Biology-H Chapter 43: The Biosphere

Climate

The average weather conditions in an area over a long period of time

What can climate refer to?

cloud cover, temperature, humidity, wind speed

Regional climates are influenced by factors that affect…

winds + ocean currents (intensity of sunlight, distribution of land masses + sea, elevation)

Why do seasonal changes in day length and temperature occur?

Earth is tilted on a 23 degree angle

What is the correlation between seasonal change in day length and latitude?

as the latitude increases, so does the day length

Which gets more sun energy: equatorial regions or those in higher latitudes?

equatorial regions

What do variations in energy from sunlight cause?

surface warming

What does surface warming drive?

global air circulation + rainfall patterns

What is the difference between warm air and cold air?

warm air is less dense and rises, and can hold more water than cooler air

What happens to the air at 30 degrees north/south

dry + cool air sinks, forming deserts

What happens to the air at 60 degrees north/south?

warm air risies and cool air sinks at poles

What happens to the air at the equator

warm moist air rises and flows to the north + south, releasing rain

Westerlies

prevailing winds that blow from west to east between 30 degrees and 60 degrees latitude in both hemispheres

Air masses

Large bodies of air with uniform temperature and humidity.

Are air masses attached to earth's surface?

no

What direction to winds in the Northern Hemisphere curve in?

right

What direction to winds in the Southern Hemisphere curve in?

left

Air masses move faster at the ___ and slower at the ___

equator; poles

What percentage of the Earth does the ocean cover?

71%

Where do warm and cold surface currents usually affect?

coastal climates

Water moves in ___ that distribute nutrients through marine ecosystems

currents

What direction do the surface currents move in the Northern Hemisphere?

clockwise

What direction do the surface currents move in the Southern Hemisphere?

counterclockwise

What were the currents like along the eastern coast of the continents?

deep + narrow and the moved away from the equator

What were the currents like along the western coast of the continents?

shallow + wide and the moved toward from the equator

___ affects ocean temp + sets major currents moving away from equator

sunlight

What does the difference of heating in the water and land cause?

monsoons

What are monsoons?

Wind that reverses direction seasonally

Mountains, valleys, + other land features affect…

climate

rain shadow

A dry area on the downwind side of a coastal mountain range.

Afternoon or evening: In coastal regions land is warmer than sea, so breeze blows onto shore

afternoon

Afternoon or evening: In coastal regions sea is warmer than land, so breeze blows onto sea

evening

Biomes

communities w/ similar climates + vegetation

Ghost forests

coastal forests dropped down into salt water and killed

What are the main determinants of the type of biome in a given region?

rainfall + temp

What influences biome distribution

soil

Properties of soils vary depending on…

types, proportions, + compaction of mineral particles + varying amounts of humus

humus

material formed from decaying leaves and other organic matter

Unrelated species in widely separated parts of a biome may have…

similar body structures by morphological convergence

morphological convergence

independent evolution of similar body parts in different lineages

Tropical Rainforests

climate regions found near the equator that have a lot of rainfall and high biodiversity

What type of trees usually dominate the tropical rainforest area?

evergreen broadleaf trees

How much rain usually falls in tropical rainforests?

130-200 cm annually (50-80 in)

How does the abundance of rain in a tropical rainforest affect the population?

it creates a highly productive and species rich biome

Tropical rainforests are the most…

productive, structurally complex, + biodiverse biome

In tropical rainforests, how do trees hinder the progress of photosynthesis (even if it happens year round)?

it blocks the sunlight

How is the soil in a tropical rainforest?

highly weathered, heavily leached, + poor nutrient reservoirs

What is an ongoing threat in tropical rainforests?

deforestation (especially in developing countries)

True or False: In a tropical rainforest, the rate of decomposition and mineral cycling is slow in the warm, moist environment

false

How is the temp. + humidity in the air of a tropical rainforest?

warm + moist

temperate deciduous forest

forest in a temperate region, characterized by trees that drop their leaves annually

What type of trees usually dominate the temperate deciduous forest area?

broadleaf trees that lose their leaves in fall and become dormant in winter

How does the soil and open canopy affect the plants in a temperate deciduous forest?

rich soil and canopy result in understory plants to flourish

What is an invasive species in the temperate deciduous forest?

earthworm, as it is efficient in breaking down nutrients to the point it affects the cycle

How much rain usually falls in temperate deciduous forests?

60-150 cm (20-60 in) annually

What is the pattern of trees in a temperate deciduous forest?

trees are dormant in the winter, but flower and put out new leaves in the spring

What is the climate like in a temperate deciduous forest?

cool winters + warm summers

Coniferous forests

a biome characterized by conifers, cone-bearing evergreen trees

Which type of tree can withstand harsher conditions, conifers or broad-leaved trees?

conifers

Where are conifer forests usually?

Asia, EU, + North America

What type of climate are coniferous forests usually in?

Winters are long, cold, + dry; most rain falls in cool summer

What are the other names for coniferous

boreal forest or tiaga

Coniferous forests are known as the most…

extensive land biome

Conifers are adapted to conserve water, specifically when…

ther is a drought or the grounds are frozen

Grasslands

A biome dominated by grasses and associated herbaceous plants

Where do the grasslands form?

interior of continents between deserts + temperate forests

What is the rain like in the grasslands?

enough rain to prevent desert forming, but not enough to support woodlands

Perennial grasses (main plants) have adapted to…

fire, grazing, strong winds, + infrequent rain

True or False: it is normal for the grasslands to catch on fire

true

What are North America's grasslands?

praries

What is the climate of a temperate grassland?

Warm in summer, cold in winter, w/ rains throughout yr

Savannas

Broad belts of grasslands w/ scattered shrubs + trees that lie between tropical forests + deserts

Climate of savannas

Temp. is warm yr round but rain is seasonal

Chaparral

Biome of drought-resistant fire-adapted shrubs

Climate of Chaparral

Hot, dry summers and mild, wet winters.

The rain in both chaparral biomes and savannas are…

seasonal

What can happen during a dry season in a chaparral biome?

lighting sparked fires can sweep through

Deserts

a barren region with little or no rainfall, usually sandy and without trees..

Climate of deserts

low humidity, large temp. shifts (hot in day + cold in night), + little topsoil

How much rainfall does a desert usually receive?

Where are deserts located?

30 degrees north and south, usually in rain shadows

What adaptations do desert plants have to reduce water loss?

Desert plants have adaptations such as spines that reduce water loss and deter herbivory.

How do cacti manage water during different seasons?

Cacti store water during the wet season and use it during the dry season.

What type of root systems do woody desert shrubs have?

Woody desert shrubs have extensive and efficient root systems.

What is the purpose of alternative carbon-fixing pathways in desert plants?

Alternative carbon-fixing pathways help minimize water loss.

desert crust

a community that can include cyanobacteria, lichens, mosses, and fungi that is layered over the soil

What is the purpose of the desert crust?

to hold soil in place

What is the role of cyanobacteria in a desert crust?

it fixes nitrogen + makes ammonia available for plants

Arctic Tundra

This biome supports a low number of plant species, receives little rain, and plants have shallow root zones due to permafrost and wet soil.

The arctic tundra is in the highest..

latitude northern biome

What type of plants are in the arctic tundra?

low, cold tolerant plants survive w/ brief growing pd

Where do arctic tundras form?

between former ice cap + belts of boreal forests in North Hem

Permafrost

Ground that is permanently frozen

What lies below the soil in an arctic tundra?

permafrost

How thich can permafrost be in an arctic tundra?

500m (1,600 ft)

How does permafrost affect decomposition?

it can slow or completely stop decomposition, leading to a build up in organic remains

Freshwater ecosystem example

Lakes, ponds, and rivers

Gradients in ___ affect the distribution of life in aquatic habitiats, meaning that they decide which organisms thrive where

light penetration, temp. + dissolved gases affect distribution

What happens if a freshwater ecosystem (namely a lake) is deep enough?

it will have zones that differ in physical traits + species composition

littoral zone

the shallow zone of soil and water in lakes and ponds where most algae and emergent plants grow