Does selective logging affect the leaf structure of a late successional species?

Abstract

The anatomical characteristics of both sun and shade leaves of Alseis pickelii were investigated in order to evaluate the consequences of selective logging (in seasonally dry Atlantic Forest) on the leaf structure of this species. Fully expanded sun and shade leaves were collected in two distinct stands of tabuleiro forest; a stand of recently logged forest and an unlogged stand. Only leaves from the unlogged stand revealed significantly different magnitudes of response to light regimes, producing leaves with structural characteristics associated with different levels of irradiance. The sun leaves from this stand had a thicker adaxial surface, mesophyll, palisade and spongy parenchyma, a secondary cell wall of fibers and a lower leaf area compared with the shade leaves. However, in the logged stand, the leaf cuticles of sun and shade leaves showed no significant differences, although the leaf area of the sun leaves was higher than the shade leaves. According to these data, we concluded that the unlogged stand produced typical "sun" and "shade" leaves. In contrast, leaves from the logged stand showed a lower variation of types, where neither typical "sun" nor typical "shade" leaves were produced, suggesting lower leaf plasticity of this late successional tree in this area.

Modelos alométricos para determinação da área foliar de cacaueiro ‘PH-16’ em sombreamento e pleno sol

“…A relação entre comprimento e largura (C/L) foi estatisticamente superior para as médias no ambiente sombreado. Outros trabalhos, com outras espécies, abordam a comparação da área foliar entre plantas nos ambientes sombreado e a pleno sol, mostrando que as plantas, via de regra, apresentam diferenças de área foliar entre os dois ambientes (ROSSATO et al, 2010;RABELO et al, 2012). Rabelo et al (2012), ao trabalhar com a espécie arbórea Alseis pickelii na Mata Atlântica verificaram que a área foliar pode ser maior tanto na sombra quanto no sol, dependendo da exploração da área.…”

“…Outros trabalhos, com outras espécies, abordam a comparação da área foliar entre plantas nos ambientes sombreado e a pleno sol, mostrando que as plantas, via de regra, apresentam diferenças de área foliar entre os dois ambientes (ROSSATO et al, 2010;RABELO et al, 2012). Rabelo et al (2012), ao trabalhar com a espécie arbórea Alseis pickelii na Mata Atlântica verificaram que a área foliar pode ser maior tanto na sombra quanto no sol, dependendo da exploração da área. Assim, detectaram que folhas do setor preservado da mata apresentavam maior área foliar na sombra do que no sol e, o oposto ocorreu quando se avaliaram as folhas em parte explorada da floresta.…”

Ecological significance of wood anatomy of Alseis pickelii Pilg. & Schmale (Rubiaceae) in a Tropical Dry Forest

“…Thus, anatomical characteristics can influence the functional performance of xylem in various environmental conditions and under different ecological trends (Carlquist 2001). The variation found in the wood of A. pickelii may explain the fitness of this species to its environment, where wood plasticity counterbalances the lower leaf plasticity found for this late successional tree in this area (Rabelo et al 2012). Other examples of fitness counterbalance by wood/leaf plasticity were the vessel lumina area and frequency that were higher in US, possibly allowing greater hydraulic conductance and, consequently, promoting a better water supply to the leaves, confirming that the leaf and wood plasticity can be related (e.g.…”

“…The study took place in the same two sites studied by Rabelo et al (2012) at GES, the "unlogged stand" (US) and "logged stand" (LS). These sites differ in irradiation, humidity and temperature, with LS having higher irradiation, and thus higher temperature and lower humidity than US.…”

“…A study of the effects of selective logging on the anatomical characteristics of sun and shade leaves of A. pickelii found that the "unlogged stand" produce trees with typical leaves of "sun" and "shade", but, in contrast, the "logged stand" produced trees with less variation among types of leaves (Rabelo et al 2012).…”