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Rangsdorf, Germany

Hornemann G.,Helmholtz Center for Environmental Research | Weiss G.,Ecostrat GmbH | Durka W.,Helmholtz Center for Environmental Research
Flora: Morphology, Distribution, Functional Ecology of Plants | Year: 2012

In plant populations a positive correlation between population size, genetic variation and fitness components is often found, due to increased pollen limitation or reduced genetic variation and inbreeding depression in smaller populations. However, components of fitness also depend on environmental factors which can vary strongly between years. The dry grassland species Muscari tenuiflorum experiences long term habitat isolation and small population sizes. We analyzed seed production of M. tenuiflorum in four years and its dependence on population size and genetic variation. Genetic diversity within populations was high (AFLP: H e=0.245; allozymes: H e=0.348). An analysis of molecular variance revealed considerable population differentiation (AFLP: 26%; allozyme: 17%). An overall pattern of isolation by distance was found, which, however was not present at distances below 20km, indicating stronger effects of genetic drift. Genetic diversity was positively correlated to population size. Self pollination reduced seed set by 24%, indicating inbreeding depression. Reproductive fitness was not correlated to genetic diversity and a positive correlation with population size was present in two of four study years. The absence of a general pattern stresses the importance for multi-year studies. Overall, the results show that despite long term habitat isolation M. tenuiflorum maintains seed production in many years independent of population size. The long term persistence of populations is thus expected to depend less on intrinsic genetic or demographic properties affecting seed production but on successful plant establishment and persistence, which latter are based on conservation and protection of suitable habitats. © 2012 Elsevier GmbH. Source


Neumann C.,Helmholtz Center Potsdam | Itzerott S.,Helmholtz Center Potsdam | Weiss G.,Ecostrat GmbH
International Geoscience and Remote Sensing Symposium (IGARSS) | Year: 2012

Imaging spectroscopy holds specific applications in mapping natural vegetation structures for nature conservation and ecological quantities for a better process understanding. However, common methods of vegetation classification often fail to cover variability of ecological surface parameter, especially in transition zones. In this paper we analyze the potential of two hyperspectral sensors (HyMap, AISA) to bridge ecological models with spectral information in order to map vegetational continuum, habitat types as well as assessment categories for legal authorities. As a first step a new method of aggregating ordination space structure via Kriging estimators were introduced to parameterize vegetation characteristics. With regard to future sensor design a higher spectral resolution could be detected as preferable in predicting ordination axes metrics with PLS-models. Furthermore an increasing spatial resolution was identified as a key factor observing small scale heterogeneity for habitat encroachment whereas habitat distinction can be adequately realized on the basis of occurrence probabilities. © 2012 IEEE. Source


Dolezel M.,Umweltbundesamt GmbH | Miklau M.,Umweltbundesamt GmbH | Hilbeck A.,Ecostrat GmbH | Otto M.,Bundesamt fur Naturschutz | And 4 more authors.
Environmental Sciences Europe | Year: 2011

Purpose: The prevailing controversies on the potential environmental risks of genetically modified organisms [GMOs] still fuel ongoing discussions among European Union [EU] member states, risk assessors, applicants and scientists, even several years after the commercial introduction of GMOs. The disagreements mainly derive from the current risk assessment practice of GMOs and differences in the perceived environmental risks. Against this background, the aim of this study was to scrutinize the current practice of environmental risk assessment [ERA] of several GMO applications currently pending for authorisation in the EU. Methods: We analysed the data presented for three assessment categories of the ERA of genetically modified [GM] maize applications for cultivation in the European Union: the agronomic evaluations and the assessments of the effects of GM maize on target organisms and of its potential adverse effects on non-target organisms. Results: Major shortcomings causing considerable uncertainties related to the risk assessment were identified in all three categories. In addition, two principles of Directive 2001/18/EC are largely not fulfilled - the consideration of the receiving environment and the indirect effects, as mediated, e.g. by the application of the complementary herbicide in the case of herbicide-tolerant GM maize. Conclusions: We conclude that the current practice of ERA does not comprehensively fulfil the scientific and legal requirements of Directive 2001/18/EC, and we propose improvements and needs for further guidance and development of standards. The recommendations address likewise applicants, risk assessors as well as decision makers. © 2011 Dolezel et al; licensee Springer. This is an Open Acces. Source


Jansch S.,ECT Oekotoxikologie GmbH | Rombke J.,ECT Oekotoxikologie GmbH | Hilbeck A.,Ecostrat GmbH | Weiss G.,Ecostrat GmbH Berlin | And 2 more authors.
BioRisk | Year: 2011

According to the current legal background for the regulation of genetically modified plants (GMPs) in Europe, an environmental risk assessment (ERA) has to be performed considering i) the crop plant, ii) the novel trait relating to its intended effect and phenotypic characteristics of the GM crop plant and iii) the receiving environment related to the intended use of the GMP. However, the current GMP-ERA does not differentiate between different intended receiving environments. Therefore, the question is to be raised: How can the 'receiving environment' be classified on the European scale, both in an ecologically relevant and feasible way? As a first step this proposal focuses on invertebrates in the terrestrial environmental compartment. In order to check if already existing regionalization concepts are suitable for the above raised question the following selection criteria were employed: - Distribution of non-target organisms (NTOs): A suitable regionalization concept should appropriately reflect the specific characteristics of the animal and plant communities of the different receiving environments of a GMP. Therefore, such a classification should be done by an ecoregion approach, meaning that different ecoregions support different organism communities that may play a different role in supporting relevant ecosystem services. However, information on the distribution of invertebrates in Europe is not available in sufficient detail for this purpose. Hence, it is proposed to use the information about site conditions like climatic, vegetation and soil parameters, which determine the composition of invertebrate communities, for the selection of an appropriate classification concept. - Size and number of geographical units: This is a trade-off between the total number of 'receiving environments' in Europe manageable in a regulatory context and the ecological uniformity of a single geographical unit. An intermediate size and number of geographical units should be the aim of the classification. With the 'Indicative map of European biogeographical regions' (IMEBR) there is an existing regionalization concept that meets many of the requirements identified above: the classification is based on parameters that also determine the distribution of invertebrate communities (i.e., the potential natural vegetation) and nine biogeographical regions represented within the 27 member states of the European Union (EU-27) are a manageable number for regulatory purposes. However, epigeic (living above ground) and endogeic (living below ground) faunal communities are determined by different biotic and abiotic parameters. For example, climate data is much more relevant for epigeic species than for endogeic organisms. The most important soil properties related to the distribution of endogeic organisms and plants are pH, texture, organic matter content and/or content of organic carbon, C/N ratio, and water-holding capacity. Hence, for endogeic non-target organisms there is currently no suitable regionalization concept available. For the time being, it is recommended to identify important species for testing purposes in each ecoregion with GMP cultivation by means of expert knowledge using the IMEBR for both epigeic and endogeic communities. The regionalization concept is intended to be used in the context of the ERA of GMPs for the assessment of risk for NTOs. Hence, it should be tailored for the area in the EU where GMPs are likely to be grown. The overlap between the biogeographical regions and the intended area of cultivation for a novel GMP form the different cases, each of which should undergo a specific ERA process. For example, there would be eight or nine separate potato cases for the EU-27 area, i.e. the Alpine, Atlantic, Boreal, Continental, Macaronesian, Mediterranean, Pannonian, Steppic and possibly the Black Sea biogeographical regions. For grain maize there would be five to nine separate cases, i.e. the Atlantic, Continental, Mediterranean, Pannonian, Steppic and possibly the Alpine, Black Sea, Boreal and Macaronesian biogeographical regions. copyright S. Jänsch et al. Source


Szekacs A.,Hungarian Academy of Sciences | Weiss G.,Ecostrat GmbH | Quist D.,Genok Center for Biosafety | Takacs E.,Hungarian Academy of Sciences | And 5 more authors.
Food and Agricultural Immunology | Year: 2012

A laboratory ring trial was performed in four laboratories for determination of Cry1Ab toxin in leaf material of MON 810 maize using a standardised enzyme-linked immunoassay protocol. Statistical analysis was carried out by the ISO 5725-2 guidelines, sample standard deviation and standard error, within-laboratory and inter-laboratory SD and SE were calculated. Measured inter-laboratory average values were 12.5±4.0, 15.3±4.6 and 72.6±17.8 μg/g for three lyophilised samples, and 27.8±4.3 μg/g for a frozen sample, yet, Cry1Ab concentrations ranged 66.5-160.1% of the corresponding IA. Determined concentrations by in-house protocols were statistically not different in one laboratory and different in two laboratories from the corresponding values by the joint protocol. Results emphasise the importance of a standardised protocol among laboratories for comparable quantitative Cry1Ab toxin determination. However, even when using a standardised protocol, significant differences still occur among toxin concentrations detected in different laboratories, although with a smaller range of variation. © 2012 Copyright Taylor and Francis Group, LLC. Source

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