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How To Compare Different Conceptual Approaches To Metapopulation Modelling, Frank M. Hilker, Martin Hinsch, Hans Joachim Poethke Jul 2004

How To Compare Different Conceptual Approaches To Metapopulation Modelling, Frank M. Hilker, Martin Hinsch, Hans Joachim Poethke

International Congress on Environmental Modelling and Software

Models are essential tools in understanding population dynamics and deriving management measuresin the context of population viability analysis. However, very often the question arises which type ofmodel architecture is appropriate for a given situation. Mostly this situation is characterized by a shortage ofdata for model parameterization. In this study, an approach is presented to overcome this lack of real-worlddata by using the output of long-term simulation runs of specific individual-based models. Thus, it is possibleto evaluate the quality of macroscopic model predictions. Furthermore, this setting allows to compare totallydifferent types of metapopulation models. As an exemplary case study, this approach …

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Ecosystems As Evolutionary Complex Systems: A Synthesis Of Two System-Theoretic Approaches Based On Boolean Networks, Brian D. Fath, W. E. Grant Jul 2004

Ecosystems As Evolutionary Complex Systems: A Synthesis Of Two System-Theoretic Approaches Based On Boolean Networks, Brian D. Fath, W. E. Grant

International Congress on Environmental Modelling and Software

Understanding and managing ecosystems as biocomplex wholes is the compelling scientific challenge of our times. Several different system-theoretic approaches have been proposed to study biocomplexity and two in particular, Kauffman’s NK networks and Patten’s ecological network analysis, have shown promising results. This research investigates the similarities between these two approaches, which to date have developed separately and independently. Kauffman (1993) has demonstrated that networks of non-equilibrium, open thermodynamic systems can exhibit profound order (subcritical complexity) or profound chaos (fundamental complexity). He uses Boolean NK networks to describe system behavior, where N is the number of nodes in the network and …

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Stability Analyses Of The 50/50 Sex Ratio Using Lattice Simulation, Y. Itoh, K. Tainaka, J. Yoshimura Jul 2004

Stability Analyses Of The 50/50 Sex Ratio Using Lattice Simulation, Y. Itoh, K. Tainaka, J. Yoshimura

International Congress on Environmental Modelling and Software

The observed sex ratio is nearly one half in many animals including humans. Fisher explained thatthe 50/50 sex ratio is optimal. However, the 50/50 sex ratio seems highly unstable because a slight deviationfrom 50/50 changes the optimal ratio to the opposite extremes; zero or unity. Thus sex ratio should befluctuating wildly around 50/50. In contrast, the observed 50/50 sex ratios in wild populations seem to bevery stable. There should be some unknown mechanisms to stabilize the sex ratio 50/50. We build the latticemodel of mating populations. Each cell represents a male, a female, or an empty site. We perform latticesimulation …

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Participatory Spatial Modeling And The Septic Dilemma, Alexey Voinov, Erica Gaddis, Helena Vladich Jul 2004

Participatory Spatial Modeling And The Septic Dilemma, Alexey Voinov, Erica Gaddis, Helena Vladich

International Congress on Environmental Modelling and Software

Whereas point sources of nutrients are quite well known and controlled, there is growing concern about non-point sources, especially those that are related to individual homeowners and citizens' practices. They seem to be the hardest to manage and reduce. On-site sewage disposal systems (OSDS) are among the major contributors to the nutrient pollution of surface and ground waters. In Calvert County, Maryland, up to 25% of the non point source nitrogen pollution originates from septic systems. A participatory landscape modeling approach has been used to analyze and visualize the impact of septic systems on the water quality entering the estuary. …

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Simulation Of Water And Carbon Fluxes In Agro- And Forest Ecosystems At The Regional Scale, J. Post, Valentina Krysanova, F. Suckow Jul 2004

Simulation Of Water And Carbon Fluxes In Agro- And Forest Ecosystems At The Regional Scale, J. Post, Valentina Krysanova, F. Suckow

International Congress on Environmental Modelling and Software

To investigate effects of different land use management practices on carbon fluxes at the regional scale we developed an integrated model by coupling an ecohydrological river basin model SWIM (Soil and Water Integrated Model) and a soil organic matter model SCN (Soil-Carbon-Nitrogen model). The latter is a submodel of the forest growth model 4C. The extended integrated model combines hydrological processes, crop and vegetation growth, carbon, nitrogen, phosphorus cycles and soil organic matter turnover. It is based on a three level spatial disaggregation scheme (basin, subbasin and hydrotopes), whereas a hydrotope is a set of elementary units in the subbasin …

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Knowledge Discovery In Environmental Data Bases Using Gesconda, Karina Gibert, Xavier Flores, Ignasi Rodríguez-Roda, Miquel Sànchez-Marrè Jul 2004

Knowledge Discovery In Environmental Data Bases Using Gesconda, Karina Gibert, Xavier Flores, Ignasi Rodríguez-Roda, Miquel Sànchez-Marrè

International Congress on Environmental Modelling and Software

In this work, last results of the research project “Development of an Intelligent Data Analysis System for Knowledge Management in Environmental Data Bases (DB)” are presented. The project is focussed on the design and development of a prototype for Knowledge Discovery (KD) and intelligent data analysis, and specially oriented to environmental DB. It is remarkable the high quantity of information and knowledge patterns that are implicit in large DB coming from environmental domains. In this project, several environmental DB such as meteorological phenomena, wastewater treatment plants (WWTP), or environmental emergencies were used for testing. KD is a prior and mandatory …

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How Tight Are The Limits To Land And Water Use? – Com-Bined Impacts Of Food Demand And Climate Change, Hermann Lotze-Campen, Christoph Mülle, Alberte Bondeau, Pascalle Smith, Wolfgang Lucht Jul 2004

How Tight Are The Limits To Land And Water Use? – Com-Bined Impacts Of Food Demand And Climate Change, Hermann Lotze-Campen, Christoph Mülle, Alberte Bondeau, Pascalle Smith, Wolfgang Lucht

International Congress on Environmental Modelling and Software

In the coming decades, world agricultural systems will face serious transitions. Population growth, income and lifestyle changes will lead to considerable increases in food demand. Moreover, a rising demand for renewable energy and biodiversity protection may restrict the area available for food production. On the other hand, global climate change will affect production conditions, for better or worse depending on re-gional conditions. In order to simulate these combined effects consistently and in a spatially explicit way, we have linked the Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ) with a "Management model of Agricultural Production and its Impact on the Environment" (MAgPIE). …

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The Role Of Local Spatial Heterogeneity In The Maintenance Of Parapatric Boundaries: Agent Based Models Of Competition Between Two Parasitic Ticks, A. J. Tyre, Brigitte Tenhumberg, C. M. Bull Jul 2004

The Role Of Local Spatial Heterogeneity In The Maintenance Of Parapatric Boundaries: Agent Based Models Of Competition Between Two Parasitic Ticks, A. J. Tyre, Brigitte Tenhumberg, C. M. Bull

International Congress on Environmental Modelling and Software

Recent models of ecological parapatry, where the geographical distributions of two similar species abut without overlapping, have shown that spatial gradients in intrinsic growth rates can lead to sharp boundaries when dispersal is density dependent. However, a well documented parapatric boundary in southern Australia between two tick species that parasitise a large lizard lacks one or both of these features; dispersal of ticks is random and there may not be a gradient of population growth rates for one of the species. There is local variation in population growth rates arising from variation in the number of host lizards with overlapping …

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A Model Of The Biocomplexity Of Deforestation In Tropical Forest: Caparo Case Study, Raquel Quintero, Rodrigo Barros, Jacinto Dávila, Niandry Moreno, Giorgio Tonella, Magdiel Ablan Jul 2004

A Model Of The Biocomplexity Of Deforestation In Tropical Forest: Caparo Case Study, Raquel Quintero, Rodrigo Barros, Jacinto Dávila, Niandry Moreno, Giorgio Tonella, Magdiel Ablan

International Congress on Environmental Modelling and Software

This paper presents some preliminary results with a multi-agents modeling approach to understand the complexity of deforestation in tropical forests. The approach was applied to the study of the deforestation of the Caparo Forest Reserve, in the western part of Venezuela. The model includes, among others, the following types of agents: several instances of settlers, government and lumber concessionaries. Settler agents represent people of limited economical resources that occupied land of the reserve with the aims of improving their socio-economical status and obtaining in the future the property of the occupied land. They use subsistence agriculture and they try to …

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Endowed With Power, Steven C. Harper Jul 2004

Endowed With Power, Steven C. Harper

Religious Educator: Perspectives on the Restored Gospel

No abstract provided.

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The Utility Of Gis Delivered Environment Models In The Characterisation Of Surface Water Bodies Under The Water Framework Directive Low Flows 2000 – A Case Study., T. H. Goodwin, M. Fry, M. G. R. Holmes, Andrew Young Jul 2004

The Utility Of Gis Delivered Environment Models In The Characterisation Of Surface Water Bodies Under The Water Framework Directive Low Flows 2000 – A Case Study., T. H. Goodwin, M. Fry, M. G. R. Holmes, Andrew Young

International Congress on Environmental Modelling and Software

The implementation of the Water Framework Directive (WFD), requires Water Resource Managers to characterise and assess the status of surface water bodies and apply management practices in order to achieve Good Ecological Status (GES), at a national scale. GES is assessed by considering the biological, hydromorphological and physico-chemical characteristics of a water body. There is a need for a suite of tools which will aid in carrying out this assessment quickly and reliably at a large number of sites. Low Flows 2000 (LF2000), combines aquatic environmental and hydrological models within a user-friendly GIS interface. The software can be used to …

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Soil Hydraulics Properties Estimation By Using Pedotransfer Functions In A Northeastern Semiarid Zone Catchment, Brazil, Lúcio Flávio Ferreira Moreira, A. M. Righetto, V. M. De A. Medeiros Jul 2004

Soil Hydraulics Properties Estimation By Using Pedotransfer Functions In A Northeastern Semiarid Zone Catchment, Brazil, Lúcio Flávio Ferreira Moreira, A. M. Righetto, V. M. De A. Medeiros

International Congress on Environmental Modelling and Software

Hydrological modeling of the unsaturated soil zone fluxes allows the transfer processes simulation through the hydrological active soil zone. The pedotransfer functions (FTP) are useful tools in the modeling process. They contain analytical functions derived through statistic optimization process using a large amount of soil information data. This paper aims to analyze the level of reliability of two different pedotransfer functions [Wösten et al. (2001); Hodnett and Tomasella (2000)] by using field measurement of soil properties and experimental infiltration data through a disc infiltrometer in an experimental catchment at northeastern semi arid zone of Brazil. FTP’s used in this study …

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The Evolution Of Economic Structure Under Biotechnological Progress, Haoran Pan Jul 2004

The Evolution Of Economic Structure Under Biotechnological Progress, Haoran Pan

International Congress on Environmental Modelling and Software

There are obvious gaps between long-term change of economic structure and its principle drivingforce – technological progress. History has shown the influence of technological progress on economy andcurrent insights in technological development can almost foresee the coming technological waves in next 50years, but their possible impacts on economy are not yet assessed. In this paper, we define that RandDinvestment drives the development of biotechnology, capacity building brings new bio-technical processesinto sectoral production, new or old technical processes within a sector exchange their relative positions asphasing in and out, and sectors evolve or transform along time. An exercise on US economy …

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Water Management, Public Participation And Decision Support Systems: The Mulino Approach, J. Feás, Carlo Giupponi, P. Rosato Jul 2004

Water Management, Public Participation And Decision Support Systems: The Mulino Approach, J. Feás, Carlo Giupponi, P. Rosato

International Congress on Environmental Modelling and Software

One of the main issues in the environmental decision making field is the necessity, sometimes obligation imposed by the legislation, to communicate the decision process and make it more comprehensible. In other words, the objective is to increase the transparency of the decision making available all the relevant information related to the decision process for all interested actors. For this reason, many tools have been developed over the last decades: indicators, conceptual frameworks, and impact assessment studies are examples. However, many of these tools try to represent the environmental situation or hypothetical future states without any explicit reference to how …

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Land Use Change For Salinity Management: A Participatory Model, Nigel Hall, Mark Oliver, Tony Jakeman, Allan Nicholson, Bill Watson Jul 2004

Land Use Change For Salinity Management: A Participatory Model, Nigel Hall, Mark Oliver, Tony Jakeman, Allan Nicholson, Bill Watson

International Congress on Environmental Modelling and Software

This paper describes the use of spreadsheet models to help farmers and their advisors to makedecisions on land and water use to manage dryland salinity. Salinity management requires an understandingof catchment data and processes. Modelling forms part of the process of understanding the catchment and theturning of data into useable information for salt management. The TARGET project is a NSW governmentpilot program to support integrated catchment management in selected catchments in New South Wales. Amajor feature of the program is the simultaneous progress of research and implementation of salinitymanagement measures in a context of adaptive learning. The research described here …

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Benthic Macroinvertebrates Modelling Using Artificial Neural Networks (Ann): Case Study Of A Subtropical Brazilian River, D. Pereiraa Jul 2004

Benthic Macroinvertebrates Modelling Using Artificial Neural Networks (Ann): Case Study Of A Subtropical Brazilian River, D. Pereiraa

International Congress on Environmental Modelling and Software

Back-propagation Artificial Neural Networks (ANN) were tested with the aim of modelling the occurrence of benthic macroinvertebrate families in a south Brazilian river. The dataset, consisting of 67 sets of observations of macroinvertebrate abundance (families Hydrobiidae, Tubificidae, Chironomidae, Baetidae and Leptophlebiidae) and water quality variables (pH, temperature, dissolved oxygen, biochemical oxygen demand, nitrate, phosphate, total solids, turbidity and fecal coliforms), was collected at eleven sampling sites in the Sinos River Basin during 1991-1993. Five different ANN architectures, with one hidden layer and 2, 5, 10, 20 and 25 neurons were tested. The ANN models were trained using the gradient descendent …

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Visual Sample Plan (Vsp): A Tool For Balancing Sampling Requirements Against Decision Error Risk, B. A. Pulsipher, R. O. Gilbert, J. E. Wilson Jul 2004

Visual Sample Plan (Vsp): A Tool For Balancing Sampling Requirements Against Decision Error Risk, B. A. Pulsipher, R. O. Gilbert, J. E. Wilson

International Congress on Environmental Modelling and Software

Environmental characterization is necessary to support remediation and monitoring decisions andto construct and validate contaminant dispersion models. The more samples obtained, the greater is theprotection against making incorrect decisions. However, taking too many samples wastes valuable resources.The US Environmental Protection Agency has developed several guidance documents on the Data QualityObjectives process to support systematic planning of data gathering campaigns to ensure that the right type,quality, and quantity of data are obtained to support confident decision making.Visual Sample Plan (VSP) is a publicly available software tool sponsored by the US Department of Energy,US Environmental Protection Agency, and the US Department of …

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Developing Natural Resource Models Using The Object Modeling System: Feasibility And Challenges, L.R. Ahuja, Olaf David, James C. Ascough Ii Jul 2004

Developing Natural Resource Models Using The Object Modeling System: Feasibility And Challenges, L.R. Ahuja, Olaf David, James C. Ascough Ii

International Congress on Environmental Modelling and Software

Current challenges in natural resource management have created demand for integrated, flexible, and easily parameterized hydrologic models. Most of these monolithic models are not modular, thus modifications (e.g., changes in process representation) require considerable time, effort, and expense. In this paper, the feasibility and challenges of using the Object Modeling System (OMS) for natural resource model development will be explored. The OMS is a Java-based modeling framework that facilitates simulation model development, evaluation and deployment. In general, OMS consists of a library of science, control, and database modules and a means to assemble the selected modules into an application-specific modeling …

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Aphid Population Dynamics In Agricultural Landscapes: An Agent-Based Simulation Model, Hazel Parry, Andrew J. Evans, Derek Morgan Jul 2004

Aphid Population Dynamics In Agricultural Landscapes: An Agent-Based Simulation Model, Hazel Parry, Andrew J. Evans, Derek Morgan

International Congress on Environmental Modelling and Software

Presently, there are many population models in existence, but these are often case specific,function at a single spatial scale and fail to tackle the complexity arising from individual actions andinteractions that exist in the real-world. A spatially explicit agent-based simulation model has beendeveloped to represent aphid population dynamics in agricultural landscapes. Over time, the aphid agentsinteract with the landscape and with one another. The construction of the model is detailed, includingparameterisation and coupling to a geographical information system (GIS). The results show that a spatialmodelling approach that considers both landscape properties and factors such as wind speed and directionprovides greater …

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Modelling Self-Organization Processes In Socio- Economic And Ecological Systems For Supporting The Adaptive Management Of Forests, Alexander Kaufmann, Ernst Gebetsroither Jul 2004

Modelling Self-Organization Processes In Socio- Economic And Ecological Systems For Supporting The Adaptive Management Of Forests, Alexander Kaufmann, Ernst Gebetsroither

International Congress on Environmental Modelling and Software

Managing the numerous and interrelated processes between man and nature in order to userenewable resources in a sustainable way is confronted with conflicting objectives, external effects, complexinterdependencies, uncertainty and other features that make it nearly impossible to come to unambiguousoptimal decisions. Self-organization in socio-economic and ecological systems - the process of structuring asystem by the elements of the system themselves without hierarchical or external control - is often the reasonfor ambiguity and uncertainty. Adaptive management is an approach to deal with these challenges. Thisnatural resource management method is permanently monitoring both socio-economic and ecological systemsin order to be able to …

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Reduction Of Complex Models Using Data-Mining And Nonlinear Projection Techniques, K. Bernhardt, K. W. Wirtz Jul 2004

Reduction Of Complex Models Using Data-Mining And Nonlinear Projection Techniques, K. Bernhardt, K. W. Wirtz

International Congress on Environmental Modelling and Software

Complex models of environmental systems typically depend on a large amount of uncertain parameters. Therefore, they are often difficult to handle and do not provide an insight into effective modes of the underlying system’s dynamics. Unlike earlier analytical attempts to find more effective model representations, we present a new combination of methods that only relies on data generated by complex, process-based models. These methods are taken from the field of data-mining and enable the recognition of patterns in measured or modelled data by unsupervised learning strategies. As these methods do not directly lead to a better understanding of the systems’ …

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Water Quality Modelling In Rivers With Limited Observational Data: River Elbe Case Study, Renata J. Romanowicz, Ulrich Callies, Peter C. Young Jul 2004

Water Quality Modelling In Rivers With Limited Observational Data: River Elbe Case Study, Renata J. Romanowicz, Ulrich Callies, Peter C. Young

International Congress on Environmental Modelling and Software

Water quality predictions in an ungauged catchment require the development of a model that is able to capture the basic physical features of the process and depends only on variables that are easily available. From this point of view, the model has similar requirements to those used in future climate scenario analysis. The mechanistic water quality model, developed in GKSS, Germany, for the purpose of climate change analysis, uses only climatic variables, such as temperature, radiation and discharge, to predict the time variability of algae concentrations. This paper presents the development of a statistical analogue to this mechanistic model. The …

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A Spatial Dss For South Australia's Prawn Fisheries. Using Historic Knowledge Towards Environmental And Economical Sustainability, B. Ostendorf, N. Carrick Jul 2004

A Spatial Dss For South Australia's Prawn Fisheries. Using Historic Knowledge Towards Environmental And Economical Sustainability, B. Ostendorf, N. Carrick

International Congress on Environmental Modelling and Software

The Spencer Gulf Penaeid prawn fishery is an example of a sustainable fishery due to close collaboration between fishers, research and government. The fishery has undergone substantial increase in fishing efficiency due to improvement in gear, increase in crew skill, effective use of communication networks for monitoring catch, stock assessment, and for rapid response for change in harvest strategies. Spatial decision-making has reduced the fishing effort to around 60 days per year and less than 10% of the area of the Gulf is trawled, with increasing economic gain due to development of real time adaptive harvest strategies undertaken in collaboration …

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Assessing The Ecological Impacts Of Salinity Management Using A Bayesian Decision Network, A. Sadoddin, R. A. Letcher, Lachlan T. H. Newham Jul 2004

Assessing The Ecological Impacts Of Salinity Management Using A Bayesian Decision Network, A. Sadoddin, R. A. Letcher, Lachlan T. H. Newham

International Congress on Environmental Modelling and Software

This paper outlines a component of a study currently being undertaken to provide a new tool for the holistic management of dryland salinity. The Little River catchment in the upper Macquarie River basin of New South Wales (NSW), Australia, is used as a case study. The model uses a Bayesian Decision Network (BDN) approach to integrating the various system components – biophysical, social, ecological, and economic. The method of integration of the system components is demonstrated through an example application showing the impacts of various scenarios on terrestrial and riparian ecology. The paper outlines these scenarios and demonstrates the way …

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A Conceptual Model About The Application Of Adaptive Management For Sustainable Development, Markus Knoflacher, U. Gigler Jul 2004

A Conceptual Model About The Application Of Adaptive Management For Sustainable Development, Markus Knoflacher, U. Gigler

International Congress on Environmental Modelling and Software

This conceptual model is based on theoretical implications and analyses of empirical examples, and focuses on how functional processes in the environmental system affect decisions taken in the social system. Complex functional relationships at several temporal and spatial scales such as climate conditions or pollutant emissions characterise functional processes in the environmental system. Actions of humans in the environmental system are crucially constrained by limited information about system conditions, and limited predictability of system development. Both constraints are not equally valid for all functional processes, and all interactions between humans and the environmental system, because diverse human activities and interests …

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Combining Dynamic Economic Analysis And Environmental Impact Modelling: Addressing Uncertainty And Complexity Of Agricultural Development, Heikki Lehtonen, Ilona Bärlund, Sirkka Tattari, Mikael Hilden Jul 2004

Combining Dynamic Economic Analysis And Environmental Impact Modelling: Addressing Uncertainty And Complexity Of Agricultural Development, Heikki Lehtonen, Ilona Bärlund, Sirkka Tattari, Mikael Hilden

International Congress on Environmental Modelling and Software

In this study the impacts of different agricultural policies on agricultural production and nutrient leaching from agricultural lands are evaluated using the economic DREMFIA agricultural sector model and a field scale nutrient transport model ICECREAM. DREMFIA includes an evolutionary scheme of technology diffusion which considers farm investments, evolving farm size structure and technological change explicitly. The technology diffusion model allows self-inforcing patterns of technical change driven by the spread of information and farmers’ knowledge related to different technological alternatives. Hence the long-term changes in agriculture due to policy changes may be essentially larger than those predicted by traditional static equilibrium …

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Mathematical Models For Gene Flow From Gm Crops In The Environment, O. Richter, K. Foit, Ralf Seppelt Jul 2004

Mathematical Models For Gene Flow From Gm Crops In The Environment, O. Richter, K. Foit, Ralf Seppelt

International Congress on Environmental Modelling and Software

Risk assessment of gene flow from GM crops into the environment requires both the development of physical transport models and biological models for the assessment of outcrossing probabilities. Our starting point is a Lagrangian approach for pollen dispersal, which describes the concentration statistics in terms of the stochastic properties of the paths of ensembles of particles. Transport of a particle from a location (x’,y’,z’) to a location (x,y,z) is mediated by a probability density or transfer function Q(x,y,z|x’,y’,z’). The transfer function depends on the statistics of the wind field during pollination. The total amount of pollen, which reaches a single …

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Robustness Against Different Implementation Of Uncertainty In A Contingency Dss: The Prestige Oil Spill Revised, K. W. Wirtz, S. Adam, X. Liu, N. Baumberger Jul 2004

Robustness Against Different Implementation Of Uncertainty In A Contingency Dss: The Prestige Oil Spill Revised, K. W. Wirtz, S. Adam, X. Liu, N. Baumberger

International Congress on Environmental Modelling and Software

The dramatic consequences of oil or chemical spills for coastal ecosystems and economic uses make contingencymanagement a politically sensitive task. We here propose a new Decision Support System (DSS)consisting of a combination of modeling and evaluation methods with which different containment strategiescan be compared in the light of a variety of potential ecological and economic damages. In this study, the DSSis tested by hindcasting the Prestige accident off the coast of Spain in 2002. In particular, an oil spill contingencysimulation model coupled with multi-criteria analysis techniques was used to assess oil spill impacts forweather and current forecasts available at that …

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Predicting The Hydraulic And Morphological Consequences Of River Rehabilitation, S. Schweizer, M. E. Borsuk, Peter Reichert Jul 2004

Predicting The Hydraulic And Morphological Consequences Of River Rehabilitation, S. Schweizer, M. E. Borsuk, Peter Reichert

International Congress on Environmental Modelling and Software

Decisions about flood protection and river rehabilitation require prediction of the consequences of each possible management alternative. To provide such predictions, an integrative model is required that represents the cause-effect relations between revitalisation measures and morphologic, hydraulic and ecological consequences. This paper describes the hydraulics submodel of such an integrative model. This submodel is subdivided into four modules predicting channel morphology, gravel transport, velocity distribution, and riverbed clogging. The channel morphology module predicts natural channel form based on a simple regression model of its dependence on easily available influence factors (valley slope, annual discharge, and median gravel size). Morphology predictions …

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On The Local Coexistence Of Species In Plant Communities, J. Yoshimura, K. Tainaka, M. Shiyomi, T. Suzuki Jul 2004

On The Local Coexistence Of Species In Plant Communities, J. Yoshimura, K. Tainaka, M. Shiyomi, T. Suzuki

International Congress on Environmental Modelling and Software

Coexistence of many competitive species is very common in natural plant communities. For example, almost all forests and grasslands consist of various species. Extremely high biodiversity is seen in tropical rain forests. Grassland communities also often consist of many species. In plant communities, spatially competitive species of plants coexist in a mosaic pattern. Communities with a single species are very extremely rare in nature. However, mathematical studies show that the local coexistence of spatially competitive species is rarely achieved even with two competitive species. Many studies have introduced external factors to promote coexistence, such as immigration of seeds, seed dormancy, …

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