Biome characteristics

Quick Recap… As latitude gets

higher Less direct sunlight More seasonal

variation Extreme changes in

day / night at poles Lower temperatures

Geographic features

Biomes and Climate

Land locations characterized by distinct climate and vegetation.

Understanding the general characteristics of each biome leads to a general understanding of 1. the range of biodiversity on earth 2. how this biodiversity is distributed3. how all biomes are connected through

global climate patterns, energy flow, and chemical cycling.

Deserts Areas where evaporation > precipitation

Tropical Deserts

Tropical DesertsCover much of northern Africa (the

Sahara), and parts of the Middle East (Saudi Arabia)

Surface areas have little vegetation and are dominated by rocks and sand that are often blown about by windstorms

Extremely high daytime temperatures

Temperate Deserts

Temperate Deserts Found in the southwestern US (Mojave

and Sonoran Deserts) Receive more precipitation than tropical

deserts Characterized by patchy drought-

resistant shrubs, cacti, and other succulents

Have high daytime and low nighttime temps

Cold Deserts

Cold DesertsArea of the United States known as the Great Basin (Idaho, Utah), Gobi Desert in Northern China and Southern Mongolia

Vegetation is very sparseWinters are extremely cold

Desert soils Not suitable for

abundant growth due to slow decomposition rate due to lack of moisture.

Limiting factors: lack of rainfall, wind, lack of soil nutrients

LOW PRIMARY PRODUCTIVITY

Driest Desert of all

Atacama DesertTemperature inversion:

The cool air coming from the coast gets trapped below a layer of hot air. Since the desert is also at high altitudes the air can only hold small amounts of moisture.

Rain shadow impacts the Atacama Desert Blocking moisture from the Amazon

Polar GrasslandsArctic Tundra

Polar Grasslands: Arctic Tundra Found in the northern regions of North America

(Canada), Asia, and Europe Frigid, treeless plains that are covered with snow

and ice much of the year Vegetation is limited to low-growing grasses,

moss, and lichen Animals, such as Arctic foxes and wolves, have

adaptations such as thick coats of fur to survive the harsh climate and wide paws or hoofs to not fall into snow

Limiting factors: Permafrost, wind, lack of accessible water, temperature

Soil of the tundra Extreme cold forms permafrost-

underground soil in which captured water stays frozen for more than two consecutive years

Tropical GrasslandsSavannas

Tropical GrasslandsSavannas

Location: Found largely in Eastern Africa and also parts of South America and Australia

Characteristics: Warm temperatures and alternating

warm and dry seasons (will experience several months of little/no rainfall)

Large grazing herbivores such as gazelles, zebras, wildebeests

Plants have deep roots to utilize groundwater supplies

Limiting factors: Water availability

Temperate Grasslands(Tall grass and short grass prairies)

Temperate Grasslands Locations: found in midwestern and

Western US and Canada; also found in parts of South America and Russia

Rainfall determines whether it is a tall-grass or short-grass prairie

Winters are cold, summers are hot and dry

High winds and rapid evaporation promote fires in the summer and fall that eliminate other competing species

LIMITING FACTORS: winds, dry season.

As grasses die and decompose annually, large amounts of organic matter accumulates in the soil

This area is highly fertile and productive for crops

Chaparral

ChaparralTemperate Shrubland

Found along coastal areas of southern California, parts of the Mediterranean, and central Chile

Low growing evergreen shrubs and some small trees

Plants adapted to occasional fires, which encourage seed production in many plant species

Fires can increase nutrient availability in soil depending on intensity and duration

Chaparral Soils tend to lack structure

Tropical Rainforest

Tropical Rain Forest Location: along the equator- from 0-30 degrees

N and S in Brazil, Central America, Indonesia, Central Africa

Characteristics: Warm temperatures, high humidity and

heavy rainfall year round Dominated by broadleaf evergreen plants Distinct zones such as canopy, emergent,

sapling, and ground, provide habitat space for abundance of life

High Primary Productivity (Photosynthesis) and Biodiversity

Poor soil quality due to low concentrations of stored nutrients

Temperate Rainforest

Near oceanic climates along coasts Long growing seasons but do have

seasonal variation as well with short dry summer

Lots of precipitation in addition to coastal fog that adds moisture Adaptation of canopy trees, moss and

lichen is ability to absorb moisture from air.

Fertile soil due to decomposition

Nurse logs: fallen trees that break down and add nitrogen to soil

Chilliwack River Provincial Park, BC

Temperate Deciduous Forest

Temperate Deciduous Forest Location: Found between 30 and 60

degrees north and south latitudes Eastern US, most of Europe

Moderate temperatures that fluctuate with seasons

Dominated by a few species of broadleaf deciduous trees such as maple, beech, oak, and hickory

Trees go dormant in winter by dropping their leaves in the fall to prevent water loss

Slow rate of decomposition of leaves provides abundant leaf litter and nutrients stored in the soil

Evergreen Coniferous Forest (Taiga or Boreal forest)

Evergreen Coniferous Forest (Taiga or Boreal forest) Location: Just south of the Arctic

tundra In northern regions of Northern America (Canada), Asia and Europe

Characteristics: Winters are long, dry, and extremely

cold Dominated by a few species of conifers

such as pine, hemlock, cedar, and spruce.

Trees have small, waxy, needle-shaped leaves to survive the cold winters

Plant diversity is low

Needles of the conifer trees add acidity to the soil when decompose

Slow decomposition of needles; nutrient poor, acidic soils

Alpine *mountain* Biomes

Alpine *mountain* Biomes Mountains are places where dramatic changes in

altitude, climate, soil, and vegetation take place over a very short distance.

Above the snow line, temperatures are so clod that the mountain is almost permanently covered in snow and ice.

Because of steep slopes, they are prone to erosion They are important ecologically because they

contain majority of the Earth’s forests, are home to lots of biodiversity, and regulate Earths climate when ice/snow reflects solar radiation back into space (this is called having high albedo)

Reminder of Themes Climates are different because if

different air and water currents flowing over an unevenly heated planet

A biome map of earth can be drawn based on knowledge of the uneven heating of Earth

The organisms in each biome are uniquely adapted to them based on climate