taihu's nutrient input

“…From these data we know that blooms have occurred at nutrient loads of around 0.4 gP.m -2 .yr -1 and 8 gN.m -2 .yr -1 (Yan et al, 2011). Furthermore, previous regime shift analysis with data of Lake Taihu suggest a regime shift between late 1980s and early 1990s when nutrient loads were between 0.38-0.58 gP.m -2 .yr -1 and 7.6-15 gN.m -2 .yr -1 (Xu et al, 2015a;Yan et al, 2011). These load values just exceeded our predicted critical nutrient loads for the minimum allowable chlorophyll-a concentration of 20 μg.L -1 .…”

“…By overexploiting the source functions and overusing the sink functions of Lake Taihu, the societal functions of the lake are lost (e.g. An et al, 1998;Xu et al, 2015a). Drinking water becomes undrinkable, fish becomes inedible or extinct, and residents that live in the catchment suffer from health problems.…”