TERRESTRIAL BIOMES

Large-scale environments that are distinguished by characteristic temperature ranges and amounts of precipitation with specific set of biotic and abiotic features

Biomes

In his pioneering work on plant geography found a close relationship between climate and vegetation in geographically disjunct regions, exhibiting climatic similarity in similar regions

Alexander van Humboldt

Who developed the biome concept and what is it about?

Developed by Schimper (1903)

• based on the idea that similar climates select for similar plant forms independent of differences in history

The land biomes of the world are controlled by?

The land biomes of the world are controlled by climate

Is the characteristic condition of the atmosphere near the earth’s surface at a certain place on earth. It is the long-term weather of that area (at least 30 years)

climate

Two of the most important factors determining an area’s climate are?

Two of the most important factors determine an area’s climate are air temperature and precipitation

What are Whittaker’s biome-types?

1. Tropical rain forests

2. Tropical dry forest

3. Savanna

4. Temperate grassland

5. Desert

6. Mediterranean Shrubland and Woodland

7. Temperate forest

8. Boreal forest (Taiga)

9. Tundra

• the most biodiverse terrestrial biome

• Have high net primary productivity

• Cover about 6-7% of the earth’s land surface

• Found in regions close to the equator

Tropical rain forests

• warm and humid all year long

• Always moist and lacking temperature seasonality

• Average temperatures ranging from 20C to 34C

• Annual rainfall ranges from 125-660 cm (50-200 in) with considerable seasonal variation

Climate: Tropical rain forests

• highly acidic

• The type of clay particles present in tropical rainforest has a poor ability to trap nutrients and stop them from washing away

• Lack’s minerals and contains little remains of dead plants and animals

• Decomposition is rapid on warm wet soil

• <1cm of topsoil; not very fertile

• Mycorrhizae help gather nutrients

Soil: Tropical rainforest forests

• characterized by vertical layering of vegetation and the formation of distinct habitats for animals within each layer

• Dominated by a continuous canopy of tall evergreen trees rising to 30-40 m

• Occasional emergent trees rise above the canopy to heights of 55 m or so

• Climbing lianas, or woody vines, and epiphytes, plants that grow on the branches of other plants and are not rooted in soil are prominent in the forest canopy itself

Vegetation: Tropical rainforest forests

• very tall trees that rise above the canopy

• Gets lots of sunlight and strong winds

• Birds and insects are common here

The emergent layer

• thick, leafy roof formed by tall trees

• Blocks most sunlight from reaching lower layers

• Many animals like monkeys and birds live here

The canopy

• layer above the forest floor

• Small plants and young trees grow here

• Very shady and humid

The understory

• bottom layer

• Very dark, little sunlight

• Home to decomposes like fungi and insects

The forest floor

Plant adaptations: What is the major limiting factor of tropical rain forests?

Sunlight is a major limiting factor

• shallow, wide roots since soil is so thin and poor in nutrients

• Little sun reaches the floor

• Plants grow in layers (canopy receives most light)

Examples of plants found in tropical rainforest forest

Ex: Bougainvillea and Bangul Bamboo

What are the dominant wildlife included in the animal life of tropical rainforest forests

Dominant wildlife includes:

• herbivores ( sloths, tapirs, and capybaras)

• Predators (jaguars); anteaters; monkeys

• Birds (toucans, parrots, and parakeets)

• Insects (butterflies, ants and beetles)

• Piranhas and other freshwater fishes

• Reptiles (frogs, caymans, boa constrictors, and anacondas)

What are the other animal adaptations of tropical rain forest animals?

• Many animals are specialists and require special habitat components to survive (Silvery Gibbon)

• Camouflage is common (Wagler’s pit viper)

• Many symbiotic relationships

• Live in different level of canopy (Slender Loris)

• usually located between 10 to 25 latitude

• Heavily settled by humans within each layer extensive clearing for agriculture

Tropical dry forest

• climate more seasonal ( with a pronounced dry season during part of the year) than tropical rainforest

• Responds to the rhythms of the annual solar cycle which drive the oscillation between wet and dry seasons

• Characterizes by little change in temperature (alternation of wet and dry season)

Climate: Tropical dry forest

• soils generally less acidic and richer in nutrients than tropical rainforests

• The annual pulses of torrential rain make the soil highly vulnerable to erosion, particularly when deforested and converted to agriculture

Soil: Tropical dry forest

• height of trees is correlated with average precipitation. Tallest trees are found in wettest areas

• Over 50% of trees are evergreen in wetter areas

• Have deciduous species of trees that lose their leaves at the onset of the dry season

• Many plants produce animal-dispersed seeds

Vegetation: Tropical dry forest

• many birds, mammals, and even insects make seasonal migrations to wetter habitats along rivers or to the nearest rainforest

• Many animals reduce their need for water by entering long periods of inactivity called estivation

Animal life: tropical dry forest

• found in parts of the tropics where there is not enough rainfall throughout the year to create a rainforest

• Transitional between tropical rain forest and desert

• Located closer to the equator than prairies

• Grasslands with scattered trees and are found in Africa, South America, and northern Australia

Savanna

• rainy and dry season

• With seasonal drought

• Rain comes in summer accompanied by intense lightning starting fire

Climate : Savanna

• soil layer with low water permeability

• Impermeable subsoil keeps surface soil waterlogged during the wet season

• Nutrients in soil are present mainly due to a thin layer of humus

Soil: savanna

• grasses with few scattered trees

• Fire and grazing undoubtedly play important roles in maintaining the character of the ??? Biome

• The woody trees are very limited and usually do not get very tall

Vegetation: savanna

• grows in tufts

• Resistance to drought

• Many plants have thorns and sharp leaves to protect against predation

Plant adaptations: savanna

Ex: whistling thorn, umbrella thorn, kangaroos paws

• adapt for short rainy season-migrate as necessary

• Reproduce during rainy season-ensures more young survive

Animal adaptations: savanna

Ex: zebras, chacma baboon

• largest biome in North America

• The major manifestations are veldts of South Africa, the puszta of Hungary, the pampas of Argentina, the steppes of the former Soviet Union and the prairies of Central America

Temperate Grassland

• hot summers and cold winters

• Rainfall is moderate (300-1000mm). the amount of annual rainfall influences the height of the grass land vegetation with taller grasses in other regions

• Maximum precipitation occurs in summer

Climate: Temperate grassland

• the soil is deep and dark with fertile upper layers

• It is nutrient-rich from the growth and decay and many branched grass roots. The rotted roots hold the soil together. The soil is fertile because of the remains of plants and animals and dried leaves of plant fell on the ground

Soil: Temperate grassland

Why is the soil fertile in temperate grassland?

• soils are fertile because the subsurface of the soil is packed with the roots and rhizomes (underground stems) of these grasses

• The roots and rhizomes act to anchor plants into the ground and replenish the organic material (humus) in the soil when they die and decay

• the dominant vegetation tends to consist of grasses

• The treeless condition is maintained by low precipitation, frequent fires, and grazing. The vegetation is very dense due to fertile soil

Vegetation: Temperate grassland

what are the plant adaptations of the Steppe?

• most abundant are plants called Bunch grasses, fine bladder grasses that grow in clumps to preserve water

• Ex: Tumbleweed, Sweet Vernal

What are the adaptations of Prairie plant adaptations

• sod-forming grasses that won’t dry out or blow away in wind

• Ex: Fleabane, Buffalo grass

• supported huge herds of roving herbivores (bison, pronghorns and wild horses)

• Herbivores band together in social groups in open grasslands just like predators in steppe and prairie wolves

• Smaller animals such as grasshoppers and mice are more numerous than the large herbivores

Animal life: Temperate grassland

What are the adaptations of steppe animals?

What are the adaptations of Prairie animals?

• occupy 20% of land surface

• Low species diversity

• Low water vapor content

• Evaporation and transpiration exceed precipitation

Desert

• very hot and dry

• Receive less than 25 cm of rain per year while some receive NO precipitation at all during one year

• Receive more than twice as much incoming solar radiation as humid regions

• Often undergo large shifts in temperature during the course of a day

Climate: desert

• sandy, dry and loose; contains minerals like calcite

• Course-textured, shallow, rocky or gravely with good drainage and have no subsurface water

• Little to no topsoil due to high winds

• Minerals not deep in soil

• Too dry for decay (like OM)

Soil: desert

What are the plant adaptations of desert

What are the animal adaptations of desert?

What are the 4 major types of desert?

• the seasons are generally warm throughout the year and very hot in the summer. The winters usually bring little rainfall

Hot and dry desert

What are the 4 major North American the hot and dry desert?

How is the vegetation in hot and dry desert?

• vegetation is very rare

• Plants are almost all ground-hugging shrubs and short woody trees. All of the leaves store nutrients

• Some of the adaptations in this case are the ability to store water for long periods of time and the ability to stand the hot weather

What animals are included in hot and dry desert?

• animals include small nocturnal carnivores

• The dominant animals are burrowers. The animals stay inactive in protected hideaways during the hot day and come out to forage at dusk, dawn or at night, when the desert is cooler

• characterized by cold winters with snowfall and high overall rainfall throughout the winter and occasionally over the summer

• Have a short, moist and moderately warm summers with fairly long, cold cactus winters. Usually occur in Antarctic, Greenland and Nearctic realm

Cold desert

How is the vegetation in cold desert?

• there are no trees and shrubs present at all. The only vegetation able to survive are liverworts, lichens and mosses.

• Few amphibians, reptiles or mammals are native to cold deserts, but humans have introduced some animals, such as rats and mice

• Native fauna includes spiders, earthworms, beetles and the Arctic fox

• summers are moderately long and dry and like hot deserts

• Winters normally bring low concentration of rainfall

• Summer temperatures usually average between 21-27C does not go above 38C and evening temperatures are cool at around 10C

Semiarid desert

What are the major deserts in Semiarid desert?

Major deserts of this type include the sage brush of Utah, Montana and Great Basin

• The cool winter’s coastal deserts are followed by moderately long, warm summers

• The average summer temperature ranges from 13-24C winter temperatures are 5C or below

• These deserts occur in moderately cool to warm areas such as the Nearctic and Neotrophical realm. A good example of this Atacam and Chile

Coastal desert

What is the maximum annual temperatures of coastal desert?

The maximum annual temperatures are about 35C and the minimum is about -4C

• occur in all continents except Antarctica

• Most extensive around Mediterranean Sea; extend from California into northern Mexico; also found central Chile, southern Australia, and Southern Africa

• Chaparral (western North America); mayoral (Mediterranean); fynbos (South Africa); mallee (Australia)

Mediterranean shrubland and woodland

• cool and moist during fall, winter and spring

• Summers are hot and dry

• Usually get more rain than deserts and grasslands but less than forested areas

• The combination of dry summers and dense vegetation, rich in essential oils, creates ideal conditions for frequent and intense fires

Climate: Mediterranean shrubland and woodland

• generally low to moderate fertility and fragile

• Soil erosion can be severe following fire

Soil: Mediterranean shrubland and woodland

• fire coupled with overgrazing has stripped the soil from some Mediterranean woodland and shrubland landscapes

Describe the vegetation of Mediterranean shrubland and woodland

• dense low plants that contain flammable oils make fire a constant threat

• Trees and shrubs are evergreen and have small, tough leaves, which conserve both water and nutrients

• Sclerophyllous (hard-leaved) vegetation

• Most herbaceous plants grow during the cool, moist season and die back in summer, avoiding both drought and fire

Describe the animal life of Mediterranean shrubland and woodland

• animals tend to be browsers

• Some prominent wildlife are coyotes, wild goats, mule deer, and the Mediterranean gecko

• Camouflage is common in exposed shrubland

• found mid-latitude regions

• Harbor ancient trees

• The second largest terrestrial biome

• Most of the human population lives in this biome

Temperate forest

• temperatures are not extreme

• Annual precipitation averages from 650-3000mm

• Receive more winter precipitation

Climate: temperate forest

• soils are usually fertile

• Most fertile develops in deciduous forests with generally neutral or slightly acidic and rich in OM and inorganic nutrients

Soil: temperate forest

• lower diversity of trees compared to tropical forests

• Vertically, stratified (herb layer, shrub layer, shade- tolerant understory trees and canopy)

• More sunlight reaches the ground compared to a rainforest so more ground dwelling plants are found on the floor

• May either be deciduous (more dominant) or coniferous

Vegetation: Temperate forest

• birds, mammals , and insects make use of all the forest strata

• Fungi, bacteria, microscopic invertebrates consume large quantities of wood stored on the floor of old-growth temperate forest

• The activities of these organisms recycle nutrients

Animal life: temperate forest

• found only in northern hemisphere (northern parts of Alaska, Canada, Asia and Europe)

• The NPP is lower than that of temperate forests and tropical wet forests

• The above- ground biomass is high because these slow- growing tree species are long-lived and accumulate a large standing biomass over time

Boreal forest (Taiga)

• warm, and rainy summers

• Very long and cold winter lasting to about half a year; precipitation is in the form of snow about. 60cm

• Below -20C in winter and about 15C in summer

Climate: boreal forest (taiga)

• soil is not fertile. It takes very long for needlelike leaves to decompose and decomposition is very slow in cold weather

• A layer of now covers the ground during much of the year

• Soil beneath the snow is grayish on top and brown below and lacks minerals needed by plants to grow

Soil: boreal forest (taiga)

• mostly contains evergreen coniferous trees like pines, spruce, and fir, which retain their needle shaped leaves year-round

• Evergreen trees can photosynthesize earlier in the spring than deciduous trees because less energy from the sun is required to warm a needle- like leaf than a broad leaf

Vegetation: boreal forest (taiga)

What are the plant adaptations of boreal forests?

• coniferous (needle-bearing) trees are abundant

• Roots long to anchor trees

• Needles long, thin and waxy (low sunlight and poor soil keeps plants from growing on forest floor)

• Ex: Balsam Fir

What are the animal adaptations on boreal forest?

• adapt for cold winters

• Burrow, hibernate, warm coat, insulation etc

• Ex: great grey owl, moose, deer, mosquito, bear, hares, porcupine, squirrel

• found north of the arctic circle

• Treeless plain

• Coldest biome

• “Permafrost”

Tundra

• extremely cold and dry biome

• Usually receives NO more precipitation than a desert biome (<25 in/year)

• Short growing season

• Limited sunlight

• Average temperature is. 23F or 5C

Climate: Tundra

• ground covered with little snow

• Below the surface soil is permanently frozen (permafrost)

• During summer, the top layer of soil thaws, but the rest remains frozen

• Decomposition is very slow because of the extreme cold

Soil: Tundra

• biodiversity of plant is very low

• Lichens, mosses and short shrubs are dominant

• Plants are dwarf, prostrate woody shrubs grow low to the ground to gain protection under the winter blanket of snow and ice

Vegetation: Tundra

What are the plant adaptations of tundra?

• growing close to the ground

• Having shallow roots to absorb the limited water resources

• Trees grow less than 1 m high

• Ex: Reindeer lichen, cottongrass

Many birds that occur in Arctic tundra are?

Many birds that occur in Arctic tundra are migratory (summer)

The main animal population in the Arctic tundra consists of?

The main animal population in the Arctic Tundra consists of reindeer, polar bears, arctic fox, arctic hare, snowy owls, lemmings and musk ox

Animals living in the alpine tundra are?

Animals living in the alpine tundra are, pikas, marmots, mountain goats, sheep elk, grouse like birds, springtails, beetles, grasshoppers, and butterflies

Describe the animal adaptations of tundra

What are the types of tundra

• a layer of permanently frozen subsoil (permafrost) exists consisting mostly of gravel and finer material

• The growing season ranges from 50-60 days

The Arctic tundra

Where is the Arctic tundra located?

Located between the North Pole and Coniferous forest or taiga region. It is extremely cold temperatures and land that remains frozen year-round

• North America- Nothern Alaska, Canada Greenland, Northern Europe- Scandinavia Northern Asia- Siberia

• the growing season is approximately 180 days

• Very windy

• Typically covered in snow for most of the year

Alpine tundra

Where is the alpine tundra located?

Located on mountains throughout the world at high altitude where trees cannot grow

• North America-Alaska, Canada, U.S.A and Mexico

• Northern Europe- Finland, Norway, Russia, and Sweden

• Asia- Southern Asia (Mt. Himalayan) and Japan. (Mt. Fuji)

• Africa- Mt. Kilimanjava

• South America- Andes Mountains

Why is the conservation and preservation of biomes should be a major concern to all?

Because we share the worlds with many other species of plants and animals, we must consider the consequences of our actions. It is important to preserve all types of biomes as each houses many unique forms of life