| 1. |
- Householder, John Ethan, et al.
(författare)
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One sixth of Amazonian tree diversity is dependent on river floodplains
- 2024
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Ingår i: NATURE ECOLOGY & EVOLUTION. - 2397-334X.
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Tidskriftsartikel (refereegranskat)abstract
- Amazonia's floodplain system is the largest and most biodiverse on Earth. Although forests are crucial to the ecological integrity of floodplains, our understanding of their species composition and how this may differ from surrounding forest types is still far too limited, particularly as changing inundation regimes begin to reshape floodplain tree communities and the critical ecosystem functions they underpin. Here we address this gap by taking a spatially explicit look at Amazonia-wide patterns of tree-species turnover and ecological specialization of the region's floodplain forests. We show that the majority of Amazonian tree species can inhabit floodplains, and about a sixth of Amazonian tree diversity is ecologically specialized on floodplains. The degree of specialization in floodplain communities is driven by regional flood patterns, with the most compositionally differentiated floodplain forests located centrally within the fluvial network and contingent on the most extraordinary flood magnitudes regionally. Our results provide a spatially explicit view of ecological specialization of floodplain forest communities and expose the need for whole-basin hydrological integrity to protect the Amazon's tree diversity and its function.
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| 2. |
- Luize, Bruno Garcia, et al.
(författare)
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Geography and ecology shape the phylogenetic composition of Amazonian tree communities
- 2024
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Ingår i: JOURNAL OF BIOGEOGRAPHY. - 0305-0270 .- 1365-2699.
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Tidskriftsartikel (refereegranskat)abstract
- 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's 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 v & aacute;rzea forest types, the phylogenetic composition varies by geographic region, but the igap & oacute; 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 (R-2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R-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.
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| 3. |
- ter Steege, Hans, et al.
(författare)
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Mapping density, diversity and species-richness of the Amazon tree flora
- 2023
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Ingår i: COMMUNICATIONS BIOLOGY. - 2399-3642. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- 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. A study mapping the tree species richness in Amazonian forests shows that soil type exerts a strong effect on species richness, probably caused by the areas of these forest types. Cumulative water deficit, tree density and temperature seasonality affect species richness at a regional scale.
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| 4. |
- Peripato, Vinicius, et al.
(författare)
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More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia
- 2023
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Ingår i: Science (New York, N.Y.). - 1095-9203. ; 382:6666, s. 103-109
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Tidskriftsartikel (refereegranskat)abstract
- Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state.
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| 5. |
- Posthouwer, Chantal, et al.
(författare)
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Quantitative market survey of non-woody plants sold at Kariakoo Market in Dar es Salaam, Tanzania
- 2018
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Ingår i: Journal of Ethnopharmacology. - : Elsevier BV. - 0378-8741 .- 1872-7573. ; 222, s. 280-287
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Tidskriftsartikel (refereegranskat)abstract
- Ethnopharmacological relevance: In Tanzania, traditional medicine plays a significant role in health care and local economies based on the harvesting, trade and sale of medicinal plant products. The majority of this plant ma- terial is said to originate from wild sources, and both traditional healers and vendors are concerned about the increasing scarcity of certain species.Aim of the study: A market survey of non-powdered, non-woody medicinal plants was conducted at Kariakoo Market in Dar es Salaam, the major hub for medicinal plant trade in Tanzania, to assess sustainability of traded herbal medicine. Materials and Methods: For this study, fresh and dried herbs, seeds and fruits were collected and interviews were conducted to obtain information on vernacular names, preparation methods, monthly sales, uses and prices. Bundles of herbal medicine offered for sale were weighed and counted to calculate the value and volumes of daily stock at the market.Results: A total of 71 medicinal plant products belonging to 62–67 different species from at least 41 different plant families were identified. We identified 45 plant products to species level, 20 products to genus level and four to family level. Plant species most encountered at the market were Suregada zanzibariensis, Myrothamnus flabellifolia and Sclerocarya birrea. The major use categories reported by the vendors were ritual purposes, di- gestive disorders and women's health. Annual sales are estimated to be in excess of 30 t and close to 200,000 USD, and trade in herbal medicine at Kariakoo Market provides subsistence income to many local vendors. Conclusions: A large diversity of wild-harvested plant species is traded as medicinal products in Tanzania, in- cluding species listed on CITES Appendices. Identifying and monitoring temporal changes in availability per season and from year to year will reveal which species are most affected by this trade, and help relevant au- thorities in Tanzania to find alternative sources of income for dependent stakeholders and initiate targeted efforts to protect threatened plant species.
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| 6. |
- Veldman, Sarina, et al.
(författare)
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A quantitative market survey of medicinal plants used in Dar-es-Salaam and Tanga.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Tanzania has a thriving medicinal plant trade, which is solely based on the harvest of wild plant resources. Many of the plants are dried or powdered and often lack sufficient morphological characters for species-level identification. It is thus unclear which species exactly are traded and in what amounts. This study provides an overview of species traded in the main Tanzanian coastal trade hubs Dar-es-Salaam and Tanga, quantifies the annual sales volumes of these plants and gives an overview of the possible conservation issues arising from the wild-harvest of Tanzanian medicinal plants. Based on the interview data from 46 questionnaires an overview was compiled of the plants most frequently mentioned by the market vendors as well as a list with plants that were considered to become more difficult to obtain. A total of >850 single ingredient samples was collected. The main health categories for which these plants are reported to be used are women’s health, ritual purposes and respiratory problems. In addition to vouchers from the plants sold on the market, reference herbarium vouchers were made in the field together with a medicinal plant collector for the twenty most frequently mentioned plants. Results from the field indicate that there are high harvesting pressures on some of the most commonly traded medicinal plant species. The top five plants that are considered to be becoming scarcer are Zanha africana (Radlk.) Exell. (Sapindaceae), Zanthoxylum chalybeum Engl. (Rubiaceae), Warburgia elongata Verdc. (Canellaceae), Allophylus rubifolius (Hochst. ex A.Rich.) Engl. (Sapindaceae) and Cassia abbreviata Oliv. (Leguminosae). Alarmingly, four out of these five plants also figure in the list of most frequently mentioned plants and several vendors indicate they each sell up to 200kg of these species per month. Warburgia elongata is included on the global Red List as endangered, as well as several Zanthoxylum species. From these plants the bark, roots and branches are used for medicine, parts which are often harvested unsustainably. In order to conserve local medicinal plant populations and ensure a sustainable herbal medicine supply, it is essential to look at sustainable harvesting strategies as well as cultivation possibilities in collaboration with the harvesters, middlemen and vendors.
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| 7. |
- Veldman, Sarina, et al.
(författare)
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DNA barcoding augments conventional methods for identification of medicinal plant species traded at Tanzanian markets
- 2020
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Ingår i: Journal of Ethnopharmacology. - : ELSEVIER IRELAND LTD. - 0378-8741 .- 1872-7573. ; 250
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Tidskriftsartikel (refereegranskat)abstract
- Ethnopharmalogical relevance: In Africa, traditional medicine is important for local healthcare and plants used for these purposes are commonly traded. Identifying medicinal plants sold on markets is challenging, as leaves, barks and roots are often fragmented or powdered. Vernacular names are often homonymic, and identification of material lacking sufficient morphological characters is time-consuming, season-dependent and might lead to incorrect assessments of commercialised species diversity.Aim of the study: In this study, we identified cases of vernacular heterogeneity of medicinal plants using a tiered approach of literature research, morphology and DNA barcoding.Material and methods: A total of 870 single ingredient medicinal plant samples corresponding to 452 local names were purchased from herbal markets in Dar-es-Salaam and Tanga, Tanzania, and identified using conventional methods as well as DNA barcoding using rbcL, matK and nrITS.Results: Using conventional methods, we could identify 70% of samples to at least family level, while 62% yielded a DNA barcode for at least one of the three markers. Combining conventional methods and DNA barcoding, 76% of the samples could be identified to species level, revealing a diversity of at least 175 species in 65 plant families. Analysis of the market samples revealed 80 cases of multilingualism and over- and under-differentiation. Afzelia quanzensis Welw., Zanthoxylum spp., Allophylus spp. and Albizia anthelmintica Brongn. were the most evident cases of multilingualism and over-differentiation, as they were traded under 8-12 vernacular names in up to five local languages. The most obvious case of under-differentiation was mwingajini (Swahili), which matched to eight scientific species in five different plant families.Conclusions: Use of a tiered approach increases the identification success of medicinal plants sold in local market and corroborates findings that DNA barcoding can elucidate the identity of material that is unidentifiable based on morphology and literature as well as verify or disqualify these identifications. Results of this study can be used as a basis for quantitative market surveys of fragmented herbal medicine and to investigate conservation issues associated with this trade.
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| 8. |
- Veldman, Sarina, et al.
(författare)
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High-throughput sequencing of African chikanda cake highlights conservation challenges in orchids
- 2017
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Ingår i: Biodiversity and Conservation. - : Springer Science and Business Media LLC. - 0960-3115 .- 1572-9710. ; 26:9, s. 2029-2046
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Tidskriftsartikel (refereegranskat)abstract
- Chikanda is a traditional dish made with wild-harvested ground orchid tubers belonging to three orchidioid genera, Disa, Satyrium and Habenaria, all of which are CITES appendix II-listed. Identification of collected orchid tubers is very difficult and documentation of constituent species in prepared chikanda has hitherto been impossible. Here amplicon metabarcoding was used in samples of six prepared chikanda cakes to study genetic sequence diversity and species diversity in this product. Molecular operational taxonomic unit identification using similarity-matching reveals that species of all three genera were present in the chikanda samples studied. Disa was present in all of the samples, Satyrium in five out of six and Habenaria in one of the samples, as well as a number of other plants. The fact that each sample contained orchids and the presence of a wide variety of species from all genera in this traditional dish raise serious concerns about the sustainability of this trade and the future of wild orchid populations in the main harvest areas. This proof-of-concept study shows that Ion-Torrent PGM is a cost-effective scalable platform for metabarcoding using the relatively long nrITS1 and nrITS2 regions. Furthermore, nrITS metabarcoding can be successfully used for the detection of specific ingredients in a highly-processed food product at genus level, and this makes it a useful tool in the detection of possible conservation issues arising from commercialized trade or processed plant products.
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| 9. |
- Veldman, Sarina
(författare)
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Markets, mixtures and molecular methods : Investigating medicinal plant and edible orchid diversity in Tanzania and Zambia
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Medicinal plants are an important source of primary healthcare for many people in Tanzania. These medicinal plants are harvested from the wild, and increasing commercial trade poses a serious threat to local plant populations. Currently it is unknown which species are traded and in what amounts. Across the southwestern border in Zambia, the traditional dish chikanda has transformed from a niche product to being a mainstream delicacy. One of the main ingredients are wild-harvested orchids, and these have become depleted throughout the country as an effect of the increased trade. It is unclear which orchid species are targeted and might be at risk of overharvesting. The aims of my doctorate are to map harvest and trade of Tanzanian medicinal plants and Tanzanian and Zambian edible orchids, to investigate whether species that are traded on local markets can be identified using molecular methods such as DNA barcoding and metabarcoding and identify conservation issues arising from wild-harvesting of medicinal plants and edible orchids.In Paper I DNA metabarcoding analysis of Tanzanian chikanda cake show the presence of 17 different orchids species belonging to the genera Disa, Satyrium and Habenaria, and in Paper V the analysis of chikanda tubers sold on Zambian markets reveals that at least 16 orchid species from 6 different orchid genera are targeted in local orchid trade. Paper II describes a quantitative market survey of the non-woody, non-powdered medicinal plants sold on Kariakoo market in Dar-es-Salaam that shows that a total of 67 species are traded in an annual volume of nearly 31 tonnes of fresh and dried medicinal leaves, seeds and fruits with an estimated value of 200,000 USD. For Paper III 873 medicinal plant products were analysed using DNA barcoding, literature and morphology to determine which species are traded on the Dar-es-Salaam and Tanga markets. In total, 509 identifications could be made corresponding to 91 species, 124 genera and 65 plant families, and several cases of over- and under-differentiation were detected. Paper IV builds upon the identifications in Paper III to determine in what amount the medicinal plant species present at the local markets are traded and to investigate if commercial trade poses a threat to local plant populations. It was found that several of the most highly favored medicinal plants were perceived to becoming more difficult to obtain in the wild.This thesis shows that DNA barcoding is a powerful rapid identification method for morphologically unidentifiable specimens. It also shows that commercialization of wild-harvested plant products threatens local plant populations, and highlights the need for conservation measures to avoid local extinction of economically and socially important plant species.
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| 10. |
- Veldman, Sarina, et al.
(författare)
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Trade in Zambian Edible Orchids-DNA Barcoding Reveals the Use of Unexpected Orchid Taxa for Chikanda
- 2018
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Ingår i: Genes. - : MDPI AG. - 2073-4425 .- 2073-4425. ; 9:12
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Tidskriftsartikel (refereegranskat)abstract
- In Zambia, wild edible terrestrial orchids are used to produce a local delicacy called chikanda, which has become increasingly popular throughout the country. Commercialization puts orchid populations in Zambia and neighbouring countries at risk of overharvesting. Hitherto, no study has documented which orchid species are traded on local markets, as orchid tubers are difficult to identify morphologically. In this study, the core land-plant DNA barcoding markers rbcL and matK were used in combination with nrITS to determine which species were sold in Zambian markets. Eighty-two interviews were conducted to determine harvesting areas, as well as possible sustainability concerns. By using nrITS DNA barcoding, a total of 16 orchid species in six different genera could be identified. Both rbcL and matK proved suitable to identify the tubers up to the genus or family level. Disa robusta, Platycoryne crocea and Satyrium buchananii were identified most frequently and three previously undocumented species were encountered on the market. Few orchid species are currently listed on the global International Union for the Conservation of Nature (IUCN) Red List. Local orchid populations and endemic species could be at risk of overharvesting due to the intensive and indiscriminate harvesting of chikanda orchids, and we therefore encourage increased conservation assessment of terrestrial African orchids.
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