Phylogenetic ecology of foliar N and P concentrations and N:P ratios across mediterranean‐type ecosystems

Abstract

Aim Interpretations of global-scale patterns in foliar N and P concentrations and N:P ratios across climatic gradients and biomes often ignore complications imposed by taxonomic and phylogenetic structure in the nutrient concentrations of the constituent taxa. We analysed foliar N and P concentrations and N:P ratios of species from similar climate zones, but with contrasting soil fertility, to determine the relative importance of phylogeny and geographic region in driving foliar nutrient concentrations. Location Mediterranean climate regions. Methods Mean foliar N and P concentrations of 564 species from five mediterranean climate regions were compiled. Regional comparisons of foliar N and P concentrations and N:P ratios were performed using a phylogenetically independent contrasts (PIC) procedure. We also evaluated phylogenetic structuring in these variables, determining for each clade whether (1) the mean trait value and (2) the variance in trait values deviate significantly from chance expectation. Results Foliar N and P concentrations were found to vary between regions, a result confirmed using PIC. Tests of phylogenetic structure identified lineages having unusually high or low N and P concentrations, these being largely consistent amongst two of the regions. There was a general pattern of conservatism in foliar N and P concentrations and N:P ratios with localized instances of overdispersion. Main conclusions Our findings identify soil fertility as a strong environmental filter which has led to the dominance of low-nutrient adapted lineages in the South African Cape and Western Australia. There is also a pronounced clade-specific \u27stoichiometric homeostasis\u27 in foliar N and P concentrations and N:P ratios and this strong phylogenetic conservatism, together with the narrow range of foliar concentrations, is an evolutionary outcome of factors associated with developmental and physiological nutrient requirements specific to each lineage. Our results reinforce the need to include phylogenetic considerations in discussions of the biological stoichiometry of plants if we are to expand our current knowledge of foliar N and P concentrations and N:P patterns from an ecological to a biogeographic scale

Invariant allometric scaling of nitrogen and phosphorus in leaves, stems, and fine roots of woody plants along an altitudinal gradient

“…log-transformed values of N and P concentration (Sokal and Rohlf 1981). Parameter estimation of the allometric equations was implemented by using the "lmodel2" function in the "lmodel2" package of R (Legendre and Legendre 1998).…”

Biodiversity hotspots and Ocbil theory

“…de Campos et al (2013) x Hakea prostrata (Proteaceae) Kuppusamy et al (2014) x x global Phylogenetic ecology of foliar N and P and N:P Mediterranean-type ecosystems Stock and Verboom (2012) x x x Many species Lambers et al (2010) x Various species Oliveira et al (2015) Plant Soil (2012) 6 (e) Complex seed biology, germination strategies…”

Detecting Terrestrial Nutrient Limitation: A Global Meta-Analysis of Foliar Nutrient Concentrations after Fertilization

“…In addition, key families such as the Proteaceae, known to thrive under low nutrient conditions (Witkowski, 1990;Lambers and Shane, 2007;Stock and Verboom, 2012) and to have adaptations for efficient P use (de Campos et al, 2013), could not be included due to low sample sizes (i.e., not enough fertilization experiments). However, some interesting phylogenetic patterns were observed.…”

“…We argue that a broader mindset needs to be employed when considering nutrient limitation, taking into account that many factors beyond soil age and climate. Some of these factors are: soil alkalinity (Drenovsky and Richards, 2005), fire (Sardans et al, 2006;Stock and Verboom, 2012), flooding (Day, 1987;Feller et al, 2007), size class (Alvarez-Clare et al, 2013), species and phylogeny (AlvarezClare et al, 2013), and anthropogenic disturbance (Gariola et al, 2009). …”