The concept of nestedness originated from the field of biogeography decades ago and has been widely used in metacommunities and biological interaction networks,but there is still a lack of research within local commun...The concept of nestedness originated from the field of biogeography decades ago and has been widely used in metacommunities and biological interaction networks,but there is still a lack of research within local communities.Moreover,studies on nestedness usually rarely incorporate the functional traits of the species and the environmental characteristics of the sites.In this study,we constructed a species presence–absence matrix of a 50-ha forest plot,used the simulated annealing algorithm to reveal the maximum nested structure and further tested the significance of nestedness patterns by constructing null ensembles.The nested ranks were used to represent the orders of species and quadrats in the maximum nestedness matrix.The regression tree analysis was used to reveal the relationships of nested ranks with environmental factors and functional traits.We found that the co-occurrence pattern of local plant communities was significantly nested.The regression tree results showed that the nested ranks of quadrats were determined by soil available phosphorus,soil water content,soil organic carbon and soil pH.Intraspecific variation of functional traits,including leaf C,leaf pH,leaf dry matter content and maximum photosynthetic rate rather than means of functional traits,provided a better explanation for the formation of species’nested ranks.Understanding the causes of species and quadrats nested ranks provides novel lens and useful insights into ecological processes underlying nestedness,and further improves our knowledge of how local plant communities are assembled.展开更多
In this paper, spatial patterns of a diffusive predator-prey model with sigmoid （Holling type III） ratio-dependent functional response which concerns the influence of logistic population growth in prey and intra-spe...In this paper, spatial patterns of a diffusive predator-prey model with sigmoid （Holling type III） ratio-dependent functional response which concerns the influence of logistic population growth in prey and intra-species competition among predators are investigated. The （local and global） asymptotic stability behavior of the corresponding non- spatial model around the unique positive interior equilibrium point in homogeneous steady state is obtained. In addition, we derive the conditions for Turing instability and the consequent parametric Turing space in spatial domain. The results of spatial pat- tern analysis through numerical simulations are depicted and analyzed. ~rthermore, we perform a series of numerical simulations and find that the proposed model dynamics exhibits complex pattern replication. The feasible results obtained in this paper indicate that the effect of diffusion in Turing instability plays an important role to understand better the pattern formation in ecosystem.展开更多
基金This study was funded by the National Science Foundation of China(31925027)the Fundamental Research Funds for the Central Universities(20lgpy116,2021qntd18).
文摘The concept of nestedness originated from the field of biogeography decades ago and has been widely used in metacommunities and biological interaction networks,but there is still a lack of research within local communities.Moreover,studies on nestedness usually rarely incorporate the functional traits of the species and the environmental characteristics of the sites.In this study,we constructed a species presence–absence matrix of a 50-ha forest plot,used the simulated annealing algorithm to reveal the maximum nested structure and further tested the significance of nestedness patterns by constructing null ensembles.The nested ranks were used to represent the orders of species and quadrats in the maximum nestedness matrix.The regression tree analysis was used to reveal the relationships of nested ranks with environmental factors and functional traits.We found that the co-occurrence pattern of local plant communities was significantly nested.The regression tree results showed that the nested ranks of quadrats were determined by soil available phosphorus,soil water content,soil organic carbon and soil pH.Intraspecific variation of functional traits,including leaf C,leaf pH,leaf dry matter content and maximum photosynthetic rate rather than means of functional traits,provided a better explanation for the formation of species’nested ranks.Understanding the causes of species and quadrats nested ranks provides novel lens and useful insights into ecological processes underlying nestedness,and further improves our knowledge of how local plant communities are assembled.
文摘In this paper, spatial patterns of a diffusive predator-prey model with sigmoid （Holling type III） ratio-dependent functional response which concerns the influence of logistic population growth in prey and intra-species competition among predators are investigated. The （local and global） asymptotic stability behavior of the corresponding non- spatial model around the unique positive interior equilibrium point in homogeneous steady state is obtained. In addition, we derive the conditions for Turing instability and the consequent parametric Turing space in spatial domain. The results of spatial pat- tern analysis through numerical simulations are depicted and analyzed. ~rthermore, we perform a series of numerical simulations and find that the proposed model dynamics exhibits complex pattern replication. The feasible results obtained in this paper indicate that the effect of diffusion in Turing instability plays an important role to understand better the pattern formation in ecosystem.
