Different profiles of soil phosphorous compounds depending on tree species and availability of soil phosphorus in a tropical rainforest in French Guiana.

BACKGROUND: The availability of soil phosphorus (P) often limits the productivities of wet tropical lowland forests. Little is known, however, about the metabolomic profile of different chemical P compounds with potentially different uses and about the cycling of P and their variability across space under different tree species in highly diverse tropical rainforests. RESULTS: We hypothesised that the different strategies of the competing tree species to retranslocate, mineralise, mobilise, and take up P from the soil would promote distinct soil 31P profiles. We tested this hypothesis by performing a metabolomic analysis of the soils in two rainforests in French Guiana using 31P nuclear magnetic resonance (NMR). We analysed 31P NMR chemical shifts in soil solutions of model P compounds, including inorganic phosphates, orthophosphate mono- and diesters, phosphonates, and organic polyphosphates. The identity of the tree species (growing above the soil samples) explained > 53% of the total variance of the 31P NMR metabolomic profiles of the soils, suggesting species-specific ecological niches and/or species-specific interactions with the soil microbiome and soil trophic web structure and functionality determining the use and production of P compounds. Differences at regional and topographic levels also explained some part of the the total variance of the 31P NMR profiles, although less than the influence of the tree species. Multivariate analyses of soil 31P NMR metabolomics data indicated higher soil concentrations of P biomolecules involved in the active use of P (nucleic acids and molecules involved with energy and anabolism) in soils with lower concentrations of total soil P and higher concentrations of P-storing biomolecules in soils with higher concentrations of total P. CONCLUSIONS: The results strongly suggest "niches" of soil P profiles associated with physical gradients, mostly topographic position, and with the specific distribution of species along this gradient, which is associated with species-specific strategies of soil P mineralisation, mobilisation, use, and uptake.

A Late Pleistocene coastal ecosystem in French Guiana was hyperdiverse relative to today.

Warmer temperatures and higher sea level than today characterized the Last Interglacial interval [Pleistocene, 128 to 116 thousand years ago (ka)]. This period is a remarkable deep-time analog for temperature and sea-level conditions as projected for 2100 AD, yet there has been no evidence of fossil assemblages in the equatorial Atlantic. Here, we report foraminifer, metazoan (mollusks, bony fish, bryozoans, decapods, and sharks among others), and plant communities of coastal tropical marine and mangrove affinities, dating precisely from a ca. 130 to 115 ka time interval near the Equator, at Kourou, in French Guiana. These communities include ca. 230 recent species, some being endangered today and/or first recorded as fossils. The hyperdiverse Kourou mollusk assemblage suggests stronger affinities between Guianese and Caribbean coastal waters by the Last Interglacial than today, questioning the structuring role of the Amazon Plume on tropical Western Atlantic communities at the time. Grassland-dominated pollen, phytoliths, and charcoals from younger deposits in the same sections attest to a marine retreat and dryer conditions during the onset of the last glacial (ca. 110 to 50 ka), with a savanna-dominated landscape and episodes of fire. Charcoals from the last millennia suggest human presence in a mosaic of modern-like continental habitats. Our results provide key information about the ecology and biogeography of pristine Pleistocene tropical coastal ecosystems, especially relevant regarding the-widely anthropogenic-ongoing global warming.

Adaptive ecological knowledge among the Ndjuka Maroons of French Guiana; a case study of two 'invasive species': Melaleuca quinquenervia and Acacia mangium.

BACKGROUND: To understand how local ecological knowledge changes and adapts, here in the case of the recent introduction of plant species, we report the knowledge and perceptions of the Ndjuka (Maroon) of French Guiana concerning two tree species, Acacia mangium and niaouli (Melaleuca quinquenervia), which are categorized as "invasive alien plants" in the savannas of their territory. METHODS: To this end, semi-structured interviews were conducted between April and July 2022, using a pre-designed questionnaire, plant samples and photographs. The uses, local ecological knowledge, and representations of these species were surveyed among populations of Maroon origin in western French Guiana. All responses to closed questions collected during the field survey were compiled into an Excel spreadsheet in order to perform quantitative analyses, including the calculation of use reports (URs). RESULTS: It appears that the local populations have integrated these two plant species, which are named, used and even traded, into their knowledge systems. On the other hand, neither foreignness nor invasiveness seem to be relevant concepts in the perspective of the informants. The usefulness of these plants is the determining factor of their integration into the Ndjuka medicinal flora, thus resulting in the adaptation of their local ecological knowledge. CONCLUSION: In addition to highlighting the need for the integration of the discourse of local stakeholders into the management of "invasive alien species," this study also allows us to observe the forms of adaptation that are set in motion by the arrival of a new species, particularly within populations that are themselves the result of recent migrations. Our results furthermore indicate that such adaptations of local ecological knowledge can occur very quickly.

A severe case of Plasmodium falciparum malaria imported by a French traveler from Cameroon to French Guiana despite regular intake of Artemisia annua herbal tea.

The use of herbal tea with Artemisia annua by travelers and traditional communities in Africa has increased in recent years as a supposed form of malaria prophylaxis, although its use is not recommended due to lack of efficacy. The risk of severe malaria complications that can lead to death is real regarding said behavior, and awareness needs to be raised. We report a case of severe Plasmodium falciparum malaria imported in the Amazon rainforest by a traveler returning from Cameroon who treated himself with Artemisia annua herbal tea.

Health professionals and Amerindian patients: representations and practices in French Guiana / Professionnels de santé et patients amérindiens : représentations et pratiques en Guyane française

CONTEXT: In French Guiana, Amerindian populations find themselves in a health system whose therapeutic itinerary revolves around their traditional medicine and modern medicine provided by health professionals mostly from hexagonal France. The latter intervene in a “complexity of intercultural contact” which influences the caregiver-patient relationship and affects therapeutic adherence. METHOD: To better understand the practices and representations of the health system in an intercultural context, qualitative research was carried out in the field between 2018 and 2019 with seventeen health professionals working in health centers located in the municipalities of the Interior of French Guiana. Semi-structured individual interviews were conducted in order to explore the representations, the difficulties encountered, and the tools used by these caregivers in their daily practice. These interviews were crossed with participant observations and bibliographical research in the medical and anthropological fields. RESULTS: The caregiver-patient encounter was asymmetrical, unequal and was part of a power relationship. The caregivers remained marked by ethnocentric representations -inherent to each culture- far removed from those of the populations and this divergence impacted the practice. DISCUSSION: It would be advisable to shift the focus in order to « penetrate » the frame of reference of the Other and rebalance relationships. The exploration of popular knowledge and skills and the application of proven teaching methods would encourage therapeutic adherence. « Homethnic workers » and intercultural training could help promote community health.

Contexte: En Guyane française, les populations amérindiennes se retrouvent dans un système de santé dont l'itinéraire thérapeutique s'articule autour de leur médecine traditionnelle et d'une médecine moderne prodiguée par des professionnels de santé originaires, pour la plupart, de la France hexagonale. Ces derniers interviennent dans une « complexité de contact interculturel ¼ qui influence la relation soignant soigné et affecte l'adhésion thérapeutique. Méthode: Pour mieux comprendre les représentations et pratiques du système de santé en contexte interculturel, une recherche qualitative a été menée sur le terrain, en 2018 et 2019, auprès de dix-sept professionnels de santé exerçant dans les centres de santé situés dans les communes de l'Intérieur de la Guyane. Des entretiens individuels semi-structurés ont été menés afin d'explorer les représentations, les difficultés rencontrées et les outils mobilisés par ces soignants dans leur pratique courante. Ces entretiens ont été croisés avec des observations participantes et des recherches bibliographiques dans les champs médicaux et anthropologiques. Résultats: La rencontre soignant soigné était asymétrique, inégale et s'inscrivait dans un rapport de pouvoir. Les soignants restaient marqués de représentations ethnocentriques - inhérentes à chaque culture - éloignées de celles des populations amérindiennes, et cette divergence impactait la pratique. Discussion: Il conviendrait de se décentrer, pour « pénétrer ¼ dans le cadre de référence de l'Autre et rééquilibrer les rapports. L'exploration des savoirs et savoir-faire populaires et l'application de méthodes éprouvées d'enseignement encourageraient l'adhésion thérapeutique. Les « intervenants homethniques ¼ et une formation à l'interculturalité pourraient favoriser la promotion de la santé communautaire.

In a life full of risks, COVID-19 makes little difference. Responses to COVID-19 among mobile migrants in gold mining areas in Suriname and French Guiana.

Worldwide, the socioeconomic impacts of COVID-19 disproportionally affect vulnerable groups in society. This paper assesses responses to, and impacts of, the pandemic among mobile migrant populations who work in Artisanal and Small-scale Gold Mining (ASGM) in Suriname and French Guiana. These populations are characterized by poverty, informal or illegal status, and limited access to health care and information. Field research in Suriname (November 2020-January 2021) and French Guiana (January, May, June 2021) included qualitative interviews, informal conversations and observations, and a quantitative survey with 361 men and women in ASGM communities. Contrary to reports from the ASGM sector elsewhere, interviewed inhabitants of ASGM areas in Suriname and French Guiana showed little concern about COVID-19. Respondents reported feeling safer in the forest where they work than in the urban areas or in their home country. Trust in home remedies and over-the-counter pharmaceuticals further reduced anxiety about the pandemic. Three-quarters of survey respondents reported that the COVID-19 pandemic had not affected their work or income at all. The researchers conclude that in these remote Amazon communities, responses to COVID-19 mirror attitudes and behavior vis-à-vis malaria and other health risks: self-medicate, ignore, and pray. Living on the margins of society mitigates the socioeconomic impacts of COVID-19, as containment measures are not applied to these socially invisible populations. Whereas the urban poor are severely hit by the pandemic, this hidden population benefits from high gold prices, an outdoors lifestyle, and traditional resourcefulness in dealing with a life full of risks.

Vitamin D Deficiency in Patients with Diabetes in French Guiana: Epidemiology and Relation with Microvascular and Macrovascular Complications.

Vitamin D (VD) insufficiency is common among patients with diabetes in French Guiana. The study aimed to evaluate the prevalence of VD deficiency in the different type of diabetes encountered and to analyze the relationship between VD deficiency and diabetes complications. METHODS: An observational study was conducted between May 2019 and May 2020 in French Guiana, based on data from the CODIAM study (Diabetes Cohort in French Amazonia), describing the characteristics of patients with diabetes mellitus. Among 600 patients enrolled with diabetes, 361 had an available VD assay. RESULTS: The mean 25(OH)VD (hydroxycalciferol) level was 27.9 ng/mL. The level of VD was inversely proportional to the HbA1c (glycated hemoglobin) level. Patients with angina pectoris had a greater proportion of deficiencies VD < 20 ng/mL than those without angina. By contrast, patients with retinopathy had higher vitamin D concentrations than those without retinopathy. There was no association between vitamin D and arteriopathy, stroke, nephropathy and polyneuropathy. VD deficiency was more frequent in women, and in patients with a high school education. CONCLUSION: The prevalence of VD deficiency was high in patients with diabetes in French Guiana, emphasizing the importance of VD supplementation.

When local phytotherapies meet biomedicine. Cross-sectional study of knowledge and intercultural practices against malaria in Eastern French Guiana.

ETHNOPHARMACOLOGICAL RELEVANCE: In French Guiana, traditional phytotherapies are an important part of self-healthcare, however, a precise understanding of the interactions between local phytotherapies and biomedicine is lacking. Malaria is still endemic in the transition area between French Guiana and Brazil, and practices of self-treatment, although difficult to detect, have possible consequences on the outcome of public health policies. AIM OF THE STUDY: The objectives of this research were 1) to document occurences of co-medication (interactions between biomedicine and local phytotherapies) against malaria around Saint-Georges de l'Oyapock (SGO), 2) to quantify and to qualify plant uses against malaria, 3) and to discuss potential effects of such co-medications, in order to improve synergy between community efforts and public health programs in SGO particularly, and in Amazonia more broadly. MATERIALS AND METHODS: This cross-sectional study was conducted in 2017 in SGO. Inhabitants of any age and nationality were interviewed using a questionnaire (122 questions) about their knowledge and habits regarding malaria, and their use of plants to prevent and treat it. They were invited to show their potential responses on a poster illustrating the most common antimalarial plants used in the area. In order to correlate plant uses and malaria epidemiology, all participants subsequently received a medical examination, and malaria detection was performed by Rapid Diagnostic Test (RDT) and Polymerase Chain Reaction (PCR). RESULTS: A total of 1566 inhabitants were included in the study. Forty-six percent of them declared that they had been infected by malaria at least once, and this rate increased with age. Every person who reported that they had had malaria also indicated that they had taken antimalarial drugs (at least for the last episode), and self-medication against malaria with pharmaceuticals was reported in 142 cases. A total of 550 plant users was recorded (35.1% of the interviewed population). Among them 95.5% associated pharmaceuticals to plants. All plants reported to treat malaria were shared by every cultural group around SGO, but three plants were primarily used by the Palikur: Cymbopogon citratus, Citrus aurantifolia and Siparuna guianensis. Two plants stand out among those used by Creoles: Eryngium foetidum and Quassia amara, although the latter is used by all groups and is by far the most cited plant by every cultural group. Cultivated species accounts for 91.3% of the use reports, while wild taxa account for only 18.4%. CONCLUSIONS: This study showed that residents of SGO in French Guiana are relying on both traditional phytotherapies and pharmaceutical drugs to treat malaria. This medical pluralism is to be understood as a form of pragmatism: people are collecting or cultivating plants for medicinal purposes, which is probably more congruent with their respective cultures and highlights the wish for a certain independence of the care process. A better consideration of these practices is thus necessary to improve public health response to malaria.

Hg concentrations and stable isotope variations in tropical fish species of a gold-mining-impacted watershed in French Guiana.

The aim of the study was to determine if gold-mining activities could impact the mercury (Hg) concentrations and isotopic signatures in freshwater fish consumed by riparian people in French Guiana. Total Hg, MeHg concentrations, and Hg stable isotopes ratios were analyzed in fish muscles from different species belonging to three feeding patterns (herbivorous, periphytophagous, and piscivorous). We compared tributaries impacted by gold-mining activities (Camopi, CR) with a pristine area upstream (Trois-Sauts, TS), along the Oyapock River. We measured δ15N and δ 13C to examine whether Hg patterns are due to differences in trophic level. Differences in δ 15N and δ 13C values between both studied sites were only observed for periphytophagous fish, due to difference of CN baselines, with enriched values at TS. Total Hg concentrations and Hg stable isotope signatures showed that Hg accumulated in fish from both areas has undergone different biogeochemical processes. Δ199Hg variation in fish (-0.5 to 0.2‰) was higher than the ecosystem baseline defined by a Δ199Hg of -0.66‰ in sediments, and suggested limited aqueous photochemical MeHg degradation. Photochemistry-corrected δ202Hg in fish was 0.7‰ higher than the baseline, consistent with biophysical and chemical isotope fractionation in the aquatic environment. While THg concentrations in periphytophagous fish were higher in the gold-mining area, disturbed by inputs of suspended particles, than in TS, the ensemble of Hg isotope shifts in fish is affected by the difference of biotic (methylation/demethylation) and abiotic (photochemistry) processes between both areas and did therefore not allow to resolve the contribution of gold-mining-related liquid Hg(0) in fish tissues. Mercury isotopes of MeHg in fish and lower trophic level organisms can be complementary to light stable isotope tracers.

Geopolitics of bitterness: Deciphering the history and cultural biogeography of Quassia amara L.

ETHNOPHARMACOLOGICAL RELEVANCE: Quassia amara L. recently came into the spotlight in French Guiana, when it became the object of a biopiracy claim. Due to the numerous use records throughout the Guiana shield, at least since the 18th century, a thorough investigation of its origin seemed relevant and timely. In the light of the Convention on Biological Diversity (CBD) and the Nagoya protocol, questions about the origin of local knowledge are important to debate. AIM OF THE STUDY: Defining cultural biogeography as the dynamics through space and time of biocultural complexes, we used this theoretical framework to shed light on the complex biogeographical and cultural history of Q. amara. We explored in particular the possible transfer of medicinal knowledge on an Old World species to a botanically related New World one by enslaved Africans in Suriname. MATERIALS AND METHODS: Historical and contemporary literature research was performed by means of digitized manuscripts, archives and databases from the 17th to the 21st century. We retrieved data from digitized herbarium vouchers in herbaria of the Botanic Garden Meise (Belgium); Naturalis Biodiversity Center (the Netherlands); Missouri Botanical Garden, the Smithsonian National Museum of Natural History, the Field Museum (USA); Royal Botanic Gardens Kew (UK); the IRD Herbarium, French Guiana and the Museum National d'Histoire Naturelle (France). Vernacular names were retrieved from literature and herbarium specimens and compared to verify the origin of Quassia amara and its uses. RESULTS: Our exploration of digitized herbarium vouchers resulted in 1287 records, of which 661 were Q. amara and 636 were Q. africana. We observed that the destiny of this species, over at least 300 years, interweaves politics, economy, culture and medicine in a very complex way. Quassia amara's uses are difficult to attribute to specific cultural groups: the species is widely distributed in Central and South America, where it is popular among many ethnic groups. The species spread from Central to South America during the early 18th century due to political and economic reasons. This migration possibly resulted from simultaneous migration by religious orders (Jesuits) from Central America to northern South America and by Carib-speaking Amerindians (from northern South America to Suriname). Subsequently, through colonial trade networks, Q. amara spread to the rest of the world. The absence of African-derived local names in the Guiana shield suggests that Q. africana was not sufficiently familiar to enslaved Africans in the region that they preserved its names and transferred the associated medicinal knowledge to Q. amara. CONCLUSIONS: Cultural biogeography has proven an interesting concept to reconstruct the dynamics of biocultural interactions through space and time, while herbarium databases have shown to be useful to decipher evolution of local plant knowledge. Tracing the origin of a knowledge is nevertheless a complex adventure that deserves time and interdisciplinary studies.

31P-NMR Metabolomics Revealed Species-Specific Use of Phosphorous in Trees of a French Guiana Rainforest.

Productivity of tropical lowland moist forests is often limited by availability and functional allocation of phosphorus (P) that drives competition among tree species and becomes a key factor in determining forestall community diversity. We used non-target 31P-NMR metabolic profiling to study the foliar P-metabolism of trees of a French Guiana rainforest. The objective was to test the hypotheses that P-use is species-specific, and that species diversity relates to species P-use and concentrations of P-containing compounds, including inorganic phosphates, orthophosphate monoesters and diesters, phosphonates and organic polyphosphates. We found that tree species explained the 59% of variance in 31P-NMR metabolite profiling of leaves. A principal component analysis showed that tree species were separated along PC 1 and PC 2 of detected P-containing compounds, which represented a continuum going from high concentrations of metabolites related to non-active P and P-storage, low total P concentrations and high N:P ratios, to high concentrations of P-containing metabolites related to energy and anabolic metabolism, high total P concentrations and low N:P ratios. These results highlight the species-specific use of P and the existence of species-specific P-use niches that are driven by the distinct species-specific position in a continuum in the P-allocation from P-storage compounds to P-containing molecules related to energy and anabolic metabolism.

Phytotherapies in motion: French Guiana as a case study for cross-cultural ethnobotanical hybridization.

BACKGROUND: French Guiana is characterized by a very multicultural population, made up of formerly settled groups (Amerindians, Maroons, Creoles) and more recent migrants (mostly from Latin America and the Caribbean). It is the ideal place to try to understand the influence of intercultural exchanges on the composition of medicinal floras and the evolution of phytotherapies under the effect of cross-culturalism. METHODS: A combination of qualitative and quantitative methods was used. Semi-directive interviews were conducted in 12 localities of French Guiana's coast between January 2016 and June 2017, and the responses to all closed questions collected during the survey were computerized in an Excel spreadsheet to facilitate quantitative processing. Herbarium vouchers were collected and deposited at the Cayenne Herbarium to determine Linnaean names of medicinal species mentioned by the interviewees. A list of indicator species for each cultural group considered was adapted from community ecology to this ethnobiological context, according to the Dufrêne-Legendre model, via the "labdsv" package and the "indval" function, after performing a redundancy analysis (RDA). RESULTS: A total of 205 people, belonging to 15 distinct cultural groups, were interviewed using semi-structured questionnaires. A total of 356 species (for 106 botanical families) were cited. We observed that pantropical and edible species hold a special place in these pharmacopeias. If compared to previous inventories, 31 recently introduced species can be counted. Furthermore, this study shows that the majority of the plants used are not specific to a particular group but shared by many communities. However, despite this obvious cross-culturalism of medicinal plants between the different cultural communities of French Guiana, divergent trends nevertheless appear through the importance of 29 indicator/cultural keystone species in 10 cultural groups. Finally, we have emphasized that the transmission of herbal medicine's knowledge in French Guiana is mainly feminine and intra-cultural. CONCLUSION: French Guianese medicinal flora is undoubtedly related to the multiple cultures that settled this territory through the last centuries. Cultural pharmacopeias are more hybrid than sometimes expected, but cultural keystone species nevertheless arise from a common background, allowing to understand, and define, the relationships between cultural groups.

Towards the optimization of botanical insecticides research: Aedes aegypti larvicidal natural products in French Guiana.

Natural products have proven to be an immeasurable source of bioactive compounds. The exceptional biodiversity encountered in Amazonia, alongside a rich entomofauna and frequent interactions with various herbivores is the crucible of a promising chemodiversity. This prompted us to search for novel botanical insecticides in French Guiana. As this French overseas department faces severe issues linked to insects, notably the strong incidence of vector-borne infectious diseases, we decided to focus our research on products able to control the mosquito Aedes aegypti. We tested 452 extracts obtained from 85 species originating from 36 botanical families and collected in contrasted environments against an Ae. aegypti laboratory strain susceptible to all insecticides, and a natural population resistant to both pyrethroid and organophosphate insecticides collected in Cayenne for the most active of them. Eight species (Maytenus oblongata Reissek, Celastraceae; Costus erythrothyrsus Loes., Costaceae; Humiria balsamifera Aubl., Humiriaceae; Sextonia rubra (Mez) van der Werff, Lauraceae; Piper hispidum Sw., Piperaceae; Laetia procera (Poepp.) Eichl., Salicaceae; Matayba arborescens (Aubl.) Radlk., Sapindaceae; and Cupania scrobitulata Rich., Sapindaceae) led to extracts exhibiting more than 50% larval mortality after 48 h of exposition at 100 µg/mL against the natural population and were considered active. Selectivity and phytochemistry of these extracts were therefore investigated and discussed, and some active compounds highlighted. Multivariate analysis highlighted that solvents, plant tissues, plant family and location had a significant effect on mortality while light, available resources and vegetation type did not. Through this case study we highlighted that plant defensive chemistry mechanisms are crucial while searching for novel insecticidal products.

African biomass burning is a substantial source of phosphorus deposition to the Amazon, Tropical Atlantic Ocean, and Southern Ocean.

The deposition of phosphorus (P) from African dust is believed to play an important role in bolstering primary productivity in the Amazon Basin and Tropical Atlantic Ocean (TAO), leading to sequestration of carbon dioxide. However, there are few measurements of African dust in South America that can robustly test this hypothesis and even fewer measurements of soluble P, which is readily available for stimulating primary production in the ocean. To test this hypothesis, we measured total and soluble P in long-range transported aerosols collected in Cayenne, French Guiana, a TAO coastal site located at the northeastern edge of the Amazon. Our measurements confirm that in boreal spring when African dust transport is greatest, dust supplies the majority of P, of which 5% is soluble. In boreal fall, when dust transport is at an annual minimum, we measured unexpectedly high concentrations of soluble P, which we show is associated with the transport of biomass burning (BB) from southern Africa. Integrating our results into a chemical transport model, we show that African BB supplies up to half of the P deposited annually to the Amazon from transported African aerosol. This observational study links P-rich BB aerosols from Africa to enhanced P deposition in the Amazon. Contrary to current thought, we also show that African BB is a more important source of soluble P than dust to the TAO and oceans in the Southern Hemisphere and may be more important for marine productivity, particularly in boreal summer and fall.

Long-term influence of early human occupations on current forests of the Guiana Shield.

To decipher the long-term influences of pre-Columbian land occupations on contemporary forest structure, diversity, and functioning in Amazonia, most of the previous research focused on the alluvial plains of the major rivers of the Amazon basin. Terra firme, that is, nonflooded forests, particularly from the Guiana Shield, are yet to be explored. In this study, we aim to give new insights into the subtle traces of pre-Columbian influences on present-day forests given the archaeological context of terra firme forests of the Guiana Shield. Following archaeological prospects on 13 sites in French Guiana, we carried out forest inventories inside and outside archaeological sites and assessed the potential pre-Columbian use of the sampled tree species using an original ethnobotanical database of the Guiana Shield region. Aboveground biomass (320 and 380 T/ha, respectively), basal area (25-30 and 30-35 m2 /ha, respectively), and tree density (550 and 700 stem/ha, respectively) were all significantly lower on anthropized plots (As) than on nonanthropized plots (NAs). Ancient human presence shaped the species composition of the sampled forests with Arecaceae, Burseraceae, and Lauraceae significantly more frequent in As and Annonaceae and Lecythidaceae more frequent in NAs. Although alpha diversity was not different between As and NAs, the presence of pre-Columbian sites enhances significantly the forest beta diversity at the landscape level. Finally, trees with edible fruits are positively associated with pre-Columbian sites, whereas trees used for construction or for their bark are negatively associated with pre-Columbian sites. Half a millennium after their abandonment, former occupied places from the inner Guiana Shield still bear noticeable differences with nonanthropized places. Considering the lack of data concerning archaeology of terra firme Amazonian forests, our results suggest that pre-Columbian influences on the structure (lower current biomass), diversity (higher beta diversity), and composition (linked to the past human tree uses) of current Amazonian forests might be more important than previously thought.

Decreased antibiotic susceptibility of Enterobacteriaceae causing community-acquired urinary tract infections in French Amazonia.

OBJECTIVES: Urinary tract infections (UTIs) have rarely been studied in the Amazon region. We aimed to describe the epidemiology of bacteria causing UTIs in French Guiana. PATIENTS AND METHODS: We performed a monocenter retrospective study of adults consulting at the emergency department of Cayenne Hospital in 2014 with a diagnosis of UTI. The bacterial species and resistance profile were described. RESULTS: Two-hundred-and-eighty-nine patients presenting with UTI were included: 82 (28.4%) presented with cystitis, 166 (57.4%) with pyelonephritis, and 41 (14.2%) with male UTI. E. coli was predominant (74.1%), and had decreased susceptibility to ampicillin, amoxicillin-clavulanic acid, fluoroquinolones, co-trimoxazole, and furans compared with data from metropolitan France. Extended-spectrum beta-lactamases (ESBL) was isolated in 3.1% of E. coli and 31.6% of K. pneumoniae. CONCLUSIONS: Antibiotic susceptibility in UTI is lower than reported in metropolitan France without evidence for an excessive consumption of antibiotics.

Palikur traditional roundwood construction in eastern French Guiana: ethnobotanical and cultural perspectives.

BACKGROUND: Palikur Amerindians live in the eastern part of French Guiana which is undergoing deep-seated changes due to the geographical and economic opening of the region. So far, Palikur's traditional ecological knowledge is poorly documented, apart from medicinal plants. The aim of this study was to document ethnobotanical practices related to traditional construction in the region. METHODS: A combination of qualitative and quantitative methods was used. Thirty-nine Palikur men were interviewed in three localities (Saint-Georges de l'Oyapock, Regina and Trois-Palétuviers) between December 2013 and July 2014. Twenty-four inventories of wood species used in traditional buildings were conducted in the villages, as well as ethnobotanical walks in the neighboring forests, to complete data about usable species and to determine Linnaean names. RESULTS: After an ethnographic description of roundwood Palikur habitat, the in situ wood selection process of Palikur is precisely described. A total of 960 roundwood pieces were inventoried in situ according to Palikur taxonomy, of which 860 were beams and rafters, and 100 posts in 20 permanent and 4 temporary buildings. Twenty-seven folk species were identified. Sixty-three folk species used in construction were recorded during ethnobotanical walks. They correspond to 263 botanical species belonging to 25 families. Posts in permanent buildings were made of yawu (Minquartia guianensis) (51%) and wakap (Vouacapoua americana) (14%). Beams and rafters were made of wood from Annonaceae (79%) and Lecythidaceae (13%) families. The most frequently used species were kuukumwi priye (Oxandra asbeckii), kuukumwi seyne (Pseudoxandra cuspidata), and pukuu (Xylopia nitida and X. cayennensis). CONCLUSIONS: Although the Palikur's relationship with their habitat is undergoing significant changes, knowledge about construction wood is still very much alive in the Oyapock basin. Many people continue to construct traditional buildings alongside modern houses, using a wide array of species described here for the first time, along with the techniques used.

Mercury behaviour and C, N, and P biogeochemical cycles during ecological restoration processes of old mining sites in French Guiana.

Several decades of gold mining extraction activities in the Amazonian rainforest have caused deforestation and pollution. While ecological rehabilitation is essential for restoring biodiversity and decreasing erosion on deforested lands, few studies note the behaviour or toxicity of trace elements during the rehabilitation process. Our original study focused on the potential use of microbial activity and Hg speciation and compared them with As, Cu, Zn and Cr speciation in assessing the chemical and biological quality of ecological restoration efforts. We sampled two sites in French Guyana 17 years after rehabilitation efforts began. The former site was actively regenerated (R) with the leguminous species Clitoria racemosa and Acacia mangium, and the second site was passively regenerated with spontaneous vegetation (Sv). We also sampled soil from a control site without a history of gold mining (F). We performed microcosm soil experiments for 30 days, where trace element speciation and enzyme activities (i.e., FDA, dehydrogenase, ß-glucosidase, urease, alkaline and acid phosphatase) were estimated to characterise the behaviour of trace elements and the soil microbial activity. As bioindicators, the use of soil microbial carbon biomass and soil enzyme activities related to the carbon and phosphorus cycles seems to be relevant for assessing soil quality in rehabilitated and regenerated old mining sites. Our results showed that restoration with leguminous species had a positive effect on soil chemical quality and on soil microbial bioindicators, with activities that tended toward natural non-degraded soil (F). Active restoration processes also had a positive effect on Hg speciation by reducing its mobility. While in Sv we found more exchangeable and soluble mercury, in regenerated sites, Hg was mostly bound to organic matter. These results also suggested that enzyme activities and mercury cycles are sensitive to land restoration and must be considered when evaluating the efficiency of restoration processes.