Nitrogen use strategies of seedlings from neotropical tree species of distinct successional groups

Nitrogen use plasticity in response to light intensity in neotropical tree species of distinct functional groups

“…In both light intensities, C. pachystachya seedlings had a large predominance of NO 3 − in relation to amino acids in the xylem sap, in addition to high NR activity, especially in the leaves. This strategy corroborates the results found by Oliveira et al (2017) and Debiasi et al (2019) for shade‐intolerant species, characterized by the preferential use of NO 3 − in the leaves. However, in the HL treatment, C. pachystachya roots and leaves increased the assimilation of both 15 NO 3 − and 15 NH 4 + into amino acids.…”

“…Studies using seedlings of tree species native to the Brazilian Atlantic Rain Forest have demonstrated that shade‐intolerant species have a clear preference for NO 3 − , exhibit high NO 3 − translocation in the xylem sap, and assimilate this anion mainly in the leaves, with high foliar activity of the NR enzyme (Debiasi et al, 2019; Oliveira et al, 2017). Seedlings of shade‐tolerant trees assimilated N mainly in the roots, but their N use strategies varied between understory and canopy species (Debiasi et al, 2019, Oliveira et al, 2017). Overall, these contrasting strategies of N use have been considered adaptive responses to the distinct light environments that these species occupy.…”

BRIEF COMMUNICATIONPhotosynthetic light-response curves of light-demanding and shade-tolerant seedlings of neotropical tree species

“…Due to the adaptation to the different strata that C. canjerana and C. estrellensis explore throughout the life cycle, exposing their leaves to high irradiances at some point, it is reasonable that the photosynthetic characteristics of their seedlings resemble those of some LD species. Consistent with this hypothesis, our group have already demonstrated that C. estrellensis seedlings have nitrogen-use strategies intermediary to LD and understory ST species (Oliveira et al 2017). In this previous study, we have also detected variations in nitrogen-use strategies among LD species, according to their specific ecological characteristics (Oliveira et al 2017).…”

“…Consistent with this hypothesis, our group have already demonstrated that C. estrellensis seedlings have nitrogen-use strategies intermediary to LD and understory ST species (Oliveira et al 2017). In this previous study, we have also detected variations in nitrogen-use strategies among LD species, according to their specific ecological characteristics (Oliveira et al 2017). Here, L. muehlbergianus and H. popayanensis differed from C. pachystachya in some parameters (Imax and PNmax for L. muehlbergianus; Ф, RD, RP, Imax, and PNmax for H. popayanensis), indicating different light requirements among the LD species, despite their need for a high-light environment for establishment.…”

Nitrogen source utilization in co-existing canopy tree and dwarf bamboo in a northern hardwood forest in Japan

“…This result may indicate that NO3 − assimilation of Sasa primarily takes place in the roots rather than in the leaves, if the roots can access soil NO3 − sources. Root NO3 − assimilation of understory species was also reported by Oliveira et al (2017), suggesting that it might have an adaptive advantage in shady environments because N assimilation would compete with carbon assimilation in the leaves (Bloom et al 2010 (Näsholm et al 1998(Näsholm et al , 2009, while report of δ 15 N value of EON have been very limited until recently (Houlton et al 2007;Takebayashi et al 2010;Koba et al 2010Koba et al , 2012. In right of the ectomycorrhizal associations and low NRA (Fig.…”