Systems approaches are excellent in integrating insights in the physical, chemical, Systemsapproachesareexcellentinintegratinginsightsinthephysical, chemical, physiological and ecological processes that dictate the behaviour of living systems, of physiologicalandecologicalprocessesthatdictatethebehaviouroflivingsystems, of which which agro-ecosystems agro-ecosystems are are important importantones. ones. Furthermore, Furthermore, they theyhelp help to tobridge bridge the the gap gap between betweendetailed detailed process processoriented oriented studies studies and and higher higherintegration integration levels. levels. Systems Systems approaches approaches are are roughly roughlycategorized categorized in inthree three groups groups of of studies: studies: (i) (i) predictive predictive studies studies to to support support decision decision making making and and guide guide interventions, interventions, (ii) (ii) systems systemsanalysis analysis and and simulation simulation in inorder order to toget get insight insight and and understanding understandingof of the the functioning functioningof of (living) (living) systems, systems, and and (iii) (iii) explorative explorative studies studies to to investigate investigate possible possible options options for for development development and and trade trade offs offs of of aims, aims, objectives objectives and andconstraints. constraints. All All these these systems systems approaches approaches are are now nowwidely widely used used in inecological ecological systems systems including including agriculture, agriculture, and and applied appliedin in land landuse use planning. planning. This This book book is is an an introduction introduction to toone one of ofthe the major majorfields: fields: systems systems analysis analysis and and simula simula tion. tion."

Systems approaches are excellent in integrating insights in the physical, chemical, Systemsapproachesareexcellentinintegratinginsightsinthephysical, chemical, physiological and ecological processes that dictate the behaviour of living systems, of physiologicalandecologicalprocessesthatdictatethebehaviouroflivingsystems, of which which agro-ecosystems agro-ecosystems are are important importantones. ones. Furthermore, Furthermore, they theyhelp help to tobridge bridge the the gap gap between betweendetailed detailed process processoriented oriented studies studies and and higher higherintegration integration levels. levels. Systems Systems approaches approaches are are roughly roughlycategorized categorized in inthree three groups groups of of studies: studies: (i) (i) predictive predictive studies studies to to support support decision decision making making and and guide guide interventions, interventions, (ii) (ii) systems systemsanalysis analysis and and simulation simulation in inorder order to toget get insight insight and and understanding understandingof of the the functioning functioningof of (living) (living) systems, systems, and and (iii) (iii) explorative explorative studies studies to to investigate investigate possible possible options options for for development development and and trade trade offs offs of of aims, aims, objectives objectives and andconstraints. constraints. All All these these systems systems approaches approaches are are now nowwidely widely used used in inecological ecological systems systems including including agriculture, agriculture, and and applied appliedin in land landuse use planning. planning. This This book book is is an an introduction introduction to toone one of ofthe the major majorfields: fields: systems systems analysis analysis and and simula simula tion. tion."

Presenting a method for the analysis of ecological ecosystems using numerical models, this text describes the development of these models by means of relational diagrams and rate equations. The calculation of the dynamic behaviour of the models is studied through small computer programs. The approach is illustrated by treating examples ranging from simple exponential growth to the development of an insect population and transport phenomena in soils. About 100 worked examples clarify the theoretical concepts presented and give the book a tutorial nature. The examples often illustrate the process, from defining the problem to the development of a computer program. Examples include models about yeasts, prey-predator interactions, pollutant and organic matter dynamics and heat flow in soil. A simulation language is used to develop the programs, so that the need to learn technical programming details is minimized and attention can be focused on the ecological problem. Use of this language is described in the text. The book concludes with the presentation of a simulation environment in FORTRAN, assuring a high model portability. Those interested in applying systems analysis and simulation in the study of ecological processes, like biologists, agriculturalists and soil scientists, should find this book a valuable introduction. After studying the book, readers should be able to develop their own models and to critically follow the literature on more complex ecosystem models.