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Author Lehnebach, R.; Doumerc, L.; Clair, B.; Alméras, T. url  doi
openurl 
  Title Mechanical stress in the inner bark of 15 tropical tree species and the relationship with anatomical structure Type Journal Article
  Year 2020 Publication (up) Botany Abbreviated Journal Bot.  
  Volume 98 Issue 1 Pages 1-8  
  Keywords Bark anatomical structure; Mechanical stress; Sclereids; Secondary phloem; Tree biomechanics; Tropical species  
  Abstract Recent studies have shown that the inner bark is implicated in the postural control of inclined tree stems through the interaction between wood radial growth and tangential expansion of a trellis fiber network in bark. Assessing the taxonomic extent of this mechanism requires a screening of the diversity in bark anatomy and mechanical stress. The mechanical state of bark was measured in 15 tropical tree species from various botanical families on vertical mature trees, and related to the anatomical structure of the bark. Significant tensile or compressive longitudinal stresses were observed in the stems of most species. Tensile longitudinal stress was observed in various botanical families and was always associated with fibers arranged in a trellis-like structure and strong dilatation of rays. The highest tensile stress was recorded in species with gelatinous fibers forming a treillis. Compressive stress was typically associated with a large amount of sclereids in the bark, supporting the differentiation of sclereids as a potential origin of the generation of longitudinal compressive stresses in bark. In species exhibiting both a fibrous trellis structure and a significant amount of sclereids, the sign of longitudinal stress may depend on the balance between these two mechanisms.  
  Address Faculty of Bioscience Engineering, Laboratory of Wood Technology, Woodlab, Coupure Links 653, Gent, B-9000, Belgium  
  Corporate Author Thesis  
  Publisher Canadian Science Publishing Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 19162804 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Cited By :1; Export Date: 20 January 2020; Correspondence Address: Lehnebach, R.; Laboratoire de Mécanique et Génie Civil (LMGC), Université de Montpellier, CNRS, 860 rue de St. Priest, France; email: lehnebach.romain@hotmail.fr Approved no  
  Call Number EcoFoG @ webmaster @ Serial 913  
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Author Dessert, C.; Clergue, C.; Rousteau, A.; Crispi, O.; Benedetti, M.F. url  doi
openurl 
  Title Atmospheric contribution to cations cycling in highly weathered catchment, Guadeloupe (Lesser Antilles) Type Journal Article
  Year 2020 Publication (up) Chemical Geology Abbreviated Journal Chem. Geol.  
  Volume 531 Issue 119354 Pages  
  Keywords Atmospheric deposit; Cation-nutrient recycling; Critical Zone; Saharan dust; Sr and Nd isotopes; Atmospheric chemistry; Biogeochemistry; Catchments; Deposits; Dust; Ecosystems; Forestry; Isotopes; Lakes; Positive ions; Rain; Recycling; Runoff; Soil moisture; Soil surveys; Tropics; Vegetation; Volcanoes; Weathering; Atmospheric deposits; Critical zones; Nutrient recycling; Saharan dust; Sr and Nd isotopes; Nutrients; catchment; cation; dust; isotopic composition; neodymium isotope; regolith; strontium isotope; trace element; water chemistry; water quality; Guadeloupe; Leeward Islands [Lesser Antilles]; Sahara  
  Abstract The important fertilizing role of atmospheric dust, and particularly African dust, in tropical rainforests is increasingly recognized but still poorly quantified. To better evaluate dust input into the Caribbean basin, we sampled critical zone compartments of a small forested volcanic catchment in Guadeloupe (soils, parent rock, atmospheric dust, plants, soil solutions, stream and rain waters). The aims of this study are to track sources of cation nutrients (Ca, Mg, K, Sr) developed on highly weathered soil in the rainforest of Guadeloupe, to quantify plant recycling of these nutrients, and to identify constraints on regolith development and its associated nutrient pool. In the Quiock Creek catchment, a large isotopic range of 87Sr/86Sr and eNd values was observed despite the small scale of observation. Sr isotopic composition of the dissolved load varied from 0.7084 in rainfall to 0.7110 in soil solution, whereas it ranges between 0.7068 and 0.7153 for soil samples and between 0.7096 and 0.7102 for plants. The Nd isotopic composition varied between -8.39 in near-surface soil samples to 2.71 in deeper soil. All samples had an intermediate signature between that of the bedrock endmember (87Sr/86Sr = 0.7038; eNd = 4.8) and the atmospheric endmember (sea salt: 87Sr/86Sr = 0.7092 and Saharan dust: 87Sr/86Sr = 0.7187, eNd=-11.5). The regolith was built on pyroclastic deposits, but, because of extreme leaching, the regolith has lost its original bedrock signature and inherited an exogenous atmospheric signature. Our results show that only the chemical weathering of the fresh near-surface minerals can provide nutrients to the ecosystem (first 30 cm). However, this dust weathering is too low to sustain the tropical forest ecosystem on its own. The cationic mass balance at the catchment scale, as well as the Sr isotopic signature, show that cation and Sr fluxes are of atmospheric origin only and that original bedrock no longer participates in nutrient cycles. The vegetation reflects the 87Sr/86Sr of the dissolved pool of atmospheric Sr. At the soil-plant scale, the cation-nutrient fluxes provided by vegetation (litter fall + leaf excretion) are major compared to input and output fluxes. The annual Ca, K, Sr and Mg fluxes within the vegetation are, respectively, 31, 28, 20 and 3 times greater than the exported fluxes at the outlet of the basin. The residence time of nutrients in the vegetation is 16 years for K and close to 45 years for Sr, Ca and Mg. These results emphasize the highly efficient vegetative turnover that dominates the nutrient cycle in the Quiock Creek catchment. This first characterization of biogeochemical cycles in the Guadeloupean rainforest suggests that the forest community of Quiock Creek is sustained by a small near-surface nutrient pool disconnected from the deep volcanic bedrock. We also demonstrated that, even with efficient nutrient recycling, Saharan dust plays a significant role in maintaining ecosystem productivity in Guadeloupe over long-time scales.  
  Address Laboratoire de biologie et de physiologie végétales, UMR EcoFoG, CNRS, Cirad, INRA, Université des Antilles, Université de Guyane, Pointe-à-Pitre, 97159, France  
  Corporate Author Thesis  
  Publisher Elsevier B.V. Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 00092541 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 18 November 2019; Correspondence Address: Dessert, C.; Université de Paris, Institut de physique du globe de Paris, CNRSFrance; email: dessert@ipgp.fr Approved no  
  Call Number EcoFoG @ webmaster @ Serial 895  
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Author de Aguiar, H.J.A.C.; Barros, L.A.C.; Silveira, L.I.; Petitclerc, F.; Etienne, S.; Orivel, J. pdf  url
doi  openurl
  Title Cytogenetic data for sixteen ant species from North-eastern Amazonia with phylogenetic insights into three subfamilies Type Journal Article
  Year 2020 Publication (up) Comparative Cytogenetics Abbreviated Journal Comp. Cytogenet.  
  Volume 14 Issue 1 Pages 43-60  
  Keywords Biodiversity; Formicidae; Karyotype; Neotropical ants  
  Abstract Ants play essential roles in most terrestrial ecosystems and may be considered pests for agriculture and agroforestry. Recent morphological and molecular data have challenged conventional ant phylogeny and the interpretation of karyotypic variations. Existing Neotropical ant cytogenetic data focus on Atlantic rainforest species, and provide evolutionary and taxonomic insight. However, there are data for only 18 Amazonian species. In this study, we describe the karyotypes of 16 ant species belonging to 12 genera and three subfamilies, collected in the Brazilian state of Amapa, and in French Guiana. The karyotypes of six species are described for the first time, including that of the South American genus Allomerus Mayr, 1878. The karyotype of Crematogaster Lund, 1831 is also described for the first time for the New World. For other species, extant data for geographically distinct populations was compared with our own data, e.g. for the leafcutter ants Acromyrmex balzani (Emery, 1890) and Atta sexdens (Linnaeus, 1758). The information obtained for the karyotype of Dolichoderus imitator Emery, 1894 differs from extant data from the Atlantic forest, thereby highlighting the importance of population cytogenetic approaches. This study also emphasizes the need for good chromosome preparations for studying karyotype structure.  
  Address INRA, UMR EcoFoG, AgroParisTech, CIRAD, CNRS, Université de Guyane, Université des Antilles, Campus Agronomique, BP 316, Kourou Cedex, 97379, France  
  Corporate Author Thesis  
  Publisher Pensoft Publishers Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 19930771 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 917  
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Author Privet, K.; Vedel, V.; Fortunel, C.; Orivel, J.; Martinez, Q.; Cerdan, A.; Baraloto, C.; Pétillon, J. pdf  url
doi  openurl
  Title Relative effciency of pitfall trapping vs. nocturnal hand collecting in assessing soil-dwelling spider diversity along a structural gradient of neotropical habitats Type Journal Article
  Year 2020 Publication (up) Diversity Abbreviated Journal Diversity  
  Volume 12 Issue 2 Pages 81  
  Keywords Araneae; Diversity indices; Functional diversity; Guiana shield; Sampling methods; Species richness; Turnover; Araneae  
  Abstract Assessing spider diversity remains a great challenge, especially in tropical habitats where dozens of species can locally co-occur. Pitfall trapping is one of the most widely used techniques to collect spiders, but it suffers from several biases, and its accuracy likely varies with habitat complexity. In this study, we compared the efficiency of passive pitfall trapping versus active nocturnal hand collecting (\"HC) to capture low understory-dwelling spider taxonomical (morpho-species) and functional (hunting guilds) diversity along a structural gradient of habitats in French Guiana. We focused on four habitats describing a structural gradient: garden to the orchard to the forest edge to the undisturbed forest. Overall, estimated morpho-species richness and composition did not vary consistently between habitats, but abundances of ground-hunting spiders decreased significantly with increasing habitat complexity. We found habitat-dependence differences in taxonomic diversity between sampling strategies: NHC revealed higher diversity in the orchard, whereas pitfalls resulted in higher diversity in the forest. Species turnover resulted in high dissimilarity in species composition between habitats using either method. This study shows how pitfall trapping is influenced by habitat structure, rendering this sampling method incomplete for complex, tropical environments. However, pitfall traps remain a valuable component of inventories because they sample distinct assemblage of spiders. © 2020 by the authors.  
  Address International Center for Tropical Botany, Department of Biological Sciences, Florida International University, 11200 S.W. 8th Street, Miami, FL 33199, United States  
  Corporate Author Thesis  
  Publisher Mdpi Ag Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 14242818 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Export Date: 16 March 2020; Correspondence Address: Privet, K.; CNRS, Ecobio (Ecosystèmes, biodiversité, évolution), Université de RennesFrance; email: kprivet@hotmail.fr Approved no  
  Call Number EcoFoG @ webmaster @ Serial 923  
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Author Chave, J.; Piponiot, C.; Maréchaux, I.; de Foresta, H.; Larpin, D.; Fischer, F.J.; Derroire, G.; Vincent, G.; Hérault, B. url  doi
openurl 
  Title Slow rate of secondary forest carbon accumulation in the Guianas compared with the rest of the Neotropics Type Journal Article
  Year 2020 Publication (up) Ecological Applications Abbreviated Journal Ecol. Appl.  
  Volume 30 Issue 1 Pages e02004  
  Keywords biomass; carbon; forest; French Guiana; regeneration; secondary forests; tropics; accumulation rate; Bayesian analysis; biomass; carbon sequestration; chronosequence; fertility; old-growth forest; pioneer species; regeneration; secondary forest; Costa Rica; French Guiana; Guyana Shield; Goupia glabra; Laetia procera; Xylopia  
  Abstract Secondary forests are a prominent component of tropical landscapes, and they constitute a major atmospheric carbon sink. Rates of carbon accumulation are usually inferred from chronosequence studies, but direct estimates of carbon accumulation based on long-term monitoring of stands are rarely reported. Recent compilations on secondary forest carbon accumulation in the Neotropics are heavily biased geographically as they do not include estimates from the Guiana Shield. We analysed the temporal trajectory of aboveground carbon accumulation and floristic composition at one 25-ha secondary forest site in French Guiana. The site was clear-cut in 1976, abandoned thereafter, and one large plot (6.25 ha) has been monitored continuously since. We used Bayesian modeling to assimilate inventory data and simulate the long-term carbon accumulation trajectory. Canopy change was monitored using two aerial lidar surveys conducted in 2009 and 2017. We compared the dynamics of this site with that of a surrounding old-growth forest. Finally, we compared our results with that from secondary forests in Costa Rica, which is one of the rare long-term monitoring programs reaching a duration comparable to our study. Twenty years after abandonment, aboveground carbon stock was 64.2 (95% credibility interval 46.4, 89.0) Mg C/ha, and this stock increased to 101.3 (78.7, 128.5) Mg C/ha 20 yr later. The time to accumulate one-half of the mean aboveground carbon stored in the nearby old-growth forest (185.6 [155.9, 200.2] Mg C/ha) was estimated at 35.0 [20.9, 55.9] yr. During the first 40 yr, the contribution of the long-lived pioneer species Xylopia nitida, Goupia glabra, and Laetia procera to the aboveground carbon stock increased continuously. Secondary forest mean-canopy height measured by lidar increased by 1.14 m in 8 yr, a canopy-height increase consistent with an aboveground carbon accumulation of 7.1 Mg C/ha (or 0.89 Mg C·ha−1·yr−1) during this period. Long-term AGC accumulation rate in Costa Rica was almost twice as fast as at our site in French Guiana. This may reflect higher fertility of Central American forest communities or a better adaptation of the forest tree community to intense and frequent disturbances. This finding may have important consequences for scaling-up carbon uptake estimates to continental scales.  
  Address INPHB, Institut National Polytechnique Félix Houphouët-Boigny, Yamoussoukro, Cote d'Ivoire  
  Corporate Author Thesis  
  Publisher Ecological Society of America Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 19395582 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 914  
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Author Céréghino, R.; Françoise, L.; Bonhomme, C.; Carrias, J.-F.; Compin, A.; Corbara, B.; Jassey, V.; Leflaive, J.; Rota, T.; Farjalla, V.; Leroy, C. doi  openurl
  Title Desiccation resistance traits predict freshwater invertebrate survival and community response to drought scenarios in a Neotropical ecosystem Type Journal Article
  Year 2020 Publication (up) Ecological Indicators Abbreviated Journal Ecol. Indic.  
  Volume 119 Issue 106839 Pages  
  Keywords 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  
  Abstract 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  
  Address ECOFOG, AgroParisTech, CIRAD, CNRS, INRA, Université de Guyane, Université des Antilles, Campus Agronomique, Kourou, 97379, France  
  Corporate Author Thesis  
  Publisher Elsevier B.V. Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1470160x (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 941  
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Author Srivastava, D.S.; Céréghino, R.; Trzcinski, M.K.; MacDonald, A.A.M.; Marino, N.A.C.; Mercado, D.A.; Leroy, C.; Corbara, B.; Romero, G.Q.; Farjalla, V.F.; Barberis, I.M.; Dézerald, O.; Hammill, E.; Atwood, T.B.; Piccoli, G.C.O.; Ospina-Bautista, F.; Carrias, J.-F.; Leal, J.S.; Montero, G.; Antiqueira, P.A.P.; Freire, R.; Realpe, E.; Amundrud, S.L.; de Omena, P.M.; Campos, A.B.A. doi  openurl
  Title Ecological response to altered rainfall differs across the Neotropics Type Journal Article
  Year 2020 Publication (up) Ecology Abbreviated Journal Ecology  
  Volume 101 Issue 4 Pages e02984  
  Keywords contingency; distributed experiment; freshwater; global change biology; macroinvertebrates; phytotelmata; precipitation; aquatic ecosystem; climate change; climate conditions; ecosystem response; extreme event; functional group; invertebrate; Neotropical Region; rainfall; species pool; Bacteria (microorganisms); Invertebrata; rain; animal; climate change; drought; ecosystem; invertebrate; Animals; Climate Change; Droughts; Ecosystem; Invertebrates; Rain  
  Abstract There is growing recognition that ecosystems may be more impacted by infrequent extreme climatic events than by changes in mean climatic conditions. This has led to calls for experiments that explore the sensitivity of ecosystems over broad ranges of climatic parameter space. However, because such response surface experiments have so far been limited in geographic and biological scope, it is not clear if differences between studies reflect geographic location or the ecosystem component considered. In this study, we manipulated rainfall entering tank bromeliads in seven sites across the Neotropics, and characterized the response of the aquatic ecosystem in terms of invertebrate functional composition, biological stocks (total invertebrate biomass, bacterial density) and ecosystem fluxes (decomposition, carbon, nitrogen). Of these response types, invertebrate functional composition was the most sensitive, even though, in some sites, the species pool had a high proportion of drought-tolerant families. Total invertebrate biomass was universally insensitive to rainfall change because of statistical averaging of divergent responses between functional groups. The response of invertebrate functional composition to rain differed between geographical locations because (1) the effect of rainfall on bromeliad hydrology differed between sites, and invertebrates directly experience hydrology not rainfall and (2) the taxonomic composition of some functional groups differed between sites, and families differed in their response to bromeliad hydrology. These findings suggest that it will be difficult to establish thresholds of “safe ecosystem functioning” when ecosystem components differ in their sensitivity to climatic variables, and such thresholds may not be broadly applicable over geographic space. In particular, ecological forecast horizons for climate change may be spatially restricted in systems where habitat properties mediate climatic impacts, and those, like the tropics, with high spatial turnover in species composition. © 2020 by the Ecological Society of America  
  Address Departamento de Ciencias Biológicas, Universidad de Caldas, Caldas, 170001, Colombia  
  Corporate Author Thesis  
  Publisher Ecological Society of America Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 00129658 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 979  
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Author Tysklind, N.; Etienne, M.-P.; Scotti-Saintagne, C.; Tinaut, A.; Casalis, M.; Troispoux, V.; Cazal, S.-O.; Brousseau, L.; Ferry, B.; Scotti, I. doi  openurl
  Title Microgeographic local adaptation and ecotype distributions: The role of selective processes on early life-history traits in sympatric, ecologically divergent Symphonia populations Type Journal Article
  Year 2020 Publication (up) Ecology and Evolution Abbreviated Journal Ecology and Evolution  
  Volume 10 Issue 19 Pages 10735-10753  
  Keywords determinants of plant community diversity and structure; evolutionary ecology; landscape ecology; local adaptation; Neotropical forest; plant development and life-history traits; reciprocal transplantation experiments; Symphonia  
  Abstract Trees are characterized by the large number of seeds they produce. Although most of those seeds will never germinate, plenty will. Of those which germinate, many die young, and eventually, only a minute fraction will grow to adult stage and reproduce. Is this just a random process? Do variations in germination and survival at very young stages rely on variations in adaptations to microgeographic heterogeneity? and do these processes matter at all in determining tree species distribution and abundance?. We have studied these questions with the Neotropical Symphonia tree species. In the Guiana shield, Symphonia are represented by at least two sympatric taxa or ecotypes, Symphonia globulifera found almost exclusively in bottomlands, and a yet undescribed more generalist taxon/ecotype, Symphonia sp1. A reciprocal transplantation experiment (510 seeds, 16 conditions) was set up and followed over the course of 6 years to evaluate the survival and performance of individuals from different ecotypes and provenances. Germination, survival, growth, and herbivory showed signs of local adaptation, with some combinations of ecotypes and provenances growing faster and surviving better in their own habitat or provenance region. S. globulifera was strongly penalized when planted outside its home habitat but showed the fastest growth rates when planted in its home habitat, suggesting it is a specialist of a high-risk high-gain strategy. Conversely, S. sp1 behaved as a generalist, performing well in a variety of environments. The differential performance of seeds and seedlings in the different habitats matches the known distribution of both ecotypes, indicating that environmental filtering at the very early stages can be a key determinant of tree species distributions, even at the microgeographic level and among very closely related taxa. Furthermore, such differential performance also contributes to explain, in part, the maintenance of the different Symphonia ecotypes living in intimate sympatry despite occasional gene flow. © 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd  
  Address UMR AMAP, IRD, Cirad, CNRS, INRAE, Université Montpellier, Montpellier, France  
  Corporate Author Thesis  
  Publisher John Wiley and Sons Ltd Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 20457758 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 951  
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Author Binelli, G.; Montaigne, W.; Sabatier, D.; Scotti-Saintagne, C.; Scotti, I. doi  openurl
  Title Discrepancies between genetic and ecological divergence patterns suggest a complex biogeographic history in a Neotropical genus Type Journal Article
  Year 2020 Publication (up) Ecology and Evolution Abbreviated Journal Ecology and Evolution  
  Volume 10 Issue 11 Pages 4726-4738  
  Keywords allopatric divergence; Amazon; Guiana Shield; interspecific gene flow; Myristicaceae; secondary contact; Virola  
  Abstract Phylogenetic patterns and the underlying speciation processes can be deduced from morphological, functional, and ecological patterns of species similarity and divergence. In some cases, though, species retain multiple similarities and remain almost indistinguishable; in other cases, evolutionary convergence can make such patterns misleading; very often in such cases, the “true” picture only emerges from carefully built molecular phylogenies, which may come with major surprises. In addition, closely related species may experience gene flow after divergence, thus potentially blurring species delimitation. By means of advanced inferential methods, we studied molecular divergence between species of the Virola genus (Myristicaceae): widespread Virola michelii and recently described, endemic V. kwatae, using widespread V. surinamensis as a more distantly related outgroup with different ecology and morphology—although with overlapping range. Contrary to expectations, we found that the latter, and not V. michelii, was sister to V. kwatae. Therefore, V. kwatae probably diverged from V. surinamensis through a recent morphological and ecological shift, which brought it close to distantly related V. michelii. Through the modeling of the divergence process, we inferred that gene flow between V. surinamensis and V. kwatae stopped soon after their divergence and resumed later, in a classical secondary contact event which did not erase their ecological and morphological differences. While we cannot exclude that initial divergence occurred in allopatry, current species distribution and the absence of geographical barriers make complete isolation during speciation unlikely. We tentatively conclude that (a) it is possible that divergence occurred in allopatry/parapatry and (b) secondary contact did not suppress divergence. © 2020 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.  
  Address INRAE, URFM, Avignon, France  
  Corporate Author Thesis  
  Publisher John Wiley and Sons Ltd Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 20457758 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 963  
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Author Sardans, J.; Urbina, I.; Grau, O.; Asensio, D.; Ogaya, R.; Peñuelas, J. doi  openurl
  Title Long-term drought decreases ecosystem C and nutrient storage in a Mediterranean holm oak forest Type Journal Article
  Year 2020 Publication (up) Environmental and Experimental Botany Abbreviated Journal Environ. Exp. Bot.  
  Volume 177 Issue 104135 Pages  
  Keywords Aridity; Carbon stocks; Climate change; Nitrogen; Phosphorus; Potassium; Stoichiometry; carbon sequestration; deciduous forest; drought; experimental study; forest soil; long-term change; Mediterranean environment; net ecosystem exchange; nutrient cycling; shrub; stoichiometry; Mediterranean Sea; Phillyrea latifolia  
  Abstract Aridity has increased in recent decades in the Mediterranean Basin and is projected to continue to increase in the coming decades. We studied the consequences of drought on the concentrations, stoichiometries and stocks of carbon (C), nitrogen (N), phosphorus (P) and potassium (K) in leaves, foliar litter of a three dominant woody species and soil of a Mediterranean montane holm oak forest where soil-water content was experimentally reduced (15 % lower than the control plots) for 15 years. Nitrogen stocks were lower in the drought plots than in the control plots (8.81 ± 1.01 kg ha−1 in the forest canopy and 856 ± 120 kg ha−1 in the 0−15 cm soil layer), thus representing 7 and 18 % lower N stocks in the canopy and soil respectively. δ15N was consistently higher under drought conditions in all samples, indicating a general loss of N. Foliar C and K stocks were also lower but to a lesser extent than N. Decreases in biomass and C and N stocks due to drought were smallest for the most dominant tall shrub, Phillyrea latifolia, so our results suggest a lower capacity of this forest to store C and nutrients but also substantial resulting changes in forest structure with increasing drought. © 2020 Elsevier B.V.  
  Address Cirad, UMR EcoFoG (AgroParisTech, CNRS, Inra, Univ Antilles, Univ Guyane), Campus Agronomique, Kourou, 97310, French Guiana  
  Corporate Author Thesis  
  Publisher Elsevier B.V. Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 00988472 (Issn) ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number EcoFoG @ webmaster @ Serial 954  
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