Modeling Method Enhances Temporal Resolution of Deep-Time Food Web Stability Evolution:A Case Study on Permian-Triassic Ecological Record from the Meishan Section
Huang Yuangeng
Xin Bailun
Guo Zhen
Li Ziheng
Qiao Huijie
Huang Xinyue
Chen Zhong-Qiang
Abstract：The Permian-Triassic(P-Tr)mass extinction,which occurred approximately 252 million years ago,represents the largest ecological crisis in Earth's geological history and is often regarded as a reference case for modern ecological crises.However,studies that integrate multiple taxa and systematically characterize the overall evolutionary trajectory of food web structures in communities remain scarce.In particular,the incompleteness of fossil records and their low temporal resolution within stratigraphic records pose significant challenges to using deep-time crises as analogs for modern ecological crises.This study focuses on the fossil-rich Meishan Section in Zhejiang Province,the global stratotype section and point(GSSP)for the P-Tr boundary.Using Bayesian modeling with the PyRate method,we recalculated the true first and last appearances of all fossil species within this section.The results reveal a three-phase decline in species diversity:rapid drops in the first and third phases,with a gradual decline in the second phase.Building on these results,we explored schemes for delineating paleocommunities at varying temporal resolutions,ranging from 50 ka per community down to 1 ka per community.We then analyzed species composition similarity between adjacent communities under each scheme.As the temporal resolution increases,adjacent communities exhibit increasingly similar species compositions.Notably,for resolutions of 1-4 ka years per community,over 5%of adjacent communities show identical species compositions.Adopting a temporal resolution of 5 ka per community,we constructed a continuous sequence of paleocommunities and quantitatively assessed the evolutionary dynamics of community composition,simulated food web stability,and resistance across the P-Tr boundary.The results indicate minimal changes in ecological structure and community stability during the first and second phases,followed by abrupt shifts in the third phase.Communities in the first and second phases retained relatively high resistance,likely due to the loss of redundant species that did not compromise the integrity of ecological structure and function.In contrast,the third phase witnessed the collapse and reorganization of ecological structures as multiple functional groups disappeared.This study provides a detailed examination of paleocommunity delineation at varying temporal resolutions and reconstructs the evolutionary trajectory of paleoecological structures at a resolution of 5 ka.These findings offer a novel approach for investigating high-resolution deep-time ecosystem evolution and facilitate comparative studies between ancient and modern ecological systems.
Keywords：mass extinctionecological structurepaleocommunitiesfood websstabilityecosystemsstratigraphy
Publication Date：2025-03-14
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：13( 951-963 )