Stoichiometric homeostasis as a trait to predict invasiveness
Alternanthera philoxeroides (Amaranthaceae, EPPO A2 List) is an emergent aquatic plant that can be found growing in both aquatic and terrestrial habitats. The species originates from South America, and it is invasive in Australia, the USA, New Zealand and numerous countries of Asia (e.g. India, Thailand). The invasive success of A. philoxeroides, and other invasive plant species, is often attributed to some of their traits, such as phenotypic plasticity, spatial growth, fecundity, leaf area, functional traits and resource-use efficiency. Stoichiometric homeostasis is the ability of an organism to maintain constant internal nutrient ratios or concentrations despite environmental fluctuations. Stoichiometric homeostasis has the potential to be used as an additional trait to predict the potential invasiveness of a species. A study was conducted in China where A. philoxeroides plants were collected along with the soil from 45 sites (across different latitudes and longitudes) and analysed for nitrogen, phosphorus and potassium homeostasis. These measurements were also carried out in the associated soils. The results showed that nitrogen and phosphorus homeostasis in leaves was high and stable across the sites and potassium homeostasis increased with latitude. Potassium plays an important role in plant metabolism to support plant functions of vegetative growth and storage structures. A. philoxeroides may conservatively utilise potassium to ensure rapid growth, and its ability to spread into new environments, promoting its rapid expansion in China.
Sources
Gao A, Xiao H, Chen F, Zhang M, Yang J, Zhang J, Zhang Z, Balah MA, Delgado AN, Wu A (2026) High and stable nutrient homeostasis correlates with the invasion of Alternanthera philoxeroides. Biological Invasions. 28, 35 https://doi.org/10.1007/s10530-025-03708-z