Forest vs Savanna dynamics in the contact zones of French Guiana

  • Gaëlle Viennois UMR AMAP CNRS
  • Eric A. Nicolini Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), UMR AMAP
  • Frédéric Borne Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), UMR AMAP

Résumé

Savannas and tropical forests delineated by sharp boundaries are two alternative stable ecosystems. What is the natural evolution of forests over savannas in coastal savanna in French Guiana? The dynamic balance between forest advance and retreat is a response to disturbances such as fire or extreme drought events. Fire maintains savanna by its action on forest-savanna contact areas, while a dry climate prevents forest expansion. This paper focuses on coastal savannas of French Guiana nested in the Guiana Space Center (CSG) that is occasionally threatened by bushfires in the dry season. This study spanned over 60 years of landscape changes around the CSG and used a georeferenced set of aerial and Pléiades satellite images. Forest and savanna dynamics were mapped and highlighted with the computing of shape indicators. This study showed that the forest progressed of 23% onto savanna and mainly at the forest–savanna contact zones.

Références

Adjanohoun, E. 1964. Végétation des savanes et des rochers découverts en Côte d’Ivoire centrale. In Mémoires ORSTOM,
Aubréville, A. 1966. Les lisières forêt-savane des régions tropicales. Adansonia 175–187.
Barret, J., Blancaneaux, P., Caillé, O., Charron, C., Gaucherel, C., Granville, J.-J. de, Grenand, P., Guiral, D., Lointier, M., & Mérona, B. de. 2001. Atlas illustré de la Guyane.
Beerling, D.J., & Osborne, C.P. 2006. The origin of the savanna biome. Global Change Biology 12: 2023–2031.
Behling, H., Pillar, V.D., & Bauermann, S.G. 2005. Late Quaternary grassland (Campos), gallery forest, fire and climate dynamics, studied by pollen, charcoal and multivariate analysis of the São Francisco de Assis core in western Rio Grande do Sul (southern Brazil). Review of Palaeobotany and Palynology 133: 235–248.
Bond, W.J., Woodward, F.I., & Midgley, G.F. 2005. The global distribution of ecosystems in a world without fire. New Phytologist 165: 525–538.
Bowman, D.M., Balch, J.K., Artaxo, P., Bond, W.J., Carlson, J.M., Cochrane, M.A., D’Antonio, C.M., DeFries, R.S., Doyle, J.C., & Harrison, S.P. 2009. Fire in the Earth system. science 324: 481–484.
Brook, B.W., & Bowman, D.M. 2006. Postcards from the past: charting the landscape-scale conversion of tropical Australian savanna to closed forest during the 20th century. Landscape Ecology 21: 1253–1266.
Chaix, M. 2002. Connaissance et conservation des savanes de Guyane. IRD-WWF Guyane.
Chave, J. 2000. Dynamique spatio-temporelle de la forêt tropicale. In Annales de Physique,
Coster, M., & Chermant, J.L. 1989. Précis d’analyse d’images. Paris.
Eden, M.J., & McGregor, D.F.M. 1992. Dynamics of the forest–savanna boundary in the Rio Branco–Rupunumi region of northern Amazonia. In Nature and Dynamics of Forest Savanna Boundaries., pp. 77–89. Chapman & Hall, London.
Fölster, H., & Dezzeo, N. 1994. Ecología de la altiplanicie de la Gran Sabana (Guayana Venezolana)I. Investigaciones sobre la dinámica bosque-sabana en el sector SE: subcuencas de los ríos Yuruaní,. vol. 4Arabopó y Alto Kukenán,.
De Foresta, H. 1990. Origine et evolution des savanes intramayombiennes. In Paysages quaternaires de l’Afrique centrale atlantique., pp. 326–335. Bondy.
Gautier, L. 1989. Contact forˆet-savane en Cˆote d’Ivoire centrale: évolution de la surface forestière de la réserve de Lamto (sud du V-Baoulé). Bull. Soc. Bot. France, Actual. Bot 85–92.
Granville, J.-J. de. 1990. Recherche sur la flore et la végétation guyanaise.
Hills, T.L., & Randall, R.E. 1968. The Ecology of the Forest/savanna Boundary (proceedings of the Igu Humid Tropics Commission Symposium, Venezuela, 1964). DTIC Document.
Hoff, M., & Brisse, H. 1990. Diversité et répartition des formations végétales en Guyane française à partir d’une base de données sur l’environnement. In p. 20.
Hoffmann, W.A., Orthen, B., & Franco, A.C. 2004. Constraints to seedling success of savanna and forest trees across the savanna-forest boundary. Oecologia 140: 252–260.
Hoffmann, W.A., Orthen, B., & Nascimento, P.K.V. do. 2003. Comparative fire ecology of tropical savanna and forest trees. Functional Ecology 17: 720–726.
Hoock, J. 1971. Les Savanes guyanaises: Kourou, essai de phytoécologie numérique. IRD Editions.
Hudak, A.T., & Wessman, C.A. 1998. Textural analysis of historical aerial photography to characterize woody plant encroachment in South African savanna. Remote Sensing of Environment 66: 317–330.
Ibanez, T., Borgniet, L., Mangeas, M., Gaucherel, C., Geraux, H., & Hely, C. 2012. Rainforest and savanna landscape dynamics in New Caledonia: Towards a mosaic of stable rainforest and savanna states? Austral Ecology
Iriarte, J., Power, M.J., Rostain, S., Mayle, F.E., Jones, H., Watling, J., Whitney, B.S., & McKey, D.B. 2012. Fire-free land use in pre-1492 Amazonian savannas. Proceedings of the National Academy of Sciences 109: 6473–6478.
Krummel, J.R., Gardner, R.H., Sugihara, G., O’neill, R.V., & Coleman, P.R. 1987. Landscape patterns in a disturbed environment. Oikos 48: 321–324.
Louppe, D., Outtara, N., & Coulibaly, A. 1995. Effets des feux de brousse sur la végétation. Bois et Forêts des Tropiques 55–59.
McGarigal, K., & Marks, B.J. 1995. Spatial pattern analysis program for quantifying landscape structure. Gen. Tech. Rep. PNW-GTR-351. US Department of Agriculture, Forest Service, Pacific Northwest Research Station
McKey, D., Rostain, S., Iriarte, J., Glaser, B., Birk, J.J., Holst, I., & Renard, D. 2010. Pre-Columbian agricultural landscapes, ecosystem engineers, and self-organized patchiness in Amazonia. Proceedings of the National Academy of Sciences 107: 7823–7828.
Puyravaud, J.-P., Dufour, C., & Aravajy, S. 2003. Rain forest expansion mediated by successional processes in vegetation thickets in the Western Ghats of India. Journal of Biogeography 30: 1067–1080.
Ratnam, J., Bond, W.J., Fensham, R.J., Hoffmann, W.A., Archibald, S., Lehmann, C.E., Anderson, M.T., Higgins, S.I., & Sankaran, M. 2011. When is a “forest”a savanna, and why does it matter? Global Ecology and Biogeography 20: 653–660.
Rossatto, D.R., Hoffmann, W.A., & Franco, A.C. 2009. Differences in growth patterns between co-occurring forest and savanna trees affect the forest–savanna boundary. Functional Ecology 23: 689–698.
Rostain, S. 2008. Le littoral des guyanes, héritage de l’agriculture précolombienne. Etudes rurales 9–38.
Russell-Smith, J., Stanton, P.J., Edwards, A.C., & Whitehead, P.J. 2004. Rain forest invasion of eucalypt-dominated woodland savanna, Iron Range, north-eastern Australia: II. Rates of landscape change. Journal of Biogeography 31: 1305–1316.
Rutledge, D.T. 2003. Landscape indices as measures of the effects of fragmentation: can pattern reflect process?
Schoene, D., Killmann, W., von Lüpke, H., & Wilkie, M.L. 2007. Definitional Issues Related to Reducing Emissions from Deforesation in Developing Countries. Food and Agriculture Organization of the United Nations.
Schwartz, D., De Foresta, H., Mariotti, A., Balesdent, J., Massimba, J.P., & Girardin, C. 1996. Present dynamics of the savanna-forest boundary in the Congolese Mayombe: a pedological, botanical and isotopic (13C and 14C) study. Oecologia 106: 516–524.
Silva, J.M.C.D., & Bates, J.M. 2002. Biogeographic Patterns and Conservation in the South American Cerrado: A Tropical Savanna Hotspot The Cerrado, which includes both forest and savanna habitats, is the second largest South American biome, and among the most threatened on the continent. BioScience 52: 225–234.
Da Silva, J.M.C., & Bates, J.M. 2002. Biogeographic Patterns and Conservation in the South American Cerrado: A Tropical Savanna Hotspot The Cerrado, which includes both forest and savanna habitats, is the second largest South American biome, and among the most threatened on the continent. BioScience 52: 225–234.
Silva, L.C., Sternberg, L., Haridasan, M., Hoffmann, W.A., MIRALLES-WILHELM, F., & Franco, A.C. 2008. Expansion of gallery forests into central Brazilian savannas. Global Change Biology 14: 2108–2118.
Soledad, G.-G., & Santiago, S. 2005. Forest fragmentation estimated from remotely sensed data: is comparison across scales possible? Forest Science 51: 51–63.
Vrabel, J. 1996. Multispectral imagery band sharpening study. Photogrammetric Engineering and Remote Sensing 62: 1075–1084.
Youta Happy, J. 1998. Arbres contre graminées : la lente invasion de la savane par la forêt au Centre-Cameroun.
Publiée
2014-09-05
Comment citer
VIENNOIS, Gaëlle; NICOLINI, Eric A.; BORNE, Frédéric. Forest vs Savanna dynamics in the contact zones of French Guiana. Revue Française de Photogrammétrie et de Télédétection, [S.l.], n. 208, p. 89-95, sep. 2014. ISSN 1768-9791. Disponible à l'adresse : >https://www.sfpt.fr/rfpt/index.php/RFPT/article/view/104>. Date de consultation : 20 jan. 2019
Rubrique
Articles

Mots-clés

Pléiades , Shape Indices, Classification, Forest – Savanna Dynamic, Forest, Savanna, Guiana