Foraminiferal assemblages as palaeoenvironmental bioindicators in Late Jurassic epicontinental platforms: relation with trophic conditions

Foraminiferal assemblages from the neritic environment reveal the palaeoecological impact of nutrient types in relation to shore distance and sedimentary setting. Comparatively proximal siliciclastic settings from the Boreal Domain (Brora section, Eastern Scotland) were dominated by inner−shelf primary production in the water column or in sea bottom, while in relatively seawards mixed carbonate−siliciclastic settings from the Western Tethys (Prebetic, Southern Spain), nutrients mainly derived from the inner−shelf source. In both settings, benthic foraminiferal assemblages increased in diversity and proportion of epifauna from eutrophic to oligotrophic conditions. The proximal setting example (Brora Brick Clay Mb.) corresponds to Callovian offshore shelf deposits with a high primary productivity, bottom accumulation of organic matter, and a reduced sedimentation rate for siliciclastics. Eutrophic conditions favoured some infaunal foraminifera. Lately, inner shelf to shoreface transition areas (Fascally Siltstone Mb.), show higher sedimentation rates and turbidity, reducing euphotic−zone range depths and primary production, and then deposits with a lower organic matter content (high−mesotrophic conditions). This determined less agglutinated infaunal foraminifera content and increasing calcitic and aragonitic epifauna, and calcitic opportunists (i.e., Lenticulina). The comparatively distal setting of the Oxfordian example (Prebetic) corresponds to: (i) outer−shelf areas with lower nutrient input (relative oligotrophy) and organic matter accumulation on comparatively firmer substrates (lumpy lithofacies group) showing dominance of calcitic epifaunal foraminifera, and (ii) mid−shelf areas with a higher sedimentation rate and nutrient influx (low−mesotrophic conditions) favouring potentially deep infaunal foraminifers in comparatively unconsolidated and nutrient−rich substrates controlled by instable redox boundary (marl−limestone rhythmite lithofacies).This research was carried out with the financial support of projects CGL2005−06636−C0201 and CGL2005−01316/BTE, and University of Oslo, Norway−Statoil cooperation. M.R. holds a Juan de la Cierva grant from the Ministry of Science and Technology of Spain

Biodiversity and ecosystem functioning: current knowledge and future challenges

The ecological consequences of biodiversity loss have aroused considerable interest and controversy during the past decade. Major advances have been made in describing the relationship between species diversity and ecosystem processes, in identifying functionally important species, and in revealing underlying mechanisms. There is, however, uncertainty as to how results obtained in recent experiments scale up to landscape and regional levels and generalize across ecosystem types and processes. Larger numbers of species are probably needed to reduce temporal variability in ecosystem processes in changing environments. A major future challenge is to determine how biodiversity dynamics, ecosystem processes, and abiotic factors interact

On the statistical significance of functional diversity effects

Changes in biodiversity can affect ecosystem processes through a variety of pathways, such as changes in community structure, loss of a keystone or changes in resource use patterns among species. The latter, also known as resource use complementarity, is an established mechanistic link between species and ecosystems. At present, functional group richness is the dominant measure of the extent of resource use complementarity and has been manipulated in several experiments. These groups are constructed a priori using information about differences between species and a statistically significant effect is typically identified by standard parametric tests. These tests implicitly assume that the a priori functional groups are correct. Avoiding this assumption requires a randomization (bootstrap) test of statistical significance that accounts for the effects of grouping per se. This test compares the observed test statistic to the distribution of the test statistic resulting from random assignment of species to groups. Re-analyses of experimental manipulations of plant functional diversity by bootstrapping the critical significance value changed the ecological interpretation of results in nearly half of the experiments. This occurred because random assignment of species to functional groups frequently creates a strong relationship between functional diversity and ecosystem functioning. The significant bootstrapped results that were found perhaps represent some of the most convincing evidence that functional diversity is an important determinant of local-scale ecosystem functionin

Photovoltaik in Gebaeuden Abschlussbericht

The feasibility in principle of photovoltaic plants integrated in buildings was proved in the 1980's in the context of several pilot and demonstration projects both in Germany and internationally. However, the realisation and operation of these plants showed the necessity for further research and development work both in the system technique and particularly in the architectural area. The research project 'Photovoltaics in buildings' reached the target of establishing a bridge between the technically orientated work of the researchers, developers and manufacturers of photovoltaic components on the one hand, and the architects and town planners on the other hand. (orig./AKF)Die prinzipielle Machbarkeit gebaeudeintegrierter Photovoltaikanlagen wurde in den 80er Jahren im Rahmen mehrerer Pilot- und Demonstrationsprojekte sowohl in der Bundesrepublik Deutschland als auch international nachgewiesen. Die Realisierung und der Betrieb dieser Anlagen zeigte jedoch die Notwendigkeit weiterer Forschungs- und Entwicklungsarbeiten sowohl im systemtechnischen als insbesondere auch im architektonischen Bereich auf. Mit dem Forschungsprojekt 'Photovoltaik in Gebaeuden' wurde das Ziel erreicht, eine Bruecke zu schlagen zwischen den eher technisch orientierten Arbeiten der Forscher, Entwickler und Hersteller von Photovoltaikkomponenten auf der einen Seite und den Architekten und Stadtplanern auf der anderen. (orig./AKF)Available from TIB Hannover: F97B1268+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Functional diversity: back to basics and looking forward

Functional diversity is a component of biodiversity that generally concerns the range of things that organisms do in communities and ecosystems. Here, we review how functional diversity can explain and predict the impact of organisms on ecosystems and thereby provide a mechanistic link between the two. Critical points in developing predictive measures of functional diversity are the choice of functional traits with which organisms are distinguished, how the diversity of that trait information is summarized into a measure of functional diversity, and that the measures of functional diversity are validated through quantitative analyses and experimental tests. There is a vast amount of trait information available for plant species and a substantial amount for animals. Choosing which traits to include in a particular measure of functional diversity will depend on the specific aims of a particular study. Quantitative methods for choosing traits and for assigning weighting to traits are being developed, but need much more work before we can be confident about trait choice. The number of ways of measuring functional diversity is growing rapidly. We divide them into four main groups. The first, the number of functional groups or types, has significant problems and researchers are more frequently using measures that do not require species to be grouped. Of these, some measure diversity by summarizing distances between species in trait space, some by estimating the size of the dendrogram required to describe the difference, and some include information about species' abundances. We show some new and important differences between these, as well as what they indicate about the responses of assemblages to loss of individuals. There is good experimental and analytical evidence that functional diversity can provide a link between organisms and ecosystems but greater validation of measures is required. We suggest that non-significant results have a range of alternate explanations that do not necessarily contradict positive effects of functional diversity. Finally, we suggest areas for development of techniques used to measure functional diversity, highlight some exciting questions that are being addressed using ideas about functional diversity, and suggest some directions for novel research