Terrestrial Biomes - Forests, Deserts and Grasslands.
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Transcript of Terrestrial Biomes - Forests, Deserts and Grasslands.
Terrestrial Biomes - Forests, Deserts and
Grasslands
What is a biome?
Biome – a major ecological community type
Conifer forestDeciduous forestTemperate forestTropical rainforestShrublandGrasslandDesertTundraTaiga
Coniferous Forests
Long, extremely cold winters with 6-8 hours of sunlight
Short, cool summers with 19 hours of sunlight
Annual precipitation (both rain and snow) 14-30”.
Coniferous Forest - Plants
Primarily conifersAlso called evergreensStiff needles instead of leavesDeep green colorShed their needles slowlyCone shaped seed cases
Cones must open to release the seeds
Coniferous Forests – Animals
Populations are scarce, mostly herbivores
Large herbivoresReach high into trees or dig into deep snow
Seed eatersPull seeds from conesEat fallen seeds on the ground
Carnivore size variesLynx, wolf
Temperate Forests - Facts
Also called deciduous forestsdrop leaves completely every winter
Found in eastern N. America, western Europe and eastern AsiaLong, very warm summersCold winters (not severe)Forest soil is thick and very fertile
Deciduous Forest - Plants
High biodiversity from canopy to ground
Canopy is primarily deciduous trees
Includes maples, birches and oaks
Plant Adaptations
Leaves – broad and flat for maximum photosynthesis
Excess carbohydrates made during photosynthesis is stored in the sap
Leaves are dropped in winter
Plant Adaptations - Seeds
Seeds can’t grow in shadow, so they must be dispersed.Done by:
Brightly colored fruitHard shellsWings
Deciduous Forest - Animals
High biodiversityIncludes:
BirdsSmall and large herbivoresSmall and large carnivores
High degree of resource partitioning
Tropical Rainforests - Facts
Found along or near the equatorAmazon River (S. America), Indonesia, Africa and Central America
Currently covers about 2% of the earth’s land surface
Believed to be the major source of the world’s fresh air
Tropical Rainforest - Climate
Hot all year…very little variation in temperatureNo true seasonsHumidity is always highRains almost every day, usually in the afternoon.Annual precipitation – 80-160”
Rainforest Vegetation
Trees are very tall (180’) with broad, evergreen leaves.
Mahogany
Leaf cover is very dense, restricting growth of competing plants
Roots are shallow to increase absorption of soil nutrients
Rainforest Animals
Highest biodiversity in the world
Contains at least ½ of the entire world’s plant and animal species
Species are highly stratified. There is very little competition between species.
Most animals live in the canopy because of the presence of sunlight.
Shrublands - Facts
Shrublands usually get more rain than grasslands and deserts but less than forests.Rainfall is between 7.8” to 39”.Rain is unpredictable, varying from month to month, with distinct dry and rainy seasons.Found around the Mediterranean Sea, SW Africa and Australia and Mexico.
Shrubland - Plants
Mostly shrubs and short trees.Grasses and short plants grow between the shrubs.
Many plants have small needle-like leaves or waxy coatings on the leaves to help them adapt to drought like conditions during the dry season.
Shrublands - AnimalsAnimals have adapted to the heat by only coming out in the early morning, late afternoon, or night to find food and hunt.
Many get their water directly from their food.
Deserts - Facts
“An area where evaporation exceeds precipitation”.
Make up about 30% of earth’s land surface.
Daytime temperatures can be <30 and >100 oF.
Soils are hard, dry and sandy with few nutrients.
Most are found on either side of the equator.
Desert
There are three categories of desert based on:
temperature rangeamount of precipitationvegetation/animal species
Tropical desertsDriest places on earth (<5” rain/year)
Temperate desertsSometimes caused by rainshadow effect
Cold desertsAlso called interior deserts
Desert Plants
Called xerophytesAdaptations:
Require few nutrientsRequire little waterLeaves are small, thick and waxy or have become spinesCan expand to hold extra water
Desert Animals - Adaptations
Usually nocturnalUsually smallHard shells or thick skinsPoisonousHibernate or enter suspended animation during droughtsCan conserve water
Tropical Grassland
Also called savannaCover large areas of Africa, South America and AustraliaWarm weather year round3 Seasons – 1 dry season, 1 rainy season and 1 wet season Mostly grasses with individual stands of trees and shrubs
Savanna - Animals
Many species of small animalsRodents, birds
Large populations of herbivoresAfrica – Gazelles, wildebeestAustralia - kangaroo
Savanna Animals – Herbivore Adaptations
Evolution of eating strategies to minimize competition
By food typeBy migrationBy food height
Giraffes Elephant Zebra Gazelle Wildebeest
Savanna Animals – Carnivore Adaptations
Eat both small and large animalsSmall animals require more individuals per meal
Hunting strategyCooperative – lionSolo – cheetahAmbush – lion Pursuit – cheetahScavenge – hyena, vulture, eagle
Temperate Grasslands
Vast expanses of grasses without treesSummer hot/dry. Winter bitterly cold.Wildfires common in summer and fall.Soils are thick and fertile.Found in interior of N. and S. America, and China
Temperate Grasslands - Plants
Similar to tropical grassland plantsEvolved to fit the environment
Drought tolerantExtensive root systemsReproduce by seed or rhizomeRegrow from bottom – very important to survival
Temperate Grasslands - Animals
Complex food webs
Animals are mostly small
Herbivores – prairie dogs, squirrelsCarnivores – coyotes, snakes, foxes
Large carnivoreseliminated by hunters and farmers
Arctic Tundra
Also called polar grasslands because of their location near the North Pole
Winter is bitterly cold, with ice, snow, high winds and weeks of total darkness.
Arctic Tundra - Facts
Treeless. Covered with a thick, spongy layer of low-growing plants
Summer lasts 2 months. Gets warm enough to melt the upper soil layer allowing plant growth.
Arctic Plants
Small, low–growing with most of the plant underground as roots and bulbs
Thick, waxy leaves above ground
Some dehydrate to prevent freezing
Do all of their growing, blooming and seeding in the 2 month long summer.
Tundra - Animals
Temporary residents Migrating/nesting birdsMigrating herbivores and carnivores
AdaptationsThick coatsLive undergroundSmall sizeDon’t hibernate