Inter-specific and sexual differences in architectural traits of two dioecious Lindera species (Lauraceae)

Abstract

The architecture of trees is a crucial determinant of their performance through light capture and mechanical stability. Comparison of architectural traits between closely related dioecious species is predicted to reveal both inter-specific and sexual differences. The former may reflect life-history characteristics such as microhabitat preferences, and the latter may reflect costs of reproductive allocation. We measured branching structure, leaf traits, wood density, and biomass of each vegetative component in the dioecious shrubs Lindera praecox and Lindera triloba to explore architectural differences according to species and gender. L. triloba was less branched but had a greater total leaf mass per shoot having larger and heavier leaves than L. praecox; most of these traits did not differ by gender. Allometric relationships between height and branch biomass corroborated our results of branching structure. The allometric relationships between tree size and leaf biomass demonstrated that in larger size classes females of both species had greater leaf biomass than males. Females of both species also showed lower tree height than males. This study suggests that tree architecture is influenced by both life-history strategy and resourceallocation pattern. Branching structure and branch biomass showed inter-specific differences, with the highly branched L. praecox apparently more shade tolerant than L. triloba; its tolerance is likely adaptive in its preferred microhabitat where is often lit poorly. Sexual differences in leaf biomass and tree height growth may reflect higher reproductive costs incurred by females.

Do male and female Lindera benzoin L. (Lauraceae) differ in stem mass/volume relationships and degree of lateral branching?1

“…Sexual dimorphism has been shown to exist for these components in other species (Popp and Reinartz 1988, Sánchez Vilas and Pannell 2011, Wheelwright et al . 2012) including other species of Lindera (Nakagawa et al . 2015).…”

“…Thus, allometric effects are not likely sufficient to confound results of earlier studies that used stem volume as a surrogate for stem mass. That said, allometric differences could appear in later or larger stages as reproductive maturity ensues and fruit production increases (Nakagawa et al . 2015).…”

“…It is possible that stem mass/volume relationships, wood density, and/or the degree of lateral branching might differ between males and females. If so, estimates of aboveground resource allocation based upon stem volume could potentially be confounded by anatomical or allometric differences (Nagakawa et al . 2015).…”

Sex-different response in growth traits to resource heterogeneity explains male-biased sex ratio

“…For example, males and females differ in architectural traits (Nakagawa et al, 2015) and physiological integration (Isogimi et al, 2011(Isogimi et al, , 2014Matsushita et al, 2011). Males tend to have larger sizes than females (Zhang et al, 2010) and show higher rates of growth (Ortiz et al, 2002;Nanami et al, 2005), survival (Allen and Antos, 1993) clonal growth (Mizuki et al, 2005;Matsushita and Tomaru, 2012).…”

Biomass allocation patterns and allometric relationships between components of the androdioecious Acer tegmentosum

“…They found that females of these two species had more foliage, branch, and trunk biomass than males. Michiko et al (2015) analyzed the allometric relationship between tree size and vegetative components of both genders. Their results demonstrate that females have greater leaf biomass than males.…”