| |
Records |
Links |
|
Author |
Barantal, S.; Schimann, H.; Fromin, N.; Hattenschwiler, S. |
|
| |
Title |
Nutrient and Carbon Limitation on Decomposition in an Amazonian Moist Forest |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
Ecosystems |
Abbreviated Journal |
Ecosystems |
|
| |
Volume |
15 |
Issue  |
7 |
Pages |
1039-1052 |
|
| |
Keywords |
energy limitation; labile carbon; litter quality; nitrogen; phosphorus; priming effect; soil fauna; tropical forest |
|
| |
Abstract |
Tropical forests determine global biogeochemical cycles to a large extent, but control factors for key ecosystem processes such as decomposition remain poorly understood. With a full-factorial C (cellulose), N (urea), and P (phosphate) fertilization experiment, we tested the relative importance of C and nutrient limitation on litter decomposition in a mature lowland moist forest of French Guiana. Despite the previously demonstrated litter C quality control over decomposition and the very low soil P content (0. 1 mg g -1 of soil) at our study site, fertilization with C or P alone did not increase the decomposition of a wide range of litter types (N:P ratios between 20 and 80). Nitrogen fertilization alone also had no effect on decomposition. However, the combined fertilization with N and P resulted in up to 33. 5% more initial litter mass lost, with an increasing effect with wider litter N:P ratios. Soil fauna strongly stimulated litter mass loss and enhanced nutrient fertilization effects. Moreover, nutrient effects on decomposition increased with additional C fertilization in the presence of fauna. Our results suggest that increased N availability is required for a positive P effect on decomposition in the studied P-poor tropical forest. Further stimulation of decomposition by C amendment through priming indicates energy limitation of decomposers that is co-determined by nutrient availability. The demonstrated intricate control of the key resources C, N, and P on decomposition calls for an intensified research effort on multiple resource limitation on key processes in tropical forests and how they change under multiple human impacts. © 2012 Springer Science+Business Media, LLC. |
|
| |
Address |
UMR Ecologie des Forêts de Guyane (ECOFOG), INRA, Kourou, French Guiana |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
14329840 (Issn) |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 2 November 2012; Source: Scopus; Coden: Ecosf; doi: 10.1007/s10021-012-9564-9; Language of Original Document: English; Correspondence Address: Schimann, H.; UMR Ecologie des Forêts de Guyane (ECOFOG), INRA, Kourou, French Guiana; email: heidy.schimann@ecofog.gf |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
442 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Coté, G.G.; Gibernau, M. |
|
| |
Title |
Distribution of calcium oxalate crystals in floral organs of araceae in relation to pollination strategy |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
American Journal of Botany |
Abbreviated Journal |
Am. J. Bot. |
|
| |
Volume |
99 |
Issue |
7 |
Pages |
1231-1242 |
|
| |
Keywords |
Araceae; Beetles; Calcium oxalate; Crystal; Defense; Flowers; Herbivory; Pollination |
|
| |
Abstract |
Premise of the study: Many flowers are pollinated by potentially hungry insects, yet flowers also contain gametes and embryos which must be protected from predation. Microscopic calcium oxalate crystals in plant tissues have been proposed to protect against herbivory. Aroids, which have an unusual diversity of such crystals, also exhibit diverse pollination strategies. Many species have pollinators that do not feed while visiting the flowers, while other species, especially those pollinated by beetles, offer sterile staminodia as food rewards. We examined flowers of 21 aroid species with various pollination strategies to test the hypothesis that crystals protect vital gametes and embryos while allowing consumption of food bribes.Methods: Aroid inflorescences collected from the field or from greenhouse material were sectioned, cleared, and examined by bright field and polarization microscopy.Key results: All species examined, regardless of pollination strategy, arrayed crystals around unshed pollen and ovules. Less vital tissues, such as odoriferous appendages, had few crystals. Staminodia offered as food to beetle pollinators, however, differed greatly between species in their crystal contents. Some had minimal crystals; some had crystals in patterns suggesting they limit beetle feeding; still others had abundant crystals in no obvious pattern.Conclusions: The results are consistent with crystals protecting against insect predation of gametes and embryos. However, the role of crystals in food-bribe staminodia is unclear. They may limit and direct feeding by beetles in some species, while in others they might have no protective role. © 2012 Botanical Society of America. |
|
| |
Address |
CNRS-Ecolog (UMR 8172), Campus Agronomique BP316, Korou cedex 97379, France |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
00029122 (Issn) |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 10 August 2012; Source: Scopus; Coden: Ajboa; doi: 10.3732/ajb.1100499; Language of Original Document: English; Correspondence Address: Coté, G. G.; Biology Department, Radford University, Radford, VA 24142-6931, United States; email: gcote@radford.edu |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
420 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Fromin, N.; Porte, B.; Lensi, R.; Hamelin, J.; Domenach, A.-M.; Buatois, B.; Roggy, J.-C. |
|
| |
Title |
Spatial variability of the functional stability of microbial respiration process: A microcosm study using tropical forest soil |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
Journal of Soils and Sediments |
Abbreviated Journal |
J. Soils Sed. |
|
| |
Volume |
12 |
Issue |
7 |
Pages |
1030-1039 |
|
| |
Keywords |
Disturbance; Diversity-stability relationship; Microbial diversity; Substrate-induced respiration |
|
| |
Abstract |
Purpose: Understanding the ability of ecosystem processes to resist to and to recover from disturbances is critical to sustainable land use. However, the spatial variability of the stability has rarely been addressed. Here, we investigated the functional stability of a soil microbial process for 24 soils collected from adjacent locations from a 0. 3 ha tropical rainforest plot in Paracou, French Guiana. Materials and methods: The 24 locations were characterized regarding soil chemical and biological (microbial diversity) parameters and forest structure. The corresponding soils were submitted to an experimental transient heat disturbance during a microcosm experiment. The response of the respiration process was followed using substrate-induced respiration (SIR). Results and discussion: The response of soil SIR to heat disturbance varied widely between samples. The variability of the SIR response increased just after the disturbance, and a global rather homogeneous decrease in SIR rates was observed 15 and 30 days after. The stability of SIR in response to heat disturbance could not be related to either the genetic or the metabolic diversity of the microbial community. The initial level of SIR before the disturbance was the soil variable that best correlated with the impact of the disturbance: the soil locations with the highest initial SIR rates were the most affected 15 and 30 days after the heat disturbance. Conclusions: Such a heterogeneous response suggests that the response of soil processes to a disturbance will be difficult to assess from only local-scale analyses and highlights the need for spatial explicitness in understanding biogeochemical processes. © 2012 Springer-Verlag. |
|
| |
Address |
UMR EcoFoG, BP 709, 97387 Kourou, French Guiana |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
14390108 (Issn) |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 30 July 2012; Source: Scopus; doi: 10.1007/s11368-012-0528-7; Language of Original Document: English; Correspondence Address: Fromin, N.; CEFE, CNRS UMR 5175, 1919 Route de Mende, 34293 Montpellier cedex 5, France; email: nathalie.fromin@cefe.cnrs.fr |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
415 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Barthe, S.; Gugerli, F.; Barkley, N.A.; Maggia, L.; Cardi, C.; Scotti, I. |
|
| |
Title |
Always look on both sides: Phylogenetic information conveyed by simple sequence repeat allele sequences |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
PLoS ONE |
Abbreviated Journal |
PLoS ONE |
|
| |
Volume |
7 |
Issue |
7 |
Pages |
e40699 |
|
| |
Keywords |
|
|
| |
Abstract |
Simple sequence repeat (SSR) markers are widely used tools for inferences about genetic diversity, phylogeography and spatial genetic structure. Their applications assume that variation among alleles is essentially caused by an expansion or contraction of the number of repeats and that, accessorily, mutations in the target sequences follow the stepwise mutation model (SMM). Generally speaking, PCR amplicon sizes are used as direct indicators of the number of SSR repeats composing an allele with the data analysis either ignoring the extent of allele size differences or assuming that there is a direct correlation between differences in amplicon size and evolutionary distance. However, without precisely knowing the kind and distribution of polymorphism within an allele (SSR and the associated flanking region (FR) sequences), it is hard to say what kind of evolutionary message is conveyed by such a synthetic descriptor of polymorphism as DNA amplicon size. In this study, we sequenced several SSR alleles in multiple populations of three divergent tree genera and disentangled the types of polymorphisms contained in each portion of the DNA amplicon containing an SSR. The patterns of diversity provided by amplicon size variation, SSR variation itself, insertions/deletions (indels), and single nucleotide polymorphisms (SNPs) observed in the FRs were compared. Amplicon size variation largely reflected SSR repeat number. The amount of variation was as large in FRs as in the SSR itself. The former contributed significantly to the phylogenetic information and sometimes was the main source of differentiation among individuals and populations contained by FR and SSR regions of SSR markers. The presence of mutations occurring at different rates within a marker's sequence offers the opportunity to analyse evolutionary events occurring on various timescales, but at the same time calls for caution in the interpretation of SSR marker data when the distribution of within-locus polymorphism is not known. |
|
| |
Address |
Unité Mixte de Recherche Ecologie des forêts de Guyane, Institut National de la Recherche Agronomique, Kourou, French Guiana |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
19326203 (Issn) |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 30 July 2012; Source: Scopus; Art. No.: e40699; doi: 10.1371/journal.pone.0040699; Language of Original Document: English; Correspondence Address: Scotti, I.; Unité Mixte de Recherche Ecologie des forêts de Guyane, Institut National de la Recherche Agronomique, Kourou, French Guiana; email: ivan.scotti@ecofog.gf |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
416 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Dejean, A.; Corbara, B.; Azémar, F.; Carpenter, J.M. |
|
| |
Title |
When attempts at robbing prey turn fatal |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
Naturwissenschaften |
Abbreviated Journal |
Naturwissenschaften |
|
| |
Volume |
99 |
Issue |
7 |
Pages |
579-582 |
|
| |
Keywords |
Ant predation; Azteca andreae; Cleptobiosis; Flies and dung beetles; Myrmecophyte; Reduviidae; Socialwasps; Stinglessbees |
|
| |
Abstract |
Because group-hunting arboreal ants spread-eagle insect prey for a long time before retrieving them, these prey can be coveted by predatory flying insects. Yet, attempting to rob these prey is risky if the ant species is also an effective predator. Here, we show that trying to rob prey from Azteca andreae workers is a fatal error as 268 out of 276 potential cleptobionts (97.1 %) were captured in turn. The ant workers hunt in a group and use the “Velcro®” principle to cling firmly to the leaves of their host tree, permitting them to capture very large prey. Exceptions were one social wasp, plus some Trigona spp. workers and flies that landed directly on the prey and were able to take off immediately when attacked. We conclude that in this situation, previously captured prey attract potential cleptobionts that are captured in turn in most of the cases. © Springer-Verlag 2012. |
|
| |
Address |
Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, United States |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
00281042 (Issn) |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 30 July 2012; Source: Scopus; Coden: Natwa; doi: 10.1007/s00114-012-0929-x; Language of Original Document: English; Correspondence Address: Dejean, A.; CNRS, Écologie des Forêts de Guyane (UMR-CNRS 8172), Campus agronomique, BP 316, 97379 Kourou cedex, France; email: alain.dejean@wanadoo.fr |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
417 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Thevenin, J.-M.; Rossi, V.; Ducamp, M.; Doare, F.; Condina, V.; Lachenaud, P. |
|
| |
Title |
Numerous clones resistant to Phytophthora palmivora in the “Guiana” genetic group of Theobroma cacao L |
Type |
Journal Article |
| |
Year |
2012 |
Publication |
PLoS ONE |
Abbreviated Journal |
PLoS ONE |
|
| |
Volume |
7 |
Issue |
7 |
Pages |
e40915 |
|
| |
Keywords |
|
|
| |
Abstract |
Cocoa black pod rot, a disease caused by Stramenopiles of the genus Phytophthora, and particularly by the pan-tropical species P. palmivora, causes serious production losses worldwide. In order to reduce the impact of these pests and diseases, preference is given to genetic control using resistant varieties and, to that end, breeders seek sources of resistance in wild cocoa trees. For instance, surveys of spontaneous cocoa trees in French Guiana between 1985 and 1995 led to the collection of abundant plant material forming a particular genetic group (the “Guiana” group). Following numerous one-off studies demonstrating the merits of this group as a source of resistance to Phytophthora, this article presents the results of a comprehensive study assessing the resistance of 186 “Guiana” clones in relation to the Guianan strain (GY 27) of P. palmivora. This study, undertaken in French Guiana, using an efficient methodology (ten series of tests and a statistical test adapted to the ordinal nature of the data) confirmed that the “Guiana” genetic group does indeed constitute an important source of resistance to P. palmivora, though with some variations depending on the demes of origin. Numerous clones (59) proved to be as resistant as the SCAVINA 6 resistance control, whilst nine were statistically more resistant. The “Resistant” and “Moderately Resistant” Guianan clones totalled 108 (58% of the total tested). Some of the clones more resistant than SCAVINA 6 could be incorporated into numerous cocoa breeding programmes, particularly those that also display other notable qualities. The same applies for numerous other clones equivalent to SCAVINA 6, especially the “elite”' clones GU 134-B, GU 139-A and GU 285-A. © 2012 Thevenin et al. |
|
| |
Address |
CIRAD, UMR BGPI, Montpellier, France |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
19326203 (Issn) |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 16 August 2012; Source: Scopus; Art. No.: e40915; doi: 10.1371/journal.pone.0040915; Language of Original Document: English; Correspondence Address: Thevenin, J.-M.; CIRAD, UPR Bioagresseurs: Analyse et Maîtrise du Risque, Kourou, Guyane, France; email: jean-marc.thevenin@cirad.fr |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
423 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Rowland, L.; Stahl, C.; Bonal, D.; Siebicke, L.; Williams, M.; Meir, P. |
|
| |
Title |
The Response of Tropical Rainforest Dead Wood Respiration to Seasonal Drought |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Ecosystems |
Abbreviated Journal |
Ecosystems |
|
| |
Volume |
16 |
Issue |
7 |
Pages |
1294-1309 |
|
| |
Keywords |
Amazon rainforest; coarse woody debris; respiration; seasonal drought; soil water content; woody moisture content |
|
| |
Abstract |
Coarse woody debris (CWD, dead wood sections ≥10 cm diameter) represents a large store of carbon in tropical forests; however, estimates of the flux of carbon from CWD in these forests remain poorly constrained. The objective of this study was to resolve the dry/wet season response of respiration in CWD (Rcwd), and investigate the importance of biotic and abiotic factors for predicting the seasonal change of Rcwd at the ecosystem level. This study presents a 4-month time series of Rcwd measurements conducted on 42 dead trees (26 species) at the Paracou Research Station in French Guiana. Rcwd measurements were repeated 13 times on each CWD sample from July to November 2011, spanning the transition from wet to dry season, and then from dry season to the following wet season. Seasonal drought caused monthly Rcwd to drop by 20.5 ± 5.1% over the wet-dry transition. Changes in woody tissue moisture content explained 41.9% of the measured seasonal variability in Rcwd, but 60% of the seasonal variability in mean forest Rcwd rates could be modelled using surface soil water content. We estimate that Rcwd is approximately 5% of annual ecosystem respiration (Reco) and that seasonal variations in Rcwd contribute appreciably to seasonal variations of Reco, and should be included in functional models simulating the response of tropical rainforest ecosystems to current and future climate. © 2013 Springer Science+Business Media New York. |
|
| |
Address |
Division of Plant Sciences, Research School of Biology, The Australian National University, ACT, Australian Capital Territory, 0200, Australia |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
14329840 (Issn) |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 18 October 2013; Source: Scopus; Coden: Ecosf; doi: 10.1007/s10021-013-9684-x; Language of Original Document: English; Correspondence Address: Rowland, L.; School of Geosciences, University of Edinburgh, Edinburgh, United Kingdom; email: lucy.rowland@ed.ac.uk; Funding Details: NE/F002149/1, NERC, Natural Environment Research Council; Funding Details: NE/J011002/1, NERC, Natural Environment Research Council; Funding Details: FT110100457, ARC, Australian Research Council |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
506 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Lefèvre, F.; Boivin, T.; Bontemps, A.; Courbet, F.; Davi, H.; Durand-Gillmann, M.; Fady, B.; Gauzere, J.; Gidoin, C.; Karam, M.-J.; Pichot, C.; Oddou-Muratorio, S.; Pichot, C. |
|
| |
Title |
Considering evolutionary processes in adaptive forestry |
Type |
Journal Article |
| |
Year |
2013 |
Publication |
Annals of Forest Science |
Abbreviated Journal |
Ann For Sci |
|
| |
Volume |
71 |
Issue |
7 |
Pages |
723-739 |
|
| |
Keywords |
Adaptation; Climate change; Evolution-oriented forest management; Genetic resources; Silviculture |
|
| |
Abstract |
Context: Managing forests under climate change requires adaptation. The adaptive capacity of forest tree populations is huge but not limitless. Integrating evolutionary considerations into adaptive forestry practice will enhance the capacity of managed forests to respond to climate-driven changes.
Aims: Focusing on natural regeneration systems, we propose a general framework that can be used in various and complex local situations by forest managers, in combination with their own expertise, to integrate evolutionary considerations into decision making for the emergence of an evolution-oriented forestry.
Methods: We develop a simple process-based analytical grid, using few processes and parameters, to analyse the impact of forestry practice on the evolution and evolvability of tree populations.
Results: We review qualitative and, whenever possible, quantitative expectations on the intensity of evolutionary drivers in forest trees. Then, we review the effects of actual and potential forestry practice on the evolutionary processes. We illustrate the complexity of interactions in two study cases: the evolutionary consequences for forest trees of biotic interactions and of highly heterogeneous environment.
Conclusion: Evolution-oriented forestry may contribute adapting forests to climate change. It requires combining short-term and long-term objectives. We propose future lines of research and experimentation. |
|
| |
Address |
INRA, UR629 Ecologie des Forêts Méditerranéennes, URFM, Domaine Saint Paul, Site AgroparcAvignon Cedex 9, France |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Cited By :2; Export Date: 13 January 2015 |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
580 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Feldpausch, T.R.; Phillips, O.L.; Brienen, R.J.W.; Gloor, E.; Lloyd, J.; Lopez-Gonzalez, G.; Monteagudo-Mendoza, A.; Malhi, Y.; Alarcón, A.; Álvarez Dávila, E.; Alvarez-Loayza, P.; Andrade, A.; Aragao, L.E.O.C.; Arroyo, L.; Aymard C., G.A.; Baker, T.R.; Baraloto, C.; Barroso, J.; Bonal, D.; Castro, W.; Chama, V.; Chave, J.; Domingues, T.F.; Fauset, S.; Groot, N.; Honorio Coronado, E.; Laurance, S.; Laurance, W.F.; Lewis, S.L.; Licona, J.C.; Marimon, B.S.; Marimon-Junior, B.H.; Mendoza Bautista, C.; Neill, D.A.; Oliveira, E.A.; Oliveira dos Santos, C.; Pallqui Camacho, N.C.; Pardo-Molina, G.; Prieto, A.; Quesada, C.A.; Ramírez, F.; Ramírez-Angulo, H.; Réjou-Méchain, M.; Rudas, A.; Saiz, G.; Salomão, R.P.; Silva-Espejo, J.E.; Silveira, M.; ter Steege, H.; Stropp, J.; Terborgh, J.; Thomas-Caesar, R.; van der Heijden, G.M.F.; Vásquez Martinez, R.; Vilanova, E.; Vos, V.A. |
|
| |
Title |
Amazon forest response to repeated droughts |
Type |
Journal Article |
| |
Year |
2016 |
Publication |
Global Biogeochemical Cycles |
Abbreviated Journal |
Global Biogeochemical Cycles |
|
| |
Volume |
30 |
Issue |
7 |
Pages |
964-982 |
|
| |
Keywords |
carbon; forest productivity; precipitation; tree mortality; vegetation dynamics; water deficit |
|
| |
Abstract |
The Amazon Basin has experienced more variable climate over the last decade, with a severe and widespread drought in 2005 causing large basin-wide losses of biomass. A drought of similar climatological magnitude occurred again in 2010; however, there has been no basin-wide ground-based evaluation of effects on vegetation. We examine to what extent the 2010 drought affected forest dynamics using ground-based observations of mortality and growth from an extensive forest plot network. We find that during the 2010 drought interval, forests did not gain biomass (net change: −0.43 Mg ha−1, confidence interval (CI): −1.11, 0.19, n = 97), regardless of whether forests experienced precipitation deficit anomalies. This contrasted with a long-term biomass sink during the baseline pre-2010 drought period (1998 to pre-2010) of 1.33 Mg ha−1 yr−1 (CI: 0.90, 1.74, p < 0.01). The resulting net impact of the 2010 drought (i.e., reversal of the baseline net sink) was −1.95 Mg ha−1 yr−1 (CI:−2.77, −1.18; p < 0.001). This net biomass impact was driven by an increase in biomass mortality (1.45 Mg ha−1 yr−1 CI: 0.66, 2.25, p < 0.001) and a decline in biomass productivity (−0.50 Mg ha−1 yr−1, CI:−0.78, −0.31; p < 0.001). Surprisingly, the magnitude of the losses through tree mortality was unrelated to estimated local precipitation anomalies and was independent of estimated local pre-2010 drought history. Thus, there was no evidence that pre-2010 droughts compounded the effects of the 2010 drought. We detected a systematic basin-wide impact of the 2010 drought on tree growth rates across Amazonia, which was related to the strength of the moisture deficit. This impact differed from the drought event in 2005 which did not affect productivity. Based on these ground data, live biomass in trees and corresponding estimates of live biomass in lianas and roots, we estimate that intact forests in Amazonia were carbon neutral in 2010 (−0.07 Pg C yr−1 CI:−0.42, 0.23), consistent with results from an independent analysis of airborne estimates of land-atmospheric fluxes during 2010. Relative to the long-term mean, the 2010 drought resulted in a reduction in biomass carbon uptake of 1.1 Pg C, compared to 1.6 Pg C for the 2005 event. ©2016. American Geophysical Union. All Rights Reserved. |
|
| |
Address |
Centro de Investigación y Promoción del Campesinado Norte Amazónico, Riberalta, Bolivia |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Export Date: 1 September 2016 |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
690 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Stahl, C.; Freycon, V.; Fontaine, S.; Dezecache, C.; Ponchant, L.; Picon-Cochard, C.; Klumpp, K.; Soussana, J.-F.; Blanfort, V. |
|
| |
Title |
Soil carbon stocks after conversion of Amazonian tropical forest to grazed pasture: importance of deep soil layers |
Type |
Journal Article |
| |
Year |
2016 |
Publication |
Regional Environmental Change |
Abbreviated Journal |
|
|
| |
Volume |
16 |
Issue |
7 |
Pages |
2059-2069 |
|
| |
Keywords |
|
|
| |
Abstract |
Recent studies suggest that carbon (C) is stored in the topsoil of pastures established after deforestation. However, little is known about the long-term capacity of tropical pastures to sequester C in different soil layers after deforestation. Deep soil layers are generally not taken into consideration or are underestimated when C storage is calculated. Here we show that in French Guiana, the C stored in the deep soil layers contributes significantly to C stocks down to a depth of 100 cm and that C is sequestered in recalcitrant soil organic matter in the soil below a depth of 20 cm. The contribution of the 50–100 cm soil layer increased from 22 to 31 % with the age of the pasture. We show that long-term C sequestration in C4 tropical pastures is linked to the development of C3 species (legumes and shrubs), which increase both inputs of N into the ecosystem and the C:N ratio of soil organic matter. The deep soil under old pastures contained more C3 carbon than the native forest. If C sequestration in the deep soil is taken into account, our results suggest that the soil C stock in pastures in Amazonia would be higher with sustainable pasture management, in particular by promoting the development of legumes already in place and by introducing new species. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
|
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1436-378x |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ Stahl2016 |
Serial |
721 |
|
| Permanent link to this record |
