1. Tropical Deserts
By: Neil Mehta
Drew Overcash
Brendon Esperancilla

2. Deserted [di-zur-tid] (adjective):
abandoned; forsaken
unfrequented; lonely
without inhabitants or life
High temperatures and dry conditions.
Subtropical latitudes (15°-30°)
Mostly near equator
South America, Africa, and Australia

3. Climate Dry (arid and semiarid) climate zone Temperature Rainfall
Average 22.8°C (73.04°F)
Can rise to over 45°C (113°F)
Rainfall
Less than 43.8 mm annual precipitation
Lack due to drying high pressure systems and rain shadows

4. Formation: High pressure systems Mountain rain shadows
Subtropical ridge (intense drying effect)
Mountain rain shadows

5. H

6. High winds can cause disturbances such as dust devils (actually pretty dangerous), sandstorms, and formation/migration of sand dunes.
Monsoon – a seasonal prevailing wind that lasts for months, carries heat (and also moisture)

7. Low biomass (look around!) Least productivity of every biome
Few photosynthetic or chemosythetic organisms
If there are many plants, then animal life will be abundant
Plants need sunlight, nutrients, warm temperatures, and water

8. Dry soil Low water, high mineral content
Lack of leaching gives more fertility than in rain forest
Plants adapted to these conditions exist in the desert
Shrubs, succulents, shallow root plants, etc.

9. Cactus “Succulent” (thick, reduced, “succulent” leaves)
Minimizing surface area (smaller leaves) decreases area available for water loss
Thick, waxy coat layer improves water retention
Spines shade the cactus and defend against animals seeking water

10. CAM plants
Fix CO2 at night, store it as malate (acid), released during day (Rubisco improves efficiency)
Allows plant to keep stomata closed during the hot, dry day to conserve water
C4 plants
Store CO2 as a 4-carbon (C4) organic acid at night
Like CAM, allows plant to conserve water
C-4

11. Animals Reptiles, insects, birds, and mammals
Reptiles: thick, scaly skin protects from sun, heat, and water loss
Insects: chitinous exoskeleton helps prevent water loss
Most sleep/shelter during the worst heat of the day
Some never drink but get water from seeds, some obtain water from plants like cacti
Kangaroo rat: does not drink water and eats primarily seeds
Survives mostly on water produced during metabolism

12. Threats Mining can lead to salinization of soil
Overgrazing/deforestation can allow deserts to spread
Off-road vehicle use
Tumbleweed
Non-native and invasive (sound familiar?)

13. Credit File:Sahara satellite hires.jpg File:Kangaroo-rat.jpg
Music: “Gritzy Koopahari”
by username: saintedix