These included soil microbes, which govern the nutrient cycling reactions in soils, and mycorrhizae, root-colonising fungi which help plants to absorb nutrients.
Not only do their root systems help stabilize soil and inhibit weeds, but they also offer movement, texture and year-round interest even when the blooms have long disappeared.
In an area of a few tens of square kilometres around this tower, the researchers will place further sensors in the soil and in local streams, to measure temperature, carbon-dioxide and nutrient levels, along with rates of root growth and the activities of microbes.