Differences in morphological and physiological leaf characteristics between Tabebuia aurea and T. impetiginosa is related to their typical habitats of occurrence

Abstract

Recebido em 18/08/2011. Aceito em 16/04/2012 RESUMO (Diferenças em características morfológicas e fisiológicas foliares entre Tabebuia aurea e T. impetiginosa estão relacionadas aos seus ambientes típicos de ocorrência). Tabebuia é um gênero representativo do bioma Cerrado, ocorrendo em formações savânicas e florestais, que diferem em termos de microclima, disponibilidade hídrica e propriedades do solo. Neste trabalho foi realizado um estudo comparativo de parâmetros morfológicos e fisiológicos entre duas espécies, sendo Tabebuia aurea (Silva Manso) Benth. & Hook. f. ex S. Moore típica de ambientes savânicos, como o cerrado sensu stricto, enquanto T. impetiginosa (Mart. Ex DC.) Standl é tipicamente encontrada nas matas de galeria, que margeiam os cursos de água. As duas espécies foram amostradas em ambientes savânicos, expostas a condições semelhantes de alta luminosidade. A espécie savânica apresentou maiores valores de espessura foliar, massa foliar específica, espessura do pecíolo, assimilação máxima de CO 2 , condutância estomática, transpiração e concentração foliar de carotenóides. A espécie de mata destacou-se pelos maiores valores de área foliar específica, comprimento do pecíolo e de assimilação de CO 2 em base de massa, parâmetros que contribuem para maior taxa de crescimento e de tolerância ao sombreamento. Esta distinção funcional entre as duas espécies em vários atributos foliares, mesmo quando situadas num mesmo tipo de ambiente, pode ser o resultado da história evolutiva dessas espécies em resposta às diferentes pressões seletivas nos ambientes típicos de ocorrência.Palavras-chave: assimilação de CO 2 , área foliar; cerrado, pigmentos fotossintéticos, Tabebuia ABSTRACT (Differences in morphological and physiological leaf characteristics between Tabebuia aurea and T. impetiginosa is related to their typical habitats of occurrence). The genus Tabebuia is representative of the Cerrado biome, occurring in savanna and forest formations. These vegetation types are associated with distinct environmental conditions in terms of water availability, microclimate and soil properties. We compared morphological and physiological traits between Tabebuia aurea (Silva Manso) Benth. & Hook. f. ex S. Moore, which is typical of the savanna vegetation, and T. impetiginosa (Mart. ex DC.) Standl, which is commonly found in the gallery forests that occur along streams and rivers. Both were sampled in savanna conditions under full sun. The savanna species had higher values of leaf and petiole thickness, specific leaf mass, maximum CO 2 assimilation on a leaf area basis, stomatal conductance, transpiration and in leaf concentration of carotenoids. The forest species stood out by higher values of specific leaf area, petiole length and of CO 2 assimilation on a mass basis, parameters related to shade tolerance and higher growth rates. This functional distinction in a range of leaf traits that was maintained when both were naturally growing under similar environmental conditions, suggests that these are probably the result of...

Leaf phenology and morphofunctional variation in Myrcia amazonica DC. (Myrtaceae) in gallery forest and “campo rupestre” vegetation in the Chapada Diamantina, Brazil

“…Studies focusing on variations in the physiological attributes of plants according to environmental conditions have been performed with a number of species (Boardman 1977;Chazdon 1986;Chen and Klinka 1997;Murchie and Horton 1997;Naramoto et al 2006;Sinclair et al 2008;Rodríguez-Garcia and Bravo 2013;Rossatto et al 2013;Puglielli et al 2015;Vieira et al 2015;Vitória et al 2016) and have demonstrated that populations established in environments with high solar irradiation have thicker leaves, with higher rates of gas exchange. Studies of morphofunctional traits have examined leaf renewal, leaf age, and wood density associated with habitat heterogeneity (Goulart et al 2005;Lemos Filho et al 2008;Toledo et al 2012;Capuzzo et al 2012). Attributes such as phenology, leaf age, gas exchange, photosynthetic pigments, water potential, wood density, and leaf morphological attributes (thicknesses, succulence, density, and leaf mass per area) have been correlated with environmental conditions such as irradiance, VPD, and water balance (Rosado and de Mattos 2007;Meinzer et al 2009;Rosado et al 2013;Rossatto et al 2013;Braga et al 2016).…”

Recruitment Niches of Enterolobium contortisiliquum (Vell.) Morong: Functional Acclimations to Light

“…Despite the great increase in SLA in 95% shade, there was not an effective increase in L A . The lower SLA in critical shade levels is a less flexible trait that is characteristic of plants adapted only to the higher irradiances of the savannas [2,62]. The present study demonstrates that E. contortisiliquum, although classified as a pioneer and adapted to high irradiances, displayed larger SLA in shade, a trait that if expressed at the right moment may positively influence L A and shade tolerance.…”

“…& Hook. f. ex S. Moore-a pioneer tree characteristic of the savanna domain [62]-suffered a reduction in its S D and L A in 70% and 95% shade compared to full sun and 50% shade in 70-day-old seedlings [63]. In fact, the lower L A of T. aurea was influenced by a low SLA in 70% shade.…”

Non-Destructive, Laser-Based Individual Tree Aboveground Biomass Estimation in a Tropical Rainforest

“…Wood density was chosen based on different tree species (see Table 1), while leaf density was taken as the mean value of 0.41 g·cm −3 [25,26]. The biomass of these individual components was assessed with values calculated using allometric equations developed by [27].…”