1. Section #3: Grassland, Desert, and Tundra Biomes

3. Biomes of the World

4. General Info found in climates that have less rainfall
less rainfall = less species diversity
although you might have less variety, you still might have high numbers of individuals in those species that are present

5. Savannas
these grasslands are located in tropical & subtropical areas near the equator
found in parts of Africa, India, Australia, and South America
overall receive little precipitation throughout the year – but there are periods of heavy rainfall followed by periods of drought

6. Vegetation of the Savannas
contain grasses, scattered trees, and shrubs
plants must be able to survive prolonged periods without water
plants have horizontal roots systems to capture as much moisture as possible
grasses have long vertical leaves that expose less surface area to the hot sun
some savanna plants even lose their leaves during the dry season to conserve water
thorns & sharp leaves keep herbivores at bay

7. African Savanna

8. Savanna Fires
during the dry season, fires often sweep across the savanna burning the grasses and shrubs
this returns nutrients to the soil
plants quickly regenerate from the shallow root systems

9. Animals of the Savanna
mostly grazing herbivores & the predators that feed on them
some grazers have adopted a migratory way of life to follow the rains & find newly sprouted grasses & fresh watering holes
predators usually follow & stalk the migratory animals
savanna animals usually give birth only during the rainy season when more food is available to increase chances of survival

10. Competition in the Savanna
herbivore species reduce the competition for food by eating vegetation at different heights
Example:
small gazelles – feed on grasses
black rhinos – feed on shrubs
giraffes – feed on tree leaves

11. Temperate Grasslands dominated by grasses, very few trees
hot summers, cold winters
moderate rainfall, cm of precipitation per year
summer temps and lack of precipitation can make the grasslands susceptible to fires that commonly sweep across the lands

12. Temperate Grasslands
located on the interior of continents - include North American prairies, steppes of Russia & the Ukraine, and the pampas of South America
few natural temperate grasslands remain, most have been replaced by farms & grazing areas
located near mountains that block the grasslands from receiving much precipitation

13. Plants of the Temperate Grasslands
mostly perennials – prairie grasses & wildflowers
grass height depends on root depth
root systems are dense – designed to survive the periods of drought & also hold the rich soil in place
few trees can survive – little rain, fires, & constant wind thwart tree growth

14. Grasslands

15. Animals of the Temperate Grasslands
grazers with large, flat teeth for chewing the coarse prairie grasses (bison & antelope)
burrowers like badgers & prairie dogs are protected underground from the weather & fires – also they burrow underground to escape predators

16. Threats of the Temperate Grasslands
most fertile soil – so many people farm or graze the grasslands
grain crops do not have good root systems to hold the soil – leads to soil erosion
overgrazing leads to grasses being overeaten & trampled – soil cannot regenerate & becomes less productive

17. Similarities? Differences?

18. The Chaparral type of temperate woodland biome
located in mid-latitudes (30° N or S)
near coastal areas with Mediterranean climates
warm, dry summers & mid, wet winters
too dry to support a forest, but more rain than a desert
receives enough precipitation to support vegetation that grows in bunches

19. Chaparral

20. The Chaparral Plants
mostly low-lying evergreen plants that grow in dense patches
dominated by broad-leafed evergreen shrubs
plants include chamise, manzanita, scrub oak, olive trees, sage and bay herbs, plus piñon & juniper trees

21. The Chaparral Plants
the small, leathery leaves retain water and contain oils that promote burning
well adapted to survive fires that kill competition for sunlight
can re-sprout from small bits of plant tissue

22. The Chaparral Animals
examples include quail, lizards, chipmunks, mule deer
most animals utilize camouflage (shape or coloring) to blend into the environment

23. Threats to the Chaparral
human development of the land for both commercial & residential use
humans like the area because of the mild climate year-round, proximity to oceans, and the large amounts of sunlight

24. Deserts areas that receive less than 25cm of precipitation a year
have little or no vegetation
extreme temperatures
located at several latitudes covering 1/5 of the Earth’s landmasses
located near large mtn. ranges that block the passage of moisture-filled clouds

26. Desert Examples hot deserts cold deserts Sonora Desert, Arizona
Sahara, Africa
Australia
cold deserts
Gobi Desert, China
Greenland
Antarctica

27. Desert Plants all plants must be adapted to obtain & conserve water
some plants even die & drop their seeds when the conditions get too dry
the seeds remain dormant until the next rainfall when they quickly germinate & grow
some can even survive when their water content drops to only 30% of their mass

28. Other Adaptations
succulents - such as cactuses – have thick fleshy stems & leaves to store water
waxy coatings to reduce water loss
sharp spines or thorns to keep thirsty animals away
plant roots that spread out just under the sand to absorb as much rain as possible

29. Desert Animals
reptiles – like the Gila monster, rattlesnakes, & lizards – have thick scaly skin to prevent water loss
amphibians – like the spadefoot toad – survive the high temps by ESTIVATING (burying themselves in the ground and sleeping through the dry season)
desert insects & spiders are covered in body armor to retain water
most creatures are nocturnal to avoid the heat of the day

30. Tundra located north of the Arctic Circle very short summers
topsoil thaws out during the summer months creating a pattern of bogs & swamps across the land
below the topsoil is PERMAFROST – permanently frozen ground
constant winds

31. Tundra Vegetation
dominated by tough grasses, lichens, herbs, & small shrubs that grow close to the ground
soil is extremely thin – wide, shallow roots anchor plants against the icy winds
lichens & mosses don’t even need soil to grow
plants try to absorb heat from the sunlit soil

32. Tundra Animals
summer wet areas are breeding grounds for huge numbers of swarming insects like mosquitoes & black flies
many migratory birds feed on these insects
some herbivores are temporary summer visitors like caribou, deer, & moose plus the wolves that hunt them

33. Tundra Animals
some very well insulated creatures stay year-round, like arctic foxes, arctic hares, ptarmigan, & lemmings
although they may burrow to escape the cold, they are still active during the winter, often growing white fur to camouflage themselves in the winter snow

34. Threats to the Tundra very fragile biome
simple food chains can be easily disrupted and lead to the demise of the other species
land is easily damaged & slow to recover
until recently, most areas were undisturbed by human activities – until oil was discovered

35. Threats to the Tundra
oil exploration, extraction, & transport has been particularly disruptive to plants and animals
pollution from spills or leaks of oil & other toxic materials can lead to the poisoning of food & water sources

37. Compare