2.4 Climate and Biomes

2.4.1 Climate describes atmospheric conditions over relatively long periods of time, whereas weather describes the conditions in the atmosphere over a short period of time.

Weather refers to the specific conditions being experienced at a particular time or over a short period, including temperature, humidity, air pressure and wind speed. Climate is the average of these conditions over approximately 30 years

Climate vs Weather

2.4.2 A biome is a group of comparable ecosystems that have developed in similar climatic conditions, wherever they occur.

Ecosystems developed in similar conditions in different parts of the world can have many parallel features.

Precipitation, temperature and insolation are major influences on the distribution of terrestrial biomes.

Ecosystems found in Hokkaido have parallels elsewhere (so the pairs of ecosystem are part of the same biome).

Hokkaido

Vermont

Tierra del Fuego

Sweden

Different tropical rainforests contain species that are different but functionally similar (e.g different species of monkeys).

Costa Rica

DR Congo

Sumatra

2.4.3 Abiotic factors are the determinants of terrestrial biome distribution.

For any given temperature and rainfall pattern, one natural ecosystem type is likely to develop. Consider a graph showing the distribution of biomes with temperature and rainfall pattern on the horizontal and vertical axes.

Analyse and discuss in pairs: do the models below match up to the model above? For example, does the total annual precipitation (note that below shows mm and above shows cm, so divide by 10 to convert) and average temperature (guesstimate the latter) in TRF shown below match with the levels above?

Sapporo and London are large cities. Use the models below to predict the vegetation type in the areas before the cities were established.

2.4.4 Biomes can be categorized into groups that include freshwater, marine, forest, grassland, desert and tundra. Each of these groups has characteristic abiotic limiting factors, productivity and diversity. They may be further classed into many subcategories (for example, temperate forests, tropical rainforests and boreal forests).

Watch the video and make notes.

2.3 Biomes

Copy and complete the table. The slides towards the end above and the biome viewer could help.

Biome Database

Include the characteristic limiting factors, productivity and resulting biodiversity of tropical rainforests, hot deserts, tundra and at least two other biomes.

2.4.5 The tricellular model of atmospheric circulation explains the behaviour of atmospheric systems and the distribution of precipitation and temperature at different latitudes. It also explains how these factors influence the structure and relative productivity of different terrestrial biomes.

Latitude is the angular distance from the equator (north or south of it) as measured from the centre of the Earth (usually in degrees). Give details of the tricellular model with the three distinct cells: the Hadley cell, the Ferrel cell and the polar cell. Include reasons for the distribution of biomes using the tricellular model.

Watch the video and make notes.