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Author Legeay, J.; Husson, C.; Boudier, B.; Louisanna, E.; Baraloto, C.; Schimann, H.; Marcais, B.; Buée, M.
Title Surprising low diversity of the plant pathogen Phytophthora in Amazonian forests Type Journal Article
Year 2020 Publication Environmental Microbiology Abbreviated Journal Environ. Microbiol.
Volume 22 Issue 12 Pages 5019-5032
Keywords
Abstract (down) The genus Phytophthora represents a group of plant pathogens with broad global distribution. The majority of them cause the collar and root-rot of diverse plant species. Little is known about Phytophthora communities in forest ecosystems, especially in the Neotropical forests where natural enemies could maintain the huge plant diversity via negative density dependence. We characterized the diversity of soil-borne Phytophthora communities in the North French Guiana rainforest and investigated how they are structured by host identity and environmental factors. In this little-explored habitat, 250 soil cores were sampled from 10 plots hosting 10 different plant families across three forest environments (Terra Firme, Seasonally Flooded and White Sand). Phytophthora diversity was studied using a baiting approach and metabarcoding (High-Throughput Sequencing) on environmental DNA extracted from both soil samples and baiting-leaves. These three approaches revealed very similar communities, characterized by an unexpected low diversity of Phytophthora species, with the dominance of two cryptic species close to Phytophthora heveae. As expected, the Phytophthora community composition of the French Guiana rainforest was significantly impacted by the host plant family and environment. However, these plant pathogen communities are very small and are dominated by generalist species, questioning their potential roles as drivers of plant diversity in these Amazonian forests. © 2020 Society for Applied Microbiology and John Wiley & Sons Ltd.
Address International Center for Tropical Botany, Department of Biological Sciences, Florida International University, Miami, FL 33199, United States
Corporate Author Thesis
Publisher Blackwell Publishing Ltd Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 14622912 (Issn) ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 940
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Author Pastorello, G.; Trotta, C.; Canfora, E.; Chu, H.; Christianson, D.; Cheah, Y.-W.; Poindexter, C.; Chen, J.; Elbashandy, A.; Humphrey, M.; Isaac, P.; Polidori, D.; Ribeca, A.; van Ingen, C.; Zhang, L.; Amiro, B.; Ammann, C.; Arain, M.A.; Ardö, J.; Arkebauer, T.; Arndt, S.K.; Arriga, N.; Aubinet, M.; Aurela, M.; Baldocchi, D.; Barr, A.; Beamesderfer, E.; Marchesini, L.B.; Bergeron, O.; Beringer, J.; Bernhofer, C.; Berveiller, D.; Billesbach, D.; Black, T.A.; Blanken, P.D.; Bohrer, G.; Boike, J.; Bolstad, P.V.; Bonal, D.; Bonnefond, J.-M.; Bowling, D.R.; Bracho, R.; Brodeur, J.; Brümmer, C.; Buchmann, N.; Burban, B.; Burns, S.P.; Buysse, P.; Cale, P.; Cavagna, M.; Cellier, P.; Chen, S.; Chini, I.; Christensen, T.R.; Cleverly, J.; Collalti, A.; Consalvo, C.; Cook, B.D.; Cook, D.; Coursolle, C.; Cremonese, E.; Curtis, P.S.; D'Andrea, E.; da Rocha, H.; Dai, X.; Davis, K.J.; De Cinti, B.; de Grandcourt, A.; De Ligne, A.; De Oliveira, R.C.; Delpierre, N.; Desai, A.R.; Di Bella, C.M.; di Tommasi, P.; Dolman, H.; Domingo, F.; Dong, G.; Dore, S.; Duce, P.; Dufrêne, E.; Dunn, A.; Dušek, J.; Eamus, D.; Eichelmann, U.; ElKhidir, H.A.M.; Eugster, W.; Ewenz, C.M.; Ewers, B.; Famulari, D.; Fares, S.; Feigenwinter, I.; Feitz, A.; Fensholt, R.; Filippa, G.; Fischer, M.; Frank, J.; Galvagno, M.; Gharun, M.; Gianelle, D.; Gielen, B.; Gioli, B.; Gitelson, A.; Goded, I.; Goeckede, M.; Goldstein, A.H.; Gough, C.M.; Goulden, M.L.; Graf, A.; Griebel, A.; Gruening, C.; Grünwald, T.; Hammerle, A.; Han, S.; Han, X.; Hansen, B.U.; Hanson, C.; Hatakka, J.; He, Y.; Hehn, M.; Heinesch, B.; Hinko-Najera, N.; Hörtnagl, L.; Hutley, L.; Ibrom, A.; Ikawa, H.; Jackowicz-Korczynski, M.; Janouš, D.; Jans, W.; Jassal, R.; Jiang, S.; Kato, T.; Khomik, M.; Klatt, J.; Knohl, A.; Knox, S.; Kobayashi, H.; Koerber, G.; Kolle, O.; Kosugi, Y.; Kotani, A.; Kowalski, A.; Kruijt, B.; Kurbatova, J.; Kutsch, W.L.; Kwon, H.; Launiainen, S.; Laurila, T.; Law, B.; Leuning, R.; Li, Y.; Liddell, M.; Limousin, J.-M.; Lion, M.; Liska, A.J.; Lohila, A.; López-Ballesteros, A.; López-Blanco, E.; Loubet, B.; Loustau, D.; Lucas-Moffat, A.; Lüers, J.; Ma, S.; Macfarlane, C.; Magliulo, V.; Maier, R.; Mammarella, I.; Manca, G.; Marcolla, B.; Margolis, H.A.; Marras, S.; Massman, W.; Mastepanov, M.; Matamala, R.; Matthes, J.H.; Mazzenga, F.; McCaughey, H.; McHugh, I.; McMillan, A.M.S.; Merbold, L.; Meyer, W.; Meyers, T.; Miller, S.D.; Minerbi, S.; Moderow, U.; Monson, R.K.; Montagnani, L.; Moore, C.E.; Moors, E.; Moreaux, V.; Moureaux, C.; Munger, J.W.; Nakai, T.; Neirynck, J.; Nesic, Z.; Nicolini, G.; Noormets, A.; Northwood, M.; Nosetto, M.; Nouvellon, Y.; Novick, K.; Oechel, W.; Olesen, J.E.; Ourcival, J.-M.; Papuga, S.A.; Parmentier, F.-J.; Paul-Limoges, E.; Pavelka, M.; Peichl, M.; Pendall, E.; Phillips, R.P.; Pilegaard, K.; Pirk, N.; Posse, G.; Powell, T.; Prasse, H.; Prober, S.M.; Rambal, S.; Rannik, Ü.; Raz-Yaseef, N.; Reed, D.; de Dios, V.R.; Restrepo-Coupe, N.; Reverter, B.R.; Roland, M.; Sabbatini, S.; Sachs, T.; Saleska, S.R.; Sánchez-Cañete, E.P.; Sanchez-Mejia, Z.M.; Schmid, H.P.; Schmidt, M.; Schneider, K.; Schrader, F.; Schroder, I.; Scott, R.L.; Sedlák, P.; Serrano-Ortíz, P.; Shao, C.; Shi, P.; Shironya, I.; Siebicke, L.; Šigut, L.; Silberstein, R.; Sirca, C.; Spano, D.; Steinbrecher, R.; Stevens, R.M.; Sturtevant, C.; Suyker, A.; Tagesson, T.; Takanashi, S.; Tang, Y.; Tapper, N.; Thom, J.; Tiedemann, F.; Tomassucci, M.; Tuovinen, J.-P.; Urbanski, S.; Valentini, R.; van der Molen, M.; van Gorsel, E.; van Huissteden, K.; Varlagin, A.; Verfaillie, J.; Vesala, T.; Vincke, C.; Vitale, D.; Vygodskaya, N.; Walker, J.P.; Walter-Shea, E.; Wang, H.; Weber, R.; Westermann, S.; Wille, C.; Wofsy, S.; Wohlfahrt, G.; Wolf, S.; Woodgate, W.; Li, Y.; Zampedri, R.; Zhang, J.; Zhou, G.; Zona, D.; Agarwal, D.; Biraud, S.; Torn, M.; Papale, D.
Title The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data Type Journal Article
Year 2020 Publication Scientific data Abbreviated Journal Sci Data
Volume 7 Issue 1 Pages 225
Keywords article; breathing; ecophysiology; ecosystem; Eddy covariance; licence; metadata; photosynthesis; pipeline; remote sensing; time series analysis; uncertainty
Abstract (down) The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible.
Address Euro-Mediterranean Centre on Climate Change Foundation (CMCC), Lecce, 73100, Italy
Corporate Author Thesis
Publisher NLM (Medline) Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 20524463 (Issn) ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 958
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Author Sayer, E.J.; Rodtassana, C.; Sheldrake, M.; Bréchet, L.M.; Ashford, O.S.; Lopez-Sangil, L.; Kerdraon-Byrne, D.; Castro, B.; Turner, B.L.; Wright, S.J.; Tanner, E.V.J.
Title Revisiting nutrient cycling by litterfall—Insights from 15 years of litter manipulation in old-growth lowland tropical forest Type Journal Article
Year 2020 Publication Advances in Ecological Researc Abbreviated Journal Adv. Ecol. Res.
Volume 62 Issue Pages 173-223
Keywords Forest floor; Litter addition; Litter removal; Litterfall; Nutrient cycling; Nutrient use efficiency; Soil fertility; Trace elements; Tropical lowland forest
Abstract (down) The crucial role of tropical forests in the global carbon balance is underpinned by their extraordinarily high biomass and productivity, even though the majority of tropical forests grow on nutrient-poor soils. Nutrient cycling by litterfall has long been considered essential for maintaining high primary productivity in lowland tropical forests but few studies have tested this assumption experimentally. We review and synthesise findings from the Gigante Litter Manipulation Project (GLiMP), a long-term experiment in lowland tropical forest in Panama, Central America, in which litter has been removed from or added to large-scale plots for 15 years. We assessed changes in soil and litter nutrient concentrations in response to the experimental treatments and estimated nutrient return and nutrient use efficiency to indicate changes in nutrient cycling. The soil concentrations of most nutrients increased with litter addition and declined with litter removal. Litter removal altered nitrogen, potassium, manganese and zinc cycling, demonstrating the importance of litter inputs for maintaining the availability of these elements to plants. By contrast, litter addition only altered nitrogen cycling and, despite low concentrations of available soil phosphorus, the effects of litter manipulation on phosphorus cycling were inconsistent. We discuss potential mechanisms underlying the observed changes, and we emphasise the importance of decomposition processes in the forest floor for retaining nutrient elements, which partially decouples nutrient cycling from the mineral soil. Finally, by synthesising GLiMP studies conducted during 15 years of litter manipulation, we highlight key knowledge gaps and avenues for future research into tropical forest nutrient cycling. © 2020 Elsevier Ltd
Address Teagasc, Johnstown Castle, Wexford, Ireland
Corporate Author Thesis
Publisher Academic Press Inc. Place of Publication Editor Dumbrell A.J.; Turner E.C.; Fayle T.M.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title Advances in Ecological Research
Series Volume 62 Series Issue Edition
ISSN 00652504 (Issn); 9780128211342 (Isbn) ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 1001
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Author Solander, K.C.; Newman, B.D.; Carioca De Araujo, A.; Barnard, H.R.; Berry, Z.C.; Bonal, D.; Bretfeld, M.; Burban, B.; Candido, L.A.; Célleri, R.; Chambers, J.Q.; Christoffersen, B.O.; Detto, M.; Dorigo, W.A.; Ewers, B.E.; Ferreira, S.J.F.; Knohl, A.; Leung, L.R.; McDowell, N.G.; Miller, G.R.; Monteiro, M.T.F.; Moore, G.W.; Negron-Juarez, R.; Saleska, S.R.; Stiegler, C.; Tomasella, J.; Xu, C.
Title The pantropical response of soil moisture to El Niño Type Journal Article
Year 2020 Publication Hydrology and Earth System Sciences Abbreviated Journal Hydrol. Earth Syst. Sci.
Volume 24 Issue 5 Pages 2303-2322
Keywords Cluster analysis; Oceanography; Soil moisture; Surface waters; Tropics; Climate anomalies; Clustered datum; Hydrologic changes; Land data assimilation systems; Sea surface temperature anomalies; Situ soil moistures; Tropical hydrologies; Tropical Pacific ocean; Soil surveys
Abstract (down) The 2015–2016 El Niño event ranks as one of the most severe on record in terms of the magnitude and extent of sea surface temperature (SST) anomalies generated in the tropical Pacific Ocean. Corresponding global impacts on the climate were expected to rival, or even surpass, those of the 1997–1998 severe El Niño event, which had SST anomalies that were similar in size. However, the 2015–2016 event failed to meet expectations for hydrologic change in many areas, including those expected to receive well above normal precipitation. To better understand how climate anomalies during an El Niño event impact soil moisture, we investigate changes in soil moisture in the humid tropics (between ±25∘) during the three most recent super El Niño events of 1982–1983, 1997–1998 and 2015–2016, using data from the Global Land Data Assimilation System (GLDAS). First, we use in situ soil moisture observations obtained from 16 sites across five continents to validate and bias-correct estimates from GLDAS (r2=0.54). Next, we apply a k-means cluster analysis to the soil moisture estimates during the El Niño mature phase, resulting in four groups of clustered data. The strongest and most consistent decreases in soil moisture occur in the Amazon basin and maritime southeastern Asia, while the most consistent increases occur over eastern Africa. In addition, we compare changes in soil moisture to both precipitation and evapotranspiration, which showed a lack of agreement in the direction of change between these variables and soil moisture most prominently in the southern Amazon basin, the Sahel and mainland southeastern Asia. Our results can be used to improve estimates of spatiotemporal differences in El Niño impacts on soil moisture in tropical hydrology and ecosystem models at multiple scales.
Address Coordination of Research and Development, National Centre for Monitoring and Early Warning of Natural Disasters, Cachoeira Paulista, Brazil
Corporate Author Thesis
Publisher Copernicus GmbH Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 10275606 (Issn) ISBN Medium
Area Expedition Conference
Notes Export Date: 29 May 2020; Correspondence Address: Solander, K.C.; Earth and Environmental Sciences, Los Alamos National LaboratoryUnited States; email: ksolander@lanl.gov Approved no
Call Number EcoFoG @ webmaster @ Serial 934
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Author Dejean, A.; Petitclerc, F.; Azémar, F.
Title Seasonality influences ant-mediated nutrient acquisition (myrmecotrophy) by a Neotropical myrmecophyte Type Journal Article
Year 2020 Publication Evolutionary Ecology Abbreviated Journal Evol. Ecol.
Volume 34 Issue 4 Pages 645-657
Keywords Ant-plant relationships; Mutualism; Myrmecophyte; Myrmecotrophy; Phenology; Stable isotopes; ant; herb; host plant; life cycle; myrmecochory; myrmecophyte; Neotropical Region; phenology; seasonality; stable isotope; understory; Gentianaceae; Tachia; Tachia guianensis
Abstract (down) Tachia guianensis (Gentianaceae), a Neotropical understory myrmecophyte, shelters ant colonies in its hollow trunks and branches (domatia). In turn, it is protected from defoliators and obtains nutrients from ant-produced wastes (myrmecotrophy). Aiming to verify if seasonality influences nitrogen assimilation via ant wastes using the stable isotope nitrogen-15, we first studied Tachia’s phenology and its seasonal leaf production, and then the life cycle of its two more frequent guest ant species. We found that leaf production was much higher during the rainy than the dry season. Mature guest ant colonies produced sexuals regardless of the season and the net weight of the waste piles inside the domatia did not vary between seasons, so that the availability of nutrients to their host plant is steady year-long. By providing the two most frequent mutualistic guest ant species with food enriched with nitrogen-15, we showed that Tachia individuals assimilate more nitrogen from ant wastes during the rainy season, when the plant is physiologically active, compared to the dry season. Thus, one can deduce that the increase in nitrogen assimilation during the rainy season is determined by the increase in Tachia’s physiological activity during that season. Information gathered through a bibliographic compilation confirms that none of the 15 ant species known to be associated with myrmecophytes for which the life cycle was studied is characterized by seasonal reproduction (which would result in fluctuating waste production). The same is true for 49.7% of 167 tropical ant species (seasonal production for the remaining species). We concluded that, in contrast to the non-seasonal ant colony reproductive cycle, Tachia’s phenology determines the myrmecotrophic assimilation rate. © 2020, Springer Nature Switzerland AG.
Address CNRS, UMR EcoFoG, AgroParisTech, CIRAD, INRAE, Université des Antilles, Université de Guyane, Kourou, 97310, France
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 02697653 (Issn) ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 956
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Author Svensk, M.; Coste, S.; Gérard, B.; Gril, E.; Julien, F.; Maillard, P.; Stahl, C.; Leroy, C.
Title Drought effects on resource partition and conservation among leaf ontogenetic stages in epiphytic tank bromeliads Type Journal Article
Year 2020 Publication Physiologia Plantarum Abbreviated Journal Physiol. Plant.
Volume 170 Issue 4 Pages 488-507
Keywords chlorophyll; nitrogen; water; Bromeliaceae; drought; metabolism; photosynthesis; plant leaf; Bromeliaceae; Chlorophyll; Droughts; Nitrogen; Photosynthesis; Plant Leaves; Water
Abstract (down) Studying the response to drought stress of keystone epiphytes such as tank bromeliads is essential to better understand their resistance capacity to future climate change. The objective was to test whether there is any variation in the carbon, water and nutrient status among different leaf ontogenetic stages in a bromeliad rosette subjected to a gradient of drought stress. We used a semi-controlled experiment consisting in a gradient of water shortage in Aechmea aquilega and Lutheria splendens. For each bromeliad and drought treatment, three leaves were collected based on their position in the rosette and several functional traits related to water and nutrient status, and carbon metabolism were measured. We found that water status traits (relative water content, leaf succulence, osmotic and midday water potentials) and carbon metabolism traits (carbon assimilation, maximum quantum yield of photosystem II, chlorophyll and starch contents) decreased with increasing drought stress, while leaf soluble sugars and carbon, nitrogen and phosphorus contents remained unchanged. The different leaf ontogenetic stages showed only marginal variations when subjected to a gradient of drought. Resources were not reallocated between different leaf ontogenetic stages but we found a reallocation of soluble sugars from leaf starch reserves to the root system. Both species were capable of metabolic and physiological adjustments in response to drought. Overall, this study advances our understanding of the resistance of bromeliads faced with increasing drought stress and paves the way for in-depth reflection on their strategies to cope with water shortage. © 2020 Scandinavian Plant Physiology Society
Address Laboratoire Ecologie Fonctionnelle et Environnement, Université de Toulouse, CNRS, Toulouse, 31062, France
Corporate Author Thesis
Publisher Blackwell Publishing Ltd Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 00319317 (Issn) ISBN Medium
Area Expedition Conference
Notes PDF trop gros voir la documentaliste – merci Approved no
Call Number EcoFoG @ webmaster @ Serial 943
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Author Fortunel, C.; Stahl, C.; Heuret, P.; Nicolini, E.; Baraloto, C.
Title Disentangling the effects of environment and ontogeny on tree functional dimensions for congeneric species in tropical forests Type Journal Article
Year 2020 Publication New Phytologist Abbreviated Journal New Phytol.
Volume 226 Issue 2 Pages 385-395
Keywords chemistry; developmental stage; habitats; Micropholis; morphology; physiology; plant traits; seasons; developmental stage; ecosystem function; forest ecosystem; habitat selection; habitat structure; nutrient availability; ontogeny; physiological response; soil water; taxonomy; tropical forest; Amazonia
Abstract (down) Soil water and nutrient availability are key drivers of tree species distribution and forest ecosystem functioning, with strong species differences in water and nutrient use. Despite growing evidence for intraspecific trait differences, it remains unclear under which circumstances the effects of environmental gradients trump those of ontogeny and taxonomy on important functional dimensions related to resource use, particularly in tropical forests. Here, we explore how physiological, chemical, and morphological traits related to resource use vary between life stages in four species within the genus Micropholis that is widespread in lowland Amazonia. Specifically, we evaluate how environment, developmental stage, and taxonomy contribute to single-trait variation and multidimensional functional strategies. We find that environment, developmental stage, and taxonomy differentially contribute to functional dimensions. Habitats and seasons shape physiological and chemical traits related to water and nutrient use, whereas developmental stage and taxonomic identity impact morphological traits –especially those related to the leaf economics spectrum. Our findings suggest that combining environment, ontogeny, and taxonomy allows for a better understanding of important functional dimensions in tropical trees and highlights the need for integrating tree physiological and chemical traits with classically used morphological traits to improve predictions of tropical forests’ responses to environmental change. © 2019 The Authors New Phytologist © 2019 New Phytologist Trust
Address Department of Biological Sciences, Florida International University, Miami, FL 33133, United States
Corporate Author Thesis
Publisher Blackwell Publishing Ltd Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028646x (Issn) ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 977
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Author Longo, M.; Saatchi, S.; Keller, M.; Bowman, K.; Ferraz, A.; Moorcroft, P.R.; Morton, D.C.; Bonal, D.; Brando, P.; Burban, B.; Derroire, G.; dos-Santos, M.N.; Meyer, V.; Saleska, S.; Trumbore, S.; Vincent, G.
Title Impacts of Degradation on Water, Energy, and Carbon Cycling of the Amazon Tropical Forests Type Journal Article
Year 2020 Publication Journal of Geophysical Research: Biogeosciences Abbreviated Journal J. Geophys. Res. Biogeosci.
Volume 125 Issue 8 Pages e2020JG005677
Keywords Amazon; drought; ecosystem modeling; evapotranspiration; forest degradation; remote sensing; carbon cycle; deforestation; dry season; evapotranspiration; hydrological cycle; logging (timber); net primary production; remote sensing; sensible heat flux; tropical forest; understory; water stress; Amazon River
Abstract (down) Selective logging, fragmentation, and understory fires directly degrade forest structure and composition. However, studies addressing the effects of forest degradation on carbon, water, and energy cycles are scarce. Here, we integrate field observations and high-resolution remote sensing from airborne lidar to provide realistic initial conditions to the Ecosystem Demography Model (ED-2.2) and investigate how disturbances from forest degradation affect gross primary production (GPP), evapotranspiration (ET), and sensible heat flux (H). We used forest structural information retrieved from airborne lidar samples (13,500 ha) and calibrated with 817 inventory plots (0.25 ha) across precipitation and degradation gradients in the eastern Amazon as initial conditions to ED-2.2 model. Our results show that the magnitude and seasonality of fluxes were modulated by changes in forest structure caused by degradation. During the dry season and under typical conditions, severely degraded forests (biomass loss ≥66%) experienced water stress with declines in ET (up to 34%) and GPP (up to 35%) and increases of H (up to 43%) and daily mean ground temperatures (up to 6.5°C) relative to intact forests. In contrast, the relative impact of forest degradation on energy, water, and carbon cycles markedly diminishes under extreme, multiyear droughts, as a consequence of severe stress experienced by intact forests. Our results highlight that the water and energy cycles in the Amazon are driven by not only climate and deforestation but also the past disturbance and changes of forest structure from degradation, suggesting a much broader influence of human land use activities on the tropical ecosystems. ©2020. The Authors.
Address AMAP, Univ Montpellier, IRD, CIRAD, CNRS, INRAE, Montpellier, France
Corporate Author Thesis
Publisher Blackwell Publishing Ltd Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 21698953 (Issn) ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number EcoFoG @ webmaster @ Serial 957
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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.
Title Slow rate of secondary forest carbon accumulation in the Guianas compared with the rest of the Neotropics Type Journal Article
Year 2020 Publication 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 (down) 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 Lehnebach, R.; Doumerc, L.; Clair, B.; Alméras, T.
Title Mechanical stress in the inner bark of 15 tropical tree species and the relationship with anatomical structure Type Journal Article
Year 2020 Publication 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 (down) 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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