Ecosystem simulation

Kremer, 3.N. and Nixon, S.W., 1978. A coastal Marine Ecosystem, Simulation and Analysis. Ecological Studies 24, Springer-Verlag, NY, 217p. 

Park R. et al, (1974). A generalized model for simulating lake ecosystems. Simulation, 23, 33-50. 

J. N. Kremer and S. W. Nixon, A Coastal Marine Ecosystem Simulation and Analysis, Ecological Studies (Springer-Verlag, Heidelberg, 1978). 

The most common way in which the global carbon budget is calculated and analyzed is through simple diagrammatical or mathematical models. Diagrammatical models usually indicate sizes of reservoirs and fluxes (Figure 1). Most mathematical models use computers to simulate carbon flux between terrestrial ecosystems and the atmosphere, and between oceans and the atmosphere. Existing carbon cycle models are simple, in part, because few parameters can be estimated reliably. 

Gbondo-Tugbawa SS, Driscoll CT, Mitchell MJ, Aber JD, Likens GE. 2002. A model to simulate the response of a northern hardwood forest ecosystem to changes in S deposition. EcolAppl 12 8-23. 

The ET cover cannot be tested at every landfill site so it is necessary to extrapolate the results from sites of known performance to specific landfill sites. The factors that affect the hydrologic design of ET covers encompass several scientific disciplines and there are numerous interactions between factors. As a consequence, a comprehensive computer model is needed to evaluate the ET cover for a site.48 The model should effectively incorporate soil, plant, and climate variables, and include their interactions and the resultant effect on hydrology and water balance. An important function of the model is to simulate the variability of performance in response to climate variability and to evaluate cover response to extreme events. Because the expected life of the cover is decades, possibly centuries, the model should be capable of estimating long-term performance. In addition to a complete water balance, the model should be capable of estimating long-term plant biomass production, need for fertilizer, wind and water erosion, and possible loss of primary plant nutrients from the ecosystem. 

Environmental Fate. Having characterized the entry of materials into the environment, we move into the second step of our procedure. The goal at this stage of analysis is to define ambient concentration of the material or its products in areas of concern for receptor (e.g., people, materials or ecosystem components) exposure. A family of computer simulation models has been developed for calculating the ambient levels of a... 

Betts R, Cox P, Collins M, Harris P, Huntingford C, Jones D. The role of ecosystem-atmosphere interactions in simulated Amazonian precipitation decrease and forest dieback under global climate warming. Theoretical and Applied Climatology, 2004. 78(1) pp. 157-175. doi 10.1007/s00704-004-0050-y... 

Gmeiner M., Kniefel W., Kulbe K.D., Wouters R., De Boever P., Nollet L. and Verstreate V. (2000). Influence of a synbiotic mixture consisting of Lactobacillus acidophilus 74—2 and a frue loo I i go s acc h ari dc preparation on the microbial ecology sustained in a simulation of the human intestinal microbial ecosystem (SHIME reactor) . Appl Microbiol Biotechnol, 53, 219-223. 

Biota estimated t,/2 = 29 h from fish in simulated ecosystem (Neely 1980). 

Blau, G.E. and W.B. Neely. 1975. Mathematical model building with an application to determine the distribution of Dursban insecticide added to a simulated ecosystem. Adv. Ecol. Res. 9 133-162. 

Disturbance of Phosphorus Biogeochemical Cycle in Agrolandscapes Conceptual ideas behind simulation of P cycling are related to construction of models for freshwater terrestrial ecosystems and a generalized oceanic system and understanding the restrictions of its application. 

The environmental impact of a new product needs to be assessed before it can be released for general use. Chemicals released into the environment can enter the food chain and be concentrated in plants and animals. Aquatic ecosystems are particularly sensitive, in this respect, since chemicals, when applied to agricultural land, can be transported in the ground water to rivers and then to the lakes, where they can accumulate in fish and plant life. The ecokinetic model presented here is based on a simple compartmental analysis and is based on laboratory ecosystem studies (Blau et ah, 1975). The model is useful in simulating the results of events, such as the accidental spillage of an agrochemical into a pond, where it is not ethical to perform actual experimental studies. 

As one procedure of simulating natural aquatic environment, a freshwater static model ecosystem was established (Figure 3)... 

Aquatic Ecosystem and Fish. Metcalf et al. (2) studied the fate of diflubenzuron (radiolabeled separately in three different positions) in their model ecosystem. Diflubenzuron was dubbed "moderately persistent" in algae, snails, salt marsh caterpillars, and mosquito larvae as evidenced by limited biodegradability (Table IV). However, diflubenzuron and its nonpolar metabolites were not prone to ecological magnification in Gambusia fish. The lack of bioaccumulation of diflubenzuron residues in fish was substantiated by Booth and Ferrell (14) who used the channel catfish, Ictalurus, in a simulated lake ecosystem. They treated separate soil samples at 0.007 and 0.55 ppm, respectively. 

Model ecosystems have been used for about 8 years to measure the distribution and fate of pesticides in the aquatic environment. Over that period of time numerous design changes have evolved that have increased the versatility of the ecosystem and improved simulation of environmental conditions. In our laboratory, we have used the static model ecosystem primarily to model the pond or small lake environment, and to simulate the likely rates and modes of pesticide entry (1). More recently, we have developed larger systems capable of providing sufficient biomass for accumulation and dissipation rate determinations (2) and for metabolic studies (3). 

RADIATION CONTAMINATION OF FOREST ECOSYSTEMS INVESTIGATION FIELD EXPERIMENTS, MODELING AND SIMULATION... 

Artificial ecosystems are used to simulate in situ environmental conditions. They are designed to function as much like the natural ocean as possible, while providing a system that can be experimentally manipulated and efficiently sampled. Some of the largest artificial ecosystems are the 14 MERL tanks (Marine Ecosystems Research Laboratory) operated by the University of Rhode Island on Narragansett Bay since 1975. 

The ozone dose responses and the specific effects on the photosynthetic activity of both herbaceous and woody plants, principally in controlled short exposures, are discussed in Chapter 11. The main aim of this section is to evaluate the effects of the chronic exposure of vegetation in natural ecosystems to total oxidants (more than 90% ozone) under field conditions or simulated field conditions. The effects of chronic exposure on agroecosystems are also discussed to a limited extent in Chapter 11. 

Lassiter, R. R., and D. W. Hayne. A finite difference model for simulation of dynamic processes in ecosystems, pp. 367-440. In B. C. Patton, Ed. Systems Analysis and Simulation In Ecology. Vol. 1. New York Academic Press. 1971. 

Fig. 8.41 Simulated Chernobyl Cs+ distribution in the soil ecosystem (A) in leaf pads and (B) in soil columns when the microbial decomposition of the organic material is enhanced by an increase in ambient temperature. (Tengen et al. 1991)...

The emerging concept of developing experimental mini-ecosystems — focused on controlled-exposure environments for testing and for developing mathematical simulations of ecosystem impact based on limited, specific tests—should be supported. 

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