Biomes - Grasslands

Relation to moisture and temp.

Relation to location

Grasslands

Grasslands

• Characterized by land dominated by grasses rather than large trees or shrubs

Grasslands

• Two main types – – Tropical grasslands or savannas– Temperate grasslands

– Based on the names – which do you think has the better climate (not too hot, not too cold…..)

Savanna

• A grassland with scattered individual trees

• Make up almost ½ Africa, large areas of Australia, South America and India

Savanna

• Always warm or hot with annual rainfall 50.8 to 127 cm.

• Rainfall during only 6-8 months of the year, followed by drought

Drought

• “A long period of abnormally low rainfall, especially one that adversely affects growing or living conditions.”

http://www.thefreedictionary.com/

Savanna

• Soil has rapid drainage• There is only a thin layer of litter (raw organic matter)

http://envirosci.net/111/soil/the_soil.htm

Savanna

• Predominant vegetation is grasses and forbs – specific on the amount of precipitation and soil conditions

Savanna

• Trees – how do they adapt?

Drought

• Keep moisture in their trunks above ground.

• Baobab tree – can store up to 31,000 gallons of water in its trunk!

Drought

• Jackal berry tree (the seeds are often found in jackal poop) – also known as ebony

• Grow in termite mounds – the mounds help maintain moisture

Savanna

• Fire plays a critical role • During the dry season

(January) may be started by thunderstorms or poachers

Savanna fires

Fires

• Why would poachers set fires?

• Better to see their prey………

Fires

• Results in a feast for birds - come to the area to eat critters driven out by the fire

Fires

• Some animals survive in underground holes • Larger animals can run fast enough to escape

Fires• The grasses?

• Tops are burned but the deep roots remain unharmed.

• Grasses grow from the roots, they have large starch reserves and will start to grow again once there is moisture.

March

• Rains come• Grasses grow quickly, some

up to 1 inch in 24 hours!• Animals time their birthing

times to when food is plentiful (antelopes)

Animals

• African savannas:• Giraffes• Zebras• Buffaloes• Lions• elephants

Temperate grassland

• Grasses are the dominant vegetation• Few or no trees and shrubs• Temperatures vary more from summer to

winter• Less rainfall than in savannas

Temperate grasslands

• South Africa (veldts)• Hungary (puszta)• Argentina (pampas)• The former Soviet Union (steppes)• Central North America (prairies and plains)

Temperate grasslands

• Hot summers (up to 38°C) and cold winters (-30°C)

• Moderate rainfall: 50.8 cm (20”)- 88.9cm (35”) – Amount decides the types of grasses– Wetter area = taller grasses

• Soil: deep and dark, fertile upper layers– Thanks to the growth and decay of the grass roots– Grass roots also hold the soil together

What prevents growth of most trees and shrubs?

• Fires• Seasonal drought• Grazing by large mammals

What trees survive?

• Cottonwoods, oaks and willows• Grow in river valleys

Not just grasses

• Wildflowers! Including asters, blazing stars, coneflowers, goldenrods, sunflowers, clovers and wild indigos.

Grassland animals – North America

• Grazing animals (large, flat back teeth for chewing)

• American Bison• Pronghorn

Grassland animals - burrowers

• Prairie dogs• Owls • Badgers

Grassland animals - predators

• Hawks

Red Tailed Hawk

Grassland animals - predators

• Coyote

Grassland animals - predators

• Coyote – poop?• About the size and

shape of a cigar• Will contain feathers,

bone, fur, and insect parts.

• Will be black or grey in color

Grassland animals – prairie chicken

Grassland animals – prairie chicken

• Member of the grouse family

• Males have large yellow neck patch

• Territorial birds that do not migrate

Grassland animals – prairie chicken

• Booming – sound made by inflating their neck sacks

• Booming grounds - for mating rituals

Prairie Chicken

Prairie Chicken

• Study at Kansas State University– Females won’t have nests within ¼ mile of power

lines or 1/3 miles of an improved road

• Major threat - development!

Environmental Concerns?

• Few natural prairie regions remain• Rich dark soil = good farming!

Konza Prairie• Konza Prairie Long-term

ecological Research (LTER)• Research, education and

outreach program• Began in 1982• Focus on fire, grazing and

climatic variability

http://www.konza.ksu.edu/

Konza Prairie

• Co-owned by The Nature Conservancy and Kansas State University

Photo by Jim Richardson

Konza Prairie

• Divided into 60 watersheds• Different fire regimes and grazers (cattle and

bison)

http://www.thewildclassroom.com/biomes/grasslands.html