Options are provided in ecosys to introduce a full range of management practices into model simulations,including tillage (defined by dates, depths, degrees of soil mixing), fertilization (dates, application methods and depths, types and amounts of: N, P lime, gypsum, residue, manure), irrigation (dates, times, amounts, chemical composition), planting (species, dates, densities), and harvesting (dates, types, heights). Options are also provided to introduce changes in atmospheric boundary conditions (incremental or step changes in Ca, radiation, temperature, precipitation, humidity, windspeed, and changes in chemical composition of precipitation). These options allow the effects of a wide range of distubances to be simulated when studying disturbance effects on ecosystem function.
The ecosys source code has been constructed such that all flux equations are solved in three dimensions for each cell of a matrix defined by row, column and layer position. Model users may thus construct simulated ecosystems in one, two or three dimensions with any length, width, depth, azimuth and inclination, and any number of competing plant populations. The capability of ecosys to function in 3 dimensions addresses the need to scale high-resolution ecosystem processes up to the landscape level. Provision is made for soil properties to vary in three dimensions through the matrix. All loops are constructed to insure independence of each cell during code execution. This restructured code could in future be implemented in a massively parallel computing environmeOptions are provided in ecosys to introduce a full range of management practices into model simulations45, including tillage (defined by dates, depths, degrees of soil mixing), fertilization (dates, application methods and depths, types and amounts of: N, P lime, gypsum, residue, manure), irrigation (dates, times, amounts, chemical composition), planting (species, dates, densities), and harvesting (dates, types, heights). Options are also provided to introduce changes in atmospheric boundary conditions (incremental or step changes in Ca, radiation, temperature, precipitation, humidity, windspeed, and changes in chemical composition of precipitation). These options allow the effects of a wide range of distubances to be simulated when studying disturbance effects on ecosystem function.
The ecosys source code has been constructed such that all flux equations are solved in three dimensions for each cell of a matrix defined by row, column and layer position. Model users may thus construct simulated ecosystems in one, two or three dimensions with any length, width, depth, azimuth and inclination, and any number of competing plant populations. The capability of ecosys to function in 3 dimensions addresses the need to scale high-resolution ecosystem processes up to the landscape level. Provision is made for soil properties to vary in three dimensions through the matrix. All loops are constructed to insure independence of each cell during code execution. This restructured code could in future be implemented in a massively parallel computing environment, such that computations for each cell could be carried out concurrently by different processors. Such implementation will eventually enable routine use of the model at the landscape level and will make an important contribution to the scaling up of ecosys performance to represent soil productivity and atmospheric gas exchange at the regional scale.
All work cited above refers to the documentation and testing of different components of a single mathematical model entitled ecosys in which all hypotheses are fully coupled to allow ecosystem behavior to be represented in a fully integrated manner under user-defined conditions of soil, climate and management. Its operation is directed by a simple shell script in which input files for soil, management and climate are read, and in which output files for C, N, P, ion, water and energy distribution are written.
nt, such that computations for each cell could be carried out concurrently by different processors. Such implementation will eventually enable routine use of the model at the landscape level and will make an important contribution to the scaling up of ecosys performance to represent soil productivity and atmospheric gas exchange at the regional scale.
All work cited above refers to the documentation and testing of different components of a single mathematical model entitled ecosys in which all hypotheses are fully coupled to allow ecosystem behavior to be represented in a fully integrated manner under user-defined conditions of soil, climate and management. Its operation is directed by a simple shell script in which input files for soil, management and climate are read, and in which output files for C, N, P, ion, water and energy distribution are written.