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Ultramafic geocology of South and Southeast Asia
Botanical Studies (2017)
  • Nishanta Rajakaruna, Biological Sciences Department, California Polytechnic State University
  • M. L Galey, Natural Resources Research Institute, University of Minnesota
  • Van Der Ent, Sustainable Minerals Institute, The University of Queensland
  • M. C. Iqbal, Plant Biology Laboratory, National Institute of Fundamental Studies
Abstract
Globally, ultramafic outcrops are renowned for hosting floras with high levels of endemism, including plants with specialised adaptations such as nickel or manganese hyperaccumulation. Soils derived from ultramafic regoliths are generally nutrient-deficient, have major cation imbalances, and have concomitant high concentrations of potentially phytotoxic trace elements, especially nickel. The South and Southeast Asian region has the largest surface occurrences of ultramafic regoliths in the world, but the geoecology of these outcrops is still poorly studied despite severe conservation threats. Due to the paucity of systematic plant collections in many areas and the lack of georeferenced herbarium records and databased information, it is not possible to determine the distribution of species, levels of endemism, and the species most threatened. However, site-specific studies provide insights to the ultramafic geoecology of several locations in South and Southeast Asia. The geoecology of tropical ultramafic regions differs substantially from those in temperate regions in that the vegetation at lower elevations is generally tall forest with relatively low levels of endemism. On ultramafic mountaintops, where the combined forces of edaphic and climatic factors intersect, obligate ultramafic species and hyperendemics often occur. Forest clearing, agricultural development, mining, and climate change-related stressors have contributed to rapid and unprecedented loss of ultramafic-associated habitats in the region. The geoecology of the large ultramafic outcrops of Indonesia’s Sulawesi, Obi and Halmahera, and many other smaller outcrops in South and Southeast Asia, remains largely unexplored, and should be prioritised for study and conservation.
Keywords
  • Adaptations,
  • Conservation,
  • Edaphic endemism,
  • Edaphic flora,
  • Extreme environments,
  • Geobotany,
  • Plant–soil relations,
  • Serpentine vegetation,
  • Ultramafic plants,
  • Metal hyperaccumulators
Disciplines
Publication Date
April 3, 2017
DOI
10.1186/s40529-017-0167-9
Publisher Statement
©  The Author(s)
Citation Information
Nishanta Rajakaruna, M. L Galey, Van Der Ent and M. C. Iqbal. "Ultramafic geocology of South and Southeast Asia" Botanical Studies Vol. 58 Iss. 1 (2017) ISSN: 1817-406X
Available at: http://works.bepress.com/nishanta_rajakaruna/70/
Creative Commons license
Creative Commons License
This work is licensed under a Creative Commons CC_BY International License.