Adaptations of Australian tree species to aridity (Ashton 1975; Moore 1981; Pate and McComb 1981; New 1984; Moore 1990; Knox et al. 1994; King 1997; Atwell et al. 1999; Ladiges et al. 2005).
| Adaptation | Mechanism | Examples |
|---|---|---|
| Sclerophylly | Maintains cellular volume | Many Australian genera, such as Acacia, and members of the Proteaceae and Myrtaceae families |
| Altered leaf anatomy | Reduces leaf surface area | Hakea and Acacia species with rolled needle like leaves |
| Phyllodes/cladodes | Reduces surface area; reduces evapotranspiration | Most Australian Acacia species |
| Vertically hanging leaves | Reduces absorption of radiation | Many eucalypt species |
| Leaf/pinnule movement | Reduces exposed leaf surface area | Bi-pinnate Acacia species; Lophostemon confertus |
| Cuticular adornment | Reduces evapotranspiration | Many genera, such as Eucalyptus, Acacia, and Casuarina, with hairy, spiny, or glaucous leaves |
| Stomatal crypts | Reduces evapotranspiration | Banksia species, Hakea species |
| Cuticular ledges | Reduces evapotranspiration | Eucalyptus preissiana, E. obliqua |
| Stomatal closure in response to atmospheric vapor deficit | Reduces transpirational water loss | Eremophila macgillivrayi, Myoporum floribundum, Myoporum platycarpum, Pittosporum phylliraeoides, Geijera parviflora |
| Facultative deciduousness | Reduces growth but allows survival over tropical dry period | Some Blakella eucalypts, such as E. clavigera, E. grandiflora, and E. brachyandra |
| Lignotubers/basal burls | Rapid regrowth after foliage loss | Most eucalypts; Acmena smithii |
| Epicormic buds | Rapid regrowth after foliage loss | Most eucalypts |
| Deep tap root | Allows access to deeper soil water profile | E. camaldulensis |
| High root:shoot ratio | Increases soil volume accessed for water supply | E. camaldulensis |