Carrias, J. - F., Céréghino, R., Brouard, O., Pélozuelo, L., Dejean, A., Couté, A., et al. (2014). Two coexisting tank bromeliads host distinct algal communities on a tropical inselberg. Plant Biol., 16(5), 997–1004.
Abstract: The tank bromeliads Aechmea aquilega (Salisb.) and Catopsis berteroniana (Schultes f.) coexist on a sun-exposed Neotropical inselberg in French Guiana, where they permit conspicuous freshwater pools to form that differ in size, complexity and detritus content. We sampled the algal communities (both eukaryotic and cyanobacterial taxa, including colourless forms) inhabiting either A. aquilega (n = 31) or C. berteroniana (n = 30) and examined differences in community composition and biomass patterns in relation to several biotic and abiotic variables. Chlorella sp. and Bumilleriopsis sp. were the most common taxa and dominated the algal biomass in A. aquilega and C. berteroniana, respectively. Using a redundancy analysis, we found that water volume, habitat complexity and the density of phagotrophic protozoa and collector-gatherer invertebrates were the main factors explaining the distribution of the algal taxa among the samples. Hierarchical clustering procedures based on abundance and presence/absence data clearly segregated the samples according to bromeliad species, revealing that the algal communities in the smaller bromeliad species were not a subset of the communities found in the larger bromeliad species. We conclude that, even though two coexisting tank bromeliad populations create adjacent aquatic habitats, each population hosts a distinct algal community. Hence, bromeliad diversity is thought to promote the local diversity of freshwater algae in the Neotropics. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.
Keywords: Algae; Bromeliaceae; Inselberg; Neotropics; Phytotelmata; Aechmea; algae; Bromeliaceae; Bumilleriopsis; Catopsis berteroniana; Chlorella (unclassified Chlorophyceae); Chlorella (unclassified Trebouxiophyceae); Chlorella sp.; Cyanobacteria; Eukaryota; Invertebrata; Protozoa
|
Leroy, C., Jauneau, A., Martinez, Y., Cabin-Flaman, A., Gibouin, D., Orivel, J., et al. (2017). Exploring fungus-plant N transfer in a tripartite ant-plant-fungus mutualism. Annals of Botany, 120(3), 417–426.
Abstract: Background and Aims The plant Hirtella physophora, the ant Allomerus decemarticulatus and a fungus, Trimmatostroma sp., form a tripartite association. The ants manipulate both the plant trichomes and the fungus to build galleries under the stems of their host plant used to capture prey. In addition to its structural role, the fungus also improves nutrient uptake by the host plant. But it still remains unclear whether the fungus plays an indirect or a direct role in transferring nutrients to the plant. This study aimed to trace the transfer of N from the fungus to the plant's stem tissue. • Methods Optical microscopy and transmission electron microscopy (TEM) were used to investigate the presence of fungal hyphae in the stem tissues. Then, a 15N-labelling experiment was combined with a nanoscale secondary-ion mass spectrometry (NanoSIMS 50) isotopic imaging approach to trace the movement of added 15N from the fungus to plant tissues. • Key Results The TEM images clearly showed hyphae inside the stem tissue in the cellular compartment. Also, fungal hyphae were seen perforating the wall of the parenchyma cell. The 15N provisioning of the fungus in the galleries resulted in significant enrichment of the 15N signature of the plant's leaves 1 d after the 15N-labelling solution was deposited on the fungus-bearing trap. Finally, NanoSIMS imaging proved that nitrogen was transferred biotrophically from the fungus to the stem tissue. • Conclusions This study provides evidence that the fungi are connected endophytically to an ant-plant system and actively transfer nitrogen from 15N-labelling solution to the plant's stem tissues. Overall, this study underlines how complex the trophic structure of ant-plant interactions is due to the presence of the fungus and provides insight into the possibly important nutritional aspects and tradeoffs involved in myrmecophyte-ant mutualisms. © The Author 2017.
Keywords: Ascomycetes; endophytic fungi; Hirtella physophora; microscopy; mutualism; myrmecophyte; NanoSIMS; stable isotope
|
Dejean, A., Groc, S., Herault, B., Rodriguez-Pérez, H., Touchard, A., Céréghino, R., et al. (2015). Bat aggregation mediates the functional structure of ant assemblages. Comptes Rendus – Biologies, 338(10), 688–695.
Abstract: In the Guianese rainforest, we examined the impact of the presence of guano in and around a bat roosting site (a cave). We used ant communities as an indicator to evaluate this impact because they occupy a central place in the functioning of tropical rainforest ecosystems and they play different roles in the food web as they can be herbivores, generalists, scavengers or predators. The ant species richness around the cave did not differ from a control sample situated 500m away. Yet, the comparison of functional groups resulted in significantly greater numbers of detritivorous fungus-growing and predatory ant colonies around the cave compared to the control, the contrary being true for nectar and honeydew feeders. The role of bats, through their guano, was shown using stable isotope analyses as we noted significantly greater δ15N values for the ant species captured in and around the cave compared to controls. © 2015 Académie des sciences.
Keywords: Ant functional groups; Bat roosts; Biogeochemical hotspots; Bioindicators; Stable isotopes
|
Rutishauser, E., Herault, B., Baraloto, C., Blanc, L., Descroix, L., Sotta, E. D., et al. (2015). Rapid tree carbon stock recovery in managed Amazonian forests. Current Biology, 25(18), R787–R788.
Abstract: Summary While around 20% of the Amazonian forest has been cleared for pastures and agriculture, one fourth of the remaining forest is dedicated to wood production [1]. Most of these production forests have been or will be selectively harvested for commercial timber, but recent studies show that even soon after logging, harvested stands retain much of their tree-biomass carbon and biodiversity [2,3]. Comparing species richness of various animal taxa among logged and unlogged forests across the tropics, Burivalova et al.[4] found that despite some variability among taxa, biodiversity loss was generally explained by logging intensity (the number of trees extracted). Here, we use a network of 79 permanent sample plots (376 ha total) located at 10 sites across the Amazon Basin [5] to assess the main drivers of time-to-recovery of post-logging tree carbon (Table S1). Recovery time is of direct relevance to policies governing management practices (i.e., allowable volumes cut and cutting cycle lengths), and indirectly to forest-based climate change mitigation interventions. © 2015 Elsevier Ltd.
|
Talaga, S., Dezerald, O., Carteron, A., Petitclerc, F., Leroy, C., Céréghino, R., et al. (2015). Tank bromeliads as natural microcosms: A facultative association with ants influences the aquatic invertebrate community structure. Comptes Rendus – Biologies, 338(10), 696–700.
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.
Keywords: Aechmea; Ant-bromeliad associations; Aquatic communities; Odontomachus; Phytotelm
|
Dejean, A., Petitclerc, F., Compin, A., Azémar, F., Corbara, B., Delabie, J. H. C., et al. (2017). Hollow internodes permit a neotropical understory plant to shelter multiple mutualistic ant species, obtaining protection and nutrient provisioning (myrmecotrophy). American Naturalist, 190(5), E124–E131.
Abstract: The Neotropical understory plant Tachia guianensis (Gentianaceae)- known to shelter the colonies of several ant species in its hollow trunks and branches-does not provide them with food rewards (e.g., extrafloral nectar). We tested whether these ants are opportunistic nesters or whether mutualistic relationships exist as for myrmecophytes or plants sheltering ant colonies in specialized hollow structures in exchange for protection from enemies and/or nutrient provisioning (myrmecotrophy). We noted 37 ant species sheltering inside T. guianensis internodes, three of them accounting for 43.5% of the cases. They protect their host plants from leaf-cutting ant defoliation and termite damage because individuals devoid of associated ants suffered significantly more attacks. Using the stable isotope 15N, we experimentally showed that the tested ant species furnish their host plants with nutrients. Therefore, a mutualism exists. However, because it is associated with numerous ant species, T. guianensis can be considered a nonspecialized myrmecophyte. © 2017 by The University of Chicago.
Keywords: Ant-plant relationships; Biotic protection; Mutualism; Myrmecotrophy; Stable isotopes; Tachia guianensis
|
Dejean, A., Delabie, J. H., Corbara, B., Azémar, F., Groc, S., Orivel, J., et al. (2012). The ecology and feeding habits of the arboreal trap-jawed ant Daceton armigerum. PLoS ONE, 7(5), e37683.
Abstract: Here we show that Daceton armigerum, an arboreal myrmicine ant whose workers are equipped with hypertrophied trap-jaw mandibles, is characterized by a set of unexpected biological traits including colony size, aggressiveness, trophobiosis and hunting behavior. The size of one colony has been evaluated at ca. 952,000 individuals. Intra- and interspecific aggressiveness were tested and an equiprobable null model used to show how D. armigerum colonies react vis-à-vis other arboreal ant species with large colonies; it happens that D. armigerum can share trees with certain of these species. As they hunt by sight, workers occupy their hunting areas only during the daytime, but stay on chemical trails between nests at night so that the center of their home range is occupied 24 hours a day. Workers tend different Hemiptera taxa (i.e., Coccidae, Pseudococcidae, Membracidae and Aethalionidae). Through group-hunting, short-range recruitment and spread-eagling prey, workers can capture a wide range of prey (up to 94.12 times the mean weight of foraging workers).
Keywords: animal; ant; article; ecology; feeding behavior; Hemiptera; physiology; predation; Animals; Ants; Ecology; Feeding Behavior; Hemiptera; Predatory Behavior
|
Maia, A. C. D., Dötterl, S., Kaiser, R., Silberbauer-Gottsberger, I., Teichert, H., Gibernau, M., et al. (2012). The Key Role of 4-methyl-5-vinylthiazole in the Attraction of Scarab Beetle Pollinators: A Unique Olfactory Floral Signal Shared by Annonaceae and Araceae. J. Chem. Ecol., 38(9), 1072–1080.
Abstract: Cyclocephaline scarabs are specialised scent-driven pollinators, implicated with the reproductive success of several Neotropical plant taxa. Night-blooming flowers pollinated by these beetles are thermogenic and release intense fragrances synchronized to pollinator activity. However, data on floral scent composition within such mutualistic interactions are scarce, and the identity of behaviorally active compounds involved is largely unknown. We performed GC-MS analyses of floral scents of four species of Annona (magnoliids, Annonaceae) and Caladium bicolor (monocots, Araceae), and demonstrated the chemical basis for the attraction of their effective pollinators. 4-Methyl-5-vinylthiazole, a nitrogen and sulphur-containing heterocyclic compound previously unreported in flowers, was found as a prominent constituent in all studied species. Field biotests confirmed that it is highly attractive to both male and female beetles of three species of the genus Cyclocephala, pollinators of the studied plant taxa. The origin of 4-methyl-5-vinylthiazole in plants might be associated with the metabolism of thiamine (vitamin B1), and we hypothesize that the presence of this compound in unrelated lineages of angiosperms is either linked to selective expression of a plesiomorphic biosynthetic pathway or to parallel evolution. © 2012 Springer Science+Business Media, LLC.
Keywords: Beetle pollination; Floral scent; Gas chromatography-mass spectrometry (GC-MS); Olfactory-mediated attraction
|
Barantal, S., Schimann, H., Fromin, N., & Hattenschwiler, S. (2012). Nutrient and Carbon Limitation on Decomposition in an Amazonian Moist Forest. Ecosystems, 15(7), 1039–1052.
Abstract: Tropical forests determine global biogeochemical cycles to a large extent, but control factors for key ecosystem processes such as decomposition remain poorly understood. With a full-factorial C (cellulose), N (urea), and P (phosphate) fertilization experiment, we tested the relative importance of C and nutrient limitation on litter decomposition in a mature lowland moist forest of French Guiana. Despite the previously demonstrated litter C quality control over decomposition and the very low soil P content (0. 1 mg g -1 of soil) at our study site, fertilization with C or P alone did not increase the decomposition of a wide range of litter types (N:P ratios between 20 and 80). Nitrogen fertilization alone also had no effect on decomposition. However, the combined fertilization with N and P resulted in up to 33. 5% more initial litter mass lost, with an increasing effect with wider litter N:P ratios. Soil fauna strongly stimulated litter mass loss and enhanced nutrient fertilization effects. Moreover, nutrient effects on decomposition increased with additional C fertilization in the presence of fauna. Our results suggest that increased N availability is required for a positive P effect on decomposition in the studied P-poor tropical forest. Further stimulation of decomposition by C amendment through priming indicates energy limitation of decomposers that is co-determined by nutrient availability. The demonstrated intricate control of the key resources C, N, and P on decomposition calls for an intensified research effort on multiple resource limitation on key processes in tropical forests and how they change under multiple human impacts. © 2012 Springer Science+Business Media, LLC.
Keywords: energy limitation; labile carbon; litter quality; nitrogen; phosphorus; priming effect; soil fauna; tropical forest
|
Arranz, S. E., Avarre, J. - C., Balasundaram, C., Bouza, C., Calcaterra, N. B., Cezilly, F., et al. (2013). Permanent Genetic Resources added to Molecular Ecology Resources Database 1 December 2012-31 January 2013. Mol. Ecol. Resour., 13(3), 546–549.
Abstract: This article documents the addition of 268 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Alburnoides bipunctatus, Chamaerops humilis, Chlidonias hybrida, Cyperus papyrus, Fusarium graminearum, Loxigilla barbadensis, Macrobrachium rosenbergii, Odontesthes bonariensis, Pelteobagrus vachelli, Posidonia oceanica, Potamotrygon motoro, Rhamdia quelen, Sarotherodon melanotheron heudelotii, Sibiraea angustata, Takifugu rubripes, Tarentola mauritanica, Trimmatostroma sp. and Wallago attu. These loci were cross-tested on the following species: Alburnoides fasciatus, Alburnoides kubanicus, Alburnoides maculatus, Alburnoides ohridanus, Alburnoides prespensis, Alburnoides rossicus, Alburnoides strymonicus, Alburnoides thessalicus, Alburnoides tzanevi, Carassius carassius, Fusarium asiaticum, Leucaspius delineatus, Loxigilla noctis dominica, Pelecus cultratus, Phoenix canariensis, Potamotrygon falkneri, Trachycarpus fortune and Vimba vimba. © 2013 Blackwell Publishing Ltd.
|
