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This article describes a 2-systems model that explains social behavior as a joint function of reflective and impulsive processes. In particular, it is assumed that social behavior is controlled by 2 interacting systems that follow different operating principles. The reflective system generates behavioral decisions that are based on knowledge about facts and values, whereas the impulsive system elicits behavior through associative links and motivational orientations. The proposed model describes how the 2 systems interact at various stages of processing, and how their outputs may determine behavior in a synergistic or antagonistic fashion. It extends previous models by integrating motivational components that allow more precise predictions of behavior. The implications of this reflective–impulsive model are applied to various phenomena from social psychology and beyond. Extending previous dual-process accounts, this model is not limited to specific domains of mental functioning and attempts to integrate cognitive, motivational, and behavioral mechanisms.
Prunus spinosa L. (Rosaceae) is one of the most widespread members of the genus Prunus in middle europe. Its morphological plasticity resulted in a number of described taxa at subspecific level. Since the early neolithic times, drupes of the plum family are recorded and exhibit already a remarkable diversity in size and form. Here we present a short historical account to the use of P. spinosa and an overview of the different taxonomic treatments. We examined distribution patterns in general and in particular in the central valley of the river Saale (Thuringia) with respect to ecological, edaphic and climatic factors. We assessed within 16 populations the variability of 22 metric and 10 qualitative morphological characters at 7 different locations. Population sites included forest-, way- and fieldsides, as well as lightish pine forests. Pollen fertility did not increase during the flowering period, all flowers were directly fully fertile from the beginning. In contrast, glucose content varied significantly depending of the status of fertilization. Epicuticular wax structure was without variation amongst the populations. P. spinosa leaves are covered with a smooth layer of slightly striated wax. Morphological characters were scored on 270 branches and 506 fruits. Most of the characters showed enormous variability among and within populations such as metrics of leaves, thorns and character states of flower morphology. The lowest variability among populations and therefore not dependend of modificatory factors was found in fruit characters. Since kernel morphology seems to be genetically rather than modificatory controlled, we applied the 3 taxonomical concepts of Werneck, Kühn and Scholz u. Scholz to identify evolutionary units at subspecific levels. However, population variability was still so high, that from our study here we can not support an infraspecific classification of Prunus spinosa L.
Based on queries of the phytosociological databank BERGWALD, a compilation of 3.504 forest vegetation plots from the Bavarian Alps, the ecological niche of Abies alba is re-assessed. The tree species occurs mostly admixed in mountain forests with Fagus and Picea rather than forming distinctive communities of its own. Climatically, Abies is widely distributed to the upper limit of the montane belt, but occurs only sparsely in subalpine forest. Analysis of Ellenberg indicator values based on total species composition yielded the following results: As a tolerant species Abies regeneration has a marked preference for shady forest, which in turn Abies tree layers themselves help create. It also has a clear preference for acidic topsoil conditions. Sites with low N-supply, such as early successional stages on raw carbonate soils, are rarely colonised by Abies. Also, dry and markedly wet forest sites in the region are avoided by Abies. Permutation-based indicator species analysis found a large number of common forest species as being significantly associated with Abies and its frequent companion Fagus sylvatica, whereas there is a negative relationship with more specialised Seslerion and Erico-Pinion species. As Abies alba has very few specific companion species not shared with either Fagus or Picea, the delimitation of Abietetum-syntaxa appears mostly motivated by ecological rather than phytosociological considerations. As a result of its susceptibility towards game browsing, Abies regeneration is an indicator of high woody species richness. The study broadly confirms Abies alba's status as a climax species intermediate between Fagus and Picea, and demonstrates the potential of large phytosociological databanks for niche modelling.
The island of Rügen (Rugia), located in the Baltic sea, is the most northeastern (NE) part of Germany. Due to its particular geographic position at the border between scandinavian, middle european and continental european floral elements, Rügen harbours several hawkweed species (Hieracia) of the scandinavian area such as Hieracium fuscocinererum, H. subramosum, H. subrigidum and H. diaphanoides subsp. neoornatum and, at the same time, is the most northwestern location of H. echioides. Two endemic Hieracium species have been identified recently, i. e. H. muorum subsp. rugianum and H. caesium subsp. zabelianum (Gottschlich et al. 1998, Bot. Rundbr. Mecklenburg-Vorpommern 31:1-94). In the present communication, two further novel endemic Hieracium taxa will be described, which are restricted to the chalk cliffs of Cape Arkona and Jasmund, i. e. H. swantevitii and H. lachenalii subsp. litocretaceum. H. swantevitii (Swantevit’s hawkweed) is intermediate between H. caesium/H. bifidum and H. lachenalii with hairy, modestly glandular involucre and slightly serrated elongated leaves . This view of an intermediate position of H. swantevitii between these species was further supported by the ultrastructure of epidermal papillae of the outer bracts of the involucre visualized by scanning electron microscopy. H. lachenalii subsp. litocretaceum (chalk cliff hawkweed) is characterized by its narrow anguste to almost linear denticulate leaves in combination with mode rately glandular heads. In addition to the description of these two new hawkweed taxa , the rediscovery of three further species will be reported for Rügen, i. e. H. echioides (W. Gager in SE Rügen), H. cymosum subsp. cymosum (close to Göhren in SE Rügen) and H. subrigidum E Glowe in N Rügen. The locality of H. echioides appears to be most north-western site in middle Europe, the locality of H. cymosum is one of the last growth sites in the northern German lowlands and H. subrigidum (so far only known as a single herbarium specimen, collected 1858 in Rügen) has so far not been recorded in other localities of middle Europe.