Impact of land-use on savanna vegetation and populations of non-timber forest product-providing tree species in West Africa

Savannas are the most important timber and non-timber forest products (NTFPs) providing ecosystems in West Africa. They have been shaped by traditional human land-use (i.e. agriculture, grazing, and harvesting) for thousands of years. In the last decades, land-use has drastically changed due to the rapid population growth and the growing production of cash-crop in West Africa and this process is still continuing. The percentage of land intensively used for agriculture has increased, while the length of fallow periods has decreased. Such changes have enormous ecological, economic, and social consequences. In the context of land-use changes, there is an urgent need to better understand and evaluate the impact of land-use on savannas. Such an understanding provides insights on appropriate management activities that ensure the maintenance of savannas and guarantee the availability of savanna products for subsistence and commercial use of rural West African people. The major objective of the present thesis was to study the impact of land-use on savanna vegetation and diversity as well as on populations of two important NTFP-providing tree species in a semi-arid area in West Africa. The study area was located in the south-eastern part of Burkina Faso and comprised the protected W National Park and its adjacent communal area. In the first study (chapter 2), I investigated in cooperation with a colleague from Burkina Faso (Blandine Nacoulma) the impact of land-use on the savanna vegetation. We analyzed which environmental factors determine the occurrence of the vegetation types and investigated the effect of land-use on vegetation structure and the occurrence of life forms and highly valued tree species. Furthermore, we tested whether land-use has an impact on plant diversity pattern and if this impact differed between the vegetation types and layers (woody and herb layer). Vegetation relevés were performed and the vegetation and plant diversity of the protected W National Park were compared with those of its surrounding communal area. Our results reveal five vegetation types occurring in both areas. Elevation and physical soil characteristics and thus soil water availability for plants played the most important role for the occurrence of the vegetation types. The influence of land-use on plant diversity differed between the five vegetation types and the two layers. The impact was highest on the vegetation types with the most favorable soil conditions for cultivation and lowest on rocky habitats with poor soils. While the diversity of the woody layer was increased under human land-use, the diversity of the herb layer was diminished. Overall, as land-use effects were not only negative, our findings suggest that land-use does not automatically lead to a loss of plant species and to a degradation of savanna habitats. We conclude that both protected and communal areas are of great importance for the conservation of savanna vegetation and diversity. Our study highlights furthermore the importance of different management strategies for each vegetation type. In the following two studies (chapter 3 and 4), the impact of land-use - and in particular of harvesting - on populations of Adansonia digitata L., the baobab tree, and Anogeissus leiocarpa (DC.) Guill. & Perr. was examined. These two tree species were chosen as they provide several NTFPs for the local population and as they show different levels of human protection and opposed life histories. Thus, they may react differently to land-use. Stands of the protected W National Park were compared with those of its surrounding communal area (in fallows, croplands, and villages). I applied dendrometric methods to study the population structures and combined it with rates and patterns of NTFP-harvesting (debarking and chopping/pruning). Furthermore, the impact of land-use and harvesting on the fruit production of A. digitata and on the sprouting ability of A. leiocarpa were studied. The inverse J-shaped size class distribution curve indicates that the stands of A. digitata were in a healthy state in the park, while the low number of smaller size classes in fallows, croplands, and villages may give evidence of an ageing population. However, a high number of seedlings were recorded in villages. The stands of A. leiocarpa were also in healthy states in the park and likewise in fallows. In contrast, the absence of saplings gives evidence of a declining population in croplands. Both species were strongly harvested by local people and harvesting was tree size-specific. Pruning in interaction with tree-size had a significant impact on fruit production of A. digitata. While smaller trees were more vulnerable to pruning, bigger trees benefited from slight-pruning. A. leiocarpa had a great ability to respond to chopping by sprouting. The sprouting ability increased even with higher chopping intensity. Results suggest that despite the intense harvesting and the land-use impact, populations of both species are still well preserved. While A. digitata can withstand the harvesting and land-use pressure by its longevity, extremely low adult mortality rates, and particularly due to positive human influences, A. leiocarpa is able to withstand the use pressure by its fast growing, high recruitment, and high sprouting ability. I conclude that a none protected tree species (A. leiocarpa) might not necessarily be at higher risk to the harvesting and land-use impact than a protected tree species (A. digitata) as the adverse impact of harvesting and land-use can be compensated by its specific life history. Important additional information to such ecological findings can be provided by local people. Learning from traditional knowledge and management systems of local people will help to produce culturally and ecologically reasonable conservation and management strategies. Thus, I investigated local uses and management strategies of A. digitata and A. leiocarpa in the last two studies (chapter 5 and 6). Quantitative ethnobotanical surveys among the Gulimanceba people were conducted in the communal area in order to document uses of the different plant parts, harvesting modes, perceptions about the population status, and conservation status of both species. Hereby, differences in knowledge between gender, generations, and people from different villages were tested. Interviews reveal that both species are harvested for multipurpose and emphasize the high importance of both species for local people. Especially the leaves and fruits of A. digitata add valuable minerals and vitamins to the otherwise micronutrient-“poor” staple crops of the Gulimanceba people. In comparison with other studies in West Africa, it has turned out that people in this area could benefit even more from A. leiocarpa, e.g. for dyeing of clothes, for treatment of malaria and skin problems. Local knowledge did not differ between genders and generations, while it slightly differed between people from different villages. The lack of age differences suggests that the traditional knowledge about these two species is passed on from one generation to another. Differences between people from different villages might be explained by influences from the neighboring countries Niger and Benin. Current local harvesting modes and management strategies of both species resulted in sustainable use. However, ongoing land-use intensifications require adapted harvesting and management techniques to guarantee the persistence of these economically important species. These results provide, in combination with the ecological findings (chapter 3 and 4), appropriate management recommendations for A. digitata and A. leiocarpa that are reliable under currently practiced management strategies

Substitut des graines de Vitellaria paradoxa, Parkia biglobosa et Adansonia digitata utilisées pour la nutrition par cinq groupes ethniques majeurs au Bénin, Afrique de l'Ouest

Essbare Wildpflanzen stellen wichtige Nahrungsergänzungen, zu einer ansonsten nährstoffarmen Ernährung ländlicher Nichtholz-Forstprodukte (non-timber forest products, NTFPs) leisten einen wesentlichen Beitrag zu den Lebensgrundlagen und der Ernährung ländlicher Haushalte in den Savannenökosystemen Westafrikas. Landnutzungsänderungen und klimatische Variabilität könnten ihre Verfügbarkeit in Zukunft jedoch beeinträchtigen. Basierend auf einer Befragung von 227 Haushalten in Nord-Benin untersuchten wir die lokalen Substitutionsmuster für die in der Ernährung genutzten Samen der drei sozioökonomisch wichtigsten NTFP-Arten in der Region, Vitellaria paradoxa, Adansonia digitata und Parkia biglobosa, die wesentliche Quellen für essentielle Proteine, Fett und Mikronährstoffe sind. Unsere Studie verglich zunächst die Substitutionsmuster zwischen drei Einkommensgruppen, um festzustellen, ob der sozioökonomische Status der privaten Haushalte einen Einfluss auf die Wahl der Substitute haben würde (geringere versus höhere Kosten bei der Beschaffung dieser Substitute). Zweitens verglichen wir die Substitutionsmuster zwischen den fünf großen ethnischen Gruppen des Untersuchungsgebietes (Fulani, Bariba, Ditammarie, Kabiyé und Yom). Die Wahl der Substitute unterschied sich signifikant zwischen den drei Einkommensgruppen, wobei die ärmsten Haushalte die höchste Vulnerabilität aufweisen: Bis zu 30% der in die Stichprobe einbezogenen Haushalte gaben an, dass ihnen ein angemessener Ersatz für die betreffenden NTFP fehle. Darüber hinaus zeigte die ethnische Zugehörigkeit einen erheblichen Einfluss auf die bevorzugten Alternativprodukte, der auf die unterschiedlichen kulturellen Traditionen bei der Nutzung der NTFPs zurückzuführen ist. Mit Blick auf die Sicherung der Beiträge von V. paradoxa, P. biglobosa und A. digitata zur lokalen Ernährung bzw. deren Verbesserung, sollte lokale Landnutzungspolitik die ethnisch bedingten Unterschiede in der Nutzung der NTFPs sowie die besonderen Bedürfnisse der unteren Einkommensgruppen stärker berücksichtigen.Non-Timber Forest Products (NTFPs) make a major contribution to the livelihoods and diets of rural households in the savanna ecosystems of West Africa. However, land use change and climatic variability might affect their availability in the future. Based on a survey among 227 households in Northern Benin, we investigated local substitution patterns for the seeds of the three socio-economically most important NTFP-species in the region, Vitellaria paradoxa, Adansonia digitata and Parkia biglobosa, being major sources for protein, fat, and micronutrients in local daily diets. Our study compared substitution patterns between, firstly, three income groups, to assess whether a households’ socio-economic status has an influence on the choice of surrogates (low cost vs. more costly options). Secondly, we compared substitution patterns between the five major ethnic groups in the study region (the Fulani, the Bariba, the Ditammarie, the Kabiyé and the Yom). The choice of substitutes differed significantly across income groups. However, the poorest households clearly show to be the most vulnerable: up to 30 % of the sampled households stated they would lack an adequate replacement for the NTFPs in question. Furthermore, ethnic affiliation showed to have a considerable impact on the preferred alternative products due to underlying cultural traditions of plant use. Subsequently, aiming at maintaining – and enhancing – the local supply of V. paradoxa, P. biglobosa and A. digitata in order to secure their contributions to local diets, local land use policy should have a particular focus on their ethnic-conditioned use and particularly the specific requirements of the poorest community members.Les produits forestiers non ligneux (PFNL) apportent une contribution majeure aux besoins quotidiens et aux régimes alimentaires des ménages ruraux dans les écosystèmes des savanes d'Afrique de l'Ouest. Cependant, le changement de l'occupation du sol et la variabilité climatique pourraient affecter leur disponibilité dans l'avenir. Sur la base d'une enquête menée auprès de 227 ménages du nord du Bénin, nous avons étudié les modèles de substitution locale pour les produits alimentaires des trois espèces de PFNL socio-économiquement les plus importantes de la région, Vitellaria paradoxa, Adansonia digitata et Parkia biglobosa. Leurs graines sont une importante source de protéines, lipides et micronutriments. Notre étude a comparé les schémas de substitution entre, premièrement, trois groupes de revenu afin d'évaluer si le statut socioéconomique des ménages aurait une influence sur le choix des substituts (coût faible par rapport aux options plus coûteuses). Deuxièmement, nous avons comparé les modes de substitution entre les cinq principaux groupes ethniques dans la région étudiée (Fulani, Bariba, Ditammarie, Kabiyé et Yom). Le choix des substituts différait considérablement d'un groupe de revenu à l'autre. Cependant, les ménages les plus pauvres sont clairement les plus vulnérables: jusqu'à 30% des ménages échantillonnés ont déclaré qu'ils n'auraient pas un remplaçant approprié pour les PFNL en question. De plus, l'appartenance ethnique s'est révélée avoir un impact considérable sur les produits alternatifs préférés en raison des traditions culturelles sous-jacentes de l'utilisation des plantes. Par la suite, dans le but de maintenir - et d'améliorer - l'approvisionnement local de V. paradoxa, P. biglobosa et A. digitata afin d'assurer leur contribution aux régimes alimentaires des ménages ruraux, la politique locale d'utilisation des terres devrait porter une attention particulière à leur utilisation, surtout aux besoins spécifiques des membres les plus pauvres de la communauté

Transition Metal and Lanthanide Complexes of 1,4,7,10-Tetraallyl- and 1,4,7,10-Tetra-3-butenyl- 1,4,7,10-tetraazacyclododecane

1,4,7,10-Tetraazacyclododecane (1) reacts with allylbromide and 3-butenylbromide giving 1,4,7,10-tetraallyl-1,4,7,10-tetraazacyclododecane (TAC) (2a) and 1,4,7,10-tetra-3-butenyl-1,4,7,10- tetraazacyclododecane (TBC) (2b), respectively. Compounds 2a and 2b react with FeCl2, CoCl2, RhCl3, NiCl2, CuBr2, and TmCl3 forming the complexes [FeCl(TAC)]Cl (3a), [FeCl(TBC)]Cl (3b), [CoCl(TAC)]Cl (4), [RhCl(TAC)]Cl2 (5), [NiCl(TAC)]Cl (6a), [NiCl(TBC)]Cl (6b), [CuBr(TAC)]Br (7), [TmCl(TAC)]Cl2 (8a), and [TmCl(TBC)]Cl2 (8b). The reaction of 6a with an excess of CuCl affords a coordination polymer in which [NiCl(TAC)]+ cations are connected by [Cu6Cl8]2− anions (9). The 1H and 13C NMR spectra of 2a, 2b, 5, and 6a, as well as the single crystal X-ray structures of 2a ・3HCl, 6a, 6b, 7, and 9 are reported and discussed

New Synthetic Routes for 1-Benzyl-1,4,7,10-tetraazacyclododecane and 1,4,7,10-Tetraazacyclododecane-1-acetic Acid Ethyl Ester, Important Starting Materials for Metal-coded DOTA-Based Affinity Tags

Two improved routes to synthesize 1-benzyl-1,4,7,10-tetraazacyclododecane (6) and 1,4,7,10- tetraazacyclododecane-1-acetic acid ethyl ester (11) are described as well as the synthesis of 1-{2-[4-(maleimido-N-propylacetamidobutyl)amino]-2-oxoethyl}-1,4,7,10-tetraazacyclododecane- 4,7,10-triacetic acid (17) and its Y, Ho, Tm, and Lu complexes. The 1H and 13C NMR spectra of the new compounds as well as the single crystal X-ray structure analyses of the intermediates 4-benzyl-1,7-bis(p-toluenesulfonyl)diethylenetriamine (3) and 1,4,7-tris(p-toluenesulfonyl)diethylenetriamine (7) are reported and discussed. The rare earth complexes of 17 have been characterized by 1H NMR spectroscopy and MALDI-TOF mass spectrometry.DFG, SPP 1166, Lanthanoidspezifische Funktionalitäten in Molekül und Materia

Usages et stratégies de gestion d'Anogeissus leiocarpa, une espèce à usage multiple dans l'Est du Burkina Faso

Für die ländliche Bevölkerung in tropischen Gebieten sind Nichtholzprodukte verschiedenster Baumarten von essenzieller Bedeutung. Die durch Übernutzung und Landnutzungsintensivierungen hervorgerufenen Bedrohungen dieser Nutzholzarten erfordern sowohl ökologische als auch ethnobotanische Studien. Eine wichtige und stark genutzte Nutzholzart in Westafrika ist Anogeissus leiocarpa. Trotz starker Nutzung gibt es erstaunlicherweise kaum detaillierte ethnobotanische Studien über diese Art. In der vorliegenden Studie dokumentieren wir Verwendungen und Managementstrategien von A. leiocarpa bei der Gulimanceba Bevölkerung im Osten Burkina Fasos. Dazu haben wir quantitative ethnobotanische Befragungen bei den Gulimanceba durchgeführt und Unterschiede im Wissen zwischen den Geschlechtern, Generationen und zwischen Bewohnern verschiedener Dörfer untersucht. Die Ergebnisse der Umfragen zeigen, dass A. leiocarpa für 18 verschiedene Zwecke genutzt wird und verdeutlichen die Bedeutung dieser Art für die lokale Bevölkerung. Das Wissen über A. leiocarpa unterschied sich kaum zwischen den Geschlechtern und Generationen, wohingegen geringfügige Unterschiede zwischen den Befragten verschiedener Dörfer ermittelt werden konnten. Obwohl A. leiocarpa nicht aktiv von der lokalen Bevölkerung geschützt wird, lässt sich feststellen, dass die gegenwärtigen lokalen Sammeltechniken und Managementstrategien von A. leiocarpa nachhaltig sind. Allerdings erfordern anhaltende Landnutzungsintensivierungen angepasste Sammel- und Managementtechniken, um das Fortbestehen dieser wichtigen Art zu gewährleisten. Mit Hilfe unserer Ergebnisse und in Kombination mit den Ergebnissen unserer vorherigen ökologischen Studie können angemessene Managementempfehlungen für eine nachhaltige Nutzung von A. leiocarpa formuliert werden. Unsere Studie verdeutlicht die Bedeutung von lokalen, ethnobotanischen Untersuchungen. Mit Hilfe solcher Studien können konkrete Managementstrategien entwickelt werden, die unter den spezifischen Bedingungen anwendbar und tragbar sind.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.Les populations des zones semi-arides dépendent fortement des produits forestiers non ligneux (PFNLx) pour la subsistance. L'augmentation des menaces sur les arbres pourvoyeurs de PFNLx en raison de l'intensification de l'utilisation des terres et la surexploitation, nécessitent des études écologiques ainsi que des informations supplémentaires fournies par la population locale. Anogeissus leiocarpa est un des plus importants arbres, pourvoyeur de PFNLx en Afrique de l'Ouest. Malgré sa forte utilisation, les études ethnobotaniques sur A. leiocarpa sont rares et traitent principalement des aspects qualitatifs. Notre étude examine les usages, les perceptions de l'évolution de la population, et les stratégies de gestion d’A. leiocarpa chez les Gulimanceba dans l'Est du Burkina Faso. Nous avons mené une enquête ethnobotanique quantitative et étudié la distribution des connaissances écologiques traditionnelles relatives à l'espèce à une échelle locale; à savoir la différence dans la connaissance entre les villages, le genre et les générations. Les interviews révèlent que A. leiocarpa intervient dans 18 usages différents d’où son importance pour la population locale. Les connaissances ethnobotaniques sur A. leiocarpa étaient équitablement réparties entre le genre et les générations, mais légèrement différentes entre les villages. Bien que A. leiocarpa ne bénéficie pas d’une protection active de la part de la population locale, les modes actuelles de récolte et la gestion qui en résulte, concourent à une utilisation durable. Toutefois, l’intensification de l'utilisation des terres en cours nécessitent des stratégies de gestion adaptée pour garantir la persistance de cette importante espèce. Nos résultats fournissent, en combinaison avec nos études écologiques antérieures, des recommandations pour une gestion appropriées d’A. leiocarpa. Notre étude souligne l'importance des études ethnobotaniques à une échelle locale afin de développer des stratégies de gestion fiables et spécifiques à une zone donnée compte tenu des circonstances spécifiques

Fragmentable Heterogeneous Cocatalysts for the Metallocene-Catalyzed Polymerization of Olefins, I. Surface Modification of Silica and Characterization of the Resulting Carriers

Surface modification of pre-dried spherical silica nano-particles with diameters of 235 nm and 10 to 20 nm and of commercially available non-spherical silica materials using various aminoalkyltrialkoxysilanes and α-ω-bis(alkoxysilyl)organyls (organyl = alkanediyl, aminoalkanediyl, polyether, polysiloxane) has been performed in suspension in solvents with water. The quantity of water has a dominating influence, as compared to the amounts and the ratios of silanes employed, on the surface morphology of the modified silicas. The morphologies observed range from weakly linked aggregates of spherical particles to large agglomerates covered by thick irregular layers of organopolysiloxane, as demonstrated by scanning electron microscopy. These carriers can be modified further with organoaluminium compounds to yield heterogeneous cocatalysts for the polymerization of ethylene.BMBF, 03C0295, Verbundprojekt: Heterogene und homogene Cokatalysatoren und Katalysatoren für die OlefinpolymerisationDFG, GRK 352, Synthetische, mechanistische und reaktionstechnische Aspekte von Metallkatalysatore

Fragmentable Heterogeneous Cocatalysts for the Metallocene-Catalyzed Polymerization of Olefins, II [1]. Preparation, Characterization and Testing of the Cocatalysts and Microscopic Evaluation of the Polyethylene

Surface modified silica were reacted with different aluminiumalkyls AlR2R’ (R = Me, Et, i-Bu, R’ = H, Me, Et, i-Bu), oligomeric methylaluminoxane (MAO) and combinations of both, to yield heterogeneous cocatalysts. These cocatalyts were employed to polymerize ethylene using zirconocene dichloride as the catalyst. The polymerization activity profiles have been recorded and compared with the information gained from the scanning electron microscopy (SEM) images of the polymers. The fragmentation of the heterogeneous cocatalyts upon polymerization has been demonstrated. The degree of fragmentation and the polymerization activity depend on the preparation of the silica supports and on the preparation of the heterogeneous cocatalysts using these supports. The most reactive, fragmentable heterogeneous cocatalysts show polymerization activities slightly higher than MAO in homogeneous solution and almost 1.5 times higher than commercially available MAO on silica (=MAO on Sylopol).BMBF, 03C0295, Verbundprojekt: Heterogene und homogene Cokatalysatoren und Katalysatoren für die OlefinpolymerisationDFG, GRK 352, Synthetische, mechanistische und reaktionstechnische Aspekte von Metallkatalysatore

Substitution des plus importantes et décroissantes espèces alimentaires sauvages au Sud-Est du Burkina Faso

Essbare Wildpflanzen stellen wichtige Nahrungsergänzungen, zu einer ansonsten nährstoffarmen Ernährung ländlicher Bevölkerung in West Afrika, dar. Aus diesem Grund hat der Rückgang von essbaren Wildpflanzen direkte negative Auswirkungen auf den Nährstoffhaushalt lokaler Haushalte. In dieser Studie dokumentierten wir erstens die bevorzugten essbaren Wildpflanzen in Südost Burkina Faso, ihre wahrgenommene Abundanzveränderung und ihren Anteil am essbaren Wildpflanzen-Einkommen. Wir untersuchten zweitens die Substituierung dieser Arten in Zeiten von Artenknappheit und drittens den Einfluss von sozio-ökonomischen Variablen auf die Auswahl der Substitute. Mit 155 Haushaltsbefragungen in zwei Dörfern erhielten wir insgesamt 21 genutzte essbare Wildpflanzen. Mit einem Beitrag von rund 70% zum essbaren Wildpflanzen-Einkommen waren Vitellaria paradoxa und Parkia biglobosa ökonomisch die wichtigsten Arten. Alle Arten wurden als mehr oder weniger zurückgehend eingestuft. Die hohe Anzahl genannter Substitute für die zehn wichtigsten essbaren Wildpflanzen zeigt ein umfassendes Wissen bezüglich alternativer Wildpflanzen in dem Untersuchungsgebiet. Die Substitutauswahl ist für die Mehrheit der essbaren Wildpflanzen nicht abhängig von sozio-ökonomischen Merkmalen. Der heimische Baum Balanites aegyptiaca wurde für mehrere essbare Wildpflanzen als Substitut genannt und war damit die wichtigste Substitutart. Viele der bevorzugten essbaren Wildpflanzen wurden mit anderen bevorzugten essbaren Wildpflanzen substituiert. Der Rückgang einer Art kann somit zum Wegfall eines anderen Substitutes führen. Obwohl unsere Ergebnisse suggerieren, dass die Menschen dem Rückgang oder Fehlen von essbaren Wildpflanzen entgegenwirken können, würde ein zunehmender Rückgang einer Art gleichzeitig den Druck auf andere heimische Wildpflanzen erhöhen.Wild plant species are important nutritious supplements to otherwise nutrient poor diets of rural populations in West Africa. Consequently, a decline of wild food species has a direct negative impact on the nutritional status of local households. In this study, we firstly investigated the preferred wild food species in south-east Burkina Faso, their perceived change in abundance as well as their contribution to wild food income. Secondly, we studied how these species might be substituted in times of species shortfall. Thirdly, we investigated the impact of socio-economic variables on the substitution choice. We conducted 155 household interviews in two villages and found 21 wild food species. With a contribution of almost 70% to wild food income, Vitellaria paradoxa and Parkia biglobosa were economically most important. All species were considered declining to some degree. The wide range of cited substitutes for the ten most important wild food species indicates a great knowledge on alternative plant species in the area. For the majority, the substitution choice did not depend on socio-economic characteristics. Cited as surrogate for several important wild food species, the native tree Balanites aegyptiaca was the most important substitute species. Many valued wild food species were substituted with other highly valued wild food species and therefore the decline of one species can lead to a shortfall of another substitute. Thus, even though our results suggest that people are able to counteract the decrease or absence of wild food species, growing decline of one species would concurrently increase the pressure on other native food species.Des espèces de plantes sauvages constituent des compléments nutritionnels importants des régimes alimentaires pauvres en micronutriments des populations rurales en Afrique de l'Ouest. Par conséquent, le déclin des espèces alimentaires sauvages a un impact négatif direct sur la nutrition des ménages locaux. Dans cette étude, nous avons premièrement investigués les espèces alimentaires sauvages préférées dans le sud-est du Burkina Faso, leur changement perçu en abondance ainsi que leur contribution au revenu alimentaire sauvage. Deuxièmement, nous avons étudié comment ces espèces pourraient être substituées en période de pénurie des espèces. Troisièmement, nous avons examiné l'impact des variables socio-économiques sur le choix de substitution. En réalisant 155 interviews auprès des ménages dans deux villages, nous avons trouvé 21 espèces alimentaires sauvages. Avec une contribution d’environ 70% au revenu alimentaire sauvage, Vitellaria paradoxa et Parkia biglobosa sont économiquement les espèces les plus importantes. Toutes les espèces sont été considérées comme étant en déclin dans une certaine mesure. La vaste gamme de substituts cités pour les dix espèces les plus importantes indique une grande connaissance sur les espèces végétales alternatives dans la zone. Pour la plupart des plus importantes espèces alimentaires sauvages, le choix de substitution ne dépend pas des caractéristiques socio-économiques. Cité comme représentant pour plusieurs espèces importantes alimentaires sauvages, l’arbre local Balanites aegyptiaca est la plus importante espèce de substitut. De nombreuses espèces alimentaires sauvages évaluées sont substitués par d'autres espèces alimentaires sauvages à grande valeur et dont le déclin d'une espèce peut conduire à un déficit d'un autre substitut. Ainsi, même si nos résultats révèlent que les populations sont potentiellement capables de contrecarrer la diminution ou l'absence des espèces alimentaires sauvages, le déclin croissant d'une seule espèce pourraient simultanément augmenter la pression sur les autres espèces alimentaires locales

Development of behavioral patterns in young C57BL/6J mice: a home cage-based study

Evidence exists that behavioral patterns only stabilize once mice reach adulthood. Detailed information about the course of behavioral patterns is of particular relevance for neuroscientific research and for the assessment of cumulative severity in genetically modified mice. The analysis considered five age groups focusing on behavioral assessments in the animals’ familiar home cage environment during the adolescence phase. We confirmed age- and sex-specific differences for several of the behavioral parameters and fecal corticosterone metabolites. Interestingly, an age-dependent decline in saccharin preference was detected in female mice. Regardless of sex, relevant levels of burrowing activity were only observed during later developmental phases. The development of nest complexity following the offer of new material was affected by age in female mice. In female and male mice, an age-dependency was evident for wheel running reaching a peak at P 50. A progressive increase with age was also observed for Open field activity. The data sets provide guidance for behavioral studies and for development of composite measure schemes for evidence-based severity assessment in young mice. Except for the burrowing test, the different behavioral tests can be applied in different age groups during post-weaning development. However, age- and sex-specific characteristics need to be considered

TU-Spektrum 3/2010, Magazin der Technischen Universität Chemnitz

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