Biomes and Ecosystems Overview

Biomes

• The Earth's major ecosystems are referred to as biomes.
• Biomes are classified according to the characteristic vegetation within them.
• Temperature and precipitation are the two most significant factors affecting the location and distribution of terrestrial biomes.
• Biomes are important to human survival and wellbeing because life can only exist where there is moisture, sunlight, and nutrients.
• Organisms (including humans) depend on each other for survival.

Ecosystems

• An ecosystem is a community of organisms that interact with each other and their non-living environment.
• Ecosystems can be divided into two groups - Aquatic (those associated with water) and terrestrial (those associated with land).
• Ecosystems exist on a local scale whereas biomes occur on a global scale.

Biotic & Abiotic Factors

• Every environment is made up of biotic and abiotic factors which interact with one another.
• Biotic factors are the living parts of the ecosystem, such as plants, animals, and bacteria.
• Abiotic factors are the nonliving parts of the environment, such as air, minerals, temperature, and sunlight.
• Organisms require both biotic and abiotic factors to survive.

Latitude & Biomes

• Temperature is influenced by latitude because of the angle of the Earth from the sun.
• Biomes located in the high latitudes, farthest from the Equator like polar and tundra receive the least amount of sunlight and have lower temperatures.
• The desert biome is most commonly found around the line of the Tropic of Cancer.
• The important line of latitude of the tropical rainforests are found around the equator.

Biosphere

• The biosphere encompasses all living things (including animals and plants), including their waste and dead remains.

Migration & Immigration

• Migration is the movement of people.
• Immigration is moving to another country.
• Many people are forced to cross international borders to escape persecution or to flee a natural disaster. These people are called refugees.

Push & Pull Factors

• Push factors are reasons why people want to leave a place or escape from a particular situation. Some examples are: war, lack of food, persecution, lack of resources and services.
• Pull factors are reasons why people are attracted to migrate to another region or country. Some examples are, more jobs/employment opportunities, more income, better living conditions, better climate, and better education.

Median Age

• Median age is the average age.

Maps & Charts

• Chloropleth maps show the geographic distribution of different species.
• Synoptic charts are the scientific term for weather maps.
• Synoptic charts provide information on the distribution, movement, and patterns of air pressure, rainfall, wind, and temperature.
• Cold front- Represented by blue lines with triangles. They occur when cold air pushes into a region of warmer air, often leading to sudden weather changes like thunderstorms.
• Warm front- Depicted by red lines with semicircles. They form when warm air moves over cold air, typically resulting in gradual weather changes and prolonged precipitation.
• Stationary front- Shown as alternating red and blue lines. These occur when two air masses meet but neither advances, leading to extended periods of cloudy and rainy weather.
• Occluded front- Illustrated by purple lines with alternating triangles and semicircles. They happen when a cold front overtakes a warm front, often resulting in complex weather patterns.
• Isobars: Lines indicating equal atmospheric pressure. Closely spaced isobars signify strong winds, while widely spaced ones indicate lighter winds.
• Latitude: the distance north or south of the equator
• Longitude: the distance west or east of the Greenwich meridian

Megacities

• Megacities are continuous urban areas with a population of 10 million people.
• People move from rural areas to megacities seeking opportunities.

Sustainable Cities

• Sustainable energy sources like solar and local power
• Urban growing
• Net zero - Cutting carbon emissions to a small amount of residual emissions that can be absorbed and durably stored by nature and other carbon dioxide removal measures, leaving zero in the atmosphere.

Slums

• Slums are densely populated areas of substandard housing, usually in a city, characterized by unsanitary conditions and social disorganisation.

Urban, Rural, & Suburban

• Urban areas are places of high populations and high density, characterized by their built-up infrastructure.
• Rural areas have low populations and density whilst maintaining a lack of large infrastructure.
• Suburban areas have lower density and separate residential and commercial areas from one another.

Population Pyramids

• Expansive pyramids depict populations with a larger percentage of people in younger age groups.
• Constrictive pyramids are characterized by their beehive-like shape which is bulged in the middle and tapers towards younger and older age groups.
• Stationary pyramids show a somewhat equal proportion of the population in each age group.

Population Density & Distribution

• Population Density: The amount of people living in an area
• Population Distribution: How spread out people are

Aspect & Relief

• Local relief is the variation in elevation or height over a relatively small, defined area. It is determined by working out the difference in height between the highest and lowest points in the area.
• Aspect of a slope refers to the direction a slope faces (e.g., Northerly, Southerly, Westerly, south-westerly etc.)
• The contour interval is the distance between the contour lines.

Geography Skills

Area Reference

• Find the square of the feature.
• Go to the bottom left corner of the square.
• Write the x-axis first (2 digits).
• Write the y-axis second (2 digits).

Grid Reference

• Find the dot point of the feature (center of the feature).
• Write the area reference in positions 1, 2, and 4, 5.
• Write the tenths as digits 3 and 6.

Contours

• Contour lines show the elevation (height).

Direction & Bearings

• Underline the word between the locations, to (first) or from (second).
• Highlight the location to start with.
• Refer to the compass and write down the direction of the arrow.
• Bearings is the angle.

Scale & Distance

• Four types of scales: Linear, Bar, Ratio, Written.
• Locate the locations in the question and read the scale.
• Measure the distance between locations on the topographic map given (with a ruler).
• Convert this measurement to the smallest scale possible.
• Tips about ratio scale:
• Always cm
• AKA representative fraction
• 1 : 100,000 = 1 cm on map = 1km real life

Population Pyramids/ Profiles

• The right/pink bars show Females.
• The left/blue bars show Males.
• The Y-Axis displays Population (%, mil).
• The X-Axis displays Ages (up by 5).
• To interpret a population pyramid, identify development through three types:
• Expansive: Population of a country is rapidly growing and is shaped like a pyramid or triangle. Expansive population pyramids tend to have a high birth rate and low life expectancy.
• Constrictive: Population is shrinking. Looks like a beehive and has less children being born than adults with a high life expectancy and low fertility rate.
• Stationary: Population is stable (not growing but not shrinking), has a high life expectancy, and a stable fertility rate. Enough children are being born or migrants moving to the country to replace those who die.

Synoptic Charts

• Synoptic charts = Weather maps.
• They show air pressure, rain, wind speed, and direction.

Test your knowledge on biomes and ecosystems, their definitions, classifications, and the interaction between biotic and abiotic factors. This quiz will challenge your understanding of how these systems affect life on Earth and their importance to human survival.