Year of publication
- Dynamics of juvenile woody plant communities on termite mounds in a West African savanna landscape (2014)
- Termites are keystone species in savanna ecology, and their mounds are thought to be an important source of habitat heterogeneity and structural complexity of the savanna. Macrotermes termitaria have been shown to allow woody plant colonisation of landscapes otherwise dominated by C4 grasses. In this study, we assess how resource-rich Macrotermes mounds affect juvenile woody plant and non-woody plant species diversity, community composition, biomass and population dynamics. We repeatedly sampled paired termite mound and savanna plots in Pendjari National Park (Sudanian vegetation zone, North Benin, West Africa) over the course of two years. Despite considerable overlap in their species pools, plant communities of mound and savanna plots were clearly separated in ordinations. Species richness and diversity of juvenile woody plants was consistently higher on termite mounds, while no differences could be detected for non-woody plants. Evenness of juvenile woody plants was generally lower on mounds, whereas density and basal area were higher on mounds. In contrast, we did not detect any influence of the mound microhabitat on colonisation, mortality and turnover of woody juveniles. Therefore, we suggest that differences in the communities on and off mounds should be strongly influenced by directed diaspore dispersal through zoochory.
- Obituary in memory of Prof. Dr. Laurent Aké-Assi (1931-2014) (2014)
- In the first month of the year 2014, the Ivorian botanist, member of the editorial board of this journal, Laurent Aké Assi, often called “the genius of the Ivorian forest”, left the stage.
- Evidence for increasing homogenization and de-ruralization of the Central European village flora (2013)
- In this study, the spontaneous flora of North Rhine-Westphalian villages (NW Germany) recorded in the periods 1980–1984 and 2004–2005 was analyzed. We asked: (i) Did the similarity of the village flora increase with time and to what extent did non-native species contribute to this? (ii) Is the ongoing trend of urbanization reflected in the village flora? (iii) Regarding the species composition and β-diversity: are there differences between the results of a repeated survey and of a type comparison? In both periods, 200 villages were visited once, using consistent criteria for village selection and floristic investigation. Of these, a subset of 61 villages was investigated in both time periods and the rest were selected randomly for the second survey but with respect to the same criteria as used in the first. Using different β -diversity indices (Sørensen index of dissimilarity, Simpson index of dissimilarity and nestedness resultant index) to disentangle pure species turnover and nestedness of species assemblages, we tested whether the similarity among the villages increased over the years. This was done by calculating all pairwise comparisons among the villages of each time period, i.e. their spatial turnover. Additionally, different ecological groups were defined (e.g. “neophytes”, “C-strategists” or “urbanophilous species”) using the subgroups of species traits (floristic status, Grime’s life strategy and urbanity) to indentify urbanization and compositional changes. Our results show that the traditional village flora (species of the Arction lappae, Bidention tripartitae and Potentillion anserinae) is further blurred towards unspecific ubiquitous assemblages found in the periphery of man and that the floristic urbanization is still ongoing. Supported by nearly all ecological groups regarded, our results corroborate that the species composition of Central European villages underwent a considerable degree of homogenization. To some extent this is caused by structural homogenization of villages. Regarding the considerable increase of common ubiquists and α-diversity in general, however, changes in weeding practices seem to be the main reason. Based on the reinvestigated subset we could show that comparable results can be obtained by a consistent use of criteria for the selection of villages, even if unpaired samples were used.
- Epilobium brachycarpum: a fast-spreading neophyte in Germany (2013)
- Only a small proportion of introduced plant species become invasive and may eventually create eco-logical or economic problems. In many species it is still not clear which traits cause biological inva-sions. As a case study we focussed on the fast-spreading Epilobium brachycarpum in Central Europe to investigate the potential of this species to become a transformer or agricultural weed. We (1) docu-mented the spread of the species in Central Europe, (2) modelled its range and (3) seed dispersal, (4) described its phytosociological alignment, (5) analysed the traits of invaded vegetation types, (6) de-scribed seed production, population densities and life cycle, (7) did competition and germination tests, and (8) drafted a risk assessment. Relevant traits and characteristics of E. brachycarpum are (i) for-mation of dense stands under ruderal conditions, (ii) high seed production, (iii) effective seed dispersal, (iv) high competitiveness on bare soils against other ruderal plants, and (v) ecological niche shift com-pared to its native range. We expect E. brachycarpum to settle in the Mediterranean, sub-Mediterranean and many parts of temperate Europe within the next decades in habitats strongly altered by human activities, especially open stands of the alliance Sisymbrion. We predict that E. brachycarpum will become a noxious weed in vineyards, and that it will also colonise vegetation of the alliances Bidention and Carici-Epilobion.
- World-wide every fifth vascular plant species is or was used as medicinal or aromatic plant (2013)
- It is common knowledge that plants have been the world-wide most important source of medicines and that they still play this role in developing countries. However, up to now, complete lists of medicinal and aromatic plants (MAP) exist for comparatively few countries. A review of all lists know to the authors reveals the following results: A total of 20.7 % of the plant species analyzed by either publications or own research are or were used as MAP. However, re¬garding single countries, the differences are considerably high. Absolutely leading the list are China (36.2 %), Burkina Faso (35.2 %) and the Korean Republic (34.5 %). Also ahead of other countries or regions are the North of Benin (32.8 %) and the entire Pakistan (30.3 %). Still above average rank Great Britain (26.7 %) and Nepal (23.3 %), while the figures for Bul¬garia (21.0 %), Germany (20.2 %) and France (19.4 %) almost represent the average. Jordan (17.3 %), Vietnam (17.1 %), Sri Lanka (16.6 %), India (16.1 %) and Thailand (15.5 %) rank slightly beneath. Clearly below the average are the percentages of MAP for Hungary (12.2 %) and the USA (11.8 %). The average numbers of MAP in the Philippines (9.5 %) and Malaysia (7.7 %) fall far behind. Calculated on a worldwide scale, every fifth plant can be regarded as MAP. This number matches that from Bulgaria, France and Germany. In northern Benin, Burkina Faso, Korea, China and Pakistan, however, every third plant is or was used as MAP, whereas in Hungary and the USA only every eighth plant can be regarded as MAP. This number drops even further for the Philippines ore Malaysia where only every tenth or thirteenth plant can be attributed to medicinal or aromatic use. These differences might be due to various factors. A geographical component of the results is obvious: in most cases geographically close countries show similar percentages. A correlation between the total number of species and the fraction of those used as MAP cannot be confirmed. The countries with percentage of MAP > 30 % in common show that they belong either entirely (Burkina Faso, Benin) or at least in their rural areas to the poorest countries of the world so that it is (was) impossible for the majority of the people to buy "modern" MAP. In those countries the number of traditional healers outnumbers largely the number of modern doctors. Therefore, the tradition of folk medicine was maintained until today. Additionally, China, Korea and partially Pakistan have a very old and well documented tradition of folk medicine. Due to this documentation even in areas where today "modern MAP" are used, the knowledge was not lost. In neighboring countries or regions, which differ with respect to a more arid or a more humid climate, for the arid country (region) more MAPs are reported than for the humid one. The potential reasons for this phenomenon are discussed in the paper. For many countries the percentage given for MAP in literature is too low. But even these low values represent a striking argu¬ment for the importance of a world-wide conservation of biodiversity.
- Changes in the species composition of hedgerows in the Westphalian Basin over a thirty-five-year period (2012)
- In the Westphalian Basin (North-Rhine Westphalia, Germany), 176 relevés of hedgerows first surveyed during the 1970s were reassessed in 2009 and 2010, and the floristic differences between these two time points were compared. The results were used to analyse the impact of exogenous factors on the species community composition using multivariate statistics (non-metric multidimensional scaling). Significant changes were found within all of the communities along the first axis of the ordination, and, in most cases, increasing average temperatures were best correlated with these alterations. However, based on the considerable evidence found, the alterations induced by land-use change and the inten - sification of agriculture appear to be the inducing factors.
- The Vegetation of Lateritic Crusts in Northwestern Benin (Atakora Region) (2012)
- Most of the grass savannas on lateritic crusts found in the North-Western of Benin are free of trees and a shrub layer is only sparsely developed. The only constant member of the shrub layer, is Terminalia laxiflora. Intermediate constancy show Entada africana and Annona senegalensis. With regard to the herbaceous layer two types can be identified: On very shallow soils (<2 cm) Loudetia togoensis is highly constant and often dominating. The same is true for Andropogon pseudapricus on soils of a little bit more than 2 cm. In those types, Lepidagathis anobrya and Spermacoce filifolia show very high constancy (constancy class V) and Cyanotis lanata and Melliniella micrantha occur with high constancy (IV).
- Zwischen Alraune und Zimmerimmergrün : eine detaillierte Führung durch den Senckenbergischen Arzneipflanzengarten im Botanischen Garten Frankfurt am Main (2011)
- Rezension zu: Theo Dingermann, Georg Schneider & Ilse Zündorf : Der neue Senckenbergische Arzneipflanzengarten im Botanischen Garten Frankfurt / Main, Eigenverlag 2010 ISBN 978-3-00-032497-0, 347 Seiten, 29,65 Euro, (zzgl. Versandkosten, bei Bestellung über die Autoren) 39,90 Euro (Buchhandel).
- The Medicinal Plants of the Woodlands in northern Malawi (Karonga District) (2011)
- In rural Africa, the use of wild plants for medicinal purposes is widespread. Many publications provide regional checklists of medicinal plants, but only a few of these checklists cover Malawi. In the Karongo district, northern Malawi, 30 traditional healers and birth attendants were interviewed regarding their use of woody medicinal plants. This survey reveals that 71 of the 102 woody species that are found in this area are used for a variety of treatments. These medicinal plants are most commonly applied in obstetrics. The favoured wild plants are frequently found in the area; however, three species are perceived as decreasing in abundance.
- Uses and Management Strategies of the Multipurpose Tree Anogeissus leiocarpa in Eastern Burkina Faso (2011)
- Many people in the semi-arid tropics strongly depend on non-timber forest products (NTFPs) for livelihood. Increasing threats on NTFP-providing tree species, due to land-use intensification and over-harvesting, require ecological studies as well as additional information provided by local people. One important NTFP-providing tree in West Africa is Anogeissus leiocarpa. Even though this species is highly used, ethnobotanical studies on A. leiocarpa are scarce and address mainly qualitative aspects. Our study investigates uses, perceptions of the population development, and management strategies of A. leiocarpa among the Gulimanceba people in eastern Burkina Faso. We conducted a quantitative ethnobotanical survey and investigated distribution of traditional ecological knowledge related to the species on a local scale, i.e. difference in knowledge between villages, genders, and generations. Interviews reveal that A. leiocarpa is harvested by local people for 18 different uses and emphasize its high importance for local people. Ethnobotanical knowledge of A. leiocarpa was mostly evenly spread between genders and generations, while it slightly differed between villages. Although local people did not actively protect A. leiocarpa, current local harvesting modes and management resulted in sustainable use. However, ongoing land-use intensifications require adapted management strategies to guarantee the persistence of this important species. Our results provide, in combination with ecological results of our previous study, appropriate management recommendations. Our study emphasizes the importance of ethnobotanical studies on a local scale level in order to develop management strategies that are reliable in the specific area under the specific circumstances.