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Author Tindo, M.; Mbenoun Masse, P.S.; Kenne, M.; Mony, R.; Orivel, J.; Doumtsop Fotio, A.; Fotso Kuaté, A.; Djiéto-Lordon, C.; Fomena, A.; Estoup, A.; Dejean, A.; Foucaud, J. url  openurl
  Title Current distribution and population dynamics of the little fire ant supercolony in cameroon Type Journal Article
  Year 2012 Publication Insectes Sociaux Abbreviated Journal Insectes Sociaux  
  Volume 59 Issue 2 Pages 175-182  
  Keywords Auropunctata; Dispersion; Invasive ants; Reproduction strategy; Unicoloniality; Wasmannia  
  Abstract (down) The little fire ant, Wasmannia auropunctata, is native to Central America, but has been introduced into many parts of the world. We examined the current distribution of W. auropunctata in Cameroon, tested for aggression between workers from different parts of the country, and examined the genotypes of workers, queens, and males to evaluate the mating system. We found W. auropunctata at 36 sites in three provinces (Centre, East, and South). We found W. auropunctata only in human-disturbed habitats. Its spread appears to be primarily human mediated. Aggressive behaviour was almost non-existent between workers from different sites, indicating that there is only one supercolony in Cameroon. Our genetic analysis found that only one male/female pair of clones was introduced into Cameroon, probably from Gabon. No new male clonal lineage was identified, whereas new sexually derived female clonal lineages were noted. Apart from the genotype of the founding queen, which was well distributed but generally not dominant, a new clonal queen genotype emerged and was both omnipresent and dominant at most sites. These results may be useful in the development of management strategies. © International Union for the Study of Social Insects (IUSSI) 2011.  
  Address Laboratoire Evolution Genome Speciation, Centre National de la Recherche Scientifique, Avenue de la Terrasse, F 91198 Gif sur Yvette, France  
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  Series Volume Series Issue Edition  
  ISSN 00201812 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 24 April 2012; Source: Scopus; Coden: Insoa; doi: 10.1007/s00040-011-0202-x; Language of Original Document: English; Correspondence Address: Tindo, M.; Département de Biologie des Organismes Animaux, Faculté des Sciences, Université de Douala, BP 24157 Douala, Cameroon; email: tindodouala@yahoo.com Approved no  
  Call Number EcoFoG @ webmaster @ Serial 392  
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Author Rey, O.; Loiseau, A.; Facon, B.; Foucaud, J.; Orivel, J.; Cornuet, J.M.; Robert, S.; Dobigny, G.; Delabie, J.H.C.; Mariano, C.D.F.; Estoup, A. openurl 
  Title Meiotic Recombination Dramatically Decreased in Thelytokous Queens of the Little Fire Ant and Their Sexually Produced Workers Type Journal Article
  Year 2011 Publication Molecular Biology and Evolution Abbreviated Journal Mol. Biol. Evol.  
  Volume 28 Issue 9 Pages 2591-2601  
  Keywords parthenogenesis; thelytoky; recombination; inbreeding; biological invasion; Wasmannia auropunctata  
  Abstract (down) The little fire ant, Wasmannia auropunctata, displays a peculiar breeding system polymorphism. Classical haplo-diploid sexual reproduction between reproductive individuals occurs in some populations, whereas, in others, queens and males reproduce clonally. Workers are produced sexually and are sterile in both clonal and sexual populations. The evolutionary fate of the clonal lineages depends strongly on the underlying mechanisms allowing reproductive individuals to transmit their genomes to subsequent generations. We used several queen-offspring data sets to estimate the rate of transition from heterozygosity to homozygosity associated with recombination events at 33 microsatellite loci in thelytokous parthenogenetic queen lineages and compared these rates with theoretical expectations under various parthenogenesis mechanisms. We then used sexually produced worker families to define linkage groups for these 33 loci and to compare meiotic recombination rates in sexual and parthenogenetic queens. Our results demonstrate that queens from clonal populations reproduce by automictic parthenogenesis with central fusion. These same parthenogenetic queens produce normally segregating meiotic oocytes for workers, which display much lower rates of recombination (by a factor of 45) than workers produced by sexual queens. These low recombination rates also concern the parthenogenetic production of queen offspring, as indicated by the very low rates of transition from heterozygosity to homozygosity observed (from 0% to 2.8%). We suggest that the combination of automixis with central fusion and a major decrease in recombination rates allows clonal queens to benefit from thelytoky while avoiding the potential inbreeding depression resulting from the loss of heterozygosity during automixis. In sterile workers, the strong decrease of recombination rates may also facilitate the conservation over time of some coadapted allelic interactions within chromosomes that might confer an adaptive advantage in habitats disturbed by human activity, where clonal populations of W. auropunctata are mostly found.  
  Address [Rey, O; Loiseau, A; Facon, B; Foucaud, J; Cornuet, JM; Robert, S; Dobigny, G] INRA, UMR Ctr Biol Gest Populat INRA IRD CIRAD Montpe, Montferrier Sur Lez, France, Email: olivier.rey@supagro.inra.fr  
  Corporate Author Thesis  
  Publisher Oxford Univ Press Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0737-4038 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000294552700019 Approved no  
  Call Number EcoFoG @ webmaster @ Serial 339  
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Author Levionnois, Sébastien ; Salmon, Camille ; Alméras, Tancrède ; Clair, Bruno ; Ziegler, Camille ; Coste, Sabrina ; Stahl, Clement ; Gonzalez-Melo, Andrés ; Heinz, Christine ; Heuret, Patrick doi  openurl
  Title Anatomies, vascular architectures, and mechanics underlying the leaf size-stem size spectrum in 42 Neotropical tree species Type Journal Article
  Year 2021 Publication Journal of Experimental Botany Abbreviated Journal  
  Volume 72 Issue 22 Pages 7957–7969  
  Keywords  
  Abstract (down) The leaf size-stem size spectrum is one of the main dimensions of plant ecological strategies. Yet the anatomical, mechanical, and hydraulic implications of small vs. large shoots are still poorly understood. We investigated 42 tropical rainforest tree species in French Guiana, with a wide range of leaf areas at the shoot level. We quantified the scaling of hydraulic and mechanical constraints with shoot size estimated as the water potential difference ΔΨ and the bending angle ΔΦ, respectively. We investigated how anatomical tissue area, flexural stiffness and xylem vascular architecture affect such scaling by deviating (or not) from theoretical isometry with shoot size variation. Vessel diameter and conductive path length were found to be allometrically related to shoot size, thereby explaining the independence between ΔΨ and shoot size. Leaf mass per area, stem length, and the modulus of elasticity were allometrically related with shoot size, explaining the independence between ΔΦ and shoot size. Our study also shows that the maintenance of both water supply and mechanical stability across the shoot size range are not in conflict.  
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  Publisher Oxford University Press Place of Publication Editor  
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  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 1050  
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Author Migliavacca, Mirco ; Musavi, Talie ; Mahecha, Miguel D. ; Nelson, Jacob A. ; Knauer, Jurgen ; Baldocchi, Dennis D. ; Perez-Priego, Oscar ; Christiansen, Rune ; Peters, Jonas ; Anderson, Karen ; Bahn, Michael ; Black, T. Andrew ; Blanken, Peter D. ; and all .................. doi  openurl
  Title The three major axes of terrestrial ecosystem function Type Journal Article
  Year 2021 Publication Nature Abbreviated Journal  
  Volume 598 Issue 7881 Pages 468-472  
  Keywords  
  Abstract (down) The leaf economics spectrum1,2 and the global spectrum of plant forms and functions3 revealed fundamental axes of variation in plant traits, which represent different ecological strategies that are shaped by the evolutionary development of plant species2. Ecosystem functions depend on environmental conditions and the traits of species that comprise the ecological communities4. However, the axes of variation of ecosystem functions are largely unknown, which limits our understanding of how ecosystems respond as a whole to anthropogenic drivers, climate and environmental variability4,5. Here we derive a set of ecosystem functions6 from a dataset of surface gas exchange measurements across major terrestrial biomes. We find that most of the variability within ecosystem functions (71.8%) is captured by three key axes. The first axis reflects maximum ecosystem productivity and is mostly explained by vegetation structure. The second axis reflects ecosystem water-use strategies and is jointly explained by variation in vegetation height and climate. The third axis, which represents ecosystem carbon-use efficiency, features a gradient related to aridity, and is explained primarily by variation in vegetation structure. We show that two state-of-the-art land surface models reproduce the first and most important axis of ecosystem functions. However, the models tend to simulate more strongly correlated functions than those observed, which limits their ability to accurately predict the full range o  
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  Publisher Nature Publishing Group Place of Publication Editor  
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  Call Number EcoFoG @ webmaster @ Serial 1044  
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Author Bonal, D.; Bosc, A.; Ponton, S.; Goret, J.Y.; Burban, B.; Gross, P.; Bonnefond, J.M.; Elbers, J.; Longdoz, B.; Epron, D.; Guehl, J.M.; Granier, A. openurl 
  Title Impact of severe dry season on net ecosystem exchange in the Neotropical rainforest of French Guiana Type Journal Article
  Year 2008 Publication Global Change Biology Abbreviated Journal Glob. Change Biol.  
  Volume 14 Issue 8 Pages 1917-1933  
  Keywords dry season; ecosystem respiration; eddy covariance; gross ecosystem productivity; Neotropical rainforest; net ecosystem productivity; soil drought; solar radiation  
  Abstract (down) The lack of information on the ways seasonal drought modifies the CO2 exchange between Neotropical rainforest ecosystems and the atmosphere and the resulting carbon balance hinders our ability to precisely predict how these ecosystems will respond as global environmental changes force them to face increasingly contrasting conditions in the future. To address this issue, seasonal variations in daily net ecosystem productivity (NEPd) and two main components of this productivity, daily total ecosystem respiration (R-Ed) and daily gross ecosystem productivity (GEP(d)), were estimated over 2 years at a flux tower site in French Guiana, South America (5 degrees 16'54'N, 52 degrees 54'44'W). We compared seasonal variations between wet and dry periods and between dry periods of contrasting levels of intensity (i.e. mild vs. severe) during equivalent 93-day periods. During the wet periods, the ecosystem was almost in balance with the atmosphere (storage of 9.0 g C m(-2)). Seasonal dry periods, regardless of their severity, are associated with higher incident radiation and lower R-Ed combined with reduced soil respiration associated with low soil water availability. During the mild dry period, as is normally the case in this region, the amount of carbon stored in the ecosystem was 32.7 g C m(-2). Severe drought conditions resulted in even lower R-Ed, whereas the photosynthetic activity was only moderately reduced and no change in canopy structure was observed. Thus, the severe dry period was characterized by greater carbon storage (64.6 g C m(-2)), emphasizing that environmental conditions, such as during a severe drought, modify the CO2 exchange between Neotropical rainforest ecosystems and the atmosphere and potentially the resulting carbon balance.  
  Address [Bonal, Damien; Goret, Jean-Yves; Burban, Benoit] INRA, UMR Ecol Forets Guyane, Kourou 97387, French Guiana, Email: damien.bonal@kourou.cirad.fr  
  Corporate Author Thesis  
  Publisher BLACKWELL PUBLISHING Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1354-1013 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000257712400015 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 133  
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Author Foucaud, J.; Orivel, J.; Fournier, D.; Delabie, J.H.C.; Loiseau, A.; Le Breton, J.; Cerdan, P.; Estoup, A. openurl 
  Title Reproductive system, social organization, human disturbance and ecological dominance in native populations of the little fire ant, Wasmannia auropunctata Type Journal Article
  Year 2009 Publication Molecular Ecology Abbreviated Journal Mol. Ecol.  
  Volume 18 Issue 24 Pages 5059-5073  
  Keywords biological invasion; clonality; human disturbance; parthenogenesis; social organization; Wasmannia auropunctata  
  Abstract (down) The invasive ant species Wasmannia auropunctata displays both ecologically dominant and non-dominant populations within its native range. Three factors could theoretically explain the ecological dominance of some native populations of W. auropunctata: (i) its clonal reproductive system, through demographic and/or adaptive advantages; (ii) its unicolonial social organization, through lower intraspecific and efficient interspecific competition; (iii) the human disturbance of its native range, through the modification of biotic and abiotic environmental conditions. We used microsatellite markers and behavioural tests to uncover the reproductive modes and social organization of dominant and non-dominant native populations in natural and human-modified habitats. Microsatellite and mtDNA data indicated that dominant and non-dominant native populations (supercolonies as determined by aggression tests) of W. auropunctata did not belong to different evolutionary units. We found that the reproductive system and the social organization are neither necessary nor sufficient to explain W. auropunctata ecological dominance. Dominance rather seems to be set off by unknown ecological factors altered by human activities, as all dominant populations were recorded in human-modified habitats. The clonal reproductive system found in some populations of W. auropunctata may however indirectly contribute to its ecological dominance by allowing the species to expand its environmental niche, through the fixation over time of specific combinations of divergent male and female genotypes. Unicoloniality may rather promote the range expansion of already dominant populations than actually trigger ecological dominance. The W. auropunctata model illustrates the strong impact of human disturbance on species' ecological features and the adaptive potential of clonal reproductive systems.  
  Address [Foucaud, Julien; Fournier, Denis; Loiseau, Anne; Estoup, Arnaud] Montpellier SupAgro, Cirad, IRD, INRA,UMR CBGP, F-34988 Montferrier Sur Lez, France, Email: julien.foucaud@legs.cnrs-gif.fr  
  Corporate Author Thesis  
  Publisher WILEY-BLACKWELL PUBLISHING, INC Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0962-1083 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000272452700009 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 191  
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Author Dezerald, O.; Talaga, S.; Leroy, C.; Carrias, J.-F.; Corbara, B.; Dejean, A.; Céréghino, R. url  doi
openurl 
  Title Environmental determinants of macroinvertebrate diversity in small water bodies: Insights from tank-bromeliads Type Journal Article
  Year 2014 Publication Hydrobiologia Abbreviated Journal Hydrobiologia  
  Volume 723 Issue 1 Pages 77-86  
  Keywords Freshwater biodiversity; Linear mixed effect modelling; Microcosms; Phytotelmata; Ponds  
  Abstract (down) The interlocking leaves of tank-forming bromeliads (Bromeliaceae) collect rainwater and detritus, thus creating a freshwater habitat for specialized organisms. Their abundance and the possibility of quantifying communities with accuracy give us unparalleled insight into how changes in local to regional environments influence community diversity in small water bodies. We sampled 365 bromeliads (365 invertebrate communities) along a southeastern to northwestern range in French Guiana. Geographic locality determined the species pool for bromeliad invertebrates, and local environments determined the abundance patterns through the selection of traits that are best adapted to the bromeliad habitats. Patterns in community structure mostly emerged from patterns of predator species occurrence and abundance across local-regional environments, while the set of detritivores remained constant. Water volume had a strong positive correlation with invertebrate diversity, making it a biologically relevant measure of the pools' carrying capacity. The significant effects of incoming detritus and incident light show that changes in local environments (e.g., the conversion of forest to cropping systems) strongly influence freshwater communities. Because changes in local environments do not affect detritivores and predators equally, one may expect functional shifts as sets of invertebrates with particular traits are replaced or complemented by other sets with different traits. © 2013 Springer Science+Business Media Dordrecht.  
  Address CNRS, EcoLab (UMR-CNRS 5245), 118 Route de Narbonne, 31062 Toulouse, France  
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  ISSN 00188158 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 517  
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Author Lauth, J.; Ruiz-González, M.X.; Orivel, J. pdf  url
openurl 
  Title New findings in insect fungiculture: Have ants developed non-food, agricultural products? Type Journal Article
  Year 2011 Publication Communicative & Integrative Biology Abbreviated Journal Comm & Integr Biol  
  Volume 4 Issue 1942-0889 Pages 728-730  
  Keywords  
  Abstract (down) The interaction between Allomerus plant-ants and an ascomycete fungus growing on and strengthening their galleries is not opportunistic. We previously demonstrated that this association is highly specific as only one fungal species represented by a few haplotypes was found associated with the ants. We also discovered that the ants' behavior revealed a major investment in manipulating and enhancing the growth of their associated fungus. We have growing evidence that this specificity is consistent with selection by the ants. Here, we discuss this selection within the framework of insect agriculture, as we believe these ants fulfill all of the prerequisites to be considered as farmers. Allomerus ants promote their symbiont's growth, protect it from potential pathogens and select specific cultivars. Taken together, we think that the interaction between Allomerus ants and their cultivar might represent the first case of insect fungiculture used as a means of obtaining building material.  
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  Publisher Landes Bioscience Inc. Place of Publication Editor  
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  Call Number EcoFoG @ webmaster @ Serial 379  
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Author Paine, C.E.T.; Harms, K.E.; Schnitzer, S.A.; Carson, W.P. openurl 
  Title Weak competition among tropical tree seedlings: Implications for species coexistence Type Journal Article
  Year 2008 Publication Biotropica Abbreviated Journal Biotropica  
  Volume 40 Issue 4 Pages 432-440  
  Keywords Brosimum alicastrum; competitive irrelevance; maintenance of biodiversity; Matisia cordata; resource competition; Panama; Peru; Pouteria reticulata; zone of influence  
  Abstract (down) The intensity of competition among forest tree seedlings is poorly understood, but has important ramifications for their recruitment and for the maintenance of species diversity. Intense competition among seedlings could allow competitively dominant species to exclude subordinate species. Alternatively, the low density and small stature of forest tree seedlings could preclude intense interseedling competition. In this case, other processes, such as size-asymmetric competition with adults, interactions with consumers, or neutral dynamics would prevail as those structuring the forest understory. We tested the intensity of, and potential for, intraspecific competition among tree seedlings of three species (Brosimum alicastrum, Matisia cordata, and Pouteria reticulata) in two Neotropical rain forests. We reduced stem densities by up to 90 percent and monitored individual growth and survival rates for up to 24 mo. Individual growth and survival rates were generally unrelated to stem density. Contrary to the predicted behavior of intensely competing plant populations, the distribution of individual heights did not become more left-skewed with time for any species, regardless of plot density; i.e., excesses of short, suppressed individuals did not accumulate in high-density plots. We further measured the overlap of zones of influence (ZOIs) to assess the potential for resource competition. Seedling ZOIs overlapped only slightly in extremely dense monodominant plots, and even less in ambient-density plots of mixed composition. Our results thus suggest that interseedling competition was weak. Given the low density of tree seedlings in Neotropical forests, we infer that resource competition among seedlings may be irrelevant to their recruitment.  
  Address [Paine, C. E. Timothy; Harms, Kyle E.] Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA, Email: cetpaine@gmail.com  
  Corporate Author Thesis  
  Publisher BLACKWELL PUBLISHING Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0006-3606 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000257717500006 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 134  
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Author Schwalm, C.R.; Williams, C.A.; Schaefer, K.; Arneth, A.; Bonal, D.; Buchmann, N.; Chen, J.Q.; Law, B.E.; Lindroth, A.; Luyssaert, S.; Reichstein, M.; Richardson, A.D. openurl 
  Title Assimilation exceeds respiration sensitivity to drought: A FLUXNET synthesis Type Journal Article
  Year 2010 Publication Global Change Biology Abbreviated Journal Glob. Change Biol.  
  Volume 16 Issue 2 Pages 657-670  
  Keywords biome; carbon cycling; drought; eddy covariance; evaporative fraction; FLUXNET; synthesis  
  Abstract (down) The intensification of the hydrological cycle, with an observed and modeled increase in drought incidence and severity, underscores the need to quantify drought effects on carbon cycling and the terrestrial sink. FLUXNET, a global network of eddy covariance towers, provides dense data streams of meteorological data, and through flux partitioning and gap filling algorithms, estimates of net ecosystem productivity (F-NEP), gross ecosystem productivity (P), and ecosystem respiration (R). We analyzed the functional relationship of these three carbon fluxes relative to evaporative fraction (EF), an index of drought and site water status, using monthly data records from 238 micrometeorological tower sites distributed globally across 11 biomes. The analysis was based on relative anomalies of both EF and carbon fluxes and focused on drought episodes by biome and climatic season. Globally P was approximate to 50% more sensitive to a drought event than R. Network-wide drought-induced decreases in carbon flux averaged -16.6 and -9.3 g C m-2 month-1 for P and R, i.e., drought events induced a net decline in the terrestrial sink. However, in evergreen forests and wetlands drought was coincident with an increase in P or R during parts of the growing season. The most robust relationships between carbon flux and EF occurred during climatic spring for F-NEP and in climatic summer for P and R. Upscaling flux sensitivities to a global map showed that spatial patterns for all three carbon fluxes were linked to the distribution of croplands. Agricultural areas exhibited the highest sensitivity whereas the tropical region had minimal sensitivity to drought. Combining gridded flux sensitivities with their uncertainties and the spatial grid of FLUXNET revealed that a more robust quantification of carbon flux response to drought requires additional towers in all biomes of Africa and Asia as well as in the cropland, shrubland, savannah, and wetland biomes globally.  
  Address [Schwalm, Christopher R.; Williams, Christopher A.] Clark Univ, Grad Sch Geog, Worcester, MA 01610 USA, Email: cschwalm@clarku.edu  
  Corporate Author Thesis  
  Publisher WILEY-BLACKWELL PUBLISHING, INC Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1354-1013 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000274419400014 Approved no  
  Call Number EcoFoG @ eric.marcon @ Serial 69  
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