Sustainability science (SS), rooted in multiple disciplines, has been developing rapidly during the last two decades and become a well-recognized new field of study. However, the “identity” of SS remains unclear. Therefore, this study was intended to help synthesize the key characteristics of SS by revisiting the question raised by the leading sustainability scientist, Robert Kates (2011): “What kind of a science is sustainability science?” Specifically, we reviewed the literature in SS, and developed a synthesis of definitions and core research questions of SS, using multiple methods including change-point detection, word cloud visualization, and content and thematic analyses. Our study has produced several main findings: (1) the development of SS exhibited an S-shaped growth pattern, with an exponential growth phase through to 2012, and a asymptotic development phase afterwards; (2) ten key elements from the existing definitions of SS were identified, of which understanding “human–environment interactions” and “use-inspired” were most prominent; and (3) sixteen core questions in SS were derived from the literature. We further proposed an eight-theme framework of SS to help understand how the sixteen questions are related to each other. We argue that SS is coming of age, but more integrative and concerted efforts are still needed to further consolidate its identity by developing a coherent and rigorous scientific core.

Fang, X., and J. Wu. 2022. Causes of overgrazing in Inner Mongolian grasslands: Searching for deep leverage points of intervention. Ecology and Society 27(1):8. https://doi.org/10.5751/ES-12878-270108

Ecosystem service (ES) bundles are widely used approaches to analyze ES tradeoffs in urban agglomeration. However, few ES bundle studies considered both the supply and demand sided. The objective of this study was to map ES supply–demand bundles to comprehensively analyze the ES tradeoffs in the Yangtze River Delta using cluster analysis, correlation analysis, hotspot analysis, and principal component analysis. We found that: (1) Both the supply and demand of ES are unevenly distributed with highly spatial autocorrelation. (2) There are significant tradeoffs and synergies between ES in terms of supply–supply, demand–demand, and supply–demand. (3) Four ES supply–demand bundle types were identified with distinct ES supply and demand relationships. (4) Land-use types, urban intensity, and climatic factors are the main social-ecological factors that distinguish the four identified clusters. The identified ES supply–demand clusters can support the main functional zoning of the Yangtze River Delta. Our results also suggest that land sharing is a more appropriate approach for the sustainable development of the Yangtze River Delta considering the balance of multiple ES supply and ES demand.