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