Chapter 1 | Chapter 2 | Chapter 3 | Chapter 4 | Chapter 5 | Chapter 6 | Chapter 7 | Chapter 8 | Chapter 9
Chapter 3 Plant Life Histories: Of Birds and Bees
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| Sotol produces a showy flowering stock that can reach over 4 meters (13 feet) high. Unlike most of its close relatives, the agaves, sotol does not die after flowering. |
Desert in Bloom provides information about the wildflower season and desert wildflower blooming. From Desert USA..
Yucca and Its Moth explores the remarkable relationship between the yucca and yucca moth. From Wayne's Word.
1. Seed dormancy is particularly common in the desert. a) Why might
seed dormancy be particularly advantageous in the desert? b) Describe
two
dormancy mechanisms used by desert plants. Include how dormancy is
broken
and how the dormancy enhances fitness.
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| In years of sufficient rain, the Texas silverleaf can be blanketed with showy blossoms that attract bees and other pollinating insects. |
3. Consider the reproduction of saguaro. Link the following ideas together: fruit eating birds; safe sites; and nurse trees. Include in your answer the definition of safe sites and nurse trees.
4. Compare and contrast the growth and survival strategies of desert annuals and herbaceous perennials.
5. On the surface it would seem that semelparous perennials would be at a disadvantage in the desert yet they do occur alongside their iteroparous competitors. Explain how it is that the semelparous strategy might persist in the desert.
6. Compare and contrast the floral characteristics of wind-pollinated and animal-pollinated flowers. Speculate why it is that animal pollination is more common in the desert.
7. Flowering in the unpredictable desert environment can be risky. Describe the options plants have to help ensure at least some success even when disaster strikes.
8. Reynolds measured plant reproduction in plots where rodents were
excluded as well as in control plots where rodents were present. The
effect
of rodents on the reproductive success of perennial plants was
different
in dry versus wet years (see table below). Explain these results.
| Reproductive success (number of seedlings established) of perennial plants | ||
| Dry years | Moist years | |
| Rodents present | very low | very high |
| Rodents excluded | low | high |
Chapter 1 | Chapter 2 | Chapter 3 | Chapter 4 | Chapter 5 | Chapter 6 | Chapter 7 | Chapter 8 | Chapter 9