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Registro Completo |
Biblioteca(s): |
Embrapa Cerrados; Embrapa Pantanal. |
Data corrente: |
11/02/1993 |
Data da última atualização: |
11/02/1993 |
Autoria: |
KLINK, C. A. |
Título: |
A comparative study of ecology of native and introduced African grasses of the Brazilian savannas. |
Ano de publicação: |
1992 |
Fonte/Imprenta: |
Cambridge, Massachusetts: Harvard University, 1992. |
Páginas: |
207p. |
Idioma: |
Inglês |
Notas: |
PhD. Thesis. |
Conteúdo: |
African grasses are becoming major invaders of crop fields, degraded rangelands, and natural reserves of the Brasilian savannas (the "cerrados"). The objective of this thesis was to compare ecological characteristics of African and native grasses in an attempt to understand the invasion of cerrados by these introduced species. The hypothesis tested were that African grasses have a higher germination rate, are better competitors in enriched soils, and resist defoliation better than native cerrado grasses. Three sets of experiments were performed: 1) field and laboratory germination; 2) growth and competition in the greenhouse; and 3) field clipping at early and late wet season, and dry season. African grasses germinate faster and more than native species. Seedling mortality is high in African and low in native species. It is suggested that the high seedling mortality of African species is compensated by a large seed production and a high germination rate, and the low seed germination of native species is compensated by a low seedling mortality. The results of the growth and competition experiment were not conclusive. A large variability in biomas production within species exist. The species that invested more in shoots than roots grew more than the species that invested more in roots. It is suggested that the African grass is suppressed more when grown in mixture than in monoculture, while the native species is suppressed more when growing in monoculture. The clipping experiments showed that defoliation decreased plant height in all species. Tillering increased in some African species but not at all in native species. Plant base circumference increased in all species during the dry season clipping, but it was a result of tillering only in the African Hyparrhenia rufa. Late wet season dry season clippings affected plant reproduction in all species that flowered, but not in H. rufa. A time trend analysis revealed that plant height of both African and native species was affected by both clipping and trend of time. Base circumference was affected by treatment only in H. rufa. Tillering in both African and native species showed a significant linear trend of time only. Clipping reduced tillering of the African species Melinis minutiflora. It is concluded that tillering is not necessarily a plant response to defoliation. The only African species resistant to grazing was H. rufa. MenosAfrican grasses are becoming major invaders of crop fields, degraded rangelands, and natural reserves of the Brasilian savannas (the "cerrados"). The objective of this thesis was to compare ecological characteristics of African and native grasses in an attempt to understand the invasion of cerrados by these introduced species. The hypothesis tested were that African grasses have a higher germination rate, are better competitors in enriched soils, and resist defoliation better than native cerrado grasses. Three sets of experiments were performed: 1) field and laboratory germination; 2) growth and competition in the greenhouse; and 3) field clipping at early and late wet season, and dry season. African grasses germinate faster and more than native species. Seedling mortality is high in African and low in native species. It is suggested that the high seedling mortality of African species is compensated by a large seed production and a high germination rate, and the low seed germination of native species is compensated by a low seedling mortality. The results of the growth and competition experiment were not conclusive. A large variability in biomas production within species exist. The species that invested more in shoots than roots grew more than the species that invested more in roots. It is suggested that the African grass is suppressed more when grown in mixture than in monoculture, while the native species is suppressed more when growing in monoculture. The clipping exper... Mostrar Tudo |
Palavras-Chave: |
Brasil; Distrito Federal; Indigenous organisms; Native grasses; Pasture; Planaltina; Planta nativa; Savana; Savanna. |
Thesagro: |
Biologia; Cerrado; Ecologia; Ecologia Vegetal; Germinação; Gramínea; Pastagem Nativa. |
Thesaurus Nal: |
Africa; Brazil; ecology; germination; grasses; plant ecology. |
Categoria do assunto: |
-- |
Marc: |
LEADER 03414nam a2200397 a 4500 001 1547855 005 1993-02-11 008 1992 bl uuuu m 00u1 u #d 100 1 $aKLINK, C. A. 245 $aA comparative study of ecology of native and introduced African grasses of the Brazilian savannas. 260 $aCambridge, Massachusetts: Harvard University$c1992 300 $a207p. 500 $aPhD. Thesis. 520 $aAfrican grasses are becoming major invaders of crop fields, degraded rangelands, and natural reserves of the Brasilian savannas (the "cerrados"). The objective of this thesis was to compare ecological characteristics of African and native grasses in an attempt to understand the invasion of cerrados by these introduced species. The hypothesis tested were that African grasses have a higher germination rate, are better competitors in enriched soils, and resist defoliation better than native cerrado grasses. Three sets of experiments were performed: 1) field and laboratory germination; 2) growth and competition in the greenhouse; and 3) field clipping at early and late wet season, and dry season. African grasses germinate faster and more than native species. Seedling mortality is high in African and low in native species. It is suggested that the high seedling mortality of African species is compensated by a large seed production and a high germination rate, and the low seed germination of native species is compensated by a low seedling mortality. The results of the growth and competition experiment were not conclusive. A large variability in biomas production within species exist. The species that invested more in shoots than roots grew more than the species that invested more in roots. It is suggested that the African grass is suppressed more when grown in mixture than in monoculture, while the native species is suppressed more when growing in monoculture. The clipping experiments showed that defoliation decreased plant height in all species. Tillering increased in some African species but not at all in native species. Plant base circumference increased in all species during the dry season clipping, but it was a result of tillering only in the African Hyparrhenia rufa. Late wet season dry season clippings affected plant reproduction in all species that flowered, but not in H. rufa. A time trend analysis revealed that plant height of both African and native species was affected by both clipping and trend of time. Base circumference was affected by treatment only in H. rufa. Tillering in both African and native species showed a significant linear trend of time only. Clipping reduced tillering of the African species Melinis minutiflora. It is concluded that tillering is not necessarily a plant response to defoliation. The only African species resistant to grazing was H. rufa. 650 $aAfrica 650 $aBrazil 650 $aecology 650 $agermination 650 $agrasses 650 $aplant ecology 650 $aBiologia 650 $aCerrado 650 $aEcologia 650 $aEcologia Vegetal 650 $aGerminação 650 $aGramínea 650 $aPastagem Nativa 653 $aBrasil 653 $aDistrito Federal 653 $aIndigenous organisms 653 $aNative grasses 653 $aPasture 653 $aPlanaltina 653 $aPlanta nativa 653 $aSavana 653 $aSavanna
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Embrapa Cerrados (CPAC) |
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Registros recuperados : 18 | |
16. | | KLINK, C. A.; SANTOS, H. G. dos; CAMPARI JÚNIOR, J. S.; MATSUMOTO, M. H.; FREITAS, G. K. de; BAUMGARTEN, L. Conservação dos recursos naturais em terras privadas: o papel das reservas legais no arranjo funcional das paisagens produtivas do bioma Cerrado. In: SANO, S. M.; ALMEIDA, S. P. de; RIBEIRO, J. F. (Ed.). Cerrado: ecologia e flora. Brasília, DF: Embrapa Informação Tecnológica: Planaltina, DF: Embrapa Cerrados, 2008. cap. 14, p. 399-406.Biblioteca(s): Embrapa Cerrados. |
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17. | | MARKEWITZ, D.; RESENDE, J. C. F.; PARRON, L.; BUSTAMANTE, M.; KLINK, C. A.; FIGUEIREDO, R. de O.; DAVIDSON, E. A. Dissolved rainfall inputs and streamwater outputs in an undisturbed watershed on highly weathered soils in the brazilian cerrado. Hydrological Processes, v. 20, n. 12, p. 2615-2639, Aug. 2006.Tipo: Artigo em Periódico Indexado | Circulação/Nível: Internacional - A |
Biblioteca(s): Embrapa Amazônia Oriental. |
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18. | | NEPSTAD, D. C.; KLINK, C. A.; UHL, C.; VIEIRA, I. C.; LEFEBVRE, P.; PEDLOWSKI, M.; MATRICARDI, E.; NEGREIROS, G.; BROWN, I. F.; AMARAL, E.; HOMMA, A.; WALKER, R. Land-use in Amazonia and the cerrado of Brazil. Ciência e Cultura, São Paulo, v. 49, n. 1/2, p. 73-86, 1997.Biblioteca(s): Embrapa Amazônia Oriental. |
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Registros recuperados : 18 | |
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