Are endemics functionally distinct? Leaf traits of native and exotic woody species in a New Zealand forest

Abstract

Recent studies have concluded that native and invasive species share a common set of trait relationships. However, native species in isolated regions might be functionally constrained by their unique evolutionary histories such that they follow different carbon capture strategies than introduced species. We compared leaf traits relating to resource investment, carbon return, and resource-use efficiency in 16 native (endemic) and three non-native (invasive) species in a temperate forest in Canterbury, South Island, New Zealand. Trait differences were more closely associated with leaf habit than nativity. Deciduous species (including invaders) exhibited greater maximum photosynthetic rates at similar resource costs, which resulted in greater nitrogen- and energy-use efficiencies than evergreen natives. Leaf area was the only trait that differed significantly by nativity (over two-fold larger in invaders). Invaders and deciduous natives both occupied the ‘fast return’ end of the leaf economics spectrum in contrast to the native evergreens which had comparatively slow return on investment. Dominant woody invaders in this forest are physiologically distinct from many New Zealand endemic species, which are overwhelmingly evergreen. It remains unclear whether these trait differences translate to an ecological divergence in plant strategy, but these results suggest that ecophysiological tradeoffs are likely constrained by biogeography.

Trait divergence and opposite above- and below-ground strategies facilitate moso bamboo invasion into subtropical evergreen broadleaf forest

“…Therefore, it can hinder broadleaf species from capturing light resources, forming a shadowing effect and thus inhibiting the growth and regeneration of broadleaf species. Bamboo species also exhibited higher leaf N and P concentrations, photosynthetic, and respiration rates than broadleaf species, similar to what has been documented for most invasive species ( Heberling and Mason, 2018 ; Mathakutha et al., 2019 ; Díaz de León Guerrero et al., 2020 ; Palma et al., 2021 ; Wang et al., 2021 ; Montesinos, 2022 ). These traits demonstrate elevated leaf nutrient status and photosynthetic potential, supporting their competitive advantage.…”

“…Conversely, the “phenotypic divergence hypothesis”, based on limiting similarity, argues that successful invaders have distinct traits from coexisting natives, enabling them to occupy vacant niches ( Ordonez, 2014 ). Traits such as higher leaf N and P concentrations (LNC and LPC), leaf area (LA), specific leaf area (SLA), leaf dry matter content (LDMC), mass-based net photosynthetic rate (A mass ), specific root length (SRL), and root diameter (RD), as well as lower mass-based dark respiration rate (R mass ) and leaf C:N ratio, have been found to benefit invasive species over native species ( Luo et al., 2015 ; Murphy et al., 2016 ; Heberling and Mason, 2018 ; Mathakutha et al., 2019 ; Díaz de León Guerrero et al., 2020 ; Palma et al., 2021 ; Wang et al., 2021 ; Montesinos, 2022 ). Furthermore, phenotypic integration, the pattern of correlations among different functional, developmental, or genetic traits, is essential for alien plants to invade native communities successfully ( Osunkoya et al., 2010 , 2014 ).…”

Functional traits of acquisitive invasive woody species differ from conservative invasive and native species

“…Although few studies have assessed functional traits in the field (e.g. Kuehne et al 2014;Lieurance and Landsbergen 2016;Heberling and Mason 2018) most of them covered few habitat types and treated resource levels discretely. For that reason there is a lack of gradient studies examining trait responses in multiple comparable sites along major environmental gradients (Hulme and Bernard-Verdier 2018).…”

A test of island plant syndromes using resource‐use traits

“…Island plant syndrome predictions are typically investigated by comparing the traits of native island species against nonnative continental plants growing in situ (Mologni et al, 2022) or by comparing a single species growing on a continent to the same species on an island (Burns, 2016). For example, a number of previous studies have tested whether natives and invasives on islands differed in their stature, dispersal mode, and growth rates (Heberling & Mason, 2018; Mathakutha et al, 2019; Sperry et al, 2021) because these traits are thought to be associated with competitive ability and persistence. However, comparisons using nonnative invasives may not be suitable given that invasive plants are not a random subset of continental plants.…”