OCR B Geography GCSE Sustaining Ecosystems

biotic

all of the living elements of the ecosystem including plants, animals and bacteria

abiotic

the physical, non-living parts of the ecosystem, including temperature, water and light

flora

another term for the plants in an ecosystem

fauna

another term for the animals in an ecosystem

biome

large scale ecosystems that are spread across continents and have plants and animals that are unique to them

ecosystem

A biological community of interacting organisms and their physical environment.

interdependence

the reliance of every form of life on other living things and on the natural resources in its environment, such as air, soil and water

temperate

Mild or moderate

coniferous forest

a forest made up of trees that are evergreen and have needle shaped leaves

temperate deciduous forest

a forest made up of broad leafed trees which shed their leaves in autumn and grow new ones in spring

tropical rainforest

forest in the tropics which produces its own rain, have very high levels of bioproductivity and biodiversity

tundra

a vast, flat, treeless Arctic region of Europe, Asia and North America in which the soil is permanently frozen

temperate grassland

grassland with moderate or mild temperatures

tropical grassland

grassland with tropical temperatures

hot desert

Hot area which recieves on average less than 250 mm rainfall per year

circumpolar wind

flow of air around the Earth's poles

deforestation

the cutting down of trees, transforming a forest into cleared land for other uses such as building, growing crops or rearing cattle

emergent

the tallest tree in the rainforest towering above the canopy

canopy

top layer of a rain forest, where the tops of tall trees form a continuous layer of leaves

under canopy

young trees awaiting an opportunity to grow into the light

shrub layer

layer of forest containing shrubs and other short plants

buttress root

Root that is shallow to soak up nutrients in thin soils, but big for stability

coral reef

a structure built up by coral animals in warm (mean of 18°C), shallow (less than 30m) ocean water.

continental shelf

a gently sloping, shallow area of the ocean floor that extends outward from the edge of a continent

parrot fish

a type of fish which feeds on coral

starfish

a marine echinoderm with five or more radiating arms

clam

a shellfish which feeds on plankton

eel

a long, thin fish that looks like a snake

mollusc

soft bodied creatures like sea snails and octupuses

dugong

a large plant-eating mammal, related to the manatee, that lives in shallow tropical coastal waters

herbivore

eats only vegetation

carnivore

eats meat

omnivore

eats both meat and vegetation

xerophytic

a type of plant that can survive on very little water

microclimate

the climate of a relatively small area, which is likely to be different from the climate of the surrounding area

biomass

the total mass of plants and animals in an ecosystem

litter

the total amount of organic matter, including humus (decomposed material) and leaf litter

soil

A loose mixture of rock fragments, organic material, water, and air that can support the growth of vegetation

convectional rainfall

occurs frequently in the tropics where it is hot; hot air close to the ground rises, cools and condenses to form rain; if the air is hot enough, it rises very quickly and can lead to thunderstorms

evapo-transpiration

the process by which water is transferred to the atmosphere by evaporation from surfaces and by transpiration from plants

transpiration

loss of water from a plant through its leaves

latosols

soils found under tropical rainforests with a relatively high content of iron and aluminium oxides

humus

rich, dark organic material formed by decay of vegetable matter, essential to soil's fertility

parent rock

the upper layer on rock on which soil forms

hunter-gatherers

nomadic people who move from place to place, hunting, fishing and harvesting (gathering) wild food

shifting cultivation

the use of tropical forest clearings for crop production until their fertility is lost. Plots are then abandoned, and farmers move on to new sites

ecosystems goods

tangible items such as crops, wood, drinking water, fish, and wildlife

ecosystems services

the services which are provided by a natural ecosystem to people; these can be seen as benefits of keeping the ecosystem functioning efficiently

carbon sink

a forest, ocean or other natural environment that is able to absorb carbon dioxide from the atmosphere

cash crops

crops grown and produced to be sold for a profit, such as wheat or cotton

biofuel

a fuel that comes from living matter, such as plant material

slash and burn

a form of shifting cultivation where the natural vegetation is cut down and burned to clear the land for cultivation; when the plot becomes infertile the farmer moves on to a fresh plot and does the same again

infrastructure

the basic structures and facilities needed for a society to function, such as buildings, roads and power supplies

mass tourism

Tourism that involves large numbers of people going to the same place at the same time

logging

cutting down trees for commercial purposes

agriculture

use of land to grow crops or raise livestock

cattle ranching

use of land exclusively to rear cows for their meat, makes up 80% of the use of deforested areas in Brazil

palm oil

a highly profitable cash crop used in food products and as a biofuel

mineral extraction

the mining of valuable resources e.g. gold, copper, silver and diamonds

energy exploitation

the mining of energy resources e.g. oil and gas

endemic

a plant or animal species which is unique, or native to a particular area

albedo

the amount of incoming solar radiation which is reflected by the Earth's surface (and the atmosphere); fresh snow and ice reflect up to 90% of energy

trophic cascade

the transfer of energy through an ecosystem as a result of food chains, at each level some energy is lost

permafrost

an area of land which is permanently frozen

active layer

the upper layer above permafrost which thaws and refreezes during the summer

talik

an area of unfrozen ground surrounded by permafrost

biodiversity

the diversity of plant and animal life in a particular habitat (or in the world as a whole)

indigenous people

people who have lived in a given area for thousands of years

whaling

hunting for whales

moratorium

a temporary ban on an activity

fishing

the activity by which 70% of global white fish is caught in Arctic waters

Antarctic treaty

agreement signed by twelve countries coming into force in 1961 and now backed by a total of 53 agreeing to preserve Antarctica for peaceful and scientific use