The influence of soil morphology on solute transport was investigated for two distinctly different Spodosols, i. In the case of bentazone, most model predictions were within the 95% confidence intervals of the observations. The larch budmoth in the Alps. Some of his more recent research activities are in macroeconimic forecasting, prediction and planning of surgical procedure times, survey effects in opinion polls, and maritime safety. Sensitive dependence on the initial state chaos and the parameters are analyzed using methods such as Lyapunov exponents and Monte Carlo simulation.
This volume addresses such problems by using tools from chaos theory and systems theory, adapted for the analysis of problems in the environmental sciences. Mixing after application, degradation and sorption are the most important processes for the fate of the relevant pesticides in the top 20 cm of the soil. However, experimental additions of gypsy moth larvae during the low density phase prevented defoliation, suggesting that some other factor, probably parasitoids, were able to respond and suppress the prey population before defoliation could occur Maksimovic et al. For a number of pesticides with different mobility and half-lives, Monte Carlo simulations were carried out with Latin Hypercube Samples in a preset range of the input parameter domain. We can also estimate the effect of the parasitoid on the rate of change of the budworm by fitting the equation Berryman 1992, 1994 4 in which the parameters A n and C n have similar meaning as for the parasitoids and B n reflects the effects of first order feedback due to competition for food, functional responses of predators, and so on. Pesticide persistence in the plow layer was found to be sensitive to K om at low transformation rates and sensitive to the transformation rate at high K om values.
Together with the fact that most modelers calibrated at least part of their model, the possibility for evaluating model concepts was limited. The map of organic-matter content of the top 30 cm was obtained by applying a conversion factor of 1. The paper addresses the important role of sensitivity and uncertainty analysis in the mathematical modeling process and discusses guidelines to perform these analyses. Environmental Economics and Natural Resources Group Wageningen University Wageningen The Netherlands About this article Cite this article as: Schmieman, E. Schoen, Firenze, 3-6 Hendrix, E. Because organic matter has a different effect on the concentration in total soil than it has on the concentration in the liquid phase, the concentration in total soil decreased in the order North-Centre-South whereas the concentration in the liquid phase decreased in the opposite order. Pseudoparasitism: detection and ecological significance in Epinotia tedella Cl.
Systems sciences -- Understanding uncertain environmental systems -- System identification by approximate realization -- Sensitivity analysis versus uncertainty analysis: when to use what? Because the leaching models are highly sensitive to the Freundlich exponent Boesten and van der Linden, 1991; Tiktak et al. Trends in Ecology and Evolution 6: 262-263. In other words we perform a simple regression on the model known as the 1 where d is the dominant lag in the density dependent feedback response Berryman 1992 , or on the multiple regression model 2 where d is now the maximum dimension of the feedback structure Turchin 1990. Theory and applications in ecotoxicology. The black-headed budworm in eastern Canada. The Panel investigated options for improvement, but could not complete its evaluation on these two topics because underlying data to test these options were not made available to the Panel. The reason for the higher leaching was that the most critical leaching conditions were not covered by the selected pH values.
An investigation on Daphnia magna populations. This, together with the fact that parasitoids often exhibit strong numerical responses to host density, can give rise to delayed negative feedback. The use of these models for registration purposes and regional scale assessments, however, is hampered by the shortage of sufficiently detailed experimental data to allow appropriate validation tests. This should not be taken to mean that I believe other factors e. Environmental Science and Technology 47: 2909—2917. Density-dependent suppression of experimentally created gypsy moth, Lymantria dispar Lepidoptera: Lymantriidae , populations by natural enemies. The extent of pesticide leaching was characterized by the percentage of the dose leached below 1 m depth.
The model assumes equilibrium sorption Freundlich equation , first-order transformation kinetics and passive plant uptake. Wesseler, Environmental Economics and Natural Resource Group, Wageningen Roebeling, P. Poster presentation at the Marie Curie Researchers Symposium. The leaching of a substance is influenced by its physico-chemical characteristics as well as environmental conditions. If generic parameter values were used, the model predictions sometimes deviated strongly from the observed data. It also offers an engaging debate as to how regional resilience can be improved and explores the social aspects of vulnerability, resilience and innovation. This report describes a new exposure scenario for soil-bound crops as part of the Dutch authorisation procedure for plant protection products.
Daily averages of meterological conditions rainfall, evapotranspiration, soil temperature were used as input. Environmental constraints are defined in terms of soil quality indicators, e. Nonylphenol act mainly by toxicity, whereas 3,4-Dichloraniline acts mainly on reproduction. This was especially true for pesticide degradation properties. Fitting this model to data on the density of budworms and larval parasitoids explains 91% of the variation in R p, demonstrating that the parasitoids have a very strong numerical response see for details of two-species models.
Feeding inhibition explains effects of imidacloprid on the growth, maturation, reproduction and survival of Daphnia magna. Among the modeled lake types temperate, boreal, and subalpine , peak radioactivity was highest for brown trout living in the warmest lake, feeding and growing at a maximum rate, and for fallout occurring early in spring. For research workers at universities and semi governmental institutes for the environment, agriculture, ecology, meteorology and water management, and theoretical economists. The concentration of pesticide in ground water was most sensitive to the Freundlich concentration exponent, and, to a lesser extent, to the Freundlich coefficient, except for some pesticides which are hardly sorbed. In general, the accumulation of pesticides in the plough layer was very sensitive to model inputs influencing the transformation rate of the pesticide soil temperature and half-life and almost insensitive to sorption characteristics and soil water fluxes.