Symbiotic

Ecto

Endo

Mycorrhizae “fungus root”

tight association of plant roots and soil fungi in virtually all terrestrial plants

few obligate associations form

root functions in sterile soil impaired

fungi improve mineral nutrient aquisition, phosphate

Fungi receive photosynthate products in return

endo, penetrate root cells: agricultural crops, some trees

small number of specialized species

ecto, around and between root cells: trees

large number of species

some plants have both: heaths, legumes, roses

other fungi are saprophytes or parasites

Mycorrhizae may limit plant distribution:

Heath: chemical competitive exclusion prevents mycorrhizae of trees to establish

The forest root system interconnected by mycorrhizae:

³²P in freshly cut stumps transfered to 18 species of trees

8 days, 72% of trees within 2.5 m, 43% of trees within 8m

Algal-Hetertotroph

Lichen

Corals

Bacteria

Gut flora

Ruminants

Sterile Mice

Flashlight fish

Non-symbiotic

Zoochory/seed predation

Cleaners

Ants & aphids

Wind pollinators:

pollen smooth, dry, copius, flowers small, inconsipicuous, no nectar or scent

Flowering plants pollinated by animals have sticky pollen, conspicuous flowers, copious nectar and scent

Pollen and nectar used as a food source

co-evolution of flowers to match morphological, physiological, and behavioral traits of pollinators

BumbleBees: blue or yellow flowers, closed

Butterflies: red flowers open during day

Moths: white, open at night

bats: white, open at night, large openings