Ecology 6th Edition by Charles Krebs

Exercise 9

The giant lobelia Lobelia deckenii keniensis on Mount Kenya produces on average 250,000 seeds and flowers every eight years. Average adult survival is 0.984 per year. Plants do not begin setting seed until they are 50 years old. Assuming for simplicity a two-stage life cycle (seeds, adult plants), calculate what survival rate of seeds would produce a stable population (? = 1.0). How would this survival rate change if the plants flowered every year instead of only once every eight years?