PLANT ADAPTATION Adaptations

Adaptations of Hyprophytes(Aquatic Plants) Challenges: Access to oxygen and sunlight might be limited Adaptations Leaves flat Few stomata/stomata on upper epidermis only Thin cuticle Aerating roots that protrude above water Large surface area to maximize light absorption Stomata in contact with air- higher concentration of gases in air than in water No need to produce a thicker cuticle if water is plentiful Greater access to oxygen

Adaptations of Hyprophytes(Aquatic Plants) Air spaces to circulate gases more efficiently Air spaces to enable floatation of leaves Diffusion is faster through air spaces than through cell cytosol Airspaces may leaves more buoyant; floating on surface provides better access to light and gases

Xerophytes Plant adapted to living in hot dry habitats 2 Types Succulents eg. cacti Sclerophylls eg. eucalypts Sclerophylls: hard leaved plants

Evading animals that will eat them to procure water Challenges Lack of water Need to store water and reduce water loss Need increased tolerance to dry conditions Evading animals that will eat them to procure water Need ways to protect themselves

Dry Habitat Ability of ‘stem’ to expand and hold water Thick cuticle (waxy coating or thick epidermis Hairs covering leaves Sunken Stomata Provides more capacity for storage of water Reduces evaporative water loss across leaf surface Increases humidity around stomata decreasing water vapour gradient and reducing rate of diffusion of water vapour from leaf. http://www.docstoc.com/docs/28209703/Plant-Adaptations-to-Dry-Environments

Dry Habitat Small, reduced or absent leaves Modified leaves; protective spines that point downward decreases surface area to volume ratio across which evaporative water loss can occur Reduces browsing And damage by animals Directs condensed water down to drip on roots

Dry Habitat CAM photosynthesis Deep Tap root Enables carbon dioxide to be taken up and stored at night when less water will be lost Enables better uptake of water.

Adaptations of Halophytes Halophytes are plants adapted to high levels of salt Challenge: high levels of salt in habitat; salt needs to be excluded or removed Adaptations Salt glands Shedding of leaves Excretion of salt Removal of leaves with high salt content

Mangrove Salt glands in mangrove Plants Lenticel in roots Allow air in but not salt

Mangrove Root adaptations Additional Challenges Shifting water logged muddy soil Adaptations Pneumatophores Aerial roots uptake of oxygen from air Prop anchor and cable root Stabilize and fix plant

Adaptations to Rain forest Low light and high rainfall Mimosa plant leaf response

Adaptation to Poor Soil Quality Insectivorous plant

Adaptation to fire Lignotubers: swellings at base of stem/trunk Regeneration after shoot perishes Epicormic bud Tissue beneath bark in some trees from which new plant tissue grows following fire damage to bark