학술논문
Shading effects on leaf life span and functional traits in the widespread species Enterolobium contortisiliquum (Vell.) Morong/Efeitos do sombreamento sobre o tempo de vida foliar e caracteristicas funcionais na especie com ampla distribuicao Enterolobium contortisiliquum (Vell.) Morong
Document Type
Academic Journal
Source
Acta Scientiarum. Biological Sciences (UEM). Jan-March, 2017, Vol. 39 Issue 1, p113, 10 p.
Subject
Language
English
ISSN
1679-9283
Abstract
Introduction Plants grown in shaded environments show a reduction in their maximum photosynthetic capacity, saturation irradiance to photosynthesis, and compensation point for light (Straus-Deberiedetti & Bazzaz, 1996). Leaves of shaded [...]
Enterolobium contortisiliquum occurs in native forests formations from southeast to northeast Brazil, and too in Argentina, Bolivia and Paraguay. The objective of this study was to evaluate shading effects in the early growth of E. contortisiliquum plants. We measured leaf gas exchange, chlorophyll content index, biomass allocation and leaf development in plants in sunny and shaded areas. The experiment was performed in Universidade Federal de Vigosa, campus Florestal, Minas Gerais, Brazil. To determine the effects of different light regimes (full sunlight and shade) on the growth of E. contortisiliquum plants, we divided plants into two groups: plants grown in a greenhouse under full sunlight, and plants grown under 70% shade tissue. E. contortisiliquum plants grown in full sunlight showed an increase in maximum net photosynthesis, root, stem, and leaf dry mass, root length, root/stem ratio, and length of the stem. However, E. contortisiliquum under shade showed larger specific leaf area, leaf area ratio, chlorophyll content, long leaf life span, and slow growth. These ecophysiological adjustments in sunny and shaded areas may explain the wide geographical distribution of E. contortisiliquum in many vegetation types. Keywords: leaf area, leaf development, maximum net photosynthesis. Enterolobium contortisiliquum ocorre em formagoes florestais nativas do sudeste ao nordeste do Brasil e tambem na Argentina, Bolivia e Paraguai. O objetivo deste estudo foi avaliar os efeitos do sombreamento no crescimento inicial de E. contortisiliquum. As trocas gasosas foliares, o indice de conteudo de clorofila, a alocacao de biomassa e o desenvolvimento foliar foram avaliados em plantas sob sol pleno e sombra. O experimento foi realizado na Universidade Federal de Vigosa, campus Florestal, Minas Gerais, Brasil. Para determinar os efeitos de diferentes regimes de luz sobre o crescimento das plantas de E. contortisiliquum, dividimos as plantas em dois grupos: plantas que cresceram em estufa a pleno sol e plantas que cresceram sob sombrite 70%. As plantas de E. contortisiliquum que cresceram em pleno sol apresentaram aumento na fotossintese liquida maxima, massa seca de raiz, de caule e folhas, comprimento de raiz, razao massa de raiz/caule e comprimento do caule. Entretanto, plantas de E. contortisiliquum sob sombra apresentaram maior area foliar especifica, razao de area foliar, conteudo de clorofila, tempo de vida foliar e crescimento lento. Esses ajustes ecofisiologicos em areas sob sol e sombra podem explicar a ampla distribuicao geografica de E. contortisiliquum em muitos tipos vegetacionais. Palavras-chave: area foliar, desenvolvimento foliar, fotossintese liquida maxima.
Enterolobium contortisiliquum occurs in native forests formations from southeast to northeast Brazil, and too in Argentina, Bolivia and Paraguay. The objective of this study was to evaluate shading effects in the early growth of E. contortisiliquum plants. We measured leaf gas exchange, chlorophyll content index, biomass allocation and leaf development in plants in sunny and shaded areas. The experiment was performed in Universidade Federal de Vigosa, campus Florestal, Minas Gerais, Brazil. To determine the effects of different light regimes (full sunlight and shade) on the growth of E. contortisiliquum plants, we divided plants into two groups: plants grown in a greenhouse under full sunlight, and plants grown under 70% shade tissue. E. contortisiliquum plants grown in full sunlight showed an increase in maximum net photosynthesis, root, stem, and leaf dry mass, root length, root/stem ratio, and length of the stem. However, E. contortisiliquum under shade showed larger specific leaf area, leaf area ratio, chlorophyll content, long leaf life span, and slow growth. These ecophysiological adjustments in sunny and shaded areas may explain the wide geographical distribution of E. contortisiliquum in many vegetation types. Keywords: leaf area, leaf development, maximum net photosynthesis. Enterolobium contortisiliquum ocorre em formagoes florestais nativas do sudeste ao nordeste do Brasil e tambem na Argentina, Bolivia e Paraguai. O objetivo deste estudo foi avaliar os efeitos do sombreamento no crescimento inicial de E. contortisiliquum. As trocas gasosas foliares, o indice de conteudo de clorofila, a alocacao de biomassa e o desenvolvimento foliar foram avaliados em plantas sob sol pleno e sombra. O experimento foi realizado na Universidade Federal de Vigosa, campus Florestal, Minas Gerais, Brasil. Para determinar os efeitos de diferentes regimes de luz sobre o crescimento das plantas de E. contortisiliquum, dividimos as plantas em dois grupos: plantas que cresceram em estufa a pleno sol e plantas que cresceram sob sombrite 70%. As plantas de E. contortisiliquum que cresceram em pleno sol apresentaram aumento na fotossintese liquida maxima, massa seca de raiz, de caule e folhas, comprimento de raiz, razao massa de raiz/caule e comprimento do caule. Entretanto, plantas de E. contortisiliquum sob sombra apresentaram maior area foliar especifica, razao de area foliar, conteudo de clorofila, tempo de vida foliar e crescimento lento. Esses ajustes ecofisiologicos em areas sob sol e sombra podem explicar a ampla distribuicao geografica de E. contortisiliquum em muitos tipos vegetacionais. Palavras-chave: area foliar, desenvolvimento foliar, fotossintese liquida maxima.