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Author Agrawal, Anurag A. ; Boroczky, Katalin ; Haribal, Meena ; Hastings, Amy P. ; White, Ronald, A. ; Jiang, Ren-Wang ; Duplais, Christophe doi  openurl
  Title Cardenolides, toxicity, and the costs of sequestration in the coevolutionary interaction between monarchs and milkweeds Type Journal Article
  Year 2021 Publication PNAS Abbreviated Journal  
  Volume 118 Issue 16 Pages e2024463118  
  Keywords  
  Abstract (up) For highly specialized insect herbivores, plant chemical defenses are often co-opted as cues for oviposition and sequestration. In such interactions, can plants evolve novel defenses, pushing herbivores to trade off benefits of specialization with costs of coping with toxins? We tested how variation in milkweed toxins (cardenolides) impacted monarch butterfly ( Danaus plexippus ) growth, sequestration, and oviposition when consuming tropical milkweed ( Asclepias curassavica ), one of two critical host plants worldwide. The most abundant leaf toxin, highly apolar and thiazolidine ring–containing voruscharin, accounted for 40% of leaf cardenolides, negatively predicted caterpillar growth, and was not sequestered. Using whole plants and purified voruscharin, we show that monarch caterpillars convert voruscharin to calotropin and calactin in vivo, imposing a burden on growth. As shown by in vitro experiments, this conversion is facilitated by temperature and alkaline pH. We next employed toxin-target site experiments with isolated cardenolides and the monarch’s neural Na + /K + -ATPase, revealing that voruscharin is highly inhibitory compared with several standards and sequestered cardenolides. The monarch’s typical >50-fold enhanced resistance to cardenolides compared with sensitive animals was absent for voruscharin, suggesting highly specific plant defense. Finally, oviposition was greatest on intermediate cardenolide plants, supporting the notion of a trade-off between benefits and costs of sequestration for this highly specialized herbivore. There is apparently ample opportunity for continued coevolution between monarchs and milkweeds, although the diffuse nature of the interaction, due to migration and interaction with multiple milkweeds, may limit the ability of monarchs to counteradapt.  
  Address  
  Corporate Author Thesis  
  Publisher National Academy of Sciences Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1014  
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Author Schmitt, Sylvain ; Derroire, Géraldine ; Tysklind, Niklas ; Heuertz, Myriam ; Hérault, Bruno doi  openurl
  Title Topography shapes the local coexistence of tree species within species complexes of Neotropical forests Type Journal Article
  Year 2021 Publication Oecologia Abbreviated Journal  
  Volume 196 Issue Pages 389-398  
  Keywords  
  Abstract (up) Forest inventories in Amazonia include around 5000 described tree species belonging to more than 800 genera. Numerous species-rich genera share genetic variation among species because of recent speciation and/or recurrent hybridisation, forming species complexes. Despite the key role that tree species complexes play in understanding Neotropical diversification, and their need to exploit a diversity of niches, little is known about the mechanisms that allow local coexistence of tree species complexes and their species in sympatry. In this study, we explored the fine-scale distribution of five tree species complexes and 22 species within these complexes. Combining forest inventories, botanical determination, and LiDAR-derived topographic data over 120 ha of permanent plots in French Guiana, we used a Bayesian modelling framework to test the role of fine-scale topographic wetness and tree neighbourhood on the occurrence of species complexes and the relative distribution of species within complexes. Species complexes of Neotropical trees were widely spread across the topographic wetness gradient at the local scale. Species within complexes showed pervasive niche differentiation along with topographic wetness and competition gradients. Similar patterns of species-specific habitat preferences were observed within several species complexes: species more tolerant to competition for resources grow in drier and less fertile plateaus and slopes. If supported by partial reproductive isolation of species and adaptive introgression at the species complex level, our results suggest that both species-specific habitat specialisation within species complexes and the broad ecological distribution of species complexes might explain the success of these species complexes at the regional scale.  
  Address  
  Corporate Author Thesis  
  Publisher Springer Link Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1018  
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Author Essebtey, Salma El Idrissi ; Villard, Ludovic ; Borderies, Pierre ; Koleck, Thierry ; Burban, Benoït ; Le Toan, Thuy doi  openurl
  Title Long-Term Trends of P-Band Temporal Decorrelation Over a Tropical Dense Forest-Experimental Results for the BIOMASS Mission Type Journal Article
  Year 2021 Publication IEEE Transactions on Geoscience and Remote Sensing Abbreviated Journal  
  Volume 60 Issue Pages 1-15  
  Keywords  
  Abstract (up) Fostered by the upcoming BIOMASS mission, this article explores long-term trends of P-band temporal decorrelation over a tropical forest due to a time series of 617 days acquired during the TropiScat-2 experiment. The interest in this unique time series is twofold. First, it provides consistent statistics to monitor the yearly evolution of temporal coherences according to specific time scales of the BIOMASS tomographic and interferometric phases. Second, it provides key insights to explore new processing approaches with the combination of data from different orbit directions (ascending/descending) and different mission cycles separated by about seven months according to the current acquisition plan. For the first time, this study shows that 18-day coherences (corresponding to the time interval between the first and last acquisitions of the BIOMASS tomographic processing) can vary significantly according to rainy and dry seasons (medians from 0.3 to 0.9). The extension to time intervals of up to 90 days within both seasons and over two consecutive years puts forward the key role of the typical sporadic rainfalls occurring during dry periods in tropical rainforests, with a stronger impact on temporal coherence evolution compared to the more reproducible rainy seasons. Furthermore, outstanding values significantly above zero have been obtained for the 7- and 14-month coherences (medians of 0.35 and 0.2, respectively), opening the way to new methods of change detection. Overall, this study highlights the role of P-band temporal decorrelation not only as a disturbance factor for coherent applications but also as a relevant indicator of forest changes.  
  Address  
  Corporate Author Thesis  
  Publisher Institute of Electrical and Electronics Engineers Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1060  
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Author de Thoisy, Benoit ; Duron, Olivier ; Epelboin, Loïc ; Musset, Lise ; Quénel, Philippe ; Roche, Benjamin ; Binetruy, Florian ; Briolant, Sébastien ; Carvalho, Luisiane ; Chavy, Agathe : Couppié, Pierre ; and all ........................... doi  openurl
  Title Ecology, evolution, and epidemiology of zoonotic and vector-borne infectious diseases in French Guiana: Transdisciplinarity does matter to tackle new emerging threats Type Journal Article
  Year 2021 Publication Infection, Génétics and Evolution Abbreviated Journal  
  Volume 93 Issue Pages 104916  
  Keywords  
  Abstract (up) French Guiana is a European ultraperipheric region located on the northern Atlantic coast of South America. It constitutes an important forested region for biological conservation in the Neotropics. Although very sparsely populated, with its inhabitants mainly concentrated on the Atlantic coastal strip and along the two main rivers, it is marked by the presence and development of old and new epidemic disease outbreaks, both research and health priorities. In this review paper, we synthetize 15 years of multidisciplinary and integrative research at the interface between wildlife, ecosystem modification, human activities and sociodemographic development, and human health. This study reveals a complex epidemiological landscape marked by important transitional changes, facilitated by increased interconnections between wildlife, land-use change and human occupation and activity, human and trade transportation, demography with substantial immigration, and identified vector and parasite pharmacological resistance. Among other French Guianese characteristics, we demonstrate herein the existence of more complex multi-host disease life cycles than previously described for several disease systems in Central and South America, which clearly indicates that today the greater promiscuity between wildlife and humans due to demographic and economic pressures may offer novel settings for microbes and their hosts to circulate and spread. French Guiana is a microcosm that crystallizes all the current global environmental, demographic and socioeconomic change conditions, which may favor the development of ancient and future infectious diseases.  
  Address  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1052  
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Author Guzman, Laura Melissa ; Trzcinski, M. Kurtis ; Barberis, Ignacio M. ; Cereghino, Régis ; Srivastava, Diane S. ; Gilbert Benjamin ; Pillar, Valerio D. ; de Omena, Paula M. ; MacDonald, A. Andrew M. ; Corbara, Bruno ; Leroy, Celine ; Bautista, Fabiola Ospina ; Romero, Gustavo Q. ; Kratina, Pavel ; Debastiani, Vanderlei J. ; Gonialves, Ana Z. ; Marino, Nicholas A.C. ; Farjalla, Vinicius F. ; Richardson, Barbara A. ; Richardson, Michael J. ; Dézerald, Olivier ; Piccoli, Gustavo, C. O. ; Jocqué, Merlijn ; Montero, Guillermo doi  openurl
  Title Climate influences the response of community functional traits to local conditions in bromeliad invertebrate communities Type Journal Article
  Year 2021 Publication Ecography Abbreviated Journal  
  Volume 44 Issue 3 Pages 440-452  
  Keywords  
  Abstract (up) Functional traits determine an organism's performance in a given environment and as such determine which organisms will be found where. Species respond to local conditions, but also to larger scale gradients, such as climate. Trait ecology links these responses of species to community composition and species distributions. Yet, we often do not know which environmental gradients are most important in determining community trait composition at either local or biogeographical scales, or their interaction. Here we quantify the relative contribution of local and climatic conditions to the structure and composition of functional traits found within bromeliad invertebrate communities. We conclude that climate explains more variation in invertebrate trait composition within bromeliads than does local conditions. Importantly, climate mediated the response of traits to local conditions; for example, invertebrates with benthic life-history traits increased with bromeliad water volume only under certain precipitation regimes. Our ability to detect this and other patterns hinged on the compilation of multiple fine-grained datasets, allowing us to contrast the effect of climate versus local conditions. We suggest that, in addition to sampling communities at local scales, we need to aggregate studies that span large ranges in climate variation in order to fully understand trait filtering at local, regional and global scales.  
  Address  
  Corporate Author Thesis  
  Publisher Nordic Society OIKOS Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1013  
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Author Li, Lingjuan ; Preece, Catherine ; Lin, Qiang ; Bréchet, Laëtitia M. ; Stahl, Clément ; Courtois, Elodie A. ; Verbruggen, Erik doi  openurl
  Title Resistance and resilience of soil prokaryotic communities in response to prolonged drought in a tropical forest Type Journal Article
  Year 2021 Publication FEMS Microbiology Ecology Abbreviated Journal  
  Volume 97 Issue 9 Pages  
  Keywords drought, microbial communities, microbial network, tropical forest, resistance, resilience  
  Abstract (up) Global climate changes such as prolonged duration and intensity of drought can lead to adverse ecological consequences in forests. Currently little is known about soil microbial community responses to such drought regimes in tropical forests. In this study, we examined the resistance and resilience of topsoil prokaryotic communities to a prolongation of the dry season in terms of diversity, community structure and co-occurrence patterns in a French Guianan tropical forest. Through excluding rainfall during and after the dry season, a simulated prolongation of the dry season by five months was compared to controls. Our results show that prokaryotic communities increasingly diverged from controls with the progression of rain exclusion. Furthermore, prolonged drought significantly affected microbial co-occurrence networks. However, both the composition and co-occurrence networks of soil prokaryotic communities immediately ceased to differ from controls when precipitation throughfall returned. This study thus suggests modest resistance but high resilience of microbial communities to a prolonged drought in tropical rainforest soils.  
  Address  
  Corporate Author Thesis  
  Publisher Oxford Academy Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1032  
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Author Nixon, Samantha A. ; Robinson, Samuel D. ; Agwa, Akello, J. ; Walker, Andrew A. ; Choudhay, Shivani ; Touchard, Axel ; Undheim, Eivind A.B. ; Robertson, Alan ; Vetter, Irina ; Schroeder, Christina I. ; Kotze, Andrew C. ; Herzig, Volker ; King, Glenn F. doi  openurl
  Title Multipurpose peptides: The venoms of Amazonian stinging ants contain anthelmintic ponericins with diverse predatory and defensive activities Type Journal Article
  Year 2021 Publication Biochemical Pharmacology Abbreviated Journal  
  Volume 192 Issue Pages 114693  
  Keywords  
  Abstract (up) In the face of increasing drug resistance, the development of new anthelmintics is critical for controlling nematodes that parasitise livestock. Although hymenopteran venom toxins have attracted attention for applications in agriculture and medicine, few studies have explored their potential as anthelmintics. Here we assessed hymenopteran venoms as a possible source of new anthelmintic compounds by screening a panel of ten hymenopteran venoms against Haemonchus contortus, a major pathogenic nematode of ruminants. Using bioassay-guided fractionation coupled with liquid chromatography-tandem mass spectrometry, we identified four novel anthelmintic peptides (ponericins) from the venom of the neotropical ant Neoponera commutata and the previously described ponericin M−PONTX−Na1b from Neoponera apicalis venom. These peptides inhibit H. contortus development with IC50 values of 2.8–5.6 μM. Circular dichroism spectropolarimetry indicated that the ponericins are unstructured in aqueous solution but adopt α-helical conformations in lipid mimetic environments. We show that the ponericins induce non-specific membrane perturbation, which confers broad-spectrum antimicrobial, insecticidal, cytotoxic, hemolytic, and algogenic activities, with activity across all assays typically correlated. We also show for the first time that ponericins induce spontaneous pain behaviour when injected in mice. We propose that the broad-spectrum activity of the ponericins enables them to play both a predatory and defensive role in neoponeran ants, consistent with their high abundance in venom. This study reveals a broader functionality for ponericins than previously assumed, and highlights both the opportunities and challenges in pursuing ant venom peptides as potential therapeutics.  
  Address  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1031  
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Author Van Langenhove, Leandro ; Depaepe, Thomas ; Verryckt, Lore T. ; Vallicrosa, Helena ; Fuchslueger, Lucia ; Lugli, Laynara F. ; Bréchet, Laëtitia M. ; Ogaya, Roma ; Llusia, Joan ; Urbina, Ifigenia ; Gargallo-Garriga, Albert ; Grau, Oriol ; Richter, Andreas ; Penuelas, Josep ; Van Der Straeten, Dominique ; August Janssens, Ivan A. doi  openurl
  Title Impact of Nutrient Additions on Free-Living Nitrogen Fixation in Litter and Soil of Two French-Guianese Lowland Tropical Forests Type Journal Article
  Year 2021 Publication JGR Biogeosciences Abbreviated Journal  
  Volume 126 Issue 7 Pages e2020JG006023  
  Keywords  
  Abstract (up) In tropical forests, free-living Biological nitrogen (N) fixation (BNF) in soil and litter tends to decrease when substrate N concentrations increase, whereas increasing phosphorus (P) and molybdenum (Mo) soil and litter concentrations have been shown to stimulate free-living BNF rates. Yet, very few studies explored the effects of adding N, P, and Mo together in a single large-scale fertilization experiment, which would teach us which of these elements constrain or limit BNF activities. At two distinct forest sites in French Guiana, we performed a 3-year in situ nutrient addition study to explore the effects of N, P, and Mo additions on leaf litter and soil BNF. Additionally, we conducted a short-term laboratory study with the same nutrient addition treatments (+N, +N+P, +P, +Mo, and +P+Mo). We found that N additions alone suppressed litter free-living BNF in the field, but not in the short-term laboratory study, while litter free-living BNF remained unchanged in response to N+P additions. Additionally, we found that P and P+Mo additions stimulated BNF in leaf litter, both in the field and in the lab, while Mo alone yielded no changes. Soil BNF increased with P and P+Mo additions in only one of the field sites, while in the other site soil BNF increased with Mo and P+Mo additions. We concluded that increased substrate N concentrations suppress BNF. Moreover, both P and Mo have the potential to limit free-living BNF in these tropical forests, but the balance between P versus Mo limitation is determined by site-specific characteristics of nutrient supply and demand.  
  Address  
  Corporate Author Thesis  
  Publisher American Geophysical Union Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1040  
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Author Amani, Bienvenu H.K. ; N'Guessan, Anny E. ; Derroire, Géraldine ; N'dja, Justin K. ; Elogne, Aka G. M. ; Traoré, Karidia ; Zo-Bi, Irie C. ; Hérault, Bruno doi  openurl
  Title The potential of secondary forests to restore biodiversity of the lost forests in semi-deciduous West Africa Type Journal Article
  Year 2021 Publication Biological Conservation Abbreviated Journal  
  Volume 259 Issue Pages  
  Keywords  
  Abstract (up) In West Africa, more than 80% of the original forest cover has disappeared due to the exponential growth of human populations in a recurrent search for new agricultural land. Once the fertility of the land is exhausted, these areas are abandoned and left to be reforested through natural succession. Despite the widespread presence of secondary forests of various ages in West African landscapes, little is known about the trajectories of recovery and the environmental factors that influence recovery rates. We set up 96 0.2 ha forest plots, along a chronosequence of 1 to 40 years and including 7 controls, on which all trees larger than 2.5 cm in diameter at breast height were inventoried. We modelled the recovery trajectories of four complementary dimensions of biodiversity (richness, diversity, composition, indicators of old-growth forest) in a Bayesian framework. Our results show that the four dimensions of biodiversity recover at different rates, with composition recovering much faster than floristic diversity. Among the local, landscape, and historical factors studied, the number of remnants and proximity to old-growth forests have a positive impact on recovery rates, with, under good environmental conditions, the composition, richness, and diversity being almost completely recovered in less than 25 years. Our results demonstrate the very high resilience of the composition of the semi-deciduous forests of West Africa, but also suggest that the management of these post-forest areas must be differentiated according to the landscape context and the presence of isolated trees, which are the last vestiges of the former forest. In unfavourable conditions, natural dynamics should be assisted by agroforestry practices and local tree planting to allow for a rapid restoration of forest goods and services to local populations.  
  Address  
  Corporate Author Thesis  
  Publisher Elsevier B.V. Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1010  
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Author Vleminckx, Jason ; Fortunel, Claire ; Valverde-Barrantes, Oscar ; Paine, C.E. Timothy ; Engel, Julien ; Petronelli, Pascal ; Dourdain, Aurélie K. ; Guevara, Juan ; Béroujon, Solène ; Baraloto, Christophier doi  openurl
  Title Resolving whole-plant economics from leaf, stem and root traits of 1467 Amazonian tree species Type Journal Article
  Year 2021 Publication Oikos Abbreviated Journal  
  Volume 130 Issue 7 Pages 1193-1208  
  Keywords  
  Abstract (up) It remains unclear how evolutionary and ecological processes have shaped the wide variety of plant life strategies, especially in highly diverse ecosystems like tropical forests. Some evidence suggests that species have diversified across a gradient of ecological strategies, with different plant tissues converging to optimize resource use across environmental gradients. Alternative hypotheses propose that species have diversified following independent selection on different tissues, resulting in a decoupling of trait syndromes across organs. To shed light on the subject, we assembled an unprecedented dataset combining 19 leaf, stem and root traits for 1467 tropical tree species inventoried across 71 0.1-ha plots spanning broad environmental gradients in French Guiana. Nearly 50% of the overall functional heterogeneity was expressed along four orthogonal dimensions, after accounting for phylogenetic dependences among species. The first dimension related to fine root functioning, while the second and third dimensions depicted two decoupled leaf economics spectra, and the fourth dimension encompassed a wood economics spectrum. Traits involved in orthogonal functional strategies, five leaf traits in particular but also trunk bark thickness, were consistently associated with a same gradient of soil texture and nutrient availability. Root traits did not show any significant association with edaphic variation, possibly because of the prevailing influence of other factors (mycorrhizal symbiosis, phylogenetic constraints). Our study emphasises the existence of multiple functional dimensions that allow tropical tree species to optimize their performance in a given environment, bringing new insights into the debate around the presence of a whole plant economic spectrum in tropical forest tree communities. It also emphasizes the key role that soil heterogeneity plays in shaping tree species assembly. The extent to which different organs are decoupled and respond to environmental gradients may also help to improve our predictions of species distribution changes in responses to habitat modification and environmental changes.  
  Address  
  Corporate Author Thesis  
  Publisher Nordic Society OIKOS Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1030  
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