A Metapopulation Model With Seeds Dispersal Among Patches In Habitat Of Plants

Metapopulation theory is important for understanding large-scale population dynamics and has been widely used in ecological conservation and spatial ecology.Although it is difficult to test and verify,metapopulation models include the key factors of population change and it provide important insights in species conservation in fragmented landscapes.Population migration is very important for the survival of the metapopulation.In the classical metapopulation model proposed by Levins and others,population migration makes the local populations located in different patches connect with each other,thus repeating the process of "extinction and reconstruction".However,plant populations migration to suitable habitats by means of seed dispersal and seed dormancy.The dynamics of metapopulations may be different due to the special population characteristics of plants.However,there are few studies on metapopulation models of plants at present.Based on the existing studies on the theory of metapopulation,this study based on the characteristics of plant population,and takes building ecological mathematical model,simulation and mathematical derivation as the means,explores which factors affect the survival and migration of plant metapopulation.Firstly,building the differential equation model and cellular automata model of plant metapopulation considering seed dormancy.Through theoretical analysis and numerical simulation,the factors affecting the survival of plant metapopulation were studied.Then,the simulation of seed dispersal process between patches was carried out.The output result of the simulation was the proportion of empty patches invaded by the population through migration in a period of time,and the factors affecting the migration of plant metapopulations were quantitatively analyzed through simulation experiments.Finally,The probability calculation of seed dispersal between two patches was deduced and a spatially realistic metapopulation model was established.Main results as follows:1.The seed dormancy mechanism makes the judgment of plant population size and plant extinction biased.The seed dormancy mechanism is beneficial to the survival of the assembled population,and the longer the seed survival time,the more the survival of the assembled population will be improved.2.Increasing the dispersal rate of seeds and decreasing the mortality rate of dormant seeds are beneficial to population maintenance,especially under conditions of high local population extinction rate.3.The Allee effects could not only reduce the metapopulation size,but also reduce the amounts of dormant seeds in the habitat.The seed dormancy mechanism mitigated the adverse effects of Allee effects when the population density was low.4.Rescue effects was beneficial to population survival but did not change the distribution pattern of dormant seeds in the habitat.5.The proportion of empty patches invaded by population increased first and then decreased with the increase of habitat patches occupied by population,decreased with the increase of patch area,and increased with the increase of seed yield and the proportion of landscape area occupied by patch.6.When the number of seeds is large,the probability of seeds spreading from one patch to another during wind dispersal can be accurately calculated.This study deduced the calculation process of the probability and established a more accurate spatial reality plant metapopulation model on this basis.7.When the number of seeds is large,the probability of seed transmission between the two patches is the same.9.Simulation experiments are test and verify the setting of Levins model quantitative relationship.10.The increase of patch area is not conducive to plant population migration.11.When the proportion of landscape area occupied by patches reaches a certain size,its influence on population migration is no longer obvious,which provides a certain theoretical basis for the research and practice of land use balance between human and plant protection.12.High seed yield does not necessarily significantly enhance population migration ability,which provides a certain theoretical basis for the study of plant seed yield.This study could provide important ideas for plant metapopulation and provide a theoretical basis to understand the formation of plant population and protect the endangered species.