plant adaptations steve blake aldo leopold high school tropical ecology
TRANSCRIPT
PLANT ADAPTATIONS
Steve BlakeAldo Leopold High School
Tropical Ecology
RAINFOREST PLANT ADAPTATIONS
Limiting Factors Adaptations
Sunlight Tall trunks, Epiphytes. 70-90%
Nutrients Efficient usage, Effective capture
Water in Canopy Reduce loss, Effective capture
Strong scent and bright colours of flowers attract insects which assist in pollination
Strong scent of fruits attracts animals, which feed on the fruit and assist in dispersal of the seeds Thick, waxy surface of leaves protects against hot sun, heavy rain, and strong winds Aerial roots of
epiphytes absorb moisture from the air
Tall straight trunks no side branches
Thin, smooth bark
Buttress roots Shallow spreading root system
A Emergent tree canopy
B Large trees of Middle layer
C Lower tree layer
D Shrub/small tree layer
E Ground vegetation
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Epiphyte adaptations
• Advantages of being an Epiphyte in the rainforest:– access to more direct sunlight– a greater number of canopy animal
pollinators,– the possibility of dispersing their seeds
via wind.
Bromeliads• The pineapple family. • Thick, waxy leaves form a bowl shape in the center for catching
rainwater. • Some bromeliads can hold several gallons of water and are
miniature ecosystems in themselves providing homes for several creatures including – frogs and their tadpoles– Salamanders– Snails– Beetles– mosquito larvae.
• Those that die decompose and furnish the plant with nutrients.
• One bromeliad was found to contain several small beetles, crane flies, earwigs, a frog, a cockroach, spiders, fly larvae, a millipede, a scorpion, woodlice and an earthworm!
Tree adaptations
• Height –50-85 m– Light competition
• Biologically diverse (100-300 species/hectare)
–Reduce disease transmission• Smooth bark– Reduce epiphytic growth
• Some rainforest trees have smooth, thin exfoliating bark
• By frequently exfoliating patches of thin, papery bark, the tree can shed epiphytes
• Here an liana is about to lose its grip on the tree trunk
Tree adaptations (continued)
• Leaf shape to shed water – discourage epiphytes, send water to
roots
• Leaf stalks rotate to follow sunlight
• Buttress Roots – Compensate for shallow roots• Because nutrients are shallow
– Support– grow out from the base of the trunk up
to 15 ft above the ground. Extended roots increase area over which nutrients can be absorbed.
Prop or Stilt Roots• Stabilize trees in flood areas like
mangrove trees
Mangrove with prop roots
Stilt roots of “Walking palm tree”
move toward light by adding prop roots to light side and losing them on dark side.
Matapalos(Strangler Fig)
• Hemiepiphytes:– Start as epiphytes and grow very slowly
to ground—then accelerate growth rapidly. Why?
– Eventually kill and replace tree and becomes hollow inside—home to animals that deposit nutrients.
• David Attenborough video of Strangler Fig!!
An adaptation rare in the Neotropics…
• Carnivorous plants!– Trap and consume
animals for their nutrients
Pitcher plant - a carnivorous plant.
slippery rim
tendril
Insects falling into the pitcher are digested, and nutrients which are released are absorbed by the plant.
• Drosera capillaris, (pink sundew)• At the end of each tentacle is a gland that secretes droplets of sticky fluid. • Insects attracted to odor become stuck. • Tentacles slowly enclose the victim and secretes digestive enzymes and acids that dissolve the body.
• Utricularia, bladderworts• Utricularia foliosa• Utricularia gibba
•D
rosera
cap
illa
ris
(sundew
)
• Utricularia gibba: trap showing trigger hairs
• Utricularia foliosa
Lianas and vines
• Thick, woody stems• up to 3,000 ft long• Begin life on forest floor but
use trees for support to climb upwards towards sunlight• 90% of species in rain forests.
Lianas (continued)• Attach to trees with sucker roots or tendrils
and grow with the sapling, or climb by winding themselves around the trunk.
• When they reach top of canopy they spread to other trees or wrap themselves around other lianas.
• Gives support against winds to the shallow-rooted, top-heavy trees. However, when one tree falls several others may be pulled down.
Seed Dispersal
• Seed dispersal processes dominated by vertebrate dispersers – involve individuals belonging to
hundreds of species
Dispersal Types
• Gravity (‘Gravichory’)• Wind (Anemochory)• Water (Hydrochory)• Ballistic (Autochory)• Animal (Zoochory)– Epizoochory (transported externally)– Inadvertent (cached)– Myrmechory (ant-dispersed)– Endozoochory (through the digestive tract)
images: http://www.cas.vanderbilt.edu/bioimages/pages/fruit-seed-dispersal.htm
Fruits
• Nutritive fleshy pericarp or pulp;
• Chemical attractant; • Colors• Fruit size varies from 0.01g to 40g • In Neotropical forests, 50 - 90 % of the
canopy trees bear fruits adapted for animal dispersal, while close to 100 % of the shrubs and sub-canopy trees produce fleshy fruits
Frugivores• High variety of tropical bird, bat, ant,
mammal dispersers• Frugivore size ranges from ~10g tyrannid
flycatchers to African Elephant• Enormous differences in fruit and frugivore
scales imply an enormous potential range of phenomena
http://sites.ac-mayotte.fr/http://www.fsd2010.org/news/65.htm
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