Showing papers in "Ecological Modelling in 2000"

TL;DR: A review of predictive habitat distribution modeling is presented, which shows that a wide array of models has been developed to cover aspects as diverse as biogeography, conservation biology, climate change research, and habitat or species management.

TL;DR: Techniques are described for evaluating reliability or calibration and discrimination capacity of habitat models developed using logistic regression which measures discrimination capacity in terms of the area under a relative operating characteristic curve relating relative proportions of correctly and incorrectly classified predictions over a wide and continuous range of threshold levels.

TL;DR: In this paper, the authors present a technique for the dynamic estimation of bounds on unmeasured variables (or parameters) of an uncertain dynamical system, which relies on interval observers: from (possibly time varying) intervals on the uncertainty and measurements, they compute guaranteed intervals for the variables.

TL;DR: In this article, the authors evaluate the effect that each of these factors has on the predictive accuracy of fitted models, using fauna and flora survey data from north-east New South Wales, and suggest that predictive accuracy is maximised by employing variable selection procedures that stringently guard against the inclusion of extraneous variables in a model.

TL;DR: In this paper, two independently developed mathematical models (GALES and HWIND) for predicting the critical wind speed and turning moment needed to uproot and break the stems of coniferous trees were compared and the results tested against field data on the forces experienced by forest trees and the wind speeds required to damage them.

TL;DR: The fuzzy methodology is illustrated by examples based on research to evaluate of the effects of finfish mariculture on coastal zone water quality and to ‘defuzzify’ them and obtain a more traditional type of index.

TL;DR: In this paper, a broad-scale probabilistic model of forest fires, EMBYR, is developed to simulate the effects of large fires burning through heterogeneous landscapes, where fire ignition and spread are simulated on a gridded landscape by examining each burning site at each time step, independently evaluating the probability of spread to eight neighbors based on fuel type, fuel moisture, wind speed and direction, and distributing firebrands to downwind sites, where the probability for ignition of new fires is a function of fuel type and moisture conditions.

TL;DR: The aim of this paper is to analyze the behavior of models which describe the population dynamics taking into account the subjectivity in the state variables or in the parameters, and to propose an interpretation which differs from the deterministic one.

TL;DR: A new approach to spatially explicit modelling that enables the influence of neighbourhood effects on the dynamics of forests and plant communities to be analysed as ‘field of neighbourhood’ (FON), which combines the ‘neighbourhood philosophy’ of grid-based models with the description of individual spacing in the ZOI approach.

TL;DR: It is concluded that the performance of the model varies between data sets, microdata generate a lower mean square error than aggregated macrodata, and time steps of one year are preferable to three months.

TL;DR: The proposed model can serve as a basis for the development of algorithms to simulate real epidemics based on real data and establish the acceleration of the epidemic propagation because of the increment, of the percentage of the moving population, or of the maximum distance of population movement.

TL;DR: In this paper, the authors quantified trends in mean and variance of understory light along the grassland/forest continuum using a spatially-explicit ray-tracing model.

TL;DR: In this article, an ecosystem model based on nitrogen cycling and oxygen has been developed for the Thau lagoon, a semi-confined system with watershed inputs and oyster farming.

TL;DR: This paper summarizes the state of the art and introduces several updated developments in analysis and description of patch patterns and patch dynamics by means of Mandelbrot’s fractal analysis, with an emphasis on current research results and a personal view.

TL;DR: In this article, the authors treat the properties of ecosystem growth and development from the perspective of open, nonequilibrium, thermodynamic systems, and interpret results for living ecosystems based on parallels between these and the much simpler nonliving ones treated rigorously in thermodynamic theory.

TL;DR: In this paper, an adaptive agent model of rangelands based on concepts of complex adaptive systems is described, and the evolution of the rangeland system is studied under different policy and institutional regimes that affect the behaviour and learning of pastoralists, and hence the state of the ecological system.

TL;DR: In this paper, a three layer Levenberg-Marquardt feedforward learning algorithm was used to model the eutrophication process in three water bodies of Turkey (Keban Dam Reservoir, Mogan and Eymir Lakes).

TL;DR: Requests from ecosystem theory are described which include the consideration of features such as self-organization, emergence, thermodynamics, gradients and ecological orientors in environmental indicator sets.

TL;DR: In this article, the authors compare two major types of static biogeographical models, climate-vegetation classification and plant functional type models, and the first generation of Dynamic Global Vegetation Models (DGVMs).

TL;DR: In this article, a general method for estimation of time-homogeneous transition probabilities applicable for any kind of successional scheme, yet with strong requirements to the expert data: average duration times should be known for each specified stage of succession as well as the likelihood proportions among the transitions from the ramifying states of the scheme.

TL;DR: The quadratic entropy index is the only ecological diversity index, the value of which reflects both the differences ‘and’ abundances of the species, and trivially satisfies set monotonicity, an important property for biodiversity indices.

TL;DR: In this paper, an Integrated Terrestrial Ecosystem C-budget model (InTEC) is presented, which integrates effects of all these factors on the annual C cycle of a forest region.

TL;DR: In these models coexistence of mixotrophs with phytoplankton and zooplankon generally occurs within reasonable parameter ranges, which suggests that mixotrophy represents a unique resource niche under summertime, quasi-steady state conditions.

TL;DR: In this article, a generalized yet detailed wetland ecosystem model was calibrated and validated with 3 years's data from four similarly constructed wetlands in northeastern Illinois, USA, and the model was used to explore the role of different wetland structure and function in relation to phosphorus retention.

TL;DR: It is suggested here that the use of a biologically reasonable predictor in a simple stochastic algorithm, used within a mechanistic model of plant growth, is a preferable improvement on how modelling mortality can be improved.

TL;DR: In this paper, a case study of a dairy farm in Puerto Rico was analyzed from this viewpoint, showing that co-production of milk and methane (or electricity) is more efficient and less impacting on the environment with respect to separate productions, while two separate processes would be more effective in using local resources.

TL;DR: Four alternative strategies to use remotely sensed data to provide estimates of variables required to drive ecological process models are identified and directions for future work are identified.

TL;DR: In this paper, the authors explored potential implications of global climate changes on lifeform distribution and growth at Wind Cave National Park (WCNP), South Dakota, which lies on a climatically determined ecotone between grassland and forest.

TL;DR: In this article, a process-based vegetation model (BIOME3) was used to reconstruct from pollen data the most probable climate under precipitation seasonality change and under lowered CO 2 concentration in the biosphere.

TL;DR: In this paper, a 1D model of reservoir hydrodynamics DYRESM has been applied to Sau Reservoir, a river valley reservoir in the North-Eastern Spain.