Adaptations to dry habitats

 

Plants in different habitats are adapted to cope with different problems of water availability.

Mesophytes      plants adapted to a habitat with adequate water

Xerophytes        plants adapted to a dry habitat

Halophytes        plants adapted to a salty habitat

Hydrophytes      plants adapted to a freshwater habitat

Some adaptations of xerophytes are:

Adaptation	How it works	Example
thick cuticle	stops uncontrolled evaporation through leaf cells	most dicots
small leaf surface area	less area for evaporation	conifer needles, cactus spines
low stomata density	fewer gaps in leaves
stomata on lower surface of leaf only	more humid air on lower surface, so less evaporation	most dicots
shedding leaves in dry/cold season	reduce water loss at certain times of year	deciduous plants
sunken stomata	maintains humid air around stomata	marram grass, pine
stomatal hairs	maintains humid air around stomata	marram grass, couch grass
folded leaves	maintains humid air around stomata	marram grass,
succulent leaves and stem	stores water	cacti
extensive roots	maximise water uptake	cacti