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Registro Completo |
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Biblioteca(s): |
Embrapa Pantanal. |
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Data corrente: |
06/08/1997 |
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Data da última atualização: |
03/04/2017 |
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Autoria: |
OESTERHELD, M.; McNAUGHTON, S. J. |
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Título: |
Intraspecific variation in the response of Themeda triandra to defoliation: the effect of time of recovery and growth rates on compensatory growth. |
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Ano de publicação: |
1988 |
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Fonte/Imprenta: |
Oecologia, v.77, p.181-186, 1988. |
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Idioma: |
Inglês |
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Conteúdo: |
The response to a single defoliation was studied on three clones of Themeda triandra collected in the short, mid, and tall grassland regions of the Serengeti Nacional Park (Tanzania). These sites represent a gradient of decreasing grazing intensity. Growth, allocation pattern, and several morphometric traits were monitored during an 80-day period. Clipped plants of the short and medium clones fully compensated for the reduction of biomass, while plants of the tall clone showed overcompensation. During the first two weeks after clipping, clipped plants showed lower relative rtates than unclipped ones, whereas the opposite was observed later on. Clipped plants compensated for the removal of leaf area by producing new leaves with lower specific weights and higher nitrogen content. They also produced more, smaller tillers, Although clipped plants mobilized monstructural carbohydrates from roots and crowns, this did not account for a significant amount of growth. Relative growth rates of unclipped plants of the short clone were higher. The relative growth rate of the short clone diminished less after clipping, but also exhibited the lowest increase later. The tall clone was the most negatively affected early, but showed the highest compensation later. Compared to the other clones, the short ecotype showed many of the characteristics that defoliation induced in each individual of any clone: higher allocation to leaf area production, higher relative growth rate, higher number but smaller size of tillers, and lower leaf specific weights. MenosThe response to a single defoliation was studied on three clones of Themeda triandra collected in the short, mid, and tall grassland regions of the Serengeti Nacional Park (Tanzania). These sites represent a gradient of decreasing grazing intensity. Growth, allocation pattern, and several morphometric traits were monitored during an 80-day period. Clipped plants of the short and medium clones fully compensated for the reduction of biomass, while plants of the tall clone showed overcompensation. During the first two weeks after clipping, clipped plants showed lower relative rtates than unclipped ones, whereas the opposite was observed later on. Clipped plants compensated for the removal of leaf area by producing new leaves with lower specific weights and higher nitrogen content. They also produced more, smaller tillers, Although clipped plants mobilized monstructural carbohydrates from roots and crowns, this did not account for a significant amount of growth. Relative growth rates of unclipped plants of the short clone were higher. The relative growth rate of the short clone diminished less after clipping, but also exhibited the lowest increase later. The tall clone was the most negatively affected early, but showed the highest compensation later. Compared to the other clones, the short ecotype showed many of the characteristics that defoliation induced in each individual of any clone: higher allocation to leaf area production, higher relative growth rate, higher number but s... Mostrar Tudo |
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Palavras-Chave: |
Allocation; Defolhacao; Ecotype; Growth. |
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Thesagro: |
Crescimento; Planta. |
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Thesaurus Nal: |
defoliation; Themeda triandra. |
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Categoria do assunto: |
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Marc: |
LEADER 02207naa a2200229 a 4500
001 1791409
005 2017-04-03
008 1988 bl --- 0-- u #d
100 1 $aOESTERHELD, M.
245 $aIntraspecific variation in the response of Themeda triandra to defoliation$bthe effect of time of recovery and growth rates on compensatory growth.
260 $c1988
520 $aThe response to a single defoliation was studied on three clones of Themeda triandra collected in the short, mid, and tall grassland regions of the Serengeti Nacional Park (Tanzania). These sites represent a gradient of decreasing grazing intensity. Growth, allocation pattern, and several morphometric traits were monitored during an 80-day period. Clipped plants of the short and medium clones fully compensated for the reduction of biomass, while plants of the tall clone showed overcompensation. During the first two weeks after clipping, clipped plants showed lower relative rtates than unclipped ones, whereas the opposite was observed later on. Clipped plants compensated for the removal of leaf area by producing new leaves with lower specific weights and higher nitrogen content. They also produced more, smaller tillers, Although clipped plants mobilized monstructural carbohydrates from roots and crowns, this did not account for a significant amount of growth. Relative growth rates of unclipped plants of the short clone were higher. The relative growth rate of the short clone diminished less after clipping, but also exhibited the lowest increase later. The tall clone was the most negatively affected early, but showed the highest compensation later. Compared to the other clones, the short ecotype showed many of the characteristics that defoliation induced in each individual of any clone: higher allocation to leaf area production, higher relative growth rate, higher number but smaller size of tillers, and lower leaf specific weights.
650 $adefoliation
650 $aThemeda triandra
650 $aCrescimento
650 $aPlanta
653 $aAllocation
653 $aDefolhacao
653 $aEcotype
653 $aGrowth
700 1 $aMcNAUGHTON, S. J.
773 $tOecologia$gv.77, p.181-186, 1988.
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Embrapa Pantanal (CPAP) |
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