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Grassland Biome

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Grassland Biome

  1. 1. Barcibal, Rachiel M. De Chavez, Noeh Ella H. Garcia, Mateo A. Tañas, Ian Dave Charlie V. BY THE STUDENTS OF DWCC BIO - SCI
  2. 2. What is Grassland Biome? Grassland biomes are large, rolling terrains of grasses, flowers and herbs. Grasslands are characterized as lands dominated by grasses rather than large shrubs or trees The grasslands are dominated by grasses.There are other plants in them as well.
  3. 3. Interesting Grassland Biome Facts: Grasslands are also known as prairies, pampas, steppes, and savannas. Grassland biomes are normally situated between a forest and a desert. In fact, grasslands surround every desert in Asia. Twenty-five percent of the Earth is covered by the grassland biome. Tropical and temperate are the two kinds of grasslands. Grasslands are perfect for cropping and pasturing because its soil runs deep and is extremely fertile.
  4. 4. Tropical grassland biomes are located in the Southern Hemisphere while temperate grassland biomes are located in the Northern Hemisphere The grasses in the tropical grassland biome tend to be taller than that of the temperate because of the constant warm weather and additional rainfall it receives There are two seasons in the temperate grassland: the growing season and the dormant season. Animals that you can expect to find in a grassland biome are zebras, lions, wolves, prairie dogs, and foxes. The animal diversity is dependent upon the location of the biome.
  5. 5. There are two main divisions of grasslands: Temperate Grassland Tropical Grassland or Savannas
  6. 6. Savanna Savanna is grassland with scattered individual trees. Climate is the most important factor in creating a savanna. Savannas are always found in warm or hot climates where the annual rainfall is from about 50.8 to 127 cm (20-50 inches) per year. The soil of the savanna is porous, with rapid drainage of water. Savannas are sometimes classified as forests. The predominant vegetation consists of grasses and forbs . Savanna has both a dry and a rainy season. . Seasonal fires play a vital role in the savanna's biodiversity. In October, a series of violent thunderstorms, followed by a strong drying wind, signals the beginning of the dry season.
  7. 7. Three Types Of Savannas climatic savannas edaphic savannas derived savannas
  8. 8. Temperate grassland Temperate grasslands are characterized as having grasses as the dominant vegetation. Trees and large shrubs are absent. Temperatures vary more from summer to winter, and the amount of rainfall is less in temperate grasslands than in savannas. Temperate grasslands have hot summers and cold winters.  Rainfall is moderate.  The soil of the temperate grasslands is deep and dark, with fertile upper layers.
  9. 9. Temperate grasslands can be further subdivided Prairie Steppes
  10. 10. Prairie grasslands with tall grasses
  11. 11. Steppes grasslands with short grasses
  12. 12. West Central East 30 20 10 PrecipitationperYear(inches) Short Grass Mixed Grass Tall Grass GrassHeight(feet) 1.510 Correlation between precipitation and prairie grass height.
  13. 13. Earlier you were introduced to the term “forbs”. In late spring Grasslands have a diversity of them. They’re not as dominant as grasses but in this photograph you can certainly see that they’re important.
  14. 14. Prairie Dock ( 6 to 8 feet tall)
  15. 15. Purple Coneflower
  16. 16. Butterfly Weed
  17. 17. ........Photographs to FileFlower PhotoDSC01200.JPGto FileFlower PhotoDSC01200.JPG Black-eyed Susan
  18. 18. Gray Coneflower
  19. 19. Blazing Star Goldenrod
  20. 20. Grasses are very productive. They support s great diversity of primary consumers.
  21. 21. Several species of toads inhabit grasslands to feed on the bounty of grass eating insects. This is the Great Plains Toad
  22. 22. Grassland squirrel species are numerous. There are no trees for them to climb. They’ve adapted by burrowing. They’re called ground squirrels. This is Franklin’s Ground Squirrel.
  23. 23. This is the Thirteen-lined Ground Squirrel. It has a great scientific name, Spermophilus tridecimliniatus. Sperm = seed; philus = to love; tri = 3; deci = 10; lineatus = lines. Translation – “13 lined seed lover” This species has invaded Ohio where grasses are cut low in big open spaces like parks and golf courses. Some of you may have encountered it at Joyce Park in Fairfield where it inhabits the low grassy soccer fields.
  24. 24. Winter conditions in the Grasslands are far too harsh for ground squirrels to remain active. They are hibernators. They have the ability to lower their body temperature but maintain it above freezing. Their heart slows from 150 beats per minute to perhaps five beats and they draw one or two breaths per minute. They will maintain this lowered metabolic rate for 5 or 6 months until warm weather returns. They eat grass seeds all summer to fatten up. This fat has to last them through the winter.
  25. 25. Ground squirrels have several predators. This Badger’s long, thick front claws and short, powerful front limbs allow it to dig ground squirrels right out of their burrows.
  26. 26. He’s either being aggressive or smiling for the camera.
  27. 27. Prairie Dogs are also ground squirrels. Unlike other ground squirrel species, Prairie Dogs are social. They live in colonies called Prairie Dog Towns. A few stand as sentinels while the others graze on grass seeds. When predators approach, the sentinels “bark” to warn the others. The bark, hence the name Prairie Dog. Cattle ranchers hate these little rodents because they dig burrows that their cattle step into, breaking their legs. To combat this, ranchers set out poisoned seeds to kill off entire Prairie Dog Towns.
  28. 28. This is a Black-footed Ferret. Their sole food source is Prairie Dogs. As ranchers eliminated Prairie Dog towns en masse, the Black-footed Ferret’s population declined dramatically. At one point there were only 21 of them left. It is now a federally endangered species and although its gene pool is limited, the species has made a recovery. Prairie Dog towns are now protected as a means of protecting this little weasel.
  29. 29. Just because there are no trees, doesn’t mean there are no owls. These are Burrowing Owls. They inhabit Short Grass Prairies where they can stand on the edge of the Prairie Dog burrow they take over to watch for the small rodents they eat. These owls do not (cannot) dig their own burrows. While most owls are nocturnal, this species is diurnal.
  30. 30. Food chain in action. This GolFood chain in action. This Golden Eagle (much larger than a Bald Eagle) is about to capture a Red Fox. The fox feeds on rodents like ground squirrels. Short Grass Prairies are widely used for sheep ranching. This bird of prey is not a friend of sheep ranchers. It frequently captures and carries off lambs. den Eagle (much larger than a Bald Eagle) is about to capture a Red Fox. The fox feeds on rodents like ground squirrels. Short Grass Prairies are widely used for sheep ranching. This bird of prey is not a friend of sheep ranchers. It frequently captures and carries off lambs.
  31. 31. Prairie birds are species that require wide open spaces. This is a Meadow Lark. It lives in pastures in Ohio but if the pasture undergoes succession and trees move in, the Meadow Larks leave by the time the trees are knee high. This species is an insectivore. It migrates to Central America during winter when insects are unavailable in the North American Grasslands.
  32. 32. Along with Badgers, Coyotes are important grassland animals because they’re proficient diggers. Their abandoned burrows are used by many other species.
  33. 33. Prairies are riddled with shallow wetla Prairies are riddled with shallow wetlands called pothole lakes. They are essential habitat for tens of thousands of ducks. These are duck species that feed on the abundant seeds of grasses and forbs.
  34. 34. Grasslands are home to many reptiles. This is a Prairie Rattlesnake. Biologists believe rattlesnakes evolved in the grasslands where the dry, overlapping skin on their tail that forms the rattle gave them the ability to warn hooved animals such as Grasslands are home to many reptiles. This is a Prairie Rattlesnake. Biologists believe rattlesnakes evolved in the grasslands where the dry, overlapping skin on their tail that forms the rattle gave them the ability to warn hooved animals such as bison, of the snake’s presence. Domestic cattle react the same way wild cows (bison) react to the buzzing of a rattlesnake’s rattle. Both stop in their tracks, then move backwards away from the source of the sound. This snake species eats ground squirrels. bison, of the snake’s presence.
  35. 35. Grasslands are very productive. On each continent there are large grazers that help control the grass populations. In North America it’s the Bison. In Africa Wildebeests and Zebras fill that niche. In Australia, Kangaroos are the grazers. These animals are unrelated but have evolved the tools to accomplish the same job. They are called ecological equivalents.
  36. 36. This is a Jack Rabbit. It’s actually a hare, not a rabbit. Rabbits give birth to blind, naked, helpless babies. Female hares have a longer pregnancy which allows the embryos to develop further before birth. Baby hares are born fully cloaked in fur, their eyes and ears are open, and they have a full set of teeth. They nurse from their mother only for a couple of days to build their immune system before setting off on their own. With few places to hide, the giant ears allow Jack Rabbits to hear potential predators and in the heat of the day, they work like radiators to cool the hare’s blood. Notice how well the color camouflages the hare with the grasses. These are big. 10 to 12 pound is normal. Our local cottontail rabbits might weigh 2 pounds.
  37. 37. Grassland ecology is maintained by fire. During summer, after the grass leaves dry, lightning strikes set the plants ablaze. If these fires don’t happen, the dead grasses from previous years for a dense mat. If this mat becomes too thick and dense is becomes difficult for new grasses to grow up through it. Likewise small animals get tangled in the mat of vegetation. When fires burn the grass mat, the ashes return their nutrients to the soil. Prairie fires burn fast. They’re not like forest fires. A few acres can burn in a couple of minutes. Birds obviously can fly away and larger mammals can move away from it. Small mammals, reptiles, and other small mammals simply retreat into their burrows. Since heat rises, no harm is done to those taking refuge below ground. Plants cannot flee the fire. During the evolution, grassland plants had to adapt to it.
  38. 38. Prairie plants are adapted to fire by having root systems that grow deep into the soil. Roots remain alive even when the leaves dry up and die or burn away. New leaves sprout from those roots to re- establish the grassland vegetation.
  39. 39. Enormous agricultural corporations have purchased land that was once native prairie and with their financial resources they use machines to do the work that thousands of humans could do. The North American Grasslands were acquired as the Louisiana Purchase. In this photo, corn is being harvested. . Grassland soils are thick and rich. The gross primary productivity of this biome is very high compared to others. In order to provide nutrients and minerals for such productive plants, the soil must be rich. Unfortunately man learned about the soils’ productivity and recognized that because it is so good for native prairie grasses, it is probably just as suitable for non- native grasses. About 99% of North American Grasslands have been converted to agriculture. Corn and wheat (both grasses) are farmed extensively where there once were native prairies. Lost with the prairies is much of the diverse plants and animals that inhabited them.