Do leaf traits in two Dalbergia species present differential plasticity in relation to light according to their habitat of origin?

Abstract

The phenotypic plasticity to light of two congeneric species of leguminous trees from distinct habitats was evaluated in a common-garden experiment. For that, we assessed the following two groups of leaf morphological and anatomical traits of 1-year-old seedlings: (1) traits related to light interception (tissues thickness and leaflet mass per area), and (2) traits related to gas exchange (number of leaflets per leaf and measurements of stomatal size and density). Dalbergia nigra (Vell.) Allemão ex Benth. is an endemic Atlantic forest species, and D. miscolobium Benth. is a typical cerrado species. Both were grown under shade and full-sunlight conditions. The phenotypic plasticity of leaves was determined by a relative distance plasticity index (RDPI). For both species, sun leaflets were thicker than shade ones, and only D. nigra presented lower values for stomatal density (nst), percentage of the leaflet area occupied by stomatal pores (nast) and estimated stomatal conductance (gst) under shade conditions. The forest species (D. nigra) had higher plasticity for variables related to gas exchange (number of leaflets per leaf, nst, ast, nast and gst), whereas the cerrado species (D. miscolobium) had higher plasticity for variables related to light interception, such as leaflet mass per area, leaflet thickness and palisade and spongy parenchyma thickness. The degree of plasticity was different for each analysed parameter, and not used to define which species is more plastic. The leaf traits of D. nigra and D. miscolobium that showed high plasticity were related to resources that are not limiting to improve its photosynthesis in a changing light environment.

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

“…The thickening of palisade parenchyma is a structural differentiation observed in sun leaves that results in increased photosynthetic rates under high irradiances [4,52,64] ( Table 3). The greater development of chlorenchyma (mesophyll palisade) is usually associated with a reduction in SLA [19,29,64,78], a characteristic observed in our study with E. contortisiliquum, as well as by Mazzanatti et al [3] in seedlings of Heliocarpus popayanensis Kunth and Aegiphila integrifolia (Jacq.) Moldenke.…”

“…While most forest pioneers exhibit high NAR-that is, high A n and high phenotypic plasticity, traits shared with savanna species-they also exhibit comparatively higher SLA and LAR along with a lower R/S under the same light environment [59], traits which are not adaptive either to low water availability and nutrient stress or higher fire frequency found in the savannas. Moreira et al [29] found that two Dalbergia spp. L.f. displayed interspecific differences in leaf plasticity to light.…”

Photochemical performance and source-sink relationships in galls induced by Pseudophacopteron longicaudatum (Hemiptera) on leaves of Aspidosperma tomentosum (Apocynaceae)

“…The maintenance of relative water content and succulence in P. longicaudatum senescent galls may be associated with the ʻgreen islandʼ effect (Kaiser et al 2010), which maintains photosynthetic and watered tissues even during senescence. In addition, the higher LSM values in galls are a response to tissue growth and tissue density (Moreira et al 2014) as a consequence of cell division and extension during gall formation. P. longicaudatum is a phloem-sucking insect obtaining resources directly from phloem (Malenovský et al 2015.…”

How the long-life span leaves of Ouratea castaneifolia Engl. (Ochnaceae) differ in distinct light conditions

“…Environmental conditions, such as luminosity, water availability, and soil nutrients, influence the ability of plants to adjust physiologically and morphologically and determine the degree of specificity of a species' adaptations (Valladares et al 2002a;Oguchi et al 2005;Reich 2014;Laanisto and Niinemets 2015). In tropical forests, light is heterogeneous in space and time (Pearcy 2007;Rodríguez-Calcerrada et al 2010;Moreira et al 2013) and it is one of the determining factors for the selection of species. The light distribution varies among vegetation strata (Pearcy 2007;Niinemets 2007Niinemets , 2010, thereby influencing seedling germination, growth, and establishment (Beckage and Clark 2003;Gómez et al 2004).…”

“…It responds to variation in environmental radiation, which results in sun and shade leaves, being the sun leaves usually thicker (Menezes et al 2006;Gomes et al 2008;Valladares and Niinemets 2008;Zhang et al 2011) and having a reduced leaf area than shade leaves, that result in an efficient energy dissipation and greater photosynthetic capacity (Niinemets et al 1998;Oguchi et al 2005;Lichtenthaler et al 2007;Ponts and Poorter 2014). Shade leaves, on the other hand, tend to have lower stomatal density and are thinner and have less leaf mass per area (Valladares and Niinemets 2008;Favaretto et al 2011;Murphy et al 2012;Moreira et al 2013).…”