| |
Records |
Links |
|
Author |
Leroy, Celine ; Maes, Arthur QuyManh ; Louisanna, Eliane ; Schimann, Heidy ; Séjalon-Delmas, Nathalie |
|
| |
Title |
Taxonomic, phylogenetic and functional diversity of rootassociated fungi in bromeliads: effects of host identity, life forms and nutritional modes |
Type |
Journal Article |
| |
Year |
2021 |
Publication |
New Phytologist |
Abbreviated Journal |
|
|
| |
Volume |
231 |
Issue |
3 |
Pages |
1195-1209 |
|
| |
Keywords |
|
|
| |
Abstract  |
Bromeliads represent a major component of neotropical forests and encompass a considerable diversity of life forms and nutritional modes. Bromeliads explore highly stressful habitats and root-associated fungi may play a crucial role in this, but the driving factors and variations in root-associated fungi remain largely unknown.
We explored root-associated fungal communities in 17 bromeliad species and their variations linked to host identity, life forms and nutritional modes by using ITS1 gene-based high-throughput sequencing and by characterizing fungal functional guilds.
We found a dual association of mycorrhizal and nonmycorrhizal fungi. The different species, life forms and nutritional modes among bromeliad hosts had fungal communities that differ in their taxonomic and functional composition. Specifically, roots of epiphytic bromeliads had more endophytic fungi and dark septate endophytes and fewer mycorrhizal fungi than terrestrial bromeliads and lithophytes.
Our results contribute to a fundamental knowledge base on different fungal groups in previously undescribed Bromeliaceae. The diverse root-associated fungal communities in bromeliads may enhance plant fitness in both stressful and nutrient-poor environments and may give more flexibility to the plants to adapt to changing environmental conditions. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
New Phytologist Foundation |
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 |
|
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
1061 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Rutishauser, E.; Herault, B.; Petronelli, P.; Sist, P. |
|
| |
Title |
Tree Height Reduction After Selective Logging in a Tropical Forest |
Type |
Journal Article |
| |
Year |
2016 |
Publication |
Biotropica |
Abbreviated Journal |
Biotropica |
|
| |
Volume |
48 |
Issue |
3 |
Pages |
285-289 |
|
| |
Keywords |
carbon sequestration; forest management; logging; tropical forests; wood production |
|
| |
Abstract |
By harvesting scattered large trees, selective logging increases light availability and thereby stimulates growth and crown expansion at early-life stage among remnant trees. We assessed the effects of logging on total and merchantable bole (i.e., lowest branch at crown base) heights on 952 tropical canopy trees in French Guiana. We observed reductions in both total (mean, −2.3 m) and bole (mean, −2.0 m) heights more than a decade after selective logging. Depending on local logging intensity, height reductions resulted in 2–13 percent decreases in aboveground tree biomass and 3–17 percent decreases in bole volume. These results highlight the adverse effects of logging at both tree and stand levels. This decrease in height is a further threat to future provision of key environmental services, such as timber production and carbon sequestration. |
|
| |
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 |
1744-7429 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
723 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Barraza, F.; Schreck, E.; Lévêque, T.; Uzu, G.; Lopez, F.; Ruales, J.; Prunier, J.; Marquet, A.; Maurice, L. |
|
| |
Title |
Cadmium bioaccumulation and gastric bioaccessibility in cacao: A field study in areas impacted by oil activities in Ecuador |
Type |
Journal Article |
| |
Year |
2017 |
Publication |
Environmental Pollution |
Abbreviated Journal |
|
|
| |
Volume |
229 |
Issue |
|
Pages |
950-963 |
|
| |
Keywords |
Cacao; Cadmium; Ecuador; Health risk assessment; Uptake and bioaccumulation |
|
| |
Abstract |
Cacao from South America is especially used to produce premium quality chocolate. Although the European Food Safety Authority has not established a limit for cadmium (Cd) in chocolate raw material, recent studies demonstrate that Cd concentrations in cacao beans can reach levels higher than the legal limits for dark chocolate (0.8 mg kg−1, effective January 1st, 2019). Despite the fact that the presence of Cd in agricultural soils is related to contamination by fertilizers, other potential sources must be considered in Ecuador. This field study was conducted to investigate Cd content in soils and cacao cultivated on Ecuadorian farms in areas impacted by oil activities. Soils, cacao leaves, and pod husks were collected from 31 farms in the northern Amazon and Pacific coastal regions exposed to oil production and refining and compared to two control areas. Human gastric bioaccessibility was determined in raw cacao beans and cacao liquor samples in order to assess potential health risks involved. Our results show that topsoils (0–20 cm) have higher Cd concentrations than deeper layers, exceeding the Ecuadorian legislation limit in 39% of the sampling sites. Cacao leaves accumulate more Cd than pod husks or beans but, nevertheless, 50% of the sampled beans have Cd contents above 0.8 mg kg−1. Root-to-cacao transfer seems to be the main pathway of Cd uptake, which is not only regulated by physico-chemical soil properties but also agricultural practices. Additionally, natural Cd enrichment by volcanic inputs must not be neglected. Finally, Cd in cacao trees cannot be considered as a tracer of oil activities. Assuming that total Cd content and its bioaccessible fraction (up to 90%) in cacao beans and liquor is directly linked to those in chocolate, the health risk associated with Cd exposure varies from low to moderate. |
|
| |
Address |
Laboratoire des Sciences du Bois, UMR EcoFoG, ZI Pariacabo, 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 |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Cited By :1; Export Date: 4 June 2018 |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
806 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Goulamoussene, Youven; Bedeau, Caroline; Descroix, Laurent; Deblauwe, Vincent; Linguet, Laurent; Herault, Bruno |
|
| |
Title |
Weak Environmental Controls of Tropical Forest Canopy Height in the Guiana Shield Remote Sensing |
Type |
Journal Article |
| |
Year |
2016 |
Publication |
Remote Sensing |
Abbreviated Journal |
Remote Sens |
|
| |
Volume |
8 |
Issue |
9 |
Pages |
747 |
|
| |
Keywords |
|
|
| |
Abstract |
Canopy height is a key variable in tropical forest functioning and for regional carbon inventories. We investigate the spatial structure of the canopy height of a tropical forest, its relationship with environmental physical covariates, and the implication for tropical forest height variation mapping. Making use of high-resolution maps of LiDAR-derived Digital Canopy Model (DCM) and environmental covariates from a Digital Elevation Model (DEM) acquired over 30,000 ha of tropical forest in French Guiana, we first show that forest canopy height is spatially correlated up to 2500 m. Forest canopy height is significantly associated with environmental variables, but the degree of correlation varies strongly with pixel resolution. On the whole, bottomland forests generally have lower canopy heights than hillslope or hilltop forests. However, this global picture is very noisy at local scale likely because of the endogenous gap-phase forest dynamic processes. Forest canopy height has been predictively mapped across a pixel resolution going from 6 m to 384 m mimicking a low resolution case of 3 points·km − 2 . Results of canopy height mapping indicated that the error for spatial model with environment effects decrease from 8.7 m to 0.91 m, depending of the pixel resolution. Results suggest that, outside the calibration plots, the contribution of environment in shaping the global canopy height distribution is quite limited. This prevents accurate canopy height mapping based only on environmental information, and suggests that precise canopy height maps, for local management purposes, can only be obtained with direct LiDAR monitoring. |
|
| |
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 |
|
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
724 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Lobova, T.A.; Mori, S.A.; Blanchard, F.; Peckham, H.; Charles-Dominique, P. |
|
| |
Title |
Cecropia as a food resource for bats in French Guiana and the significance of fruit structure in seed dispersal and longevity |
Type |
Journal Article |
| |
Year |
2003 |
Publication |
American Journal of Botany |
Abbreviated Journal |
Am. J. Bot. |
|
| |
Volume |
90 |
Issue |
3 |
Pages |
388-403 |
|
| |
Keywords |
bat dispersal; Cecropia; French Guiana; fruit anatomy; fruit morphology; mucilage; Neotropical bats; soil seed bank |
|
| |
Abstract |
Cecropia (Cecropiaceae) is a Neotropical genus of pioneer plants. A review of bat/plant dispersal interactions revealed that 15 species of Cecropia are consumed by 32 species of bats. In French Guiana, bats were captured in primary and secondary forests, yielding 936 fecal samples with diaspores, among which 162 contained fruits of C. obtusa, C. palmata, and C. sciadophylla. A comparative morphological and anatomical study of fruits and seeds taken directly from herbarium specimens, bat feces, and an experimental soil seed bank was made. Contrary to previous reports, the dispersal unit of Cecropia is the fruit not the seed. Bats consume the infructescence, digest pulp derived from the enlarged, fleshy perianth, and defecate the fruits. The mucilaginous pericarp of Cecropia is described. The external mucilage production of Cecropia may facilitate endozoochory. The exocarp and part of the mesocarp may be lost after passage through the digestive tract of bats, but fruits buried for a year in the soil seed bank remain structurally unchanged. Fruit characters were found to be useful for identifying species of bat-dispersed Cecropia. Bat dispersal is not necessary for seed germination but it increases seed survival and subsequent germination. Fruit structure plays a significant role in seed longevity. |
|
| |
Address |
New York Bot Garden, Inst Systemat Bot, Bronx, NY 10458 USA |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
BOTANICAL SOC AMER INC |
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0002-9122 |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
ISI:000183133100008 |
Approved |
no |
|
| |
Call Number |
EcoFoG @ eric.marcon @ |
Serial |
272 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Chanson, Anaïs ; Moreau, Corrie S. ; Duplais, Christophe |
|
| |
Title |
Assessing Biosynthetic Gene Cluster Diversity of Specialized Metabolites in the Conserved Gut Symbionts of Herbivorous Turtle Ants |
Type |
Journal Article |
| |
Year |
2021 |
Publication |
Frontiers in Microbiology |
Abbreviated Journal |
|
|
| |
Volume |
12 |
Issue |
|
Pages |
678100 |
|
| |
Keywords |
insect-microbe mutualism, ants, metagemonic, biosynthetic gene cluster, gut bacteria, Cephalotes |
|
| |
Abstract |
Cephalotes are herbivorous ants (>115 species) feeding on low-nitrogen food sources, and they rely on gut symbionts to supplement their diet by recycling nitrogen food waste into amino acids. These conserved gut symbionts, which encompass five bacterial orders, have been studied previously for their primary nitrogen metabolism; however, little is known about their ability to biosynthesize specialized metabolites which can play a role in bacterial interactions between communities living in close proximity in the gut. To evaluate the biosynthetic potential of their gut symbionts, we mine 14 cultured isolate genomes and gut metagenomes across 17 Cephalotes species to explore the biodiversity of biosynthetic gene clusters (BGCs) producing specialized metabolites. The diversity of BGCs across Cephalotes phylogeny was analyzed using sequence similarity networking and BGC phylogenetic reconstruction. Our results reveal that the conserved gut symbionts involved in the nutritional symbiosis possess 80% of all the 233 BGCs retrieved in this work. Furthermore, the phylogenetic analysis of BGCs reveals different patterns of distribution, suggesting different mechanisms of conservation. A siderophore BGC shows high similarity in a single symbiont across different ant host species, whereas a BGC encoding the production of non-ribosomal peptides (NRPs) found different symbionts within a single host species. Additionally, BGCs were abundant in four of the five bacterial orders of conserved symbionts co-occurring in the hindgut. However, one major symbiont localized alone in the midgut lack BGCs. Because the spatial isolation prevents direct interaction with other symbionts, this result supports the idea that BGCs are maintained in bacteria living in close proximity but are dispensable for an alone-living symbiont. These findings together pave the way for studying the mechanisms of BGC conservation and evolution in gut bacterial genomes associated with Cephalotes. This work also provides a genetic background for further study, aiming to characterize bacterial specialized metabolites and to understand their functional role in multipartite mutualisms between conserved gut symbionts and Cephalotes turtle ants. |
|
| |
Address |
|
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Frontiers Media |
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 |
|
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
1049 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Bossu, J.; Beauchene, J.; Estevez, Y.; Duplais, C.; Clair, B. |
|
| |
Title |
New insights on wood dimensional stability influenced by secondary metabolites: The case of a fast-growing tropical species Bagassa guianensis aubl |
Type |
Journal Article |
| |
Year |
2016 |
Publication |
PLoS ONE |
Abbreviated Journal |
PLoS ONE |
|
| |
Volume |
11 |
Issue |
3 |
Pages |
e0150777 |
|
| |
Keywords |
|
|
| |
Abstract |
Challenging evaluation of tropical forest biodiversity requires the reporting of taxonomic diversity but also the systematic characterization of wood properties in order to discover new promising species for timber industry. Among wood properties, the dimensional stability is regarded as a major technological characteristic to validate whether a wood species is adapted to commercial uses. Cell structure and organization are known to influence the drying shrinkage making wood density and microfibrils angle markers of choice to predict wood dimensional stability. On the contrary the role of wood extractive content remains unclear. This work focuses on the fast-growing tropical species Bagassa guianensis and we report herein a correlation between heartwood drying shrinkage and extractive content. Chemical extractions and shrinkage experiments were performed on separate wood twin samples to better evaluate correctly how secondary metabolites influence the wood shrinkage behaviour. Extractive content were qualitatively and quantitatively analysed using HPLC and NMR spectroscopy. We found that B guianensis heartwood has a homogeneous low shrinkage along its radius that could not be explained only by its basic density. In fact the low drying shrinkage is correlated to the high extractive content and a corrected model to improve the prediction of wood dimensional stability is presented. Additionally NMR experiments conducted on sapwood and heartwood extracts demonstrate that secondary metabolites biosynthesis occurs in sapwood thus revealing B. guianensis as a Juglans-Type heartwood formation. This work demonstrates that B. guianensis, a fast-growing species associated with high durability and high dimensional stability, is a good candidate for lumber production and commercial purposes. © 2016 Bossu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. |
|
| |
Address |
Cirad, UMR EcoFoG, AgroParisTech, CNRS, INRA, Université des Antilles, Université de Guyane, Kourou, 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 |
Export Date: 18 April 2016 |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
673 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Romero, G.Q.; Marino, N.A.C.; MacDonald, A.A.M.; Céréghino, R.; Trzcinski, M.K.; Mercado, D.A.; Leroy, C.; Corbara, B.; Farjalla, V.F.; Barberis, I.M.; Dézerald, O.; Hammill, E.; Atwood, T.B.; Piccoli, G.C.O.; Bautista, F.O.; 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.; Kratina, P.; O’Gorman, E.J.; Srivastava, D.S. |
|
| |
Title |
Extreme rainfall events alter the trophic structure in bromeliad tanks across the Neotropics |
Type |
Journal Article |
| |
Year |
2020 |
Publication |
Nature Communications |
Abbreviated Journal |
Nat. Commun. |
|
| |
Volume |
11 |
Issue |
3215 |
Pages |
|
|
| |
Keywords |
fresh water; rain; fresh water; agricultural intensification; angiosperm; biomass; climate change; ecosystem function; extreme event; food web; freshwater ecosystem; Neotropic Ecozone; precipitation intensity; rainfall; trophic structure; Article; biomass; Central America; controlled study; detritivore; drought; flooding; food web; hydrology; microcosm; Neotropics; nonhuman; precipitation; predator; South America; trophic level; animal; biodiversity; Bromelia; climate change; ecosystem; flooding; food chain; Central America; South America; Animals; Biodiversity; Biomass; Bromelia; Climate Change; Droughts; Ecosystem; Floods; Food Chain; Fresh Water; Hydrology; South America |
|
| |
Abstract |
Changes in global and regional precipitation regimes are among the most pervasive components of climate change. Intensification of rainfall cycles, ranging from frequent downpours to severe droughts, could cause widespread, but largely unknown, alterations to trophic structure and ecosystem function. We conducted multi-site coordinated experiments to show how variation in the quantity and evenness of rainfall modulates trophic structure in 210 natural freshwater microcosms (tank bromeliads) across Central and South America (18°N to 29°S). The biomass of smaller organisms (detritivores) was higher under more stable hydrological conditions. Conversely, the biomass of predators was highest when rainfall was uneven, resulting in top-heavy biomass pyramids. These results illustrate how extremes of precipitation, resulting in localized droughts or flooding, can erode the base of freshwater food webs, with negative implications for the stability of trophic dynamics. © 2020, The Author(s). |
|
| |
Address |
Institute of Biological Sciences, Universidade Federal do Pará, Belém, PA, Brazil |
|
| |
Corporate Author |
|
Thesis |
|
|
| |
Publisher |
Nature Research |
Place of Publication |
|
Editor |
|
|
| |
Language |
|
Summary Language |
|
Original Title |
|
|
| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
|
| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
20411723 (Issn) |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
|
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
944 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Castro, H.; Fortunel, C.; Freitas, H. |
|
| |
Title |
Effects of land abandonment on plant litter decomposition in a Montado system: relation to litter chemistry and community functional parameters |
Type |
Journal Article |
| |
Year |
2010 |
Publication |
Plant and Soil |
Abbreviated Journal |
Plant Soil |
|
| |
Volume |
333 |
Issue |
1-2 |
Pages |
181-190 |
|
| |
Keywords |
Ecosystem processes; Land use change; Leaf dry matter content; Life form; Litter quality; Mediterranean |
|
| |
Abstract |
Changes in land use and subsequent shifts in vegetation can influence decomposition through changes in litter quality (chemistry and structure) and alterations of soil temperature and moisture. Our aim was to study the effects of land abandonment on litter decomposition in a Mediterranean area of Montado, South Portugal. We tested the hypothesis that decomposition tends to slow down with abandonment, as woody species, richer in lignified structures, replace herbaceous species. We assessed the decomposition of community litter in situ using litterbag technique. To test the influence of local conditions, we simultaneously incubated a standard litter in situ. Our results showed that the shift from herbaceous to shrub-dominated communities lead to decreased decomposition rates. Changes in litter decomposition were primarily driven by changes in litter quality, even though the uneven pattern of litter mass loss over the experiment might reveal an effect from possible differences in microclimate. Shrub litter had higher nutrient content than herbaceous litter, which seemed to favour higher initial decomposition rates, but lower decomposition rate in the longer term. Shrubs also contribute to woody litter, richer in lignin, and secondary compounds that retard decomposition, and may play a role in increasing pools of slowly decomposing organic matter. |
|
| |
Address |
[Castro, Helena; Freitas, Helena] Univ Coimbra, Dept Life Sci, Ctr Funct Ecol, P-3001401 Coimbra, Portugal, Email: hecastro@ci.uc.pt |
|
| |
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 |
0032-079X |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
ISI:000280089400015 |
Approved |
no |
|
| |
Call Number |
EcoFoG @ eric.marcon @ |
Serial |
49 |
|
| Permanent link to this record |
| |
|
| |
|
Author |
Vincent, G.; Weissenbacher, E.; Sabatier, D.; Blanc, L.; Proisy, C.; Couteron, P. |
|
| |
Title |
Detection des variations de structure de peuplements en foret dense tropicale humide par lidar aeroporte |
Type |
Journal Article |
| |
Year |
2010 |
Publication |
Revue Francaise de Photogrammetrie et de Teledetection |
Abbreviated Journal |
Rev. Fr. Photogramm. Teledetect. |
|
| |
Volume |
191 |
Issue |
|
Pages |
42-51 |
|
| |
Keywords |
Above-ground biomass estimation; Canopy height model; Stem diameter distribution; Tropical moist forest; Above ground biomass; Above ground level; Airborne LiDAR; Basal area; Canopy Height Models; Carbon stocks; Characterisation; Classical fields; Coefficient of variation; Diameter distributions; Digital terrain model; Flooded areas; Forest ecology; Forest structure; Forest type; High spatial resolution; Individual tree; LIDAR data; Light detection and ranging; Local statistics; Long term; Management issues; Natural forests; Natural variation; Pearson correlation coefficients; Quadratic mean diameter; Soil characteristics; Soil cover; Spatial changes; Spatial resolution; Stem density; Stem diameter; Stem height; Strong correlation; Tree height; Tropical moist forest; Tropical rain forest; Vegetation structure; Vertical accuracy; Water regime; Discriminant analysis; Ecology; Optical radar; Remote sensing; Soils; Statistics; Stem cells; Temperature control; Tropics; Vegetation; Forestry; Biomass; Discriminant Analysis; Ecology; Forest Canopy; Forestry; Radar; Remote Sensing; Stems; Temperature Control; Tropical Atmospheres |
|
| |
Abstract |
Characterisation of forest structure is a major stake for forestry, species conservation, carbon stock estimates and many forest ecology and management issues. At large scale natural forest structure tends to vary according to climate and geomorphomology (Paget, 1999; Steege et al., 2006) while soil characteristics (and notably water regime) and syMgenetic stage add some finer scale variation (Oldeman, 1989; Sabatier et al., 1997). Forest structure characterisation traditionally relies on field-based collection of individual tree dimensions such as stem diameter and stem height sampled across tracks of forest (Hall et al., 1998). However, such field intensive methods are costly, and of low accuracy regarding measures of tree heights. Airborne light detection and ranging (LiDAR) technology provides horizontal and vertical Information at high spatial resolutions and vertical accuracies (Lim et al., 2003; Hyyppä et al., 2004). It has the potential for gathering vegetation structure data over large areas rapidly at moderate cost and hence is of particular relevance for poorly sampled, difficult to access and largely unexplored tropical rainforests. In this study we examined the ability of airborne LiDAR to detect spatial changes in the structure of dense tropical rain forest and we probed this remote sensing approach against local statistics derived from stem diameters (i.e. classical field data information) mapped across a large track of forest at a long term experimental site in French Guyana. The large variability in forest structure occurring at the experimental site is du to natural variation of the soil cover (and notably drainage properties) combined with various logging intensities applied 15 years before the LiDAR data were acquired. On this basis ten different forest types were identified at the site (figure 1 and 3). Various stem based statistics were computed for a series of meshes with cells ranging from 30 by 30 m plots to 250 by 250 m plots. These statistics included basal area, stem density, quadratic mean diameter, and diameter distribution percentiles. Similarly local statistics were extracted either from the Canopy Height Model (e.g. median height, mean height, standard height deviation, height coefficient of variation, height percentiles, frequency of hits below 5 m above ground level). Additionally a wetness index (Böhner et al., 2002) was computed at each node of a 5 by 5 m grid from the Digital Terrain Model also extracted from the LiDAR data set. We used both types of cell statistics to discriminate the various forest types. Comparison between the two approaches for a range of spatial resolution is available from in table 1. Results indicate that LiDAR based statistics are essentially as powerful as field based statistics to discriminate forest types at coarse scale. This reflects the very strong correlation between the CHM and the field based stem diameter data. For example (figure 5) the Pearson correlation coefficient between median height and quadratic mean diameter for cells of 125 by 125 m is 0.945 (n=0.72). When a finer resolution is required however as for the detection of seasonally flooded bottomland forest along thalwegs, then LiDAR technology proves more efficient than field based inventories as it combines information from the DTM and the CHM. The wetness index alone correctly retrieves about 2 thirds of the seasonally flooded areas. All in all, discriminant analysis performance of the LiDAR derived information approaches 80% when classifying forests cover at the finest scale of 5 by 5m into 10 different types and reaches 87% when a coarser classification Into 6 forest types is considered (figure 4). |
|
| |
Address |
IRD, UMR AMAP, 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 |
17689791 (Issn) |
ISBN |
|
Medium |
|
|
| |
Area |
|
Expedition |
|
Conference |
|
|
| |
Notes |
Cited By (since 1996): 1; Export Date: 21 October 2011; Source: Scopus; Language of Original Document: French; Correspondence Address: Vincent, G.; IRD, UMR AMAP, Kourou – BP 701 (CIRAD) 97387 Kourou cedex -Guyane, France |
Approved |
no |
|
| |
Call Number |
EcoFoG @ webmaster @ |
Serial |
351 |
|
| Permanent link to this record |
