Human appropriation of net primary production as determinant of avifauna diversity in Austria

The relationship between land-use induced changes in production ecology and avifauna diversity was analysed using a GIS land cover dataset on a 0.25 km × 0.25 km grid covering Austria's national territory. Considering only aboveground processes, the “human appropriation of net primary production” (HANPP = potential NPP − NPP_t), actual NPP (NPP_act), harvest (NPP_h) and NPP_t (= NPP_act − harvest) were recalculated based on existing datasets. Elevation as well as indicators of land cover heterogeneity and landscape heterogeneity were also considered. Correlation analyses were performed between these potential determinants of avifauna diversity and breeding bird species richness data as well as the percentage of endangered breeding birds included in the Austrian red list. Four spatial scales—0.25 km × 0.25 km, 1 km × 1 km, 4 km × 4 km and 16 × 16 km, were analysed. It was shown that breeding bird species richness was more strongly correlated with production ecological indicators and elevation than with heterogeneity indicators. A residual analysis in which the effect of elevation (a proxy for climate) on species richness and its potential determinants was removed confirmed the importance of the availability of trophic energy (NPP) for bird diversity patterns. The results support the species-energy hypothesis, thus confirming the notion that HANPP could be a useful pressure indicator for biodiversity loss.     

Diagnosing institutional barriers and opportunities for adaptation to climate change

Institutions are one of the decisive factors which enable, constrain and shape adaptation to the impacts of climate change, variability and extreme events. However, current understanding of institutions in adaptation situations is fragmented across the scientific community, evidence diverges, and cumulative learning beyond single studies is limited. This study adopts a diagnostic approach to elaborate a nuanced understanding of institutional barriers and opportunities in climate adaptation by means of a model-centred meta-analysis of 52 case studies of public climate adaptation in Europe. The first result is a novel taxonomy of institutional attributes in adaptation situations. It conceptually organises and decomposes the many details of institutions that empirical research has shown to shape climate adaptation. In the second step, the paper identifies archetypical patterns of institutional traps and trade-offs which hamper adaptation. Thirdly, corresponding opportunities are identified that enable actors to alleviate, prevent or overcome specific institutional traps or trade-offs. These results cast doubt on the validity of general institutional design principles for successful adaptation. In contrast to generic principles, the identified opportunities provide leverage to match institutions to specific governance problems that are encountered in specific contexts. Taken together, the results may contribute to more coherence and integration of adaptation research that we need if we are to foster learning about the role of institutions in adaptation situations in a cumulative fashion.     

Genotoxic effects of metals on human salivary gland tissue and lymphocytes as detected by the Comet assay

The etiology of salivary gland malignancies still remains unclear. Metal compounds are of special interest since they show ubiquitous presence in the environment, are present in many working places, and are accepted (co-)carcinogens in some other malignancies. Metals enter the body as xenobiotics by inhalation or ingestion. This study investigated the genotoxic potential of sodium dichromate (Na₂Cr₂O₇), nickel sulfate (NiSO₄), cadmium sulfate (CdSO₄) and zinc chloride (ZnCl₂) on human salivary gland cells and lymphocytes. Macroscopically healthy tissue of salivary glands was harvested from 46 patients during surgery and isolated to single cells by enzymatic digestion. The cells were incubated with Na₂Cr₂O₇, NiSO₄, CdSO₄ or ZnCl₂. Na₂Cr₂O₇ was also incubated in combination with the other metal compounds listed. Carcinogenic and co-carcinogenic effects of cadmium were tested by incubation with Na₂Cr₂O₇ and consecutive repair intervals. DNA damage and repair were evaluated by the Comet assay, determining DNA-strand breaks. The extent of damage was quantified using a digital analysis system. Na₂Cr₂O₇ produced significantly enhanced DNA-strand breaks in human salivary gland tissue and lymphocytes. All other metal compounds exerted no damaging effect on both cell types. Co-incubation of Na₂Cr₂O₇ with the other metals revealed a significant additive effect only for CdSO₄. Specific analysis of the influence of cadmium showed a reduction of DNA-repair after Na₂Cr₂O₇-induced strand breaks in salivary gland cells. This study provides evidence that exposure to distinct metals may significantly contribute to malignant salivary gland tumors. In consequence, further studies as epidemiological and toxicological data are warranted to determine the role of distinct metals as potential (co-) carcinogens.     

Morphological and molecular data suggest a cosmopolitan distribution of the polychaete <Emphasis Type="Italic">Proscoloplos cygnochaetus</Emphasis> Day, 1954 (Annelida,Orbiniidae)

The discovery of a possibly invasive Proscoloplos species on the French Atlantic coast led to a detailed morphological and molecular investigation. Proscoloplos consists of three nominal species, but molecular analyses of the variable ITS1 and ITS2 region revealed no clade support for samples from South Africa, France and Australia, representing at least two of these nominal species. We found no unambiguous diagnostic characters for the three different species even with scanning electron microscopy. Two main characters—first appearance of branchiae and hooks—that were used for species delineation show considerable intrapopulational variation and do not withstand critical evaluation. The obtained data and the observed regenerative capabilities point to a cautious use of the position of branchiae and hooked chaetae as taxonomic marker in Proscoloplos. After experimental bisection of animals, the recovery led to a phenotype without recognizable signs of regeneration, but neither branchiae nor hooked chaetae reoccurred at the same initial segmental position. Summarising the molecular and morphological data we suggest the synonymy of the known Proscoloplos species under the senior synonym Proscoloplos cygnochaetus Day, 1967. The enormous geographic range of this species comprises the temperate waters of the whole southern hemisphere and includes the French population. We discuss a dispersal enabled through the effective anchorage on vessels using mucous glands and chaetae possibly combined with architomic reproduction.     

Die Lösung von Nutzungskonflikten aufgrund flächenhafter Bodenkontaminationen mit Hilfe Geografischer Informationssysteme und Mitteln der Geostatistik

Goal and Scope

By means of Geographical Information Systems (GIS) and other geostatistical methods, the extensive heterogeneous data materials of large area soil contaminations are re-evaluated to eliminate exploitation conflicts and investment obstacles.

Methods

The mapping of relevant frame criteria generates the basis to solve the conflicts, such as types of exploitation of field areas, development plans, protected areas, flooded areas, etc. as well as their geo-referencing in the Geographical Information System. The critical examination of data age and quality as well as the geostatistical evaluation by means of semivariogram analysis and Kriging technique are essential prerequisites for the determination of areas related to utility and exceeding test values.

Results and Conclusions

As a result, one can modify the hazardous situation and can provide recommendations for an optimal elimination of hazards, mostly in the framework of scheduled measures in terms of town planning.

Outlook

On the basis of the results obtained, further exploitation or monitoring work can clearly be optimized.     

Asymmetries in commitment in an avian communication network

Mobbing of predators occurs within a conspecific and heterospecific context but has not been quantified within the framework of a communication network and analysed with respect to heterospecific reciprocity. Here, we used playbacks of mobbing calls to show that mobbing is unequally distributed within a community of deciduous forest birds. Five species (great tit Parus major, blue tit Cyanistes caeruleus, marsh tit Poecile palustris, nuthatch Sitta europaea and chaffinch Fringilla coelebs) responded to each other’s playbacks of mobbing calls. Commitment to mob was measured by minimum distance, response latency and uttering of calls. Commitment was higher when conspecific calls were broadcast. Yet, responses to heterospecific calls were significantly different between the five species. Chaffinches had the lowest commitment, and blue tits tended to have the highest. The communication network is asymmetric. Some species invest more than they receive from other species. As mobbing might incur costs, these are unequally distributed across the community.     

Trends in land use and land cover change in the protected and communal areas of the Zambezi Region,Namibia

Land management decisions have extensively modified land use and land cover in the Zambezi Region. These decisions are influenced by land tenure classifications, legislation, and livelihoods. Land use and land cover change is an important indicator for quantifying the effectiveness of different land management strategies. However, there has been no evidence on whether protected or communal land tenure is more affected by land use and land cover changes in southern Africa and particularly Namibia. Our study attempted to fill this gap by analyzing the relationship between land use and land cover change and land tenure regimes stratified according to protected and communal area in the Zambezi Region. Multi-temporal Landsat TM and ETM+ imagery were used to determine the temporal dynamics of land use and land cover change from 1984 to 2010. The landscape showed distinctive modifications over the study period; broad trends include the increase in forest land after 1991. However, changes were not uniform across the study areas. Two landscape development stages were deduced: (1) 1984–1991 represented high deforestation and gradual increase in shrub land; (2) 1991–2000 and 2000–2010 represented lower deforestation and slower agropastoral expansion. The results further show clear patterns of the dynamics, magnitude, and direction of land use and land cover change by tenure regime. The study concluded that land tenure has a direct impact on land use and land cover, since it may restrict some activities carried out on the land in the Zambezi Region.