Tropical seagrass meadows and coral reefs often function as interconnected marine habitats,but they are often studied and managed as homogenous units.As macrohabitats,seagrass meadows provide important benefits to adj...Tropical seagrass meadows and coral reefs often function as interconnected marine habitats,but they are often studied and managed as homogenous units.As macrohabitats,seagrass meadows provide important benefits to adjacent reef ecosystems by acting as natural filters of sediments and nutrients,and by providing critical feeding,nursery,and refuge habitats for reef fishes and other fauna.Whilst the macrohabitat functions of seagrass meadows have been often acknowledged,their microhabitats functions have largely been neglected.The purpose of the study is to explore how seagrass meadows provide multiple benefits to adjacent coral reefs through various microhabitat functions.The paper reveals some of the diversity of microhabitats that seagrass meadows contain,such as macroalgal mats,rubble cavities,sand patches with sparse seagrass,anemone gardens,hard substratum,and sponges mixed with seagrass.We highlight the ways in which reef creatures have diversified and specialized in using these different microhabitats,and postulate that seagrass microhabitat diversity enhances the habitat function and faunal diversity of seagrass meadows.展开更多
In recent years,wetland ecological water requirements (EWRs) have been estimated by using hydrological and functional approaches,but those approaches have not yet been integrated for a whole ecosystem.This paper prese...In recent years,wetland ecological water requirements (EWRs) have been estimated by using hydrological and functional approaches,but those approaches have not yet been integrated for a whole ecosystem.This paper presents a new method for calculating wetland EWRs,which is based on the response of habitats to water level,and determines water level threshold through the functional integrity of habitats.Results show that in the Huanghe (Yellow) River Delta water levels between 5.0 m and 5.5 m are required to maintain the functional integrity of the wetland at a value higher than 0.7.One of the dominant plants in the delta,Phragmites australis,tolerates water level fluctuation of about ± 0.25 m without the change in wetland functional integrity.The minimum,optimum and maximum EWRs for the Huanghe River Delta are 9.42×106 m3,15.56×106 m3 and 24.12×106 m3 with water levels of 5.0 m,5.2 m and 5.5 m,corresponding to functional integrity indices of 0.70,0.84 and 0.72,respectively.A wetland restoration program has been performed,which aims to meet these EWRs in attempt to recover from losses of up to 98% in the delta's former wetland area.展开更多
This paper is devoted to study the problem of stability, chaos behavior and parameters estimation of the habitat destruction model with three-species (prey, predator and top-predator). The mathematical formula of the ...This paper is devoted to study the problem of stability, chaos behavior and parameters estimation of the habitat destruction model with three-species (prey, predator and top-predator). The mathematical formula of the model and its proposed interactions are presented. Some important special solutions of systems are discussed. The stationary states of the model are derived. Local stability conditions for the stationary states are derived. Furthermore, the chaotic behavior of the model is discussed and presented graphically. Using Liapunov stability technique, the dynamic estimators of the unknown probabilities and their updating rules are derived. It is found that, the control laws are non-linear functions of the species densities. Numerical illustrative examples are carried out and presented graphically.展开更多
基金The present study was supported by grants from the National Key Research and Development Program of China(No.2018YFC1406503)the National Natural Science Foundation of China(no.41676096)the China-Australia Marine Ecosystem Research project,the China-ASEAN Maritime Cooperation Fund project“Monitoring and conservation of the coastal ecosystem in the South China Sea,”and the University of Malaya,Top 100 Universities in The World Fund(TU001-2018).
文摘Tropical seagrass meadows and coral reefs often function as interconnected marine habitats,but they are often studied and managed as homogenous units.As macrohabitats,seagrass meadows provide important benefits to adjacent reef ecosystems by acting as natural filters of sediments and nutrients,and by providing critical feeding,nursery,and refuge habitats for reef fishes and other fauna.Whilst the macrohabitat functions of seagrass meadows have been often acknowledged,their microhabitats functions have largely been neglected.The purpose of the study is to explore how seagrass meadows provide multiple benefits to adjacent coral reefs through various microhabitat functions.The paper reveals some of the diversity of microhabitats that seagrass meadows contain,such as macroalgal mats,rubble cavities,sand patches with sparse seagrass,anemone gardens,hard substratum,and sponges mixed with seagrass.We highlight the ways in which reef creatures have diversified and specialized in using these different microhabitats,and postulate that seagrass microhabitat diversity enhances the habitat function and faunal diversity of seagrass meadows.
基金Under the auspices of Major State Basic Research Development Program of China (No. 2006CB403303)National Natural Science Foundation of China (No. U0833002,40571149)Scientific Research Foundation of Beijing Normal University (No. 2009SD-24)
文摘In recent years,wetland ecological water requirements (EWRs) have been estimated by using hydrological and functional approaches,but those approaches have not yet been integrated for a whole ecosystem.This paper presents a new method for calculating wetland EWRs,which is based on the response of habitats to water level,and determines water level threshold through the functional integrity of habitats.Results show that in the Huanghe (Yellow) River Delta water levels between 5.0 m and 5.5 m are required to maintain the functional integrity of the wetland at a value higher than 0.7.One of the dominant plants in the delta,Phragmites australis,tolerates water level fluctuation of about ± 0.25 m without the change in wetland functional integrity.The minimum,optimum and maximum EWRs for the Huanghe River Delta are 9.42×106 m3,15.56×106 m3 and 24.12×106 m3 with water levels of 5.0 m,5.2 m and 5.5 m,corresponding to functional integrity indices of 0.70,0.84 and 0.72,respectively.A wetland restoration program has been performed,which aims to meet these EWRs in attempt to recover from losses of up to 98% in the delta's former wetland area.
文摘This paper is devoted to study the problem of stability, chaos behavior and parameters estimation of the habitat destruction model with three-species (prey, predator and top-predator). The mathematical formula of the model and its proposed interactions are presented. Some important special solutions of systems are discussed. The stationary states of the model are derived. Local stability conditions for the stationary states are derived. Furthermore, the chaotic behavior of the model is discussed and presented graphically. Using Liapunov stability technique, the dynamic estimators of the unknown probabilities and their updating rules are derived. It is found that, the control laws are non-linear functions of the species densities. Numerical illustrative examples are carried out and presented graphically.
