Nutrient contents
The range of fast-slow return trade-offs for plants is strongly related
to nutrient regimes, where fast growing species are commonly adapted to
nutrient rich sites (Wrightet al. 2004). However, few studies have compared interspecific
variation in plant nutrient concentrations to pathogen attack
(Marquis et al.2001). The majority of studies on the relationship between plant
nutrient status and pathogenicity have focused on fertilization effects
on agricultural crops , primarily for nitrogen
(Walters & Bingham
2007; Dordas 2008; Veresoglou et al. 2013). Nitrogen status can
affect pathogen susceptibility of plants in two ways; plant tissue
quality and production of secondary metabolites
(Hoffland et al.2000). Nutrient rich tissues are often more susceptible to diseases
either because they are less well defended or they are more nutrient
dense for the pathogen; however, N-limitation can weaken plant immunity
and may be a cue for development of disease symptoms by some pathogens
(Snoeijers et al.2000). Results may differ when comparing nutrient content across
species and fertilization effects on a single species. Hantsch et al.
(2014) found no
effect of tree species differences in foliar carbon and nitrogen on
pathogen load, while prior studies on intraspecific variation showed
higher leaf nitrogen was associated with increased disease
(El-Hajj et al.2004; McElrone et al. 2005). Laliberté et al.
(2015) proposed
that there is a trade-off in phosphorus acquisition and soil pathogen
attack suggesting that plants adapted for phosphorus limited soils have
poorly defended roots. However, mycorrhizal associations may ameliorate
such susceptibility.