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Author Marcon, E.; Puech, F. url  doi
openurl 
  Title A typology of distance-based measures of spatial concentration Type Journal Article
  Year 2017 Publication Regional Science and Urban Economics Abbreviated Journal Regional Science and Urban Economics  
  Volume 62 Issue Pages 56-67  
  Keywords (down) Agglomeration; Aggregation; Economic geography; Point patterns; Spatial concentration  
  Abstract Over the last decade, distance-based methods have been introduced and then improved in the field of spatial economics to gauge the geographic concentration of activities. There is a growing literature on this theme including new tools, discussions on their specific properties and various applications. However, there is currently no typology of distance-based methods. This paper fills that gap. The proposed classification helps understand all the properties of distance-based methods and proves that they are variations on the same framework. © 2016 Elsevier B.V.  
  Address RITM, Univ. Paris-Sud, CREST, Université Paris-Saclay, Sceaux, France  
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  Notes Export Date: 17 January 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 704  
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Author Dejean, A.; Ryder, S.; Bolton, B.; Compin, A.; Leponce, M.; Azémar, F.; Céréghino, R.; Orivel, J.; Corbara, B. url  openurl
  Title How territoriality and host-tree taxa determine the structure of ant mosaics Type Journal Article
  Year 2015 Publication The Science of Nature Abbreviated Journal Sci Nat  
  Volume 102 Issue 33 Pages 1-9  
  Keywords (down) Africa; Arboreal ants; Distribution; Host-tree selection; Rainforest canopies  
  Abstract Very large colonies of territorially dominant arboreal ants (TDAAs), whose territories are distributed in a mosaic pattern in the canopies of many tropical rainforests and tree crop plantations, have a generally positive impact on their host trees. We studied the canopy of an old Gabonese rainforest (ca 4.25 ha sampled, corresponding to 206 Blarge trees) at a stage just preceding forest maturity (the Caesalpinioideae dominated; the Burseraceae were abundant). The tree crowns sheltered colonies from 13 TDAAs plus a codominant species out of the 25 ant species recorded. By mapping the TDAAs' territories and using a null model cooccurrence analysis, we confirmed the existence of an ant mosaic. Thanks to a large sampling set and the use of the self-organizing map algorithm (SOM), we show that the distribution of the trees influences the structure of the ant mosaic, suggesting that each tree taxon attracts certain TDAA species rather than others. The SOMalso improved our knowledge of the TDAAs' ecological niches, showing that these ant species are ecologically distinct from each other based on their relationships with their supporting trees. Therefore, TDAAs should not systematically be placed in the same functional group even when they belong to the same genus.We conclude by reiterating that, in addition to the role played by TDAAs' territorial competition, host trees contribute to structuring ant mosaics through multiple factors, including host-plant selection by TDAAs, the age of the trees, the presence of extrafloral nectaries, and the taxa of the associated hemipterans. © Springer-Verlag Berlin Heidelberg 2015.  
  Address Université Clermont Auvergne, Université Blaise Pascal (LMGE), Clermont-Ferrand, France  
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  Notes Export Date: 16 October 2015 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 632  
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Author Kiaer, L.P.; Felber, F.; Flavell, A.; Guadagnuolo, R.; Guiatti, D.; Hauser, T.P.; Olivieri, A.M.; Scotti, I.; Syed, N.; Vischi, M.; van de Wiel, C.; Jorgensen, R.B. openurl 
  Title Spontaneous gene flow and population structure in wild and cultivated chicory, Cichorium intybus L Type Journal Article
  Year 2009 Publication Genetic Resources and Crop Evolution Abbreviated Journal Genet. Resour. Crop Evol.  
  Volume 56 Issue 3 Pages 405-419  
  Keywords (down) AFLP; GM co-existence; Gene dispersal; Introgression; Risk assessment; SSAP  
  Abstract Spontaneous gene flow between wild and cultivated chicory, Cichorium intybus L., may have implications for the genetic structure and evolution of populations and varieties. One aspect of this crop-wild gene flow is the dispersal of transgenes from genetically modified varieties, e.g. gene flow from GM chicory to natural chicory could have unwanted consequences. With the purpose to identify and quantify crop-wild gene flow in chicory, we analysed introgression in 19 wild chicory populations and 16 accessions of chicory varieties and landraces distributed across Northern, Central and Mediterranean Europe. The analysis used 281 AFLP markers and 75 SSAP markers giving a total of 356 polymorphic markers. Results from model based assignments with the program STRUCTURE indicated many incidents of recent gene flow. Gene flow was observed both between cultivars and wild populations, between landraces and wild populations, between different wild populations as well as between cultivars. Population structure visualized by distance-based clustering showed a North-South geographical structuring of the wild populations, and a general grouping of the cultivars corresponding to known origin. The results indicated, however, that the structuring between the two groups of wild and cultivated types was weak. As crop and wild recipients are genetically close and genes are transferred between the two types rather frequently, focus on mitigating crop-wild gene flow should be increased, before transgenic varieties are cultivated openly.  
  Address [Kiaer, L. P.; Jorgensen, R. B.] DTU, Riso Natl Lab, Biosyst Dept, DK-4000 Roskilde, Denmark, Email: rikke.bagger.jorgensen@risoe.dk  
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  Publisher SPRINGER Place of Publication Editor  
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  ISSN 0925-9864 ISBN Medium  
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  Notes ISI:000264835300011 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 204  
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Author Talaga, S.; Dejean, A.; Mouza, C.; Dumont, Y.; Leroy, C. doi  openurl
  Title Larval interference competition between the native Neotropical mosquito Limatus durhamii and the invasive Aedes aegypti improves the fitness of both species Type Journal Article
  Year 2018 Publication Insect Science Abbreviated Journal Insect Science  
  Volume 25 Issue Pages 1102-1107  
  Keywords (down) Aedes aegypti; increased fitness; interference competition; Limatus durhamii; phenotypic plasticity; resistance to invasion  
  Abstract Abstract Interspecific competition with native species during biological invasions can sometimes limit alien expansion. We aimed to determine the potential ecological effects of Limatus durhamii Theobald 1901, a native Neotropical mosquito (Diptera: Culicidae) species, on the invasive species Aedes (Stegomyia) aegypti (Linnaeus 1762) that breeds in the same artificial water containers. Development time and adult dry mass were measured in 3 rearing conditions: control (a single larva), intraspecific competition (2 conspecific larvae), and interspecific competition (2 heterospecific larvae). Food was provided ad libitum to eliminate exploitative competition. For Ae. aegypti, development time was not affected by interspecific interference competition (nonsignificant differences with the control) and the adult dry mass was significantly higher, meaning that individual fitness likely increased. Yet, because previous studies showed longer development time and lighter adults during competition with other invasive mosquitoes, it is likely that Ae. aegypti can express a different phenotype depending on the competing species. The similar pattern found for Li. durhamii females and the nonsignificant difference with the control for males explain in part why this species can compete with Ae. aegypti.  
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  Publisher John Wiley & Sons, Ltd (10.1111) Place of Publication Editor  
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  ISSN 1672-9609 ISBN Medium  
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  Call Number EcoFoG @ webmaster @ Serial 836  
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Author Nirma, C.; Rodrigues, A.M.S.; Basset, C.; Chevolot, L.; Girod, R.; Moretti, C.; Stien, D.; Dusfour, I.; Eparvier, V. doi  openurl
  Title Larvicidal activity of isoflavonoids from Muellera frutescens extracts against Aedes aegypti Type Journal Article
  Year 2012 Publication Natural Product Communications Abbreviated Journal  
  Volume 7 Issue 10 Pages 1319-1322  
  Keywords (down) Aedes aegypti; French Guiana; Insecticides; Isoflavonoids; Muellera frutescens  
  Abstract The biological activity of extracts from the leaves, bark and roots of Muellera frutescens, an Amazonian ichtyotoxic plant, were evaluated to find new environmentally safe insecticides. The n-hexane extracts of bark, leaf, and root showed a strong toxic activity against Aedes aegypti mosquito larvae. Bioguided fractionation of the bark extract led to the isolation of seven isoflavonoids (12a-hydroxyelliptone, elliptone, (-)-variabilin, rotenone, rotenolone, tephrosin and deguelin). Rotenone and deguelin are responsible for the larvicidal activity of the plant. M. frutescens leaves contain up to 0.6%, w/w, deguelin. These results justify the traditional ichtyotoxic use of M. frutescens. The leaves contain a relatively high proportion of deguelin and, therefore, can be considered as a renewable source of this environmentally friendly insecticidal isoflavonoid.  
  Address CNRS, Institut de Chimie des Substances Naturelles, UPR 2301, 1 avenue de la Terrasse, 91198 Gif-sur-Yvette, France  
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  Notes Export Date: 6 December 2012; Source: Scopus Approved no  
  Call Number EcoFoG @ webmaster @ Serial 448  
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Author Talaga, S.; Dezerald, O.; Carteron, A.; Leroy, C.; Carrias, J.-F.; Céréghino, R.; Dejean, A. url  doi
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  Title Urbanization impacts the taxonomic and functional structure of aquatic macroinvertebrate communities in a small Neotropical city Type Journal Article
  Year 2017 Publication Urban Ecosystems Abbreviated Journal Urban Ecosystems  
  Volume 20 Issue 5 Pages 1001-1009  
  Keywords (down) Aedes aegypti; Bioindicator; Diversity; Functional traits; Tank bromeliads; Urban ecology  
  Abstract Due to habitat fragmentation, resource disruption and pollution, urbanization is one of the most destructive forms of anthropization affecting ecosystems worldwide. Generally, human-mediated perturbations dramatically alter species diversity in urban sites compared to the surroundings, thus influencing the functioning of the entire ecosystem. We investigated the taxonomic and functional diversity patterns of the aquatic macroinvertebrate communities in tank bromeliads by comparing those found in a small Neotropical city with those from an adjacent rural site. Changes in the quality of detrital inputs in relation to lower tree diversity and the presence of synanthropic species are likely important driving forces behind the observed structural changes in the urban site. Leaf-litter processors (i.e., shredders, scrapers) were positively affected in the urban site, while filter-feeders that process smaller particles produced by the activity of the shredders were negatively affected. Because we cannot ascertain whether the decline in filter-feeders is related to food web-mediated effects or to competitive exclusion (Aedes aegypti mosquitoes were present in urban bromeliads only), further studies are necessary to account for the effects of intra-guild competition or inter-guild facilitation. © 2017, Springer Science+Business Media New York.  
  Address Ecolab, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France  
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  Notes Cited By :1; Export Date: 18 December 2017 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 776  
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Author Leroy, C.; Maes, A.Q.; Louisanna, E.; Séjalon-Delmas, N. url  doi
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  Title How significant are endophytic fungi in bromeliad seeds and seedlings? Effects on germination, survival and performance of two epiphytic plant species Type Journal Article
  Year 2019 Publication Fungal Ecology Abbreviated Journal Fungal Ecol.  
  Volume 39 Issue Pages 296-306  
  Keywords (down) Aechmea; Bromeliads; Endophytic fungi; Fusarium spp.; Germination; Survival; Trichoderma spp.; Vertical transmission  
  Abstract In bromeliads, nothing is known about the associations fungi form with seeds and seedling roots. We investigated whether fungal associations occur in the seeds and seedling roots of two epiphytic Aechmea species, and we explored whether substrate and fungal associations contribute to seed germination, and seedling survival and performance after the first month of growth. We found a total of 21 genera and 77 species of endophytic fungi in the seeds and seedlings for both Aechmea species by Illumina MiSeq sequencing. The fungal associations in seeds were found in the majority of corresponding seedlings, suggesting that fungi are transmitted vertically. Substrate quality modulated the germination and growth of seedlings, and beneficial endophytic fungi were not particularly crucial for germination but contributed positively to survival and growth. Overall, this study provides the first evidence of an endophytic fungal community in both the seeds and seedlings of two epiphytic bromeliads species that subsequently benefit plant growth. © 2019 Elsevier Ltd and British Mycological Society  
  Address INRA, UMR Ecologie des Forêts de Guyane (AgroParisTech, CIRAD, CNRS, INRA, Université de Guyane, Université des Antilles), Campus Agronomique, BP 316, Kourou cedex, F-97379, France  
  Corporate Author Thesis  
  Publisher Elsevier Ltd Place of Publication Editor  
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  ISSN 17545048 (Issn) ISBN Medium  
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  Call Number EcoFoG @ webmaster @ Serial 867  
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Author Talaga, S.; Dezerald, O.; Carteron, A.; Petitclerc, F.; Leroy, C.; Céréghino, R.; Dejean, A. url  openurl
  Title Tank bromeliads as natural microcosms: A facultative association with ants influences the aquatic invertebrate community structure Type Journal Article
  Year 2015 Publication Comptes Rendus – Biologies Abbreviated Journal Comptes Rendus – Biologies  
  Volume 338 Issue 10 Pages 696-700  
  Keywords (down) Aechmea; Ant-bromeliad associations; Aquatic communities; Odontomachus; Phytotelm  
  Abstract Many tank bromeliads have facultative relationships with ants as is the case in French Guiana between Aechmea aquilega (Salib.) Griseb. and the trap-jaw ant, Odontomachus haematodus Linnaeus. Using a redundancy analysis, we determined that the presence of O. haematodus colonies is accompanied by a greater quantity of fine particulate organic matter in the water likely due to their wastes. This increase in nutrient availability is significantly correlated with an increase in the abundance of some detritivorous taxa, suggesting a positive bottom-up influence on the aquatic macroinvertebrate communities living in the A. aquilega wells. On the other hand, the abundance of top predators is negatively affected by a lower number of available wells due to ant constructions for nesting, releasing a top-down pressure that could also favor lower trophic levels. © 2015 Académie des sciences.  
  Address CNRS, Ecolab (UMR-CNRS 5245), 118, route de Narbonne, Toulouse, France  
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  Notes Export Date: 2 October 2015 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 627  
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Author Petit, M.; Céréghino, R.; Carrias, J.-F.; Corbara, B.; Dezerald, O.; Petitclerc, F.; Dejean, A.; Leroy, C. doi  openurl
  Title Are ontogenetic shifts in foliar structure and resource acquisition spatially conditioned in tank-bromeliads? Type Journal Article
  Year 2014 Publication Botanical Journal of the Linnean Society Abbreviated Journal Bot J Linn Soc  
  Volume 175 Issue 2 Pages 299-312  
  Keywords (down) Aechmea mertensii; Camponotus femoratus; French Guiana; leaf traits; mutualistic ants; natural stable isotopes; ontogeny; Pachycondyla goeldii; phenotypic plasticity; plant morphology  
  Abstract The phenotypic plasticity of plants has been explored as a function of either ontogeny (apparent plasticity) or environment (adaptive plasticity), although few studies have analyzed these factors together. In the present study, we take advantage of the dispersal of Aechmea mertensii bromeliads by Camponotus femoratus or Pachycondyla goeldii ants in shaded and sunny environments, respectively, to quantify ontogenetic changes in morphological, foliar, and functional traits, and to analyze ontogenetic and ant species effects on 14 traits. Most of the morphological (plant height, number of leaves), foliar (leaf thickness, leaf mass area, total water content, trichome density), and functional (leaf δ13C) traits differed as a function of ontogeny. Conversely, only leaf δ15N showed an adaptive phenotypic plasticity. On the other hand, plant width, tank width, longest leaf length, stomatal density, and leaf C concentration showed an adaptation to local environment with ontogeny. The exception was leaf N concentration, which showed no trend at all. Aechmea mertensii did not show an abrupt morphological modification such as in heteroblastic bromeliads, although it was characterized by strong, size-related functional modifications for CO2 acquisition. The adaptive phenotypic variation found between the two ant species indicates the spatially conditioned plasticity of A. mertensii in the context of insect-assisted dispersal. However, ant-mediated effects on phenotypic plasticity in A. mertensii are not obvious because ant species and light environment are confounding variables. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175, 299–312.  
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  ISSN 1095-8339 ISBN Medium  
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  Call Number EcoFoG @ webmaster @ Serial 564  
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Author Leroy, C.; Petitclerc, F.; Orivel, J.; Corbara, B.; Carrias, J.-F.; Dejean, A.; Céréghino, R. doi  openurl
  Title The influence of light, substrate and seed origin on the germination and establishment of an ant-garden bromeliad Type Journal Article
  Year 2017 Publication Plant Biology Abbreviated Journal Plant Biol J  
  Volume 19 Issue 1 Pages 70-78  
  Keywords (down) Aechmea mertensii; bromeliad; French Guiana; germination; plant performance; survival  
  Abstract Plant germination and development depend upon a seed's successful dispersal into a suitable habitat and its ability to grow and survive within the surrounding biotic and abiotic environment. The seeds of Aechmea mertensii, a tank-bromeliad species, are dispersed by either Camponotus femoratus or Neoponera goeldii, two ant species that initiate ant gardens (AGs). These two mutualistic ant species influence the vegetative and reproductive traits of the bromeliad through their divergent ecological preferences (i.e. light and substrate). We hypothesised that the seeds dispersed by these two ant species have underlying genetic differences affecting germination, growth and survival of A. mertensii seedlings in different ways. To test this, we used an experimental approach consisting of sowing seeds of A. mertensii: (i) taken from the two AG–ant associations (i.e. seed origin), (ii) in two contrasting light conditions, and (iii) on three different substrates. Light and substrate had significant effects on germination, survival and on eight key leaf traits reflecting plant performance. Seed origin had a significant effect only on germination and on two leaf traits (total dry mass and relative growth rate). Overall, this bromeliad performs better (i.e. high growth and survival rates) when growing both in the shade and in the carton nest developed by C. femoratus ants. These results suggest that the plasticity of the tank bromeliad A. mertensii is mainly due to environment but also to genetic differences related to seed origin, as some traits are heritable. Thus, these two ant species may play contrasting roles in shaping plant evolution and speciation.  
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  ISSN 1438-8677 ISBN Medium  
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  Call Number EcoFoG @ webmaster @ Serial 712  
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