The grass ring phenomenon remains an interesting and enduring puzzle. Previous research has proposed various mechanisms, including Environmental stress and physical disturbance, Nutrient and water depletion, and the Self-Organization hypothesis, to explain ring formation. However, this process is highly complex and dynamic, hindering the development of a unified theory. This is primarily because grass rings of different origins, and even those at different developmental stages, are influenced by diverse factors. Furthermore, existing studies have often been limited to isolated cases, which highlights the need for more comprehensive, global-scale studies. Through a systematic analysis of publications, this review proposes three claims. First, they are classified based on genetic origin into single and multiple individual origins, which align with formation driven primarily by death-based and growth-based formation modes, respectively. Second, the grass ring is essentially a superorganism. Third, although grass rings are globally widespread, their formation mechanisms in regions above 4000 m remain elusive. Future research should prioritize key directions, including quantifying complete life cycles and elucidating mechanisms of high-altitude formation. This requires establishing international monitoring networks that integrate multi-omics with hyperspectral remote sensing to predict how grass rings develop under global climate change.
Jialin et al. (Thu,) studied this question.