An object oriented modelling strategy to depict activity pattern of organisms in heterogeneous environments

The object oriented programming and simulation approach has been used at the Project Center for Ecosystems Research (Kiel) in order to advance ecological theory and in order to integrate empirical ecological field work. In this contribution we present a general scheme, which provides a framework for the development of individual based models. The scheme covers a general layout of the organism – environment interaction; the organization of (quasi‐)parallel activities of individuals (self‐scheduling of objects versus list processing); a concept to coordinate context specific activity alternatives. Basing on these considerations we give different application examples. These examples show the potential of individual based modelling to depict the modification of organismic activity pattern and population dynamics in heterogeneous environments and to study the interaction of different levels of aggregation. The model examples are simulation of a fish school in a changing environment; simulation of a robin population in a beech forest; simulation of plant development.     

Prenatal diagnosis of PORCN-related developmental syndrome in a fetus: A novel phenotype

We report a case of a female fetus born to an unrelated couple with a complex fetal phenotype of a pleural effusion, a cardiac malformation, and syndactyly of the toes. Prenatal exome sequencing identified a variant of uncertain significance in the PORCN gene that was upgraded to likely pathogenic following postnatal clinical examination. The phenotype described in cases with variants in the PORCN gene is often associated with findings that cannot be prospectively diagnosed by ultrasonography. This is the first report of a prenatal phenotype involving a fetal effusion associated with variants in the PORCN gene, with skeletal findings identified later in gestation on ultrasonography. The diagnosis was confirmed on neonatal examination.     

Comparing measured and modelled forest carbon stocks in high-boreal forests of harvest and natural-disturbance origin in Labrador, Canada

Understanding the effects of disturbance regimes on carbon (C) stocks and stock changes is a prerequisite to estimating forest C stocks and fluxes. Live-tree, dead-tree, woody debris (WD), stump, buried wood, organic layer, and mineral soil C stock data were collected from high-boreal black spruce (Picea mariana (Mill.) B.S.P.) stands of harvest and fire origin and compared to values predicted by the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3); the core model of Canada's National Forest Carbon Monitoring, Accounting and Reporting System. Data comparing the effect of natural and anthropogenic disturbance history on forest C stocks are limited, but needed to evaluate models such as the CBM-CFS3. Results showed that adjustments to the CBM-CFS3 volume-to-biomass conversion and partitioning parameters were required for the non-merchantable and branch C pools to accurately capture live-tree C stocks in the studied black spruce ecosystems. Accuracy of the CBM-CFS3 modelled estimates of dead organic matter and soil C pools was improved relative to regional default parameters by increased snag fall and >10 cm WD base decay rates. The model evaluation process also highlighted the importance of developing a bryophyte module to account for bryophyte C dynamics and the physical burial of woody debris by bryophytes. Modelled mineral soil C estimates were improved by applying a preliminary belowground slow C pool base decay rate optimized for the soil type of the studied sites, Humo-Ferric Podzols.     

Transatlantic migration by post-breeding puffins: a strategy to exploit a temporarily abundant food resource?

The distribution of Atlantic puffins (Fratercula arctica) from Skellig Michael, south-west Ireland, was investigated using geolocation loggers between the 2010 and 2011 breeding seasons. All tracked birds travelled rapidly west into the North Atlantic at the end of the breeding season in August, with the majority undertaking transatlantic trips from Ireland to the Newfoundland-Labrador shelf. The furthest distance from the colony reached by each bird was not influenced by body mass or sex and was achieved in approximately 20 days. By October, all birds had moved back to the mid Atlantic where they remained resident until returning to the breeding colony. The most parsimonious explanation for the rapid, directed long-distance migration is that birds exploit the seasonally high abundance of prey [e.g., fish species such as capelin (Mallotus villosus) and sandlance (Ammodytes spp.)] off the Canadian coast, which is also utilised by large populations of North American seabirds at this time. Once the availability of this short-term prey resource has diminished, the tracked puffins moved back towards the north-east Atlantic. A relationship between relative abundance of puffins and zooplankton was found in all winter months, but after correcting for spatial autocorrelation, was only significant in November and January. Nevertheless, these results suggest a potential switch in diet from mainly fish during the breeding and early post-breeding periods to zooplankton over the remaining winter period. This study suggests that puffins from south-west Ireland have a long-distance migration strategy that is rare in breeding puffins from the UK and identifies a key non-breeding destination for puffins from Ireland. This has implications for the susceptibility of different breeding populations to the effects of possible climatic or oceanographic change.     

Perceptions of risk characteristics of earthquakes compared to other hazards and their impact on risk tolerance

People tolerate different levels of risk owing to a variety of hazards. Previous research shows that the psychometric properties of hazards predict people's tolerance of them. However, this work has not taken into account events such as earthquakes. The present study tested how earthquakes score vis‐à‐vis risk properties and risk tolerance as compared to five other familiar hazards. Participants from Wellington, New Zealand (N=139) rated these six hazards using measures of risk characteristics and risk tolerance. Participants demonstrated different levels of risk tolerance for the different hazards and viewed earthquakes as having similar risk features to nuclear power. They also preferred different risk mitigation strategies for earthquakes (more government funding) to the other five hazards (stronger legislation). In addition, earthquake risk tolerance was predicted by different risk characteristics than the other five hazards. These findings will help risk communicators in identifying which risk characteristics to target to influence citizens' risk tolerance.     

USING A DISTRIBUTED ROUTING RAINFALL-RUNOFF MODEL1

ABSTRACT: Urban storm water data from four catchments near Miami, Florida, were collected and compiled by the U.S. Geological Survey and were used for testing the applicability of deterministic modeling for characterizing storm water flows from small land use areas. The four sites were:

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Translocation and Growth Experiments with the Macropohyte Potamogeton Lucens L. in Traunsee (Austria), with Respect to Industrial Tailings

The absence of Potamogeton lucens L. in an area of Traunsee, Austria, which is heavily impacted by industrial sludges was related to these deposits. The hypothesis that P. lucens L. is affected by the industrial tailings was confirmed by growth experiments of the translocated plants in the field. At the unpolluted reference site of the lake, the plants grew better, they were longer and produced more leaves than at the emission site.     

COMPARISON OF BANK EROSION AT VEGETATED AND NON-VEGETATED CHANNEL BENDS1

ABSTRACT: Following major floods in 1990 which resulted in widespread bank erosion in southern British Columbia, four streams typical of the region were evaluated for the effect which riparian vegetation played in reducing erosion. A total of 748 bends in the four stream reaches were assessed by comparing pre- and post-flood aerial photography. Bends without riparian vegetation were found to be nearly five times as likely as vegetated bends to have undergone detectable erosion during the flood events. Major bank erosion was 30 times more prevalent on non-vegetated bends as on vegetated bends. The likelihood of erosion on semi-vegetated bends was between that of the vegetated and non-vegetated categories of bends.     

ADAPTING EXISTING MODELS TO EXAMINE EFFECTS OF AGRICULTURAL CONSERVATION PROGRAMS ON STREAM HABITAT QUALITY1

Annual expenditures by the federal government in the United States for agricultural conservation programs increased about 80 percent with passage of the 2002 Farm Bill. However, environmental benefits of these programs have not been quantified. A national project is under way to estimate the effect of conservation practices on environmental resources. The watershed models intended for use in that project are focused on water quantity and quality and have minimal habitat assessment capability. Major impairments to aquatic ecosystems in many watersheds consist of physical habitat degradation, not water quality, suggesting that current models for this national initiative do not address one of the most significant aspects of aquatic ecosystem degradation. Currently used models contain some components relevant to aquatic habitat, and this paper describes specific components that should be added to allow rudimentary stream habitat quality assessments. At least six types of variables could be examined for ecological impact: land use, streamflow, water temperature, streambed material type, large woody debris, and hydraulic conditions at base flow. All of these variables are influenced by the presence, location, and quality of buffers. Generation of stream corridor ecological or habitat quality indices might contribute to assessments of the success or failure of conservation programs. Additional research is needed to refine procedures for combining specific measures of stream habitat into ecologically meaningful indices.     

Genetics of larvae and spat growth rate in the oyster Crassostrea virginica

The heritability of oyster (Crassostrea virginica) larval growth rate was estimated to be in the range of 0.25 to 0.50 and a significant part of this genetic variation is of the additive type. Larval growth rate and spat growth rate were found to be highly correlated. These results suggest that a selection program for faster growing larvae and spat would be successful.