Floral Splendour and Shortage of Nutrients - Soil: Reflections on the Basis of our Existence - page 44

Competitive grass. Grass has a finely branched root system reminiscent of a mycorrhizal fun-
gus mycelium. The vast majority of plant species have less developed root systems and depend
more on collaboration with fungi to ensure nutrient uptake. Fertilising nutrient-poor land ben-
efits grasses but disadvantages species that depend on mycorrhizal fungi. Adding fertiliser to a
meadow full of wild flowers can rapidly turn it into monotonous grassland
choosing areas subject to disturbance. Marram grass, for example, grows in sand
dunes that are continually being shaped and shifted by the wind. Their roots are sen-
sitive to fungal attack but the plant is periodically covered in sand, which enables
new roots to grow and replace the old ones as they perish. If the sand dunes stabilise,
resulting in the sand remaining fixed in place, marram grass cannot survive for long.
Some Plants Thrive in Acidic Soil
Some plants thrive in acidic soil. Growers of American blueberries know that
you have to mix generous amounts of unfertilised peat into the soil or else the
leaves bleach due to insufficient nourishment. Iron deficiency is a particular prob-
lem for blueberry bushes because iron becomes more soluble in acidic condi-
tions and harder for the bushes to absorb when the soil's pH rises. Some species
have evolved to manage this problem by secreting molecules that bind iron ions
for enhanced absorbability. In strongly acidic soil, plant roots often suffer from
increased concentrations of toxic aluminium ions. Plant species that can tolerate