Phytoplankton blooms are complex environmental phenomena driven by multiple factors. Understanding their relationships with meteorological factors and climate oscillations is essential for advancing data-driven and hy...Phytoplankton blooms are complex environmental phenomena driven by multiple factors. Understanding their relationships with meteorological factors and climate oscillations is essential for advancing data-driven and hybrid statistical-dynamical models. However, these relationships have rarely been investigated across different temporal scales. This study employs wavelet transform coherence and multiple wavelet coherence to examine the multiscale and multivariate relationships between phytoplankton blooms, meteorological factors, and climate oscillations in eight large marine ecosystems of the western North Pacific. The results reveal that all phytoplankton blooms in the studied ecosystems exhibit significant annual oscillations, while seasonal climate patterns demonstrate either unimodal or bimodal distributions. A comparison of the wavelet transform coherence and multiple wavelet coherence results indicates that meteorological factors primarily drive shortperiod variations in phytoplankton blooms, whereas climate oscillations exert more influence on long-term changes. The explanation of phytoplankton blooms increases as the driver factors increase, but there are also some decreasing due to the collinearity between different factors. The sea-air temperature difference emerges as the most significant driving factor, with its mechanisms varying across marine ecosystems: one type influences mixed-layer depth, while the other arises from interspecific differences in temperature sensitivity. Furthermore,the results underscore the importance of integrating non-dominant large-scale circulation indices with predominant meteorological factors for a more comprehensive understanding.展开更多
The coastal zone,situated at the land-ocean interface,represents a complex regional system in which physical,ecological,and social subsystems are highly coupled.Under the dual impacts of global change and human activi...The coastal zone,situated at the land-ocean interface,represents a complex regional system in which physical,ecological,and social subsystems are highly coupled.Under the dual impacts of global change and human activities,shoreline dynamics and ecological degradation have intensified,and the system may be approaching or crossing tipping thresholds.This study addresses the mathematical representation and classification of tipping points in coastal zone systems.Based on dynamical systems theory,we developed a unified mathematical framework that incorporates land-sea interactions and multi-scale processes.We establish a six-category classification system encompassing bifurcation-driven,noise-driven,shock-driven,ratedriven,space-driven,and information-driven tipping points,and further elucidate the spatiotemporal characteristics and triggering mechanisms of each category.Furthermore,a classification model of tipping points was constructed using large language models and literature-based big data,and 91 typical cases worldwide are analyzed,through which the heterogeneous spatial distribution of such events is revealed.The results demonstrate that coastal tipping point research possesses both representativeness and particularity.Future research should focus on key issues of“classification-identification-response”and advance integrated efforts in data fusion,model development,and adaptive management.展开更多
Vegetation evolution is an important indicator of regional ecosystems and sea-land interactions.In this study,we investigated the evolution of coastal wetland vegetation,focusing on the core area of Yancheng City Nati...Vegetation evolution is an important indicator of regional ecosystems and sea-land interactions.In this study,we investigated the evolution of coastal wetland vegetation,focusing on the core area of Yancheng City National Rare Bird Nature Reserve.Using high-precision classification based on phenological characteristics,we delineated the evolutionary process of three predominant wetland vegetation types:Spartina alterniflora,Suaeda salsa,and Phragmites australis.Spatial and temporal patterns were analyzed using the generalized additive model to identify drivers of evolution.From 1990 to 2022,a three-stage shift in vegetation distribution from land to sea was observed.Notably,S.salsa’s distribution area consistently shrank since 2000,whereas P.australis continued to grow.Throughout the entire period,S.alterniflora consistently maintained growth and tended toward stability.The vegetation distinctly showcased zonal patterns along the coastal gradient,revealing a clear inclination to migrate toward the seaside.Specifically,S.alterniflora displayed a centroid migration rate of 195.28 m/year,shifting northward,whereas P.australis and S.salsa migrated eastward(toward the seaside)at rates of 111.84 and 70.88 m/year,respectively.Environmental factors,such as downward irradiance,sea surface salinity,and significant wave height,significantly influenced vegetation patterns.Human activities,particularly aquaculture pond construction,emerged as the primary anthropogenic factor causing the reduction in P.australis distribution.Additionally,the competition for ecological niches among vegetation emerged as a pivotal factor contributing to the alterations in the landscape pattern within the study area.展开更多
It has been two decades since virtual geographic environments(VGEs)were initially proposed.While relevant theories and technologies are evolving,data organization models have always been the foundation of VGE developm...It has been two decades since virtual geographic environments(VGEs)were initially proposed.While relevant theories and technologies are evolving,data organization models have always been the foundation of VGE development,and they require further exploration.Based on the comprehensive consideration of the characteristics of VGEs,geographic scene is proposed to organize geographic information and data.We empirically find that geographic scene provides a suitable organization schema to support geo-visualization,geo-simulation,and geo-collaboration.To systematically investigate the concept and method of geographic scene,Geographic Scenario is proposed as the theory on developing geographic scene,and corresponding key issues of the Geographic Scenario are illustrated in this article.Prospects of the proposed method are discussed with the hope of informing future studies of VGEs.展开更多
The development trend of ternary space requires the construction of the information space for information mapping,transmission and transformation of geographic elements and social-human elements. Relevant researches o...The development trend of ternary space requires the construction of the information space for information mapping,transmission and transformation of geographic elements and social-human elements. Relevant researches of information geography from the perspective of Geographic Information Science and human geography are reviewed in this paper, then the concept interpretation of information geography from the perspective of ternary space is proposed. It is presented in this paper that information geography can be constructed with a framework using seven geographic elements as the basic expressing dimensions and seven social-human elements as the basic aggregating core. Information geography analyzes spatio-temporal distribution, structural characteristics, evolution process and interactions of various elements in the information space. And it eventually realizes the actual description, multi-scenario simulation, multi-objective decision-making and multi-channel control of the physical world and the social-human world.展开更多
基金The National Natural Science Foundation of China under contract Nos 42230406, 42130103 and 42376223。
文摘Phytoplankton blooms are complex environmental phenomena driven by multiple factors. Understanding their relationships with meteorological factors and climate oscillations is essential for advancing data-driven and hybrid statistical-dynamical models. However, these relationships have rarely been investigated across different temporal scales. This study employs wavelet transform coherence and multiple wavelet coherence to examine the multiscale and multivariate relationships between phytoplankton blooms, meteorological factors, and climate oscillations in eight large marine ecosystems of the western North Pacific. The results reveal that all phytoplankton blooms in the studied ecosystems exhibit significant annual oscillations, while seasonal climate patterns demonstrate either unimodal or bimodal distributions. A comparison of the wavelet transform coherence and multiple wavelet coherence results indicates that meteorological factors primarily drive shortperiod variations in phytoplankton blooms, whereas climate oscillations exert more influence on long-term changes. The explanation of phytoplankton blooms increases as the driver factors increase, but there are also some decreasing due to the collinearity between different factors. The sea-air temperature difference emerges as the most significant driving factor, with its mechanisms varying across marine ecosystems: one type influences mixed-layer depth, while the other arises from interspecific differences in temperature sensitivity. Furthermore,the results underscore the importance of integrating non-dominant large-scale circulation indices with predominant meteorological factors for a more comprehensive understanding.
基金supported by the Key Projects of National Natural Science Foundation of China(NSFC)(Grant Nos.42230406,42130103)。
文摘The coastal zone,situated at the land-ocean interface,represents a complex regional system in which physical,ecological,and social subsystems are highly coupled.Under the dual impacts of global change and human activities,shoreline dynamics and ecological degradation have intensified,and the system may be approaching or crossing tipping thresholds.This study addresses the mathematical representation and classification of tipping points in coastal zone systems.Based on dynamical systems theory,we developed a unified mathematical framework that incorporates land-sea interactions and multi-scale processes.We establish a six-category classification system encompassing bifurcation-driven,noise-driven,shock-driven,ratedriven,space-driven,and information-driven tipping points,and further elucidate the spatiotemporal characteristics and triggering mechanisms of each category.Furthermore,a classification model of tipping points was constructed using large language models and literature-based big data,and 91 typical cases worldwide are analyzed,through which the heterogeneous spatial distribution of such events is revealed.The results demonstrate that coastal tipping point research possesses both representativeness and particularity.Future research should focus on key issues of“classification-identification-response”and advance integrated efforts in data fusion,model development,and adaptive management.
基金supported by the National Natural Science Foundation of China(grant numbers 42230406,42130103,42376223,and 42101078).
文摘Vegetation evolution is an important indicator of regional ecosystems and sea-land interactions.In this study,we investigated the evolution of coastal wetland vegetation,focusing on the core area of Yancheng City National Rare Bird Nature Reserve.Using high-precision classification based on phenological characteristics,we delineated the evolutionary process of three predominant wetland vegetation types:Spartina alterniflora,Suaeda salsa,and Phragmites australis.Spatial and temporal patterns were analyzed using the generalized additive model to identify drivers of evolution.From 1990 to 2022,a three-stage shift in vegetation distribution from land to sea was observed.Notably,S.salsa’s distribution area consistently shrank since 2000,whereas P.australis continued to grow.Throughout the entire period,S.alterniflora consistently maintained growth and tended toward stability.The vegetation distinctly showcased zonal patterns along the coastal gradient,revealing a clear inclination to migrate toward the seaside.Specifically,S.alterniflora displayed a centroid migration rate of 195.28 m/year,shifting northward,whereas P.australis and S.salsa migrated eastward(toward the seaside)at rates of 111.84 and 70.88 m/year,respectively.Environmental factors,such as downward irradiance,sea surface salinity,and significant wave height,significantly influenced vegetation patterns.Human activities,particularly aquaculture pond construction,emerged as the primary anthropogenic factor causing the reduction in P.australis distribution.Additionally,the competition for ecological niches among vegetation emerged as a pivotal factor contributing to the alterations in the landscape pattern within the study area.
基金supported by the Key Fund of National Natural Science Foundation of China[grant number 41631175]The National Key Research and Development Program of China[grant number 2017YFB0503500]+1 种基金National Natural Science Foundation of China[grant number 41622108]Priority Academic Program Development of Jiangsu Higher Education Institutions[grant number 164320H116]。
文摘It has been two decades since virtual geographic environments(VGEs)were initially proposed.While relevant theories and technologies are evolving,data organization models have always been the foundation of VGE development,and they require further exploration.Based on the comprehensive consideration of the characteristics of VGEs,geographic scene is proposed to organize geographic information and data.We empirically find that geographic scene provides a suitable organization schema to support geo-visualization,geo-simulation,and geo-collaboration.To systematically investigate the concept and method of geographic scene,Geographic Scenario is proposed as the theory on developing geographic scene,and corresponding key issues of the Geographic Scenario are illustrated in this article.Prospects of the proposed method are discussed with the hope of informing future studies of VGEs.
基金This work was supported by the National Natural Science Foundation for Distinguished Young Scholar(Grant No.41625004)the National Natural Science Foundation of China(Grant No.41930648)the National Key Research and Development Plan(Grant No.2017YFB0503500).
文摘The development trend of ternary space requires the construction of the information space for information mapping,transmission and transformation of geographic elements and social-human elements. Relevant researches of information geography from the perspective of Geographic Information Science and human geography are reviewed in this paper, then the concept interpretation of information geography from the perspective of ternary space is proposed. It is presented in this paper that information geography can be constructed with a framework using seven geographic elements as the basic expressing dimensions and seven social-human elements as the basic aggregating core. Information geography analyzes spatio-temporal distribution, structural characteristics, evolution process and interactions of various elements in the information space. And it eventually realizes the actual description, multi-scenario simulation, multi-objective decision-making and multi-channel control of the physical world and the social-human world.
