Suchergebnisse

Abstract
Background
While a dam is constructed to adjust and store water resources, it has negative impacts on biodiversity of the corresponding ecosystems. In particular, the dam regulation induces water-level fluctuations (WLFs), resulting in remarkable effects on the riparian vegetation succession of the drawdown zone ecosystem. These riparian plant responses play important roles in the biodiversity conservation. However, in-depth investigative adequate studies are still lacking. The objective of this study was to assess the community assembly under the anti-seasonal WLFs of China's Three Gorges Reservoir (TGR). To analyze the WLFs' impacts on plant community, the drawdown zone of the TGR was divided into four sub-zones (zone I, II, III, and IV) according to the inundation periods. The community biomass, height, total coverage, and species diversity in each sub-zone were surveyed. To detect the response of individual plant to the WLFs, dominant plants of Echinochloa crusgalli, Setaria viridis, Bidens pilosa, and Xanthium sibiricum were selected as targeted species to compare the plant's morphological and physiological traits between non-flooded area and the moderately inundated area.

Results
The peaks of community biomass (1859.62 ± 663.77 g), total coverage (103.93 ± 11.81%), and diversity indexes were found in zone II that experienced 90 days of inundation. Community height and total coverage were both significantly negatively correlated to the inundated gradients. Generalized linear models and quadratic regression analyses revealed that community biomass, height, and total coverage were strongly related to the inundated gradients, implying that the inundation is the major factor contributing to the variation of the riparian vegetation patterns. The values of morphological traits (plant height and biomass) in the zone II were higher than those in the non-flooded zone, and were significantly positively correlated with physiological traits.

Conclusions
Community structure, diversity, and functional traits analysis indicated that the drawdown zone referencing to the 90-day inundation was suitable for the plant community establishment. Results on plant functional traits suggest the adaption of riparian plants to the TGR hydrological regime. However, further investigative studies with more plant species are necessary to elucidate their adaptation mechanisms.

AbstractHoneybees are well-established bioindicators for different types of pollutants. This study aims to establish another species of the Apidae family as a bioindicator, with a distinct behaviour and life cycle. The bumblebee Bombus terrestris was used as a bioindicator for 12 metals. Bumblebee hives were placed at sampling sites in and around the city of Aachen, Germany, and metal concentrations were assessed using ICP-MS. Metal concentrations were compared to those found in honeybees described in the literature. Spatial differences in metal patterns were investigated by comparing two land-use types: urban and agrarian. Seasonal differences were compared by taking samples in spring and summer. All analysed metals were detected above the detection limit and within or even above the concentration range found in honeybees. Significant spatial differences were found for the metalloid B and the metal Cd with higher concentrations at the agrarian sites than the urban sites. Significant seasonal differences were found for 8 metals: Fe, Zn, Cu, Ni, Cd, and As concentrations were higher in summer than in spring, while B and V concentrations were higher in spring. To categorise the results, we applied the honeybee contamination index (HCI) and adapted it to bumblebee purposes. According to the HCI, only one agrarian site showed a high contamination level. This study shows that bumblebees are suitable bioindicators for metals. The obtained data can serve as a first baseline in the establishment of additional monitoring studies or risk assessments.

Abstract
Background
Urbanization process around the world has not only changed the patterns of land use, but also fragmented the habitat, resulting in significantly biodiversity loss. Urban rivers, serve as one of the natural corridors in urban ecosystems, are of importance for urban ecosystem stability. However, few studies have been done to explore the relationship between vegetation and pollinators in urban river segments. In this study, two urban streams in the city of Chongqing were selected as the study area, riparian vegetation, butterflies and bees were investigated along all four seasons of a year to illustrate the spatial and temporal distribution patterns. Simultaneously, the ecological functions of the river corridor were analyzed.

Result
In this study, 109 plant species belonging to 95 genera of 39 families were recorded; the number of sampled species for butterflies and bees were 12 and 13, respectively. The temporal and spatial patterns of species diversity among vegetation, butterfly, and bee are different, but the trends of variation among them are similar between the two streams. Bees were found to be more closely correlated with native flowering plants in riparian zone, rather than with cultivated riparian vegetation.

Conclusions
The native riparian vegetation in urban rivers plays an important role in urban biodiversity conservation by serving as a corridor. This study provides data supporting the protection of the remaining natural patches and restoration of damaged habitats in the city. The survey has accumulated data on native riparian vegetation and pollinators in urban rivers.

Abstract
In order to thank Prof. Dr. Hans-Toni Ratte on the occasion of his retirement for his outstanding experimental and modelling merits in the field of ecotoxicology and ecology and his personal 65th anniversary on November 25th this article will present a laudation.

Agrochemicals, such as pesticides and fertilizers, have facilitated an unprecedented intensification of agriculture [1, 2]. However, the desired yield gains come at the cost of unwanted side effects on the environment. Pesticides have been demonstrated to contribute to the decline of non-target organisms, such as bees, birds and aquatic biodiversity [3, 4, 5], fueling the global biodiversity crisis. This runs contrary to global efforts to protect biodiversity and, in particular, also to the aims of the European Union's (EU) pesticide regulation [6]. Consistent exceedances of regulatory thresholds [7] and revisions of authorizations of pesticides, such as of neonicotinoid insecticides in the EU by the Standing Committee on plants, animals, food and feed (PAFF Committee), also attest to deficiencies in regulatory pesticide risk assessment and management. ; ISSN:2190-4715 ; ISSN:2190-4707