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Dejean, A.; Compin, A.; Delabie, J.H.C.; Azémar, F.; Corbara, B.; Leponce, M. |
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Biotic and abiotic determinants of the formation of ant mosaics in primary Neotropical rainforests |
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2019 |
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Ecological Entomology |
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Ecol Entomol |
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44 |
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4 |
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560-570 |
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Ant mosaics; connections on the ground; host tree attractiveness; indicators of disturbance; primary Neotropical rainforest; territoriality |
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1. Ants are widespread in tropical rainforests, including in the canopy where territorially dominant arboreal species represent the main part of the arthropod biomass.
2. By mapping the territories of dominant arboreal ant species and using a null model analysis and a pairwise approach this study was able to show the presence of an ant mosaic on the upper canopy of a primary Neotropical rainforest (c. 1ha sampled; 157 tall trees from 28 families). Although Neotropical rainforest canopies are frequently irregular, with tree crowns at different heights breaking the continuity of the territories of dominant ants, the latter are preserved via underground galleries or trails laid on the ground.
3. The distribution of the trees influences the structure of the ant mosaic, something related to the attractiveness of tree taxa for certain arboreal ant species rather than others.
4. Small-scale natural disturbances, most likely strong winds in the area studied (presence of canopy gaps), play a role by favouring the presence of two ant species typical of secondary formations: Camponotus femoratus and Crematogaster levior, which live in parabiosis (i.e. share territories and nests but lodge in different cavities) and build conspicuous ant gardens. In addition, pioneer Cecropia myrmecophytic trees were recorded. |
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John Wiley & Sons, Ltd (10.1111) |
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doi: 10.1111/een.12735 |
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EcoFoG @ webmaster @ |
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882 |
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Schimann, H.; Petit-Jean, C.; Guitet, S.; Reis, T.; Domenach, A.M.; Roggy, J.-C. |
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Microbial bioindicators of soil functioning after disturbance: The case of gold mining in tropical rainforests of French Guiana |
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2012 |
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Ecological Indicators |
Abbreviated Journal |
Ecol. Indic. |
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20 |
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34-41 |
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Bioindicators; DEA/SIR ratio; Denitrifying Enzyme Activity (DEA); Disturbance; Substrate Induced Respiration (SIR); Tropical rainforest |
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In the context of an ongoing monitoring study on the impacts of gold-mining activities on critical ecosystem processes, we explored the use of soil Denitrifying Enzyme Activity (DEA) and Substrate Induced Respiration (SIR) as ecosystem indicators in tropical rainforests of French Guiana. We also propose DEA/SIR ratio as ecosystem attribute able to describe the state of an ecosystem and to reflect changes in ecological processes. With this purpose, we measured SIR, DEA and DEA/SIR ratio in five gold-mining areas and five surrounding natural reference rainforests. We also measured indicators in two conditions of spontaneous regeneration of vegetation (stratified or not) and two conditions of soil rehabilitation (prior preparation of soils or not). We showed a high variability of DEA, SIR and DEA/SIR ratio in the natural reference forests. This pointed out the necessity to identify relevant reference systems – i.e. proving a close match in all relevant ecological dimensions – to compare with closed perturbed systems in order to assess the levels of alterations after disturbances. Results showed a high impact of gold mine on microbial processes with a strong decrease of DEA (10-fold lower), SIR (2-fold lower) and DEA/SIR ratio (8-fold lower) in perturbed areas in comparison with natural reference forests. The type of spontaneous vegetation (stratified or not) influenced the values of indicators as well as prior rehabilitation of soils, demonstrating the capacity of DEA, SIR and DEA/SIR ratio to respond in proportion to the perturbation (robustness) and to the different levels of restoration (sensitivity). The systematic decrease of the ratio DEA/SIR observed in the studied perturbed situations demonstrates clearly that the structure of microbial communities has been also modified. The ratio DEA/SIR proved to be robust and sensitive, and able to describe in fairly fine way changes of soil microbial communities in terms of structure and function in gold mine areas and during processes of restoration. We propose to use DEA, SIR and DEA/SIR ratio as bioindicators of both structural and functional aspects of C and N cycling in soils. Together with others bioindicators based on key supporting functions in soils, these indicators should accurately evaluate the ecological potential of natural ecosystems and the levels of degradation in case of land-use changes. © 2012 Elsevier Ltd. |
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SOLICAZ – Campus Agronomique, BP 76, 97389 Kourou Cedex, France |
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1470160x (Issn) |
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Export Date: 2 May 2012; Source: Scopus; doi: 10.1016/j.ecolind.2012.01.021; Language of Original Document: English; Correspondence Address: Schimann, H.; INRA-Joint Research Unit Ecology of Guiana Forests (Ecofog), Campus Agronomique, BP 709, 97387 Kourou Cedex, France; email: heidy.schimann@ecofog.gf |
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EcoFoG @ webmaster @ |
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396 |
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Talaga, S.; Delabie, J.H.C.; Dezerald, O.; Salas-Lopez, A.; Petitclerc, F.; Leroy, C.; Herault, B.; Céréghino, R.; Dejean, A. |
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A bromeliad species reveals invasive ant presence in urban areas of French Guiana |
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2015 |
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Ecological Indicators |
Abbreviated Journal |
Ecological Indicators |
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58 |
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1-7 |
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Aechmea aquilega; Bioindicators; Non-specific ant-plant relationships; Surrogacy; Tank bromeliads; Urban ecology |
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Tank bromeliads, frequently associated with ants, are considered 'biodiversity amplifiers' for both aquatic and terrestrial organisms, and thus have a high ecological value. The focal species of this study, Aechmea aquilega, sheltered the colonies of 12 ant species in a Guianese rural habitat where Odontomachus haematodus, associated with 60% of these plants, was the most frequent. Unexpectedly, the ant species richness was higher in a compared urban habitat with 21 species, but two synanthropic and four invasive ants were noted among them. Consequently, we conducted baiting surveys (on the ground, on trees and on trees bearing A. aquilega) as well as complementary surveys using different sampling modes in urban areas to test if A. aquilega is a surrogate revealing the presence of certain invasive ants. During the baiting survey, we recorded four Neotropical and eight introduced invasive ants out of a total of 69 species. Of these 12 invasive species, five were noted by baiting A. aquilega (including two only noted in this way). A bootstrap simulation permitted us to conclude that A. aquilega significantly concentrates certain species of invasive ants. This was confirmed by complementary surveys, where we did not record further species. We conclude that baiting on trees bearing large epiphytes in human-modified, Neotropical areas is a relevant complement to the early detection of invasive ants. © 2015 Elsevier Ltd. All rights reserved. |
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CNRS Ecolab (UMR-CNRS 5245), 118 Route de Narbonne, Toulouse, France |
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Export Date: 23 June 2015 |
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EcoFoG @ webmaster @ |
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607 |
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Salas-Lopez, A. |
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Predicting resource use in ant species and entire communities by studying their morphological traits: Influence of habitat and subfamily |
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Journal Article |
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2017 |
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Ecological Indicators |
Abbreviated Journal |
Ecol. Indic. |
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78 |
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183-191 |
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Biodiversity-ecosystem functioning relationships; Ecosystem process; Food niche; Formicidae; Habitat filtering; Indicator; Land-use; Morphological traits; Taxonomic conservatism; Biodiversity; Ecology; Indicators (instruments); Land use; Natural resources management; Ecosystem functioning; Ecosystem process; Formicidae; Morphological traits; Taxonomic conservatism; Ecosystems; Formicidae |
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I investigated whether the morphological traits of Neotropical ants can be used to infer food resource use by individual species and by entire communities, and whether these relationships are related to habitat type and/or by morphological differences between ant subfamilies. I attracted ants using food baits that represented different ecological processes (e.g. predation, granivory, detritivory, nectarivory) in five habitat types along a land-use gradient (from forests to gardens). I assessed ant activity at the baits and characterized 64 species from six subfamilies according to their food use and community-level resource exploitation intensity in the different habitats. Next, I performed a Mantel test to reveal the relationships between 13 morphological measures and resource use at the species level. I then used ant clades (i.e. subfamily) and habitat to rank the ants along three axes of variation in relation to their morphology and food resource use. Finally, I tested whether associations existed between the community-level exploitation intensity for such resources and the distribution of morphological trait values using the “4th-corner” analysis. Morphological traits were closely linked to the species’ ability to exploit different resources. These relationships were affected by subfamily and, to a lesser extent, by habitat type. The characterization of trait sets for entire communities was not useful, however, in predicting the intensity of the exploitation of different types of resources in varying environmental conditions. I conclude that morphological traits are accurate predictors of the ecology of species, but they should be used with caution when trying to understand community-level patterns. © 2017 Elsevier Ltd |
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Export Date: 8 April 2017 |
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EcoFoG @ webmaster @ |
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747 |
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Jona Lasinio, G.; Pollice, A.; Marcon, E.; Fano, E.A. |
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Assessing the role of the spatial scale in the analysis of lagoon biodiversity. A case-study on the macrobenthic fauna of the Po River Delta |
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Journal Article |
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2017 |
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Ecological Indicators |
Abbreviated Journal |
Ecological Indicators |
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80 |
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303-315 |
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Biodiversity partitioning; Lagoon biodiversity; Macrobenthic fauna; Mixed effects models; Tsallis entropy |
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The analysis of benthic assemblages is a valuable tool to describe the ecological status of transitional water ecosystems, but species are extremely sensitive and respond to both microhabitat and seasonal differences. The identification of changes in the composition of the macrobenthic community in specific microhabitats can then be used as an “early warning” for environmental changes which may affect the economic and ecological importance of lagoons, through their provision of Ecosystem Services. From a conservational point of view, the appropriate definition of the spatial aggregation level of microhabitats or local communities is of crucial importance. The main objective of this work is to assess the role of the spatial scale in the analysis of lagoon biodiversity. First, we analyze the variation in the sample coverage for alternative aggregations of the monitoring stations in three lagoons of the Po River Delta. Then, we analyze the variation of a class of entropy indices by mixed effects models, properly accounting for the fixed effects of biotic and abiotic factors and random effects ruled by nested sources of variability corresponding to alternative definitions of local communities. Finally, we address biodiversity partitioning by a generalized diversity measure, namely the Tsallis entropy, and for alternative definitions of the local communities. The main results obtained by the proposed statistical protocol are presented, discussed and framed in the ecological context. © 2017 Elsevier Ltd |
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Dipartimento di Scienze della Vita e Biotecnologie, Università degli Studi di Ferrara, Ferrara, Italy |
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Export Date: 12 June 2017 |
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EcoFoG @ webmaster @ |
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755 |
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Groc, S.; Delabie, J.H.C.; Fernandez, F.; Petitclerc, F.; Corbara, B.; Leponce, M.; Céréghino, R.; Dejean, A. |
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Litter-dwelling ants as bioindicators to gauge the sustainability of small arboreal monocultures embedded in the Amazonian rainforest |
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2017 |
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Ecological Indicators |
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82 |
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43-49 |
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Ant diversity; Community alteration; Forest species; Functional traits; Human disturbance; Tree monocultures |
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One of the greatest threats to biodiversity and the sustainable functioning of ecosystems is the clearing of forests for agriculture. Because litter-dwelling ants are very good bioindicators of man-made disturbance, we used them to compare monospecific plantations of acacia trees, cocoa trees, rubber trees and pine trees with the surrounding Neotropical rainforest (in contrast to previous studies on forest fragments embedded in industrial monocultures). Although the global level of species turnover was weak, species richness decreased along a gradient from the forest (including a treefall gap) to the tree plantations among which the highest number of species was noted for the cocoa trees, which are known to be a good compromise between agriculture and conservation. Species composition was significantly different between natural habitats and the plantations that, in turn, were different from each other. Compared to the forest, alterations in the ant communities were (1) highest for the acacia and rubber trees, (2) intermediate for the cocoa trees, and, (3) surprisingly, far lower for the pine trees, likely due to very abundant litter. Functional traits only separated the rubber tree plantation from the other habitats due to the higher presence of exotic and leaf-cutting ants. This study shows that small monospecific stands are likely sustainable when embedded in the rainforest and that environmentally-friendly strategies can be planned accordingly. © 2017 Elsevier Ltd |
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Ecolab, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France |
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Export Date: 9 July 2017 |
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758 |
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Céréghino, R.; Corbara, B.; Hénaut, Y.; Bonhomme, C.; Compin, A.; Dejean, A. |
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Ant and spider species as surrogates for functional community composition of epiphyte-associated invertebrates in a tropical moist forest |
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2019 |
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Ecological Indicators |
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96 |
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694-700 |
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Functional traits; Indicator species; Phytotelmata; Rainforests; Surrogacy; Tank bromeliads |
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Epiphytes represent up to 50% of all plant species in rainforests, where they host a substantial amount of invertebrate biomass. Efficient surrogates for epiphyte invertebrate communities could reduce the cost of biomonitoring surveys while preventing destructive sampling of the plants. Here, we focus on the invertebrate communities associated to tank bromeliads. We ask whether the presence of particular ant and/or spider taxa (easily surveyed taxa) that use these plants as nesting and/or foraging habitats predicts functional trait combinations of aquatic invertebrate communities hosted by the plants. Functional community composition of invertebrates was predicted both by bromeliad habitat features and the presence of certain ant and spider species. The ant Azteca serica preferred wider bromeliad rosettes that trap large amount of detritus, indicating interstitial-like food webs dominated by deposit feeders that burrow in fine particulate organic matter. Leucauge sp. spiders preferred narrower bromeliad rosettes bearing smaller detrital loads, thereby indicating a dominance of pelagic filter-feeding and predatory invertebrates in the water-filled leaf axils. Both Neoponera villosa ants and Eriophora sp. spiders preferred rosettes at intermediate size bearing moderate amounts of detritus, indicating a benthic food web dominated by leaf shredders and gathering collectors. Owing to the animal diversity and biomass supported by rainforest epiphytes, our approach would deserve to be further tested on a range of epiphytes involved in tight interactions with invertebrates. In this context, surrogate species could serve both as indicators of functional diversity, and as early-warning indicators of network disassembly. |
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1470-160x |
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841 |
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Céréghino, R.; Françoise, L.; Bonhomme, C.; Carrias, J.-F.; Compin, A.; Corbara, B.; Jassey, V.; Leflaive, J.; Rota, T.; Farjalla, V.; Leroy, C. |
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Desiccation resistance traits predict freshwater invertebrate survival and community response to drought scenarios in a Neotropical ecosystem |
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2020 |
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Ecological Indicators |
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Ecol. Indic. |
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119 |
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106839 |
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Climate change; Functional traits; Lt50; Macroinvertebrates; Rainforests; Biodiversity; Climate change; Driers (materials); Drought; Environmental management; Population statistics; Tanks (containers); Water; Aquatic invertebrates; Climate change adaptation; Controlled conditions; Environmental managers; Freshwater biodiversity; Freshwater invertebrates; Future climate scenarios; Laboratory conditions; Aquatic organisms; aquatic community; biodiversity; climate change; cuticle; desiccation; drought stress; invertebrate; Neotropical Region; population size; survival; French Guiana; Invertebrata |
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The intensification of dry seasons is a major threat to freshwater biodiversity in Neotropical regions. Little is known about resistance to drying stress and the underpinning traits in Neotropical freshwater species, so we don't know whether desiccation resistance allows to anticipate shifts in biological diversity under future climate scenarios. Here, we used the aquatic invertebrates that live in the rainwater-filled leaves of tank bromeliads, to examine the extent to which desiccation resistance of species measured in the laboratory predicts community response to drought intensification in nature. We measured desiccation resistance in 17 invertebrate species (>90% of the biomass usually found in bromeliads of French Guiana) by recording the median lethal time (LT50) of experimental populations exposed to controlled conditions of residual moisture. In the field, we placed rainshelters above tank bromeliads to emulate drought scenarios ranging from the ambient norm to IPCC scenarios and extreme events, and we recorded the response of functional community structure. LT50 ranged from 4.18 to 19.06 days, and was related to cuticle content and dry body mass. Among other functional indicators that represent strategies to optimize resource use under stressful conditions (e.g., habitat use, trophic specialization), LT50 was the best predictor of community structure responses along a gradient of emulated drought intensities. Therefore, species’ LT50s measured under laboratory conditions can be used to forecast aquatic community response to drying stress in nature. Anticipating how species will cope with drought has never been more important for environmental managers to support climate change adaptation. We show that desiccation resistance in freshwater invertebrates is a key indicator of potential population size and local–global range shifts, and this could be especially true in the Neotropics where species have narrow physiological tolerances for climatic variation. © 2020 Elsevier Ltd |
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ECOFOG, AgroParisTech, CIRAD, CNRS, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, Kourou, 97379, France |
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Elsevier B.V. |
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EcoFoG @ webmaster @ |
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941 |
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Picard, N.; Mortier, F.; Rossi, V.; Gourlet-Fleury, S. |
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Clustering species using a model of population dynamics and aggregation theory |
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2010 |
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Ecological Modelling |
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Ecol. Model. |
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221 |
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2 |
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152-160 |
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Aggregation theory; Species grouping; Species richness; Tropical rainforest; Usher model |
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The high species diversity of some ecosystems like tropical rainforests goes in pair with the scarcity of data for most species. This hinders the development of models that require enough data for fitting. The solution commonly adopted by modellers consists in grouping species to form more sizeable data sets. Classical methods for grouping species such as hierarchical cluster analysis do not take account of the variability of the species characteristics used for clustering. In this study a clustering method based on aggregation theory is presented. It takes account of the variability of species characteristics by searching for the grouping that minimizes the quadratic error (square bias plus variance) of some model's prediction. This method allows one to check whether the gain in variance brought by data pooling compensate for the bias that it introduces. This method was applied to a data set on 94 tree species in a tropical rainforest in French Guiana, using a Usher matrix model to predict species dynamics. An optimal trade-off between bias and variance was found when grouping species. Grouping species appeared to decrease the quadratic error, except when the number of groups was very small. This clustering method yielded species groups similar to those of the hierarchical cluster analysis using Ward's method when variance was small, that is when the number of groups was small. (C) 2009 Elsevier B.V. All rights reserved. |
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[Picard, Nicolas; Mortier, Frederic; Rossi, Vivien; Gourlet-Fleury, Sylvie] CIRAD, F-34398 Montpellier 5, France, Email: nicolas.picard@cirad.fr |
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ELSEVIER SCIENCE BV |
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0304-3800 |
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ISI:000273628800004 |
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Call Number |
EcoFoG @ eric.marcon @ |
Serial |
85 |
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Author |
Flores, O.; Rossi, V.; Mortier, F. |
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Title |
Autocorrelation offsets zero-inflation in models of tropical saplings density |
Type |
Journal Article |
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Year |
2009 |
Publication |
Ecological Modelling |
Abbreviated Journal |
Ecol. Model. |
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Volume |
220 |
Issue |
15 |
Pages |
1797-1809 |
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Keywords |
Hierarchical Bayesian Modelling; Conditional Auto-Regressive model; Variable selection; Zero-Inflated Poisson; Posterior predictive; Paracou; French Guiana |
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Abstract |
Modelling the local density of tropical saplings can provide insights into the ecological processes that drive species regeneration and thereby help predict population recovery after disturbance. Yet, few studies have addressed the challenging issues in autocorrelation and zero-inflation of local density. This paper presents Hierarchical Bayesian Modelling (HBM) of sapling density that includes these two features. Special attention is devoted to variable selection, model estimation and comparison. We developed a Zero-Inflated Poisson (ZIP) model with a latent correlated spatial structure and compared it with non-spatial ZIP and Poisson models that were either autocorrelated (Spatial Generalized Linear Mixed, SGLM) or not (generalized linear models, GLM). In our spatial models, local density autocorrelation was modeled by a Conditional Auto-Regressive (CAR) process. 13 explicative variables described ecological conditions with respect to topography, disturbance, stand structure and intraspecific processes. Models were applied to six tropical tree species with differing biological attributes: Oxandra asbeckii, Eperua falcata, Eperua grandiflora, Dicorynia guianensis, Qualea rosea, and Tachigali melinonii. We built species-specific models using a simple method of variable selection based on a latent binary indicator. Our spatial models showed a close correlation between observed and estimated densities with site spatial structure being correctly reproduced. By contrast, the non-spatial models showed poor fits. Variable selection highlighted species-specific requirements and susceptibility to local conditions. Model comparison overall showed that the SGLM was the most accurate explanatory and predictive model. Surprisingly, zero-inflated models performed less well. Although the SZIP model was relevant with respect to data distribution, and more flexible with respect to response curves, its model complexity caused marked variability in parameter estimates. In the SUM, the spatial process alone accounted for zero-inflation in the data. A refinement of the hypotheses employed at the process level could compensate for distribution flaws at the data level. This study emphasized the importance of the HBM framework in improving the modelling of density-environment relationships. (C) 2008 Elsevier B.V. All rights reserved. |
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Address |
[Flores, O.] CNRS, Ctr Ecol Fonct & Evolut, UMR 5175, F-34293 Montpellier 5, France, Email: olivierflores@free.fr |
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Publisher |
ELSEVIER SCIENCE BV |
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Series Volume |
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Edition |
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ISSN |
0304-3800 |
ISBN |
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Notes |
ISI:000267585400007 |
Approved |
no |
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Call Number |
EcoFoG @ eric.marcon @ |
Serial |
201 |
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