Chapter 2: The Language of Trees

scent = communication (6)

• the african savannah

• acacia trees

• giraffes eat leaves

• trees release gas that makes leaves bitter

• also signals nearby trees to make their own leaves bitter (7)

plant electrical signals travel at 1/3 of an inch per minute (8)

trees can identify insects by the insect’s saliva taste!(9)

• can release pheremones that summon specific insect predators (8)

• elms and pines call on small parasitic wasps that lay their eggs insided leaf-eating caterpillars (8)

oaks release tannins (9)

willows release salicylic acids (9)

• relieve headaches

• reduce fevers

trees also communicate by fungal networks in root tips (10)

tree root size is crown x2+ (10)

fungi hyphae transmit signals (10)

• ‘wood wide web’ (11)

• even competing tree species in contact with one another (11)

isolated trees susceptible to insects (11)

• no communication with other species (11)

cultivated plants have also lost ability to communicate (11)

• farmed plants especially susceptible to insects because they’re ‘deaf and dumb’ (11)

sound! (13)

• roots ‘crackle’ at 220 hz (13)

! root tips orient themselves towards the sound ! (13)