Simplify the following text for a Grade 6 native English-speaking person.
Original: The seeds are released from their woody capsules ( gumnuts ) by heat and for successful germination the seedlings require a high level of light , much more than reaches the forest floor when there is a mature tree canopy .
Simplified: They grow only from seed which are released from their woody gumnuts by heat . The seedlings need a lot of light , much more than reaches the forest floor normally when there are mature trees blocking the sun .