Madagascar's grasses and grasslands: anthropogenic or natural?
Autor: | Fetra O. Randriatsara, Maria S. Vorontsova, Guillaume Besnard, Paweł Ficinski, Jacqueline Razanatsoa, W. Derek Clayton, Justin Moat, Félix Forest, John M. Kimeu, Panagiota Malakasi, H. Peter Linder, George M. Savva, Canisius Kayombo, Olinirina Prisca Nanjarisoa, W. R. Quentin Luke |
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Přispěvatelé: | University of Zurich, Vorontsova, Maria S |
Rok vydání: | 2016 |
Předmět: |
0106 biological sciences
0301 basic medicine Flora phylogenetic community assembly Biome Biodiversity species turnover 1100 General Agricultural and Biological Sciences 580 Plants (Botany) Poaceae 010603 evolutionary biology 01 natural sciences General Biochemistry Genetics and Molecular Biology Grassland 2300 General Environmental Science 03 medical and health sciences 1300 General Biochemistry Genetics and Molecular Biology 2400 General Immunology and Microbiology Grazing Madagascar Animals Humans 10211 Zurich-Basel Plant Science Center Endemism Research Articles Holocene General Environmental Science neogene geography.geographical_feature_category General Immunology and Microbiology Ecology food and beverages Tropics Agriculture General Medicine Biological Evolution 10121 Department of Systematic and Evolutionary Botany 030104 developmental biology Geography endemism Cattle General Agricultural and Biological Sciences |
Zdroj: | Proceedings of the Royal Society B: Biological Sciences |
ISSN: | 1471-2954 0962-8452 |
Popis: | Grasses, by their high productivity even under very low p CO 2 , their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics. |
Databáze: | OpenAIRE |
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