Using leaf δ13C and photosynthetic parameters to understand acclimation to irradiance and leaf age effects during tropical forest regeneration

Abstract

Regenerating forests are important for the maintenance of tropical biodiversity. Forest management in fragments of Atlantic forest in Brazil includes removal of exotic eucalyptus trees that were once part of plantations, in order to reestablish native flora. However, it is unclear how native tree saplings regenerating under former plantations respond to abrupt changes in environmental conditions associated with exotic tree removal. We used leaf carbon isotope composition (δ 13 C) and photosynthetic parameters to evaluate physiological responses of native tree saplings to canopy opening. We analyzed young and mature leaves of the three most representative species of regenerating trees (Byrsonima sericea, Siparuna guianensis, Xylopia sericea) in one secondary forest fragment and three managed areas that form an irradiance gradient (9, 85, 230 and 550 µmol m -2 s -1 ) in Brazilian Atlantic forest.Eucalyptus removal increased photosynthetic CO 2 assimilation and stomatal conductance in

Stable isotope ratios and reforestation potential in Acacia koa populations on Hawai’i

“…Leaves exposed to greater irradiances often have subsequently higher δ 13 C ratios. The δ 13 C ratios of younger leaves (-28.8 and -30.8) and mature leaves (-29.1 and -31.7) were further decreased with increased irradiance (Vitoria et al 2016). Thus, leaf age is directly related to δ 13 C enrichment.…”

“…The average δ 13 C for our data was -29.8‰ and was similar to other investigations of tropical forest species (Vitousek et al 1990, Duarte et al 2005, Ometto et al 2006, Maricle et al 2011). Average δ 13 C for tropical species varies between -26‰ and -30‰ but these numbers are highly arbitrary as leaf age and light irradiance can have dramatic effects (Vitoria et al 2016). Leaves exposed to greater irradiances often have subsequently higher δ 13 C ratios.…”

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

“…Our results indicate the existence of significant functional and structural plasticity in M. amazonica. Phenotypic plasticity has been observed in different populations of a single species, reflecting adaptations to diverse microclimates in a series of habitats (Abbruzzese et al 2009), as well as in different populations exposed to variations in irradiance in open or shaded habitats (even under otherwise similar climatic conditions) (Toledo et al 2012;Valladares and Niinemets 2008;Vieira et al 2015;Vitória et al 2016). The phenotypic plasticity index (PPI) has been Fig.…”

“…Plant survival is closely linked to the capacity to adapt to varying environmental conditions (Singh and Kushwaha 2005), which, in turn, is facilitated by plasticity of their morphological (Bloor and Grubb 2004) and/or physiological traits (Sultan 2000;Valladares et al 2000;Gamage et al 2003;Vieira et al 2015;Vitória et al 2016). This plasticity facilitates the occupation of a wide variety of microhabitats and amplifies the use of ecological niches (Ganie et al 2014).…”

“…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).…”