89 research outputs found

    Ritual uses of palms in traditional medicine in sub-Saharan Africa: a review

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    African Rice (Oryza glaberrima Steud.): Lost Crop of the Enslaved Africans Discovered in Suriname1

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    African Rice (Oryza glaberrimaSteud.): Lost Crop of the Enslaved Africans Discovered in Suriname. African rice (Oryza glaberrima Steud.) was introduced to the Americas during the slave trade years and grown by enslaved Africans for decades before mechanical milling devices facilitated the shift towards Asian rice (O. sativa L.). Literature suggests that African rice is still grown in Guyana and French Guiana, but the most recent herbarium voucher dates from 1938. In this paper, evidence is presented that O. glaberrima is still grown by Saramaccan Maroons both for food and ritual uses. Saramaccan informants claim their forefathers collected their first “black rice” from a mysterious wild rice swamp and cultivated these seeds afterwards. Unmilled spikelets (grains with their husk still attached) are sold in small quantities for ancestor offerings, and even exported to the Netherlands to be used by Maroon immigrants. Little is known of the evolution of O. glaberrima, before and after domestication. Therefore, more research is needed on the different varieties of rice and other “lost crops” grown by these descendants of enslaved Africans who escaped from plantations in the 17th and 18th centuries and maintained much of their African cultural heritage in the deep rainforest

    Famine food of vegetal origin consumed in the Netherlands during World War II

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    Background: Periods of extreme food shortages during war force people to eat food that they normally do not consider edible. The last time that countries in Western Europe experienced severe scarcities was during World War II. The so-called Dutch famine or Hunger Winter (1944-1945) made at least 25,000 victims. The Dutch government took action by opening soup kitchens and providing information on wild plants and other famine food sources in "wartime cookbooks." The Dutch wartime diet has never been examined from an ethnobotanical perspective. Methods: We interviewed 78 elderly Dutch citizens to verify what they remembered of the consumption of vegetal and fungal famine food during World War II by them and their close surroundings. We asked whether they experienced any adverse effects from consuming famine food plants and how they knew they were edible. We identified plant species mentioned during interviews by their local Dutch names and illustrated field guides and floras. We hypothesized that people living in rural areas consumed more wild species than urban people. A Welch t test was performed to verify whether the number of wild and cultivated species differed between urban and rural citizens. Results: A total number of 38 emergency food species (14 cultivated and 21 wild plants, three wild fungi) were mentioned during interviews. Sugar beets, tulip bulbs, and potato peels were most frequently consumed. Regularly eaten wild species were common nettle, blackberry, and beechnuts. Almost one third of our interviewees explicitly described to have experienced extreme hunger during the war. People from rural areas listed significantly more wild species than urban people. The number of cultivated species consumed by both groups was similar. Negative effects were limited to sore throats and stomachache from the consumption of sugar beets and tulip bulbs. Knowledge on the edibility of famine food was obtained largely by oral transmission; few people remembered the written recipes in wartime cookbooks. Conclusion: This research shows that 71years after the Second World War, knowledge on famine food species, once crucial for people's survival, is still present in the Dutch society. The information on famine food sources supplied by several institutions was not distributed widely. For the necessary revival of famine food knowledge during the 1940s, people needed to consult a small group of elders. Presumed toxicity was a major reason given by our participants to explain why they did not collect wild plants or mushrooms during the war

    Estimating the global conservation status of more than 15,000 Amazonian tree species

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    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century

    Estimating the global conservation status of more than 15,000 Amazonian tree species

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    Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

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    Aim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

    Geography and ecology shape the phylogenetic composition of Amazonian tree communities

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    Aim: Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location: Amazonia. Taxon: Angiosperms (Magnoliids; Monocots; Eudicots). Methods: Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran\u27s eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results: In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2^{2} = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2^{2} = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion: Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions

    Mapping density, diversity and species-richness of the Amazon tree flora

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    Using 2.046 botanically-inventoried tree plots across the largest tropical forest on Earth, we mapped tree species-diversity and tree species-richness at 0.1-degree resolution, and investigated drivers for diversity and richness. Using only location, stratified by forest type, as predictor, our spatial model, to the best of our knowledge, provides the most accurate map of tree diversity in Amazonia to date, explaining approximately 70% of the tree diversity and species-richness. Large soil-forest combinations determine a significant percentage of the variation in tree species-richness and tree alpha-diversity in Amazonian forest-plots. We suggest that the size and fragmentation of these systems drive their large-scale diversity patterns and hence local diversity. A model not using location but cumulative water deficit, tree density, and temperature seasonality explains 47% of the tree species-richness in the terra-firme forest in Amazonia. Over large areas across Amazonia, residuals of this relationship are small and poorly spatially structured, suggesting that much of the residual variation may be local. The Guyana Shield area has consistently negative residuals, showing that this area has lower tree species-richness than expected by our models. We provide extensive plot meta-data, including tree density, tree alpha-diversity and tree species-richness results and gridded maps at 0.1-degree resolution
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