scholarly journals A spatially explicit model for estimating risks of pesticide exposure to bird populations

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252545
Author(s):  
Matthew Etterson ◽  
Nathan Schumaker ◽  
Kristina Garber ◽  
Steven Lennartz ◽  
Andrew Kanarek ◽  
...  
Keyword(s):  
Pesticide Exposure ◽  
Integrated Modeling ◽  
Model Complexity ◽  
Spatially Explicit ◽  
Spatially Explicit Model ◽  
Bird Populations ◽  
Biological Realism ◽  
Agricultural Areas ◽  
Integrated Modeling System

Pesticides are used widely in agriculture and have the potential to affect non-target organisms, including birds. We developed an integrated modeling system to allow for spatially-explicit evaluation of potential impacts to bird populations following exposures to pesticides. Our novel methodology builds upon three existing models: the Terrestrial Investigation Model (TIM), the Markov Chain Nest Productivity Model (MCnest), and HexSim to simulate population dynamics. We parameterized the integrated modeling system using information required under the Federal Insecticide, Fungicide, and Rodenticide Act, together with species habitat and life history data available from the scientific literature as well as landcover data representing agricultural areas and species habitat. Our case study of the federally threatened California Gnatcatcher (Polioptila californica) illustrates how the integrated modeling system can estimate the population-scale consequences of pesticide applications. We simulated impacts from two insecticides applied to wheat: one causing mortality (survival stressor), and the other causing reproductive failure (reproductive stressor). We observed declines in simulated gnatcatcher abundance and changes in the species’ distribution following applications of each pesticide; however, the impacts of the two pesticides were different. Our methodology attempts to strike a balance between biological realism and model complexity and should be applicable to a wide array of species, systems, and stressors.

scholarly journals An Extended Maximum Likelihood Inference of Geographic Range Evolution by Dispersal, Local Extinction and Cladogenesis

2016 ◽  
Author(s):  
Champak Beeravolu Reddy ◽  
Fabien Condamine
Keyword(s):  
Local Extinction ◽  
Rapid Expansion ◽  
Model Complexity ◽  
Published Data ◽  
Computationally Efficient ◽  
Likelihood Methods ◽  
Origin And Evolution ◽  
Statistical Framework ◽  
Biological Realism

The origin and evolution of species ranges remains a central focus of historical biogeography and the advent of likelihood methods based on phylogenies has revolutionized the way in which range evolution has been studied. A decade ago, the first elements of what turned out to be a popular inference approach of ancestral ranges based on the processes of Dispersal, local Extinction and Cladogenesis (DEC) was proposed. The success of the DEC model lies in its use of a flexible statistical framework known as a Continuous Time Markov Chain and since, several conceptual and computational improvements have been proposed using this as a baseline approach. In the spirit of the original version of DEC, we introduce DEC eXtended (DECX) by accounting for rapid expansion and local extinction as possible anagenetic events on the phylogeny but without increasing model complexity (i.e. in the number of free parameters). Classical vicariance as a cladogenetic event is also incorporated by making use of temporally flexible constraints on the connectivity between any two given areas in accordance with the movement of landmasses and dispersal opportunity over time. DECX is built upon a previous implementation in C/C++ and can analyze phylogenies on the order of several thousand tips in a few minutes. We test our model extensively on Pseudo Observed Datasets and on well-curated and recently published data from various island clades and a worldwide phylogeny of Amphibians (3309 species). We also propose the very first implementation of the DEC model that can specifically account for trees with fossil tips (i.e. non-ultrametric) using the phylogeny of palpimanoid spiders as a case study. In this paper, we argue in favour of the proposed improvements, which have the advantage of being computationally efficient while toeing the line of increased biological realism.

Development of a risk-based TMDL assessment approach using the integrated modeling system GIBSI

2002 ◽  
Vol 45 (9) ◽  
pp. 317-324 ◽  
Author(s):  
A.N. Rousseau ◽  
A. Mailhot ◽  
J.-P. Villeneuve
Keyword(s):  
Waste Water ◽  
Point Sources ◽  
Integrated Modeling ◽  
Prolonged Contact ◽  
Assessment Approach ◽  
River Reach ◽  
Summer Time ◽  
Agricultural Nonpoint Source ◽  
Integrated Modeling System

Using the integrated modeling system GIB SI and a case study, this paper presents the development of a risk-based TMDL assessment approach that links wet (nonpoint/diffuse) and dry weather (point) sources to a probability of exceeding water quality standards (WQS) governing wateruses. The case study focused on determining whether WQS defining recreational uses of water requiring direct and prolonged contact were attainable if the waste water effluent of a small town was treated using aerated lagoons and if the agricultural nonpoint source (NPS) loads were reduced using different fertilization rates. Dry weather sources were assumed to solely contribute to bacteriological impairment of the studied river reach. Meanwhile, both wet and dry weather sources were assumed to contribute to aesthetic impairment. Simulation results showed that treating the waste water effluent while reducing the agricultural NPS loads by 27% allowed on average over a four-year study period for attainment of the bacteriological WQS 100% of the summer time while lowering the probability of exceeding theaesthetic WQS from 0.32 to 0.19 (30 to 18 days). The results of this study showed this risk-based assessment approach was well suited to establish TMDL. These probabilities should be evaluated using long meteorological series.

Site specific agricultural soil management with the use of new technologies

2013 ◽  
Vol 16 (1) ◽  
pp. 59-67
Keyword(s):  
New Technologies ◽  
Digital Interface ◽  
Appropriate Treatment ◽  
Wide Range ◽  
Soil Variation ◽  
Soil Information ◽  
Remote Sensing Techniques ◽  
Agricultural Areas

<p>The Soil Science Institute of Thessaloniki produces new digitized Soil Maps that provide a useful electronic database for the spatial representation of the soil variation within a region, based on in situ soil sampling, laboratory analyses, GIS techniques and plant nutrition mathematical models, coupled with the local land cadastre. The novelty of these studies is that local agronomists have immediate access to a wide range of soil information by clicking on a field parcel shown in this digital interface and, therefore, can suggest an appropriate treatment (e.g. liming, manure incorporation, desalination, application of proper type and quantity of fertilizer) depending on the field conditions and cultivated crops. A specific case study is presented in the current work with regards to the construction of the digitized Soil Map of the regional unit of Kastoria. The potential of this map can easily be realized by the fact that the mapping of the physicochemical properties of the soils in this region provided delineation zones for differential fertilization management. An experiment was also conducted using remote sensing techniques for the enhancement of the fertilization advisory software database, which is a component of the digitized map, and the optimization of nitrogen management in agricultural areas.</p>

scholarly journals Comparing Phylogeographic Hypotheses by Simulating DNA Sequences under a Spatially Explicit Model of Coalescence

2014 ◽  
Vol 31 (12) ◽  
pp. 3359-3372 ◽  
Author(s):  
Simon Dellicour ◽  
Chedly Kastally ◽  
Olivier J. Hardy ◽  
Patrick Mardulyn
Keyword(s):  
Dna Sequences ◽  
Spatially Explicit ◽  
Explicit Model ◽  
Spatially Explicit Model
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