1. Seaweed population dynamics
Demography of algal life-history phases

2. Rhodophyta typical life history

3. G:T ratio = NG / NT
What is the expected stable G:T ratio
when both life-history phases are
ecologically equal?

4. Mazzaella parksii

5. Model assumptions
• Same spore viability rate (100 %)
• Same reproductive maturation rate
• Same reproductive periodicity
• Same longevity (triennial thalli)
• No density-dependence or competition
• Same density-independent mortality rate (33 %)
• Spore output rates:
4 tetraspores / tetrasporophyte
1 carpospore / (male-female) gametophyte pair

6. Rhodophyta life history used for population matrix model
S = 0.67 yr-1
FTM = FTF = 2 yr-1
FM = FF = 0.5 yr-1

7. Matrix model and population vector

8. Stable stage distribution
Stable G:T ratio = 2.8