Aerial roots elevate indoor plant health: physiological and
morphological responses of three high-humidity adapted Araceae species
to indoor humidity levels
Abstract
Heightened by the COVID-19 pandemic there has been a global increase in
urban greenspace appreciation. Indoor plants are equally important for
improving mental health and air quality but despite evolving in humid
(sub)tropical environments with aerial root types, planting systems
ignore aerial resource supply. This study directly compared nutrient
uptake preferences of aerial and soil-formed roots of three common
houseplant species under high and ambient relative humidities. Growth
and physiology parameters were measured weekly for Anthurium
andreanum, Epipremnum aureum and Philodendron scandens grown in
custom made growth chambers. Both aerial and soil-formed roots were then
fed mixtures of nitrate, ammonium and glycine, with one source labelled
with 15N to determine uptake rates and maximum
capacities. Aerial roots were consistently better at nitrogen uptake
than soil roots but no species, root type or humidity condition showed a
preference for a particular nitrogen source. All three species grew more
in high humidity, with aerial roots demonstrating the greatest biomass
increase. Higher humidities for indoor niches, together with fertiliser
applications to aerial roots will support indoor plant growth, creating
lush calming indoor environments for people inhabitants.