Bio-, Magneto- and event-stratigraphy across the K-T boundary

Determining the time and the time structure of rare events in geology can be accomplished by applying three different and independent stratigraphic methods: Biostratigraphy, magneto-stratigraphy and event-stratigraphy. The optimal time resolution of the two former methods is about 1000 years, while by means of event-stratigraphy a resolution of approximately one year can be achieved. For biostratigraphy across the Cretaceous-Tertiary (K-T) boundary micro- and nannofossils have been found best suited. The qualitative and quantitative analyses of minerals and trace elements across the K-T boundary show anomalies on a millimeter scale and permit conclusions regarding the time structure of the K-T event itself. The results of the analyses find a most consistent explanation by the assumption of an extraterrestrial impact. The main portion of the material rain from the atmosphere evidently was deposited within a short time. The long-time components consist of the finest portion of the material rain from the atmosphere and the transported and redeposited fall-out

Traits of leaf anatomy of Croton lanjouwensis Jablonsky (Euphorbiaceae) in different strata of the plant.

The distribution of C. lanjouwensis, commonly known as "Dima", is restricted to the Brazilian State of Amazonas. The species is a common tree in secondary forests. In the poster, the leaf anatomy of this species is described for leaves of different strata of a plant growing in an 11 year-old secondary forest of approx. 20 m in height, in order to study the phenotypic plasticitty of the leaf as a whole and of single anatomic structures

A QTL for osteoporosis detected in an F2 population derived from White Leghorn chicken lines divergently selected for bone index

Osteoporosis, resulting from progressive loss of structural bone during the period of egg-laying in hens, is associated with an increased susceptibility to bone breakage. To study the genetic basis of bone strength, an F cross was produced from lines of hens that had been divergently selected for bone index from a commercial pedigreed White Leghorn population. Quantitative trait loci (QTL) affecting the bone index and component traits of the index (tibiotarsal and humeral strength and keel radiographic density) were mapped using phenotypic data from 372 F individuals in 32 F families. Genotypes for 136 microsatellite markers in 27 linkage groups covering ∼80% of the genome were analysed for association with phenotypes using within-family regression analyses. There was one significant QTL on chromosome 1 for bone index and the component traits of tibiotarsal and humeral breaking strength. Additive effects for tibiotarsal breaking strength represented 34% of the trait standard deviation and 7.6% of the phenotypic variance of the trait. These QTL for bone quality in poultry are directly relevant to commercial populations

Characteristics of sustainable polyculture production systems on terra firme.

The combination of soil science, forestry, agronomy and biology allowed an analytical comparison of various experimental mixed culture systems. From these studies, a descriptor system was developed which allows to understand the contribution of each plant species to nutrient cycling, water distribution, litter formation, overall biomass production and crop production. This knowledge allows to combine plants so that their properties interact to form a system, which minimizes mineral losses and which regulates air humidity and water distribution and thus leads to stable crop production. The general conclusion which can be drawn after eight years of polyculture study is: a) stable productions systems for samllholder families have bee developed; b) the systems are variable; they can be adapted to the respective site conditions; c) the manager of these plantations requires a deeper understanding of the cultivation systems and an intensive dissemination of knowledge and a well develope on-farm training system for farmers

Utilization of abandoned areas in Amazonia by polycultures of perennial useful plants.

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Characteristics of sustainable polyculture production systems on terra firme.

The combination of soil science, forestry, agronomy and biology allowed an analytical comparison of various experimental mixed culture systems. From these studies, a descriptor system was developed which allows to understand the contribution of each plant species to nutrient cycling, water distribution, litter formation, overall biomass production and crop production. This knowledge allows to combine plants so that their properties interact to form a system, which minimizes mineral losses and which regulates air humidity and water distribution and thus leads to stable crop production. The general conclusion which can be drawn after eight years of polyculture study is: a) stable productions systems for samllholder families have bee developed; b) the systems are variable; they can be adapted to the respective site conditions; c) the manager of these plantations requires a deeper understanding of the cultivation systems and an intensive dissemination of knowledge and a well develope on-farm training system for farmers

Spatial and temporal change of the spontaneous vegetation in an agricultural fields experiment.

The objective of the SHIFT field trial carried out on an area of 17 ha at the experimental site of EMBRAPA Amazônia Ocidental near Manaus, Amazonas, Brazil, is to try out the reuse of an abandoned agricultural site by mixed cropping systems and to survey some of the most important ecological interactions between the growth of the useful plants, the spontaneous vegetation in the field, and management and site factors

Structural traits of an eight year old secondary forest in the Central Amazon.

Presentation of the floristical composition, stratification and growth-form structure of the vegetation in the 1 ha secondary forest in Manaus-AM (Brasil). The variation of the vegetation within 1 ha area is analysed with the aid of multivariate analyses (PCA) of the floristical composition of the plots, and the resulting ordination model is displayed as a covariance biplot. Conclusions are drawn from the floristical and structural analyses concerning the key environmental factors leading to the vegetation studied, and the influence of the surveys on vegetation development, i.e., disturbance such as trampling and cutting of trees, is discussed

Leitlinien für das Management der Versuchsfläche.

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