Generality of Leaf Trait Relationships: A Test Across Six Biomes

Abstract

Convergence in interspecific leaf trait relationships across diverse taxonomic groups and biomes would have important evolutionary and ecological implications. Such convergence has been hypothesized to result from trade-offs that limit the combination of plant traits for any species. Here we address this issue by testing for biome differences in the slope and intercept of interspecific relationships among leaf traits: longevity, net photosynthetic capacity (A max ), leaf diffusive conductance (G s ), specific leaf area (SLA), and nitrogen (N) status, for more than 100 species in six distinct biomes of the Americas. The six biomes were: alpine tundra-subalpine forest ecotone, cold temperate forest-prairie ecotone, montane cool temperate forest, desert shrubland, subtropical forest, and tropical rain forest. Despite large differences in climate and evolutionary history, in all biomes mass-based leaf N (N mass ), SLA, G s , and A max were positively related to one another and decreased with increasing leaf life span. The relationships between pairs of leaf traits exhibited similar slopes among biomes, suggesting a predictable set of scaling relationships among key leaf morphological, chemical, and metabolic traits that are replicated globally among terrestrial ecosystems regardless of biome or vegetation type. However, the intercept (i.e., the overall elevation of regression lines) of relationships between pairs of leaf traits usually differed among biomes. With increasing aridity across sites, species had greater A max for a given level of G s and lower SLA for any given leaf life span. Using principal components analysis, most variation among species was explained by an axis related to mass-based leaf traits (A max , N, and SLA) while a second axis reflected climate, G s , and other area-based leaf traits.

Crescimento e eficiência fotossintética de uso do nitrogênio e fósforo em espécies florestais da Amazônia na fase juvenil

“…Os conteúdos de N e P foram menores (Tabela 1) que os valores relatados em florestas tropicais por outros autores (RAAIMAKERS, 1995;REICH et al, 1999;OSNAS et al, 2013). Diversos estudos têm mostrado a importância do N e P na fotossíntese (REICH et al, 1999;FYLLAS et al, 2009), no entanto há pouca informação sobre os níveis críticos e ótimos de nutrientes para espécies florestais da Amazônia.…”

“…Diversos estudos têm mostrado a importância do N e P na fotossíntese (REICH et al, 1999;FYLLAS et al, 2009), no entanto há pouca informação sobre os níveis críticos e ótimos de nutrientes para espécies florestais da Amazônia. Em Swietenia macrophylla e Brosimum alicastrum, conteúdos de nutrientes foliares abaixo de 10-14 mg g -1 (para N) e 0,6 mg g -1 (para P) são considerados deficientes para o crescimento (DRECHSEL; ZECH, 1991).…”

“…A diminuição na AFE está frequentemente associada com o aumento no conteúdo de nitrogênio e fósforo por unidade de área foliar (POORTER; EVANS, 1998;REICH et al, 1999;OSONE et al, 2008), devido, em parte, ao maior acúmulo de proteínas fotossintéticas. A eficiência no uso do N foi mais elevada nas espécies com maior área foliar específica, corroborando os resultados de Poorter e Evans (1998) e Reich et al (1998).…”

Stomatal Biology of CAM Plants

“…Males and H. Griffiths, unpublished data). Variation in stomatal traits appears to be accommodated within a network of coordinated leaf traits in CAM species in the same way as has been observed in C 3 plants (Reich et al, 1997(Reich et al, , 1999Wright et al, 2004Wright et al, , 2005Donovan et al, 2011;Vasseur et al, 2012;Díaz et al, 2016). Recent modeling and empirical studies have highlighted the importance of the alignment of variation in stomatal, xylem, and veinal traits in angiosperms for optimal physiological function (Brodribb et al, 2013(Brodribb et al, , 2016Fiorin et al, 2016;Carins Murphy et al, 2016;Scoffoni et al, 2016).…”

Foliar morphology and canopy nitrogen as predictors of light-use efficiency in terrestrial vegetation

“…Numerous studies provide support for the widespread use of N content as an index of the amount of photosynthetic enzymes, pigments and electron- transport compounds in a leaf or canopy (Field and Mooney, 1986;Evans, 1989;Hollinger, 1996;Reich et al, 1997Reich et al, , 1999Peterson et al, 1999). While positive correlations between ε and measures of foliar N have been observed by several investigators (Sinclair and Horie, 1989;Muchow and Sinclair, 1994;Gimenez et al, 1994;Bange et al, 1997a;Choudhury, 2001), such relationships are typically narrow in scope (within species or among similar species).…”