On basis of analysis on agroforestry-animal husbandry ecosystem characters, the research explored nutrient flow model of material cycle and carbon cycle and agroforestry-animal husbandry mutualism model and supporting...On basis of analysis on agroforestry-animal husbandry ecosystem characters, the research explored nutrient flow model of material cycle and carbon cycle and agroforestry-animal husbandry mutualism model and supporting technology in Yangtze-Huaihe Region, taking Robinia pseudoacacia stand and rubber garden as an example.展开更多
Through the long-term plot study on the litter and its decomposition in the evergreen broad-leaved forest ecosystem in Hangzhou for more than two years,it was resulted that the annual litter production was 5.85 t ha^-...Through the long-term plot study on the litter and its decomposition in the evergreen broad-leaved forest ecosystem in Hangzhou for more than two years,it was resulted that the annual litter production was 5.85 t ha^-1,most of which was the fallen leave (79.5 percent) and the withered branches and fruits were far less (7.1 and 13.4 percents respectively).The dynamics of the fallen litter was shown as a curve of two-peak pattern which appeared in April and September each year.The half-life of the litter was 1.59 years.The decay rate of the litter attenuted as an exponential function.The annual amount of the nutrient returned to the ground through the litter was as large as 223.69kg ha^-1.The total current amount of the litter on the ground was 7.47t ha^-1.The decay rate in the first half of a year was 45.18 percent.This ecosystem remained in the stage of litter increasing with time.展开更多
Disease in ecological systems plays an important role. In the present investigation we propose and analyze a predator-prey mathematical model in which both species are affected by infectious disease. The parasite is t...Disease in ecological systems plays an important role. In the present investigation we propose and analyze a predator-prey mathematical model in which both species are affected by infectious disease. The parasite is transmitted directly （by contact） within the prey population and indirectly （by consumption of infected prey） within the predator population. We derive biologically feasible and insightful quantities in terms of ecological as well as epidemiological reproduction numbers that allow us to describe the dynamics of the proposed system. Our observations indicate that predator-prey system is stable without disease but high infection rate drive the predator population toward extinction. We also observe that predation of vulnerable infected prey makes the disease to eradicate into the community composition of the model system. Local stability analysis of the interior equilibrium point near the disease-free equilibrium point is worked out. To study the global dynamics of the system, numerical simulations are performed. Our simulation results show that for higher values of the force of infection in the prey population the predator population goes to extinction. Our numerical analysis reveals that predation rates specially on susceptible prey population and recovery of infective predator play crucial role for preventing the extinction of the susceptible predator and disease propagation.展开更多
基金Supported by the National S&T Support Program during the Twelfth Five-year Pla Period(2012BAD14B13)~~
文摘On basis of analysis on agroforestry-animal husbandry ecosystem characters, the research explored nutrient flow model of material cycle and carbon cycle and agroforestry-animal husbandry mutualism model and supporting technology in Yangtze-Huaihe Region, taking Robinia pseudoacacia stand and rubber garden as an example.
基金Project supported by the Laboratory of Material Cycling in Pedosphere, Insitute of Soil Science, Chinese Academy of Sciences.
文摘Through the long-term plot study on the litter and its decomposition in the evergreen broad-leaved forest ecosystem in Hangzhou for more than two years,it was resulted that the annual litter production was 5.85 t ha^-1,most of which was the fallen leave (79.5 percent) and the withered branches and fruits were far less (7.1 and 13.4 percents respectively).The dynamics of the fallen litter was shown as a curve of two-peak pattern which appeared in April and September each year.The half-life of the litter was 1.59 years.The decay rate of the litter attenuted as an exponential function.The annual amount of the nutrient returned to the ground through the litter was as large as 223.69kg ha^-1.The total current amount of the litter on the ground was 7.47t ha^-1.The decay rate in the first half of a year was 45.18 percent.This ecosystem remained in the stage of litter increasing with time.
文摘Disease in ecological systems plays an important role. In the present investigation we propose and analyze a predator-prey mathematical model in which both species are affected by infectious disease. The parasite is transmitted directly （by contact） within the prey population and indirectly （by consumption of infected prey） within the predator population. We derive biologically feasible and insightful quantities in terms of ecological as well as epidemiological reproduction numbers that allow us to describe the dynamics of the proposed system. Our observations indicate that predator-prey system is stable without disease but high infection rate drive the predator population toward extinction. We also observe that predation of vulnerable infected prey makes the disease to eradicate into the community composition of the model system. Local stability analysis of the interior equilibrium point near the disease-free equilibrium point is worked out. To study the global dynamics of the system, numerical simulations are performed. Our simulation results show that for higher values of the force of infection in the prey population the predator population goes to extinction. Our numerical analysis reveals that predation rates specially on susceptible prey population and recovery of infective predator play crucial role for preventing the extinction of the susceptible predator and disease propagation.
