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This study investigated the response patterns of aboveground macrofungal communities to different management stages representing a forest conversion from Norway spruce (Picea abies) to European beech (Fagus sylvatica) in the Eifel National Park, Germany. We used a space-for-time substitution approach with three replicate study sites for each forest conversion stage: (I) even-aged single species Norway spruce, (II) unmanaged Norway spruce windthrow, (III) salvage-logged Norway spruce windthrow, (IV) single Norway spruce tree selection cutting (close-to-nature managed) with European beech underplanting and (V) old-growth, uneven-aged European beech (as reference). We assessed environmental variables and macrofungal sporocarps, while the latter were categorized into functional groups to link taxonomic information to potential ecosystem functions. Overall, we observed 235 macrofungal species. The highest species richness was found in the European beech reference stage, followed by the close-to-nature managed spruce/beech stage, while the Norway spruce stage showed approximately half the species richness, similar to the species level of both windthrow stages. Non-metric multidimensional scaling (NMDS) ordination separated each forest conversion stage into distinct fungal communities, while both windthrow stages could not be distinguished from each other. Beside tree species composition change and forest management, nutrient availability and microclimate were the main drivers of fungal community changes among the five differently-managed stages. Further, different functional groups responded in different patterns to forest management and to explanatory environmental variables. We reinforced the assumption, that old-growth, uneven-aged European beech forests (>120 years) can act as a refugium for unique forest type specific fungal communities with a higher functional structure, especially contrary to non-native, even-aged Norway spruce forests (∼70 years). Single Norway spruce tree selection cutting with further introduction of European beech trees can be an adequate strategy to allow a spruce forest conversion without necessarily reducing the macrofungal species richness and its functional structure. We displayed that ecological consequences of windthrow events can be a depression of fungal species richness and a collapse for the functional structure of fungi, especially after salvage logging. Our study underlines the need of including fungal conservation in forest conversion plans to optimize forest ecosystem integrity and resilience against biotic and abiotic agents, such as windstorm events.

Vegetation succession in the water level fluctuation zone (WLFZ) is driven by periodical water fluctuations, the mechanisms of response and synergistic evolution between aboveground vegetation (AGV) and soil seed bank (SSB) in the WLFZ remain unclear. To illustrate the response between AGV and SSB and the importance of SSB for revegetation in the WLFZ, the Three Gorges Reservoir (TGR) was taken as the target in the current study, and five sampling sites that lie in the center of reservoir and major tributaries of the TGR were selected. Plant community survey along the three water level gradients (i.e., 165-170 m, 170-175 m and 175-180 m) was conducted. Simultaneously, SSB samples on the topsoil (0-5 cm) were collected for germination experiments. A total of forty-nine species were observed from the SSB, belonging to 24 families and 47 genera, of which Asteraceae (8 species) and Poaceae (6 species) dominated. The number of total germinated seedlings species from soil samples from the sampling sites differed, i.e., was lower in Fengjie and Wushan compared to Yunyang, Gaoyang and Fengdu. The seed density in 165-170 m was significantly lower than that of 170-175 m and 175-180 m (p0.05). The Sørensen similarity coefficients between AGV and SSB tended to decrease with the increase of water level gradient, ranging from 0.04 to 0.42. SSB species composition was significantly associated with total carbon and total nitrogen contents of the soil (both p0.05). The SSB density was significantly negatively correlated with concentration of soil total nitrogen (p0.05), the species richness of SSB was significantly negatively correlated with soil pH value (p0.05). Hence, the relationship between the SSB and the soil habitat might be an important factor driving the construction of vegetation in the WLFZ. The correlation between dynamic of SSB and TGR hydrological regimes should be considered for revegetation in the WLFZ.

The aim of this study was to quantify uncertainty when assigning field investigation sites according to their species community composition to either undisturbed or disturbed reference sites by use of ecological indicators. In ecological risk assessment this problem arises when selecting control investigation sites or defining reference species communities. Uncertainty is quantified using a Type II error or misclassification rate. A probabilistic Bayesian model is used to integrate a priori domain knowledge, assess the error rate and come to recommendations about an adequate sample size. Application is demonstrated using data from a case study investigating off-crop arthropod communities in German grassy field margins and consequences for impact assessment of pesticides on terrestrial ecosystems. The model allows calculating statistical power when using such a classification system. By means of stochastic simulations, recommendations about experimental design and indicator size are derived. The study shows that to develop a classification system to typify newly observed sites a well-balanced ratio of undisturbed and disturbed sites as well as a high relevance of reference sites are needed. For the given data set, a much larger number of reference sites as well as increased relevance of selected reference sites would be needed to achieve a good classification result. An optimal number of indicators is calculated allowing for a compromise between sampling error and indicator quality. Uncertainty for correct assignment of an investigation site is compared using indicators for disturbance and reference conditions. Finally, misclassification rate is proposed as a new measure for indicator quality.

Dams have profound impacts on river ecosystems, amongst them inundation of land, altered dynamics of the water body or uprising reservoir backwaters influencing tributary or upstream river sections. Along the outstandingly ecologically important Yangtze River in China, the Three Gorges Reservoir (TGR) is the largest project, covering an area of 1080 km 2 . From the beginning, the dam-project came in for criticism on increasing environmental risks due to sub-merging former industrial and urban areas. We simulated dynamics of biotic and abiotic components of the TGR ecosystem (trophic guilds of aquatic organisms, hydrodynamics, nutrients), as well as the behaviour of the herbicidal substance propanil and its metabolites 3,4-Dichloroaniline (DCA) and 3,3′,4,4′-tetrachloroazoxybenzene (TCAB). A modelling environment, provided by the AQUATOX software, was adapted to the specific situation at a tributary reach to the Yangtze river ‘Daning River’. As the simulated food web contained several interconnected trophic levels, a significant biomagnification of metabolites was demonstrated by our simulation studies. In particular, newly emerging stagnant downstream sections of tributaries exhibited high probabilities due to accumulating pesticides from upstream sources. The common problem of algal blooms in the TGR-region was addressed by dose-response simulation experiments with essential nutrients. Impacts on structure and abundance of populations of aquatic organisms were shown. However, even high nutrient loads resulted in only slight changes of densities of organisms of all trophic levels. Nevertheless, the probabilities for large-scale algal blooms affecting drinking water quality were considered low because of high flow velocities and discharge rates towards the Yangtze River. We see high potential of simulation-based assessments that provide information for risk managers dealing with whole catchment areas. They are put in the position to differentiate the magnitude of impacts of various factors and decide about the most effective remediation measures.

Urban areas and their development depress water physicochemical properties, river habitats and aquatic biotic integrity worldwide. Benthic macroinvertebrates at 61 sites representing three types of river reach locations (upstream rural areas, intermediate and downstream of urban areas) on the Liangtan River, a rapidly urbanized river with untreated sewage discharge in southwest China, were examined to compare their community composition and diversity. Their relationships with environmental variables were also explored. The results indicate a significant reduction in sensitive EPT (Ephemeroptera, Plecoptera and Trichoptera) species, dominance by a few tolerant taxa (Oligochaeta and Chironomidae), a significant decline in biodiversity and dominance of collector-gatherers at intermediate and downstream urban sites compared with aquatic macroinvertebrates at rural sites. The community composition of urban sites were different from those of rural sites and were quite similar to those of downstream sites, but maintained a much higher Oligochaeta density. The species-environment relation was predominately explained by the percentage of impervious area (PIA) and farmland at the catchment scale. At the local scale chemical oxygen demand (COD) and pH-value explained this relationship. Six community indicators, including richness, the Shannon-Wiener index, EPT(%), collector-filterers(%), scrapers(%) and collector-gatherers(%), had exponential relationships with PIA. Density of macroinvertebrates, Oligochaeta density, Oligochaeta(%), predator(%) and shredder(%) exhibited stepped threshold response patterns with PIA. Pielou's index had an approximately negative linear relationship with PIA. For exponential pattern, a threshold value of PIA between 10.6% and 14.4% was found. For stepped threshold response pattern, the first threshold was between 11.2% and 13.8%, and the second threshold was 23.8%. Our study indicates particularly great influences of urbanization with untreated sewage on macroinvertebrates and river ecosystems. PIA also showed to be a good indicator of urbanization and an accurate predictor of urban impacts on river macroinvertebrate integrity.

Lake ecosystems are sensitive recorders of environmental changes that provide continuous archives at annual to decadal resolution over thousands of years. The systematic investigation of land use changes and emission of pollutants archived in Holocene lake sediments as well as the reconstruction of contamination, background conditions, and sensitivity of lake systems offer an ideal opportunity to study environmental dynamics and consequences of anthropogenic impact that increasingly pose risks to human well-being. This paper discusses the use of sediment and other lines of evidence in providing a record of historical and current contamination in lake ecosystems. We present a novel approach to investigate impacts from human activities using chemical-analytical, bioanalytical, ecological, paleolimnological, paleoecotoxicological, archeological as well as modeling techniques. This multi-time slice weight-of-evidence (WOE) approach will generate knowledge on conditions prior to anthropogenic influence and provide knowledge to (i) create a better understanding of the effects of anthropogenic disturbances on biodiversity, (ii) assess water quality by using quantitative data on historical pollution and persistence of pollutants archived over thousands of years in sediments, and (iii) define environmental threshold values using modeling methods. This technique may be applied in order to gain insights into reference conditions of surface and ground waters in catchments with a long history of land use and human impact, which is still a major need that is currently not yet addressed within the context of the European Water Framework Directive.

Facing the growing amount of people living in cities and, at the same time, the need for a compact and sustainable urban development to mitigate urban sprawl, it becomes increasingly important that green spaces in compact cities are designed to meet the various needs within an urban environment. Urban green spaces have a multitude of functions: Maintaining ecological processes and resulting services, e.g. providing habitat for animals and plants, providing a beneficial city microclimate as well as recreational space for citizens. Regarding these requirements, currently existing assessment procedures for green spaces have some major shortcomings, which are discussed in this paper. It is argued why a more detailed spatial level as well as a distinction between natural and artificial varieties of structural elements is justified and needed and how the assessment of urban green spaces benefits from the multidimensional perspective that is applied. By analyzing a selection of structural elements from an ecological, microclimatic and social perspective, indicator values are derived and a new, holistic metrics 1 is proposed. The results of the integrated analysis led to two major findings: first, that for some elements, the evaluation differs to a great extent between the different perspectives (disciplines) and second, that natural and artificial varieties are, in most cases, evaluated considerably different from each other. The differences between the perspectives call for an integrative planning policy which acknowledges the varying contribution of a structural element to different purposes (ecological, microclimatic, social) as well as a discussion about the prioritization of those purposes. The differences in the evaluation of natural vs. artificial elements verify the assumption that indicators which consider only generic elements fail to account for those refinements and are thus less suitable for planning and assessment purposes. Implications, challenges and scenarios for the application of such a metrics are finally discussed.

Pesticide applications in agricultural crops often comprise a mixture of plant protection products (PPP), and single fields face multiple applications per year leading to complex pesticide mixtures in the environment. Restricted to single PPP, the current European Union PPP regulation, however, disregards the ecological risks of pesticide mixtures. To quantify this additional risk, we evaluated the contribution of single pesticide active ingredients to the additive mixture risk for aquatic risk indicators (invertebrates and algae) in 464 different PPP used, 3446 applications sprayed and 830 water samples collected in Central Europe, Germany. We identified an average number of 1.3 different pesticides in a single PPP, 3.1 for complete applications often involving multiple PPP and 30 in stream water samples. Under realistic worst-case conditions, the estimated stream water pesticide risk based on additive effects was 3.2 times higher than predicted from single PPP. We found that in streams, however, the majority of regulatory threshold exceedances was caused by single pesticides alone (69% for algae, 81% for invertebrates). Both in PPP applications and in stream samples, pesticide exposure occurred in repeated pulses each driven by one to few alternating pesticides. The time intervals between pulses were shorter than the 8 weeks considered for ecological recovery in environmental risk assessment in 88% of spray series and 53% of streams. We conclude that pesticide risk assessment should consider an additional assessment factor to account for the additive, but also potential synergistic simultaneous pesticide mixture risk. Additionally, future research and risk assessment need to address the risk from the frequent sequential pesticide exposure observed in this study.

Analyzing fungal diversity and community composition through environmental DNA (eDNA) metabarcoding and high-throughput sequencing relies on sequence databases and their taxonomic coverage which are often doubted in regards of data accuracy. To assess the potential of eDNA metabarcoding to distinguish differently managed forest conversion stages, we compared an extant morphological dataset created through sporocarp surveys with a metabarcoding dataset from the same study sites. The study was conducted along a spruce forest conversion project of Norway spruce towards European beech in the Eifel National Park in Germany. Using the UNITE ITS reference database, a total of 198 fungal operational taxonomic units (OTUs) were assigned up to the species level. Comparing the morphological and metabarcoding dataset, a low species overlap was observed with 27 shared fungi. The metabarcoding dataset revealed that all investigated forest conversion management stages shared beech-associated fungi (even the spruce forests), while within the morphological dataset, only the beech-inhabiting forest conversion management stages showed beech-associated fungi. The metabarcoding dataset could not show the same fungal community response patterns on the spruce forest conversion, compared to the morphological dataset, but revealed the genetic refugium of the soil fungal community. We conclude that fungal eDNA metabarcoding should always be evaluated by taxonomic experts to identify potential sequence database errors. eDNA metabarcoding cannot be used interchangeably for morphological community analyses to identify response patterns of fungal communities on forest management strategies. However, both approaches performed well in combination and showed that beech-associated fungal communities with high functional redundancy can develop after a spruce forest conversion by restoring natural European beech forests with an appropriate close-to-nature management strategy.

To avoid potential risks of biofuels on the environment and human, ecotoxicity investigation should be integrated into the early design stage for promising biofuel candidates. In the present study, a green toxicology testing strategy combining experimental bioassays with in silico tools was established to investigate the potential ecotoxicity of biofuel candidates. Experimental results obtained from the acute immobilisation test, the fish embryo acute toxicity test and the in vitro micronucleus assay (Chinese hamster lung fibroblast cell line V79) were compared with model prediction results by ECOSAR and OECD QSAR Toolbox. Both our experimental and model prediction results showed that 1-Octanol (1-Oct) and Di-n-butyl ether (DNBE) were the most toxic to Daphnia magna and zebrafish among all the biofuel candidates we investigated, while Methyl ethyl ketone (MEK), Dimethoxymethane (DMM) and Diethoxymethane (DEM) were the least toxic. Moreover, both in vitro micronucleus assay and OECD QSAR Toolbox evaluation suggested that the metabolites present higher genotoxicity than biofuel candidates themselves. Overall, our results proved that this green toxicology testing strategy is a useful tool for assessing ecotoxicity of biofuel candidates.

3,4,3ʹ,4ʹ-tetrachloroazobenzene (TCAB) is not commercially manufactured but formed as an unwanted by-product in the manufacturing of 3,4-dichloroaniline (3,4-DCA) or metabolized from the degradation of chloranilide herbicides, like propanil. While a considerable amount of research has been done concerning the toxicological and ecotoxicological effects of propanil and 3,4-DCA, limited information is available on TCAB. Our study examined the toxicity of TCAB in comparison to its parent compounds propanil and 3,4-DCA, using a battery of bioassays including in vitro with aryl hydrocarbon receptor (AhR) mediated activity by the 7-ethoxyresorufin- O -deethylase (EROD) assay and micro-EROD, endocrine-disrupting activity with chemically activated luciferase gene expression (CALUX) as well as in vivo with fish embryo toxicity (FET) assays with Danio rerio . Moreover, the quantitative structure activity response (QSAR) concepts were applied to simulate the binding affinity of TCAB to certain human receptors. It was shown that TCAB has a strong binding affinity to the AhR in EROD and micro-EROD induction assay, with the toxic equivalency factor (TEF) of 8.7 × 10 − 4 and 1.2 × 10 − 5 , respectively. TCAB presented to be a weak endocrine disrupting compound with a value of estradiol equivalence factor (EEF) of 6.4 × 10 − 9 and dihydrotestosterone equivalency factor (DEF) of 1.1 × 10 − 10 . No acute lethal effects of TCAB were discovered in FET test after 96 h of exposure. Major sub-lethal effects detected were heart oedema, yolk malformation, as well as absence of blood flow and tail deformation. QSAR modelling suggested an elevated risk to environment, particularly with respect to binding to the AhR. An adverse effect potentially triggering ERβ, mineralocorticoid, glucocorticoid and progesterone receptor activities might be expected. Altogether, the results obtained suggest that TCAB exerts a higher toxicity than both propanil and 3,4-DCA. This should be considered when assessing the impact of these compounds for the environment and also for regulatory decisions.

Besides obvious benefits, the Three Gorges Dam's construction resulted in new pollution scenarios with the potentials to threaten the Three Gorges Reservoir (TGR) ecosystem. In order to record organic contamination, to find links to ecotoxicological impacts and to serve as reference for ensuing monitoring, several sites in the TGR area were screened applying the triad approach with additional lines-of-evidence as a holistic assessment method. Sediments and the benthic fish species Pelteobagrus vachellii were sampled in 2011 and 2012 to determine organic pollution levels, mutagenic potentials and genotoxic impacts. Two regional hot-spots near the cities of Chongqing and Kaixian were identified and further investigated in 2013. Only polycyclic aromatic hydrocarbons (PAHs) could be detected in sediments in 2011 (165-1653ng/g), emphasizing their roles as key pollutants of the area. Their ubiquity was confirmed at Chongqing (150-433ng/g) and Kaixian (127-590ng/g) in 2013. Concentrations were comparable to other major Chinese and German rivers. However, the immense sediment influx suggested a deposition of 216-636kgPAH/day (0.2-0.6mgPAH/(m(2)·day)), indicating an ecotoxicological risk. PAH source analysis highlighted primary impacts of combustion sources on the more industrialized upper TGR section, whereas petrogenic sources dominated the mid-low section. Furthermore, sediment extracts from several sites exhibited significant activities of frameshift promutagens in the Ames fluctuation assay. Additionally, significant genotoxic impairments in erythrocytes of P. vachellii were detected (Chongqing/Kaixian), demonstrating the relevance of genotoxicity as an important mode of action in the TGR's fish. PAHs, their derivatives and non-target compounds are considered as main causative agents.

Land use change next to climate change is considered an important factor for the vanishing biodiversity. Semi-natural grasslands belong to the most species-rich biotope types in Central Europe. Bridging the gap between science and application is therefore needed to deliver scientific knowledge of ecosystem-functioning and underlying key-processes to authorities allowing successful landscape management. However, current model approaches are mostly restricted to low resolution in means of space, species and complexity. The aim of this study was to develop a process-based succession model for temperate grasslands linked to a geographic information system integrating spatial explicit input data from the real landscape and visualizing output in raster maps, which is a prerequisite for application. To cope with the trade-off between the fine resolution and the data-hunger of a mechanistic landscape model, within the presented model approach the complexity was reduced to three parameters that determine species’ growth and thus competitive power: maximal growth rate, a factor for self-regulation, and Briemle's utilization numbers. Following the principles of phytosociology, we calibrated species’ growth based on the community data set for a specific location. Model calibration and model testing showed that Briemle's utilization numbers and the chosen representative species and groups are suitable to simulate grassland dynamics under different forms of land use. As we are using a general pattern of differential equations, we are confident that the model can be easily transferred to other grassland sites. Our model concept was created in close cooperation with stakeholders and has been already successfully used as a decision support system by the Eifel National Park administration.

Old growth forests in the Atlantic rainforest of Southern Brazil are increasingly replaced by secondary forests. Effects on arthropods are assumed to be particularly important as they provide the bulk of biodiversity and play an integral role for ecosystem processes and services. During forest regeneration vegetation structure, leaf litter composition and microclimatic conditions were found to strongly affect leaf litter beetle communities. This study aimed at highlighting the question whether there is evidence that restoration actions to support the regeneration of old-growth forest vegetation structure can enhance the re-establishment of old-growth forest leaf litter beetle communities in secondary forests in the Mata Atlântica. A conceptual model structure representing a causal effect chain was built and checked against observational data for vegetation and leaf litter beetles from different regeneration stages using structural and microclimatic variables. By the results in this study the hypothesis of an ecological causal effect chain was clearly supported. There was reasonable evidence that during the regeneration process varying vegetation composition results in varying structural characteristics inside the vegetation stand and the associated leaf litter. The changed structural parameters proved to alter the microclimatic conditions within the leaf-litter and subsequently the differences in microclimatic conditions showed a significant influence on the leaf litter beetle community within the forest regeneration sites. These results have important implications for arthropod species conservation as they show that the probability of conserving or re-establishing old growth leaf litter beetle communities can be increased by maintaining and restoring suitable vegetation, structure and microclimatic conditions.

The competence center InBioVeritas was founded in 2007 with the vision to integrate competences for ecological and socioeconomic research, sustainable land management and biodiversity conservation in the southern Mata Atlântica. Originating from a successful partnership in a recently terminated Brazilian-German research project (SOLOBIOMA), it is based on long experience and strong commitment of its members. It is concerned with a region of the Atlantic Forest where the largest forest remnants are found in protection areas of different status. However, cumulative effects of land use and climate change are likely to threat conservation and promote further loss of biodiversity in the future.