N : P ratios in terrestrial plants: variation and functional significance

Nitrogen (N) and phosphorus (P) availability limit plant growth in most terrestrial ecosystems. This review examines how variation in the relative availability of N and P, as reflected by N : P ratios of plant biomass, influences vegetation composition and functioning. Plastic responses of plants to N and P supply cause up to 50-fold variation in biomass N : P ratios, associated with differences in root allocation, nutrient uptake, biomass turnover and reproductive output. Optimal N : P ratios ? those of plants whose growth is equally limited by N and P ? depend on species, growth rate, plant age and plant parts. At vegetation level, N : P ratios <10 and >20 often (not always) correspond to N- and P-limited biomass...

Categories: Publication; Types: Citation, Journal Citation; Tags: New Phytologist, concentrations., critical N : P ratios, ecological, nutrient limitation, All tags... plant, species richness, stoichiometry, strategies, tissue nutrient, Fewer tags