Norway maple displays greater seasonal growth and phenotypic plasticity to light than native sugar maple

Abstract

Norway maple (Acer platanoides L), which is among the most invasive tree species in forests of eastern North America, is associated with reduced regeneration of the related native species, sugar maple (Acer saccharum Marsh) and other native flora. To identify traits conferring an advantage to Norway maple, we grew both species through an entire growing season under simulated light regimes mimicking a closed forest understorey vs. a canopy disturbance (gap). Dynamic shade-houses providing a succession of high-intensity direct-light events between longer periods of low, diffuse light were used to simulate the light regimes. We assessed seedling height growth three times in the season, as well as stem diameter, maximum photosynthetic capacity, biomass allocation above- and below-ground, seasonal phenology and phenotypic plasticity. Given the north European provenance of Norway maple, we also investigated the possibility that its growth in North America might be increased by delayed fall senescence. We found that Norway maple had significantly greater photosynthetic capacity in both light regimes and grew larger in stem diameter than sugar maple. The differences in below- and above-ground biomass, stem diameter, height and maximum photosynthesis were especially important in the simulated gap where Norway maple continued extension growth during the late fall. In the gap regime sugar maple had a significantly higher root : shoot ratio that could confer an advantage in the deepest shade of closed understorey and under water stress or browsing pressure. Norway maple is especially invasive following canopy disturbance where the opposite (low root : shoot ratio) could confer a competitive advantage. Considering the effects of global change in extending the potential growing season, we anticipate that the invasiveness of Norway maple will increase in the future.

Phenological niches and the future of invaded ecosystems with climate change

“…A pervasive non-native understorey species in the Ohio River Valley, Lonicera maacki , stays green later than any native understorey species (Becker et al 2013). Similarly, the invasive tree Acer platanoides also stays green later than one studied North American congener (Paquette et al 2012). Further, recent work suggests that these non-native species may not play by the same risk–investment rules as native species in the fall.…”

“…Alongside these theoretical developments, a growing body of research focused on plants has found phenological differences, especially in leafing and flowering times, between non-native and native species. Several studies have found that especially early (McEwan et al 2009; Wilsey et al 2011; Throop et al 2012; Wainwright et al 2012) or late (Godoy et al 2009; Fridley 2012; Paquette et al 2012; Pearson et al 2012) phenologies may aid the success of non-native species, while more recent work suggests that non-native species may be the major drivers of longer growing seasons in North America (Wolkovich et al 2013). Here we build on current theoretical perspectives and empirical work to develop predictions of how phenology may enhance plant invasions with climate change.…”

Intraspecific Trait Variation Is Correlated with Establishment Success of Alien Mammals

“…The plant invasion biology literature has paid considerable attention to one type of variation formulating the phenotypic plasticity hypothesis, which posits that phenotypically plastic species are better able to establish and spread in novel environments (Richards et al 2006;Davidson et al 2011). Several experimental and observational studies have compared native and alien/invasive plants, but their results offer mixed support for this hypothesis, including higher plasticity in invasives, no differences, and even higher plasticity in natives (Funk 2008;Davidson et al 2011;Godoy et al 2011;Palacio-López and Gianoli 2011;Paquette et al 2012). On the other hand, the majority of animal studies looking for determinants of alien species' establishment success has focused on the role of abiotic factors and/or mean trait values of the studied species without explicitly accounting for intraspecific trait variation (Duncan et al 2003;Forsyth et al 2004;Hayes and Barry 2008).…”

Effect of light intensities on the photosynthetic characteristics of Abies holophylla seedlings from different provenances

“…Photosynthetic plasticity greatly improves the resistance and the ability to obtain resources of an individual tree seedling (e Silva et al 2012) and also improves the competitive ability in the environment (Paquette et al 2012), thereby laying a solid foundation for the survival and reproduction. Therefore, studying the photosynthetic characteristics of different trees is an effective way to understand the survival mechanisms of adaptation to the light environment (Klein et al 2013, Flexas et al 2014.…”