Invasive plants
| Introduction | Kirindy | Invasive species | Ecotourism | Publications | Links |
Madagascar
| Although
invasive plants have become a major cause for concern in much of the
tropics, investigations in Madagascar have been limited. In the book
'The Natural
History of Madagascar' a preliminary review of the introduced and invasive plants
was published along with chapters on three key taxa (Eichhornia crassipes,
Lantana camara and Opuntia spp). Other
taxa were dealt with in Crop
Protection Compendium (i.e. Argemone
mexicana, Chromolaena odorata, Mimosa pigra, Mimosa
pudica, Syzygium jambos). More
recently review articles have appeared relating to acacias and forestry
trees (e.g. Kull et al.
2007).
Articles on the role of invasives in secondary vegetation of eastern
Madagascar have also published (Bollen, 2003; Brown &
Gurevitch, 2004; Carrière et
al., 2005; Ramaharitra, 2006) However, our state of knowledge is still fragmentary and much research needs to be carried out before a comprehensive picture of invasive plants in Madagascar arises. Recent field observations indicate that many species, not yet reported, are spreading. These species tend to be well known invaders and are found in many parts of the tropics and subtropics. The species given below complement the review published in 2003. Adenanthera pavonina: cultivated and probably has escaped (Schatz, 2001) . Albizia chinensis: frequent throughout the eastern lowlands (Du Puy et al., 2002). Albizia lebbeck: often colonises forest gaps in Réserve d’Ankarafantsika (Rajoelison et al., 2002). Caesalpinia decapetala: commonly found around habitations in the Central Plateau (Du Puy et al., 2002). Cajanus cajan: has escaped in much of the country (Du Puy et al., 2002). Camellia sinensis: not only is it very common in secondary forest in Andasibeb but it also occurs in areas viewed as prime lemur habitats. Individuals no taller than 1 m high are setting fruit under undisturbed canopy. Cytisus scoparius: a large population in the Central Highlands (near Faratsiho), species probably accidentally introduced along with forage-improving seeds (Du Puy et al., 2002). Clidemia hirta: extremely common on the eastern side of the island, has yet to spread to Montagne d'Ambre and Ankarana. Grevillea robusta: this tree appears to have been relatively recently introduced to the Eastern coast. Near Manakara it is spreading rapidly into secondary vegetation forming dense monotypic stands. It is extensively harvested by poor farmers who carry this firewood into town. Haematoxylum campechianum: naturalized in West and North (Schatz, 2001). Heterotis decumbens: found in wet lowland sites along the island's East coast (Almeda, 2003). Indigofera tinctoria: disturbed areas, around villages in particular, in SW and W lowlands (Du Puy et al., 2002). Jatropha curcas: often colonises forest gaps in the Réserve d’Ankarafantsika (Rajoelison et al., 2002). Leucaena leucocephala: spreading in Berenty and negatively impacting on lemur populations. Melaleuca quinquinervia: spreading in moist swampy areas of the East coast (Schatz, 2001). Melastoma malabathricum spp. malabathricum: found in wet lowland sites along the island's East coast (Almeda, 2003). Nerium oleander: spreading along rivers near and inside the Ankarana National Park. Parkinsonia aculeata: particularly common around Toliara (Du Puy et al., 2002). Pithecellobium dulce: reported as naturalized by Schatz (2001). Pinus kesiya: invading Uapaca woodland near the Tana to Fianar road. Prosopis juliflora: naturalised near Amboasary and Beza Mahafaly reserve (Du Puy et al., 2002). Sesbania sesban: mostly present around Tana (Du Puy et al., 2002). Solanum mauritianum: common in Madagascar but not in the South (D'Arcy, 1992). Solanum torvum: common in Madagascar but not in the South (D'Arcy, 1992). Ulex europaeus: a large population in Central Highlands (near Faratsiho) (Du Puy et al., 2002). Ziziphus jujuba: common in the West. Dominant shrub around the 'Avenue des baobabs'. References: Almeda, C. (2003) Melastomataceae, princess flowers. In Goodman, S.M. & Benstead, J.P. (Eds) The natural history of Madagascar, pp. 175- University of Chicago Press, Chicago. Bollen, A. (2003) Fruit-frugivore interactions in a Malagasy littoral forest: a community-wide approach of seed dispersal. Forest of south-east: a community level approach. Ph.D. Thesis, Universiteit Antwerpen. Brown, K.A. & Gurevitch, J. (2004) Long-term impacts of logging on forest diversity in Madagascar. Proc. Natl. Acad. Sci. 101, 6045-6049. Carrière, S.M., Andrianotahiananahary, H., Ranaivoarivelo, N. & Randriamalala, J. (2005) Savoirs et usages des recrus post-agricoles du pays Betsileo: valorisation d'une biodiversite oubliee a Madagascar. VertigO 6(1). D'Arcy, W.G. (1992) Solanaceae of Madagascar: form and geography. Annals of the Missouri Botanical Garden 79, 29-45. Du Puy, D.J., Labat, J.-N., Rabevohitra, R., Villiers, J.-F., Bosser, J. & Moat, J. (2002) The Leguminosae of Madagascar. Royal Botanic Gardens, Kew. Kull, C.A., Tassin, J. & Rangan, H. (2007) Multifunctional, scrubby, and invasive forests? Wattles in the highlands of Madagascar. Mountain Research and Development 27, 224-231. Rajoelison, G., Raharimalala, J., Rahajasoa, G., Andriambelo, L.H., Rabevohitra, R. & Razafindrianilana, N. (2002) Evaluation de la diversité floristique dans la Réserve d’Ankarafantsika. In Alonso, L.E., Schulenberg, T.S., Radilofe, S. & Missa, O. (Eds) Une Evaluation Biologique de la Réserve Naturelle Intégrale d’Ankarafantsika, Madagascar. Bulletin RAP d’Evaluation Rapide #No. 23, pp. 37-62. Conservation International, Washington. Ramaharitra, T. (2006) The effects of anthropogenic disturbances on the structure and composition of rain forest vegetation. Tropical Ressources (Bulletin of the Yale Tropical Resources Institute) 25, 32-37. Schatz, G.E. (2001) Generic tree flora of Madagascar. Royal Botanic Gardens, Kew and Missouri Botanical Garden, St. Louis. |
|
