Showing papers in "Ecological Modelling in 2006"

TL;DR: In this paper, the use of the maximum entropy method (Maxent) for modeling species geographic distributions with presence-only data was introduced, which is a general-purpose machine learning method with a simple and precise mathematical formulation.

TL;DR: The “adehabitat” package for the R software is presented, which offers basic GIS functions, methods to analyze radio-tracking data and habitat selection by wildlife, and interfaces with other R packages.

TL;DR: A proposed standard protocol for describing IBMs and ABMs, developed and tested by 28 modellers who cover a wide range of fields within ecology, and considered as a first step for establishing a more detailed common format of the description of IBm and ABM.

TL;DR: The Principal Coordinates of Neighbors of Neighbor Matrices (PCNM) approach as discussed by the authors was proposed to create spatial predictors that can be easily incorporated into regression or canonical analysis models, providing a flexible tool especially when contrasted to the family of autoregressive models and trend surface analysis which are of common use in ecological and geographical analysis.

TL;DR: In this article, the authors compare existing and new presence-only evaluators to usual presence/absence measures and propose a continuous Boyce index, which is a threshold independent evaluator for evaluating generalised linear models.

TL;DR: In this paper, the authors describe new C and N modules developed in EPIC built on concepts from the Century model to connect the simulation of soil C dynamics to crop management, tillage methods, and erosion processes.

TL;DR: The straightforward methodology proposed here and the broad use of Ecopath with Ecosim together give a solid empirical basis for identification of keystone functional groups, which allow us to rank functional groups by their keystoneness.

TL;DR: In this paper, two statistical modelling techniques, generalized additive models (GAM) and multivariate adaptive regression splines (MARS), were used to analyse relationships between the distributions of 15 freshwater fish species and their environment.

TL;DR: In this article, five regression models were used to assess the relationship between the abundance of a vulnerable plant species, Leionema ralstonii, and the environment and their predictive performance was evaluated with correlation, calibration and error statistics calculated within a bootstrap evaluation procedure that simulated performance for independent data.

TL;DR: In this paper, the results obtained from three models and their potential to forecast drought over different lead times are presented in the Kansabati River Basin, which lies in the Purulia district of West Bengal, India.

TL;DR: In this article, the authors compared three alternative modeling techniques for mapping presence and basal area of 13 species located in the mountain ranges of Utah, USA, and found that SGB provided the most stable predictions in these instances.

TL;DR: Wang et al. as mentioned in this paper developed an environmental numerical model using spatial principle component analysis (SPCA) method, which contains nine factors including elevation, slope, accumulated temperature, drought index, land use, vegetation, soil, water-soil erosion, and population density.

TL;DR: In this paper, the authors used the COMPAS software package to generate two types of data sets: (1) direct, where species show typical responses to variables such as radiation and (2) indirect, where variables like aspect and slope which are related to radiation by complex environmental processes.

TL;DR: In this article, the authors present the dynamic, spatially explicit, grid-based and spatially linked forest-landscape model TreeMig, which is able to produce landscape patterns resulting from both, endogenous dynamics and exogenous drivers and is suitable for a range of different applications.

TL;DR: In this paper, the authors compared prediction success of habitat models using air photo variables to models with variables derived from finer resolution, ground-sampled vegetation plots and found significant positive spatial autocorrelation in the residuals of at least one habitat model for 76% (16/21) of species examined.

TL;DR: In this paper, the water residence time of the Venice Lagoon has been computed using a 2D hydrodynamic model based on the finite element method, and the importance of the return flow from the Adriatic into the lagoon is shown.

TL;DR: Wang et al. as mentioned in this paper developed a model based on climate change, ecological stress factors and human activities to estimate vegetation coverage and soil erosion in the Loess Plateau of China and tested the model performance.

TL;DR: The most accurate algorithm is Breiman's random forest, an ensemble method which provides automatic combination of tree-classifiers trained on bootstrapped subsamples and randomised variable sets, which shows a potential area of P. sylvestris for the Iberian Peninsula which is larger than the present one.

TL;DR: In this article, the authors used emergy methodology to evaluate environmental aspects of integrated production systems of grains, pig and fish in small farms in the South region of Brazil, and the results obtained signalize that an integrated system has better emergy efficiency, is more sustainable and is less stressful on the environment in comparison with separated production subsystems.

TL;DR: In this article, an attempt to improve an existing biogeochemical model, denitrification-decomposition or DNDC, for estimation of nitrate leaching from crop fields with tile drainage system was reported.

TL;DR: In this paper, the authors used eddy-covariance observations of carbon dioxide (CO2) and water vapor exchange at three AmeriFlux mid-latitude forest stands to evaluate IBIS, a Dynamic Global Vegetation Model (DGVM).

TL;DR: A Bayesian probability network has been developed to integrate the various scientific findings of an interdisciplinary research project on brown trout and their habitat in Switzerland as discussed by the authors, which is based on a dynamic, age-structured population model, which is extended to include the effect of natural and anthropogenic influence factors.

TL;DR: In this paper, the role of zooplankton in nutrient cycles in Lake Kinneret, Israel, using field data and a numerical model was quantified using a coupled ecological and hydrodynamic model (DYRESM) and validated with an extensive field data set to simulate the seasonal dynamics of nutrients.

TL;DR: The ELAM model introduced in this paper is called the Numerical Fish Surrogate and facilitated the development of a mechanistic biological-based hypothesis describing observed 3-D movement and passage response of downstream migrating juvenile salmon at 3 hydropower dams on 2 rivers with a total of 20 different structural and operational configurations.

TL;DR: This study presents two examples where structural equation modeling is used for exploring ecological structures; i.e., summer epilimnetic phytoplankton dynamics and water clarity during the summer stratification period and demonstrates how this Bayesian methodological framework can be used for assessing eutrophic conditions and assisting water quality management.

TL;DR: The PestLCI model as discussed by the authors is a modular model for estimating pesticide emissions from field application to different environmental compartments, such as air, surface water, and groundwater, based on information which will normally be available to the model user about: type and time of application, crop species and development stage, geological and meteorological conditions and the area of application.

TL;DR: In this article, the authors used a 1m resolution laser elevation model and a standard 25m resolution digital elevation model to compute four terrain variables (slope, aspect, plan curvature and profile curvature) at six different scales and compare their predictive ability.

TL;DR: In this article, the authors adapted and validated snow transport and land surface models to simulate the heterogeneous snow distributions produced during three consecutive water years (1998, 1999, and 2000).

TL;DR: A spatial simulation model of physical and ecological processes occurring on a dominant Caribbean for reef habitat, often referred to as Montastraea reef, is described and the impact of losing the keystone herbivore, Diadema is revisited.

TL;DR: In this paper, the authors evaluated the effects of probabilistic and non-probabilistic sample surveys on resultant classification tree models for predicting the presence of four lichen species in the Pacific Northwest, USA.