Stomatal conductance in Amazonian tree saplings in response to variations in the physical environment

Marenco, Ricardo Antonio; Nascimento, Helena Cristina Santos; Magalhães, Nadja S.

doi:10.1007/s11099-014-0056-3

Cited by 19 publications

(17 citation statements)

References 51 publications

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“…The leaf takes advantage of the limited time of high relative humidity in order to perform gas exchanges under xeric conditions (Medri and Lleras 1980), which might be more efficient the higher the useful stomatal area is. Stomatal movement, density, distribution, and size are species-specific features that might change in response to environmental conditions (Camargo and Marenco 2011;Marenco et al 2014). Thus, Q. parviflora presented higher amounts of stomata in the ASR samples as a strategy to increase the photosynthetic rate in higher relative humidity periods, since this phytophysiognomy has open vegetation with abundant sunlight.…”

Section: Discussionmentioning

confidence: 99%

Leaf anatomy of Qualea parviflora (Vochysiaceae) in three phytophysiognomies of the Mato Grosso State, Brazil

Ariano

Silva

2016

Acta Amaz.

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Leaves have a variety of morphological and anatomical characters mainly influenced by climatic, edaphic and biotic factors. The aim of this study was to describe the anatomical leaf traits of Qualea parviflora from three phytophysiognomies. The studied phytophysiognomies were Amazon Savannah on rocky outcrops (ASR), Transition Rupestrian Cerrado (TRC), and Cerradão (CDA). Freehand sections of the leaf blade were made and stained with 0.5% astra blue and with basic fuchsin. From the adaxial and abaxial leaf surface, freehand paradermal sections were made for epidermis analysis. The Jeffrey´s method, with modifications, was used in the epidermis dissociation process. The samples from the TRC phytophysiognomy had relatively smaller ordinary epidermal cells, higher abundance of trichomes, and mesophyll with few intercellular spaces, in comparison to the other phytophysiognomies. The leaves from the ASR phytophysiognomy had higher stomatal index (SI = 21.02), and five to six layers of sclerenchyma surrounding the midrib vascular bundle. The secondary vascular bundles had thicker cell walls and the bundle sheath extended up to the epidermal tissue of both leaf sides. Leaves from the CDA phytophysiognomy had mesomorphic environmental traits, such as a thinner cuticle. It is concluded that trees from ASR and TRC phytophysiognomies have xeromorphic traits following the environmental conditions where they occur. KEYWORDS: Adaptations, Amazon, Cerrado, Environmental conditions. Anatomia foliar de Qualea parviflora (Vochysiaceae) em três fitofisionomias do Estado Mato Grosso, Brasil RESUMOAs folhas são órgãos vegetativos que expressam uma variedade de características morfológicas e anatômicas influenciadas, principalmente, por fatores climáticos, edáficos e bióticos. O presente estudo objetivou levantar as características anatômicas das folhas de Qualea parviflora Mart. presente em três fitofisionomias: Savana Amazônica sobre afloramentos rochosos (SAR), Cerrado Rupestre de Transição (CRT) e Cerradão (CDA). Os cortes anatômicos foram realizados a mão livre e corados com azul de astra e fucsina básica 0,5%. Para a dissociação das epidermes, foi utilizado o método de Jeffrey modificado. As amostras da fitofisionomia de CRT apresentaram células epidérmicas comuns relativamente menores, maior quantidade de tricomas e mesofilo com poucos espaços intercelulares em relação as demais fitofisionomias. As amostras da fitofisionomia de SAR apresentaram maior índice estomático (IE: 21,05), maior quantidade de esclerênquima envolvendo o feixe vascular da nervura central (5 a 6 camadas), feixes vasculares secundários com células de paredes mais espessadas, com bainha que se estende até as células epidérmicas em ambas as faces. As amostras da fitofisionomia de CDA apresentaram caracteres de ambientes mesomórficos, como cutícula mais delgada. Pôde-se concluir que os espécimes que ocorrem em SAR e CRT apresentaram características xeromórficas que estão relacionados ao ambiente de ocorrência.

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Section: Discussionmentioning

confidence: 99%

Leaf anatomy of Qualea parviflora (Vochysiaceae) in three phytophysiognomies of the Mato Grosso State, Brazil

Ariano

Silva

2016

Acta Amaz.

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“…O aumento da irradiância sob condições hídricas e nutricionais adequadas, normalmente promove o aumento da condutância estomática (Marenco et al 2014). A concentração interna de CO 2 (Ci), por sua vez, também influencia a abertura e o fechamento dos estômatos.…”

Section: Discussionunclassified

Fotossíntese de espécies de Anibae em resposta à exposição a ambientes contrastantes de luz

et al. 2018

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ResumoFotossíntese de espécies de Anibae em resposta à exposição a ambientes contrastantes de luz. Características ecofisiológicas e o ambiente de luz têm implicações sobre o estabelecimento de plantios florestais. O objetivo desse estudo foi investigar a fotossíntese de Aniba canelilla e A. rosaeodora em resposta à disponibilidade de luz no campo. As trocas gasosas, conteúdo de clorofilas (ICC) e desempenho fotoquímico (F V /F M ) foram medidos em folhas aclimatadas (sombra durante 300 dias), a pleno sol (28 dias) e novamente à sombra durante 28 dias. A fotossíntese, ICC e F V /F M de A. canelilla e A. rosaeodora foram afetadas negativamente a pleno sol, mas se recuperaram quando submetidas à sombra. A fotossíntese, ICC e F V /F M foram duas vezes superiores nas plantas de sombra. Aniba rosaeodora apresentou desempenho fotossintético duas vezes superior a A. canelilla. As diferenças nas respostas fotossintéticas à luz sugerem que as espécies poderiam ocupar "nichos" de sucessão diferentes em plantios de enriquecimento e, a plasticidade (mediada pela recuperação) implica aclimatação em ambientes de luz variável. O fato das espécies de Anibae estudadas possuírem diferenças de plasticidade para luz deve ser visto com cautela para sugerir plantios convencionais, mas reforça a indicação para plantios de enriquecimento em sítios florestais com variações na disponibilidade de luz. Palavras-chave: Aniba canelilla, Aniba rosaeodora, fluorescência da clorofila a, plantios florestais, trocas gasosas. AbstractPhotosynthesis of species of Anibae in response to the exposure to contrasting light environments. Ecophysiological traits and the light environment have implications for the establishment of forest plantations. The aim of this study was to investigate the photosynthetic activity of Aniba canelilla and A. rosaeodora in response to changes in the availability of light in the field. Gas exchange, content of chlorophylls (ICC) and photochemical performance (F V /F M ) were measured in leaves acclimated in the shade during 300 days, after in the full sun (28 days) and again in the shade by 28 days. The photosynthesis, ICC and F V /F M of A. canelilla and A. rosaeodora were negatively affected in full sunlight, but the plants recovered when submitted to shade. Photosynthesis, ICC and F V /F M were twice as high in shade plants. Aniba rosaeodora presented photosynthetic performance twice higher than A. canelilla. Differences in photosynthetic responses to light suggest that species could occupy different succession "niches" in enrichment plantation, and plasticity (recovery-mediated) implies acclimatization under variable light environments. The fact that the studied species of Anibae have differences in plasticity for light should be viewed with caution to suggest conventional plantations, but it reinforce the indication for enrichment plantations in forest sites with variations in the availability of light.

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“…The study area is a plateau at a pristine terra firme rainforest in central Amazonia with an elevation of about 125 m above sea level. The annual rainfall is about 2,400 mm, with a mild dry season (≤ 100 mm per month) which extends from June through September (Marenco et al, 2014;Dias & Marenco, 2016), and annual potential evapotranspiration is about 1300 mm. The rainy season begins in November and ends in May, October is a transition month.…”

Section: Study Site and Plant Materialsmentioning

confidence: 99%

“…Mean temperature is about 26°C. Because of cloudiness, maximum mean irradiance is about 1,000 μmol m -2 s -1 above the canopy, and relative humidity (RH) varies from 70% at noon to 100% at night (Magalhães et al, 2014;Anber et al, 2015). The soil type is an Oxisol (Yellow Latosol) of clay texture (sand 11%, silt 15% and clay 74%), pH of 4.0 and low fertility (in mg kg -1 ): Mehlich-P, 0.84; K, 29;Ca, 13 and Mg, 14 (Magalhães et al, 2014).…”

Section: Study Site and Plant Materialsmentioning

confidence: 99%

See 1 more Smart Citation

Tree growth over three years in response to monthly rainfall in central Amazonia

Camargo¹,

Marenco²

2017

Dendrobiology

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Abstract:In central Amazonia, annual rainfall distribution is characterized by a short mild dry season which is associated with a slight increase in irradiance and decline in relative humidity, but the effect of variations in these variables on tree growth is still unclear. The objective of this study was to determine how tree growth responds to monthly variations in some climate variables in central Amazonia. Trees of Protium hebetatum Daly (18-20 m tall) and Eschweilera collina Eyma (19-27 m tall) were used in the study and monthly growth rates were measured during 36 months (2010)(2011)(2012). We also measured irradiance, temperature, rainfall, and relative humidity (RH). Eschweilera and Protium grew at similar rates (0.0557 mm month -1 ). Temperature and irradiance had no effect on tree growth of these species, but there was a trend for tree growth to increase with increasing both monthly rainfall and minimum relative humidity. If the dry season becomes longer and dryer in response to climate change one can expect that trees currently sensitive to mild drought stress will be the more affected.

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Stomatal conductance in Amazonian tree saplings in response to variations in the physical environment

Cited by 19 publications

References 51 publications

Leaf anatomy of Qualea parviflora (Vochysiaceae) in three phytophysiognomies of the Mato Grosso State, Brazil

Leaf anatomy of Qualea parviflora (Vochysiaceae) in three phytophysiognomies of the Mato Grosso State, Brazil

Fotossíntese de espécies de Anibae em resposta à exposição a ambientes contrastantes de luz

Tree growth over three years in response to monthly rainfall in central Amazonia

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