Ecosystem Under Stress

Question 1

What is Biodiversity ?

Answer 1

The variation of life forms within a given ecosystem, biome, or for the entire Earth. Biodiversity is often used as a measure of the health of biological systems.

Question 2

What is Biomass ?

Answer 2

The mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community.

Question 3

What is a Biome?

Answer 3

A major habitat category, based on distinct plant assemblages which depend on particular temperature and rainfall patterns, for example, tundra, temperate forest and rainforest.

Question 4

What is a Climatic Climax ?

Answer 4

A biological community of plants and animals which, through the process of ecological succession, has reached a state of dynamic equilibrium with its climate and soils.

Question 5

What is an Ecosystem ?

Answer 5

A system in which organisms interact with each other and the environment. Open system.

Question 6

What is Fauna ?

Answer 6

The animals of a particular region, habitat or geological period.

Question 7

What is Flora ?

Answer 7

The plants of a particular region, habitat or geological period.

Question 8

What is the Food Chain ?

Answer 8

An arrangement of the organisms of an ecological community according to the order in which they eat each other, with each organism using the next lower organism in the food chain as a source of energy. Beginning with a producer.

Question 9

What is the Food Web ?

Answer 9

A scheme of feeding relationships, resembling a web, which unites the member species of a biological community.

Question 10

What is the Net Primary Production (NPP) ?

Answer 10

The rate at which an ecosystem accumulates energy or biomass, excluding the energy it uses for the process of respiration. This typically corresponds to the rate of photosynthesis minus respiration by the photosynthesisers.

Question 11

Define Plagioclimax ?

Answer 11

The plant community that exists when human interference prevents the climatic climax vegetation being reached.

Question 12

What is a Seral Stage ?

Answer 12

An individual stage of ecological succession within a sere, for example, colonisation or stabilisation.

Question 13

What is a Sere ?

Answer 13

The entire sequence of stages in a plant succession. Different seres are named after the starting point of the succession, for example, lithosere, hydrosere, psammosere and halosere.

Question 14

What is a Sub-Climax ?

Answer 14

The development of an ecological community to a stage short of the expected climax because of some factor, such as repeated fires in a forest, which arrests the normal succession.

Question 15

What is the Trophic Level ?

Answer 15

• An organism’s position in the food chain.
  Level 1 is formed of autotrophs which produce their own food. Level 2 consume level 1 and level 3 consume level 2, etc.

Question 16

Define Abiotic ?

Answer 16

Abiotic factors are all the non-living things in an ecosystem.

(Climatic - wind, precipitation, temperature).

(Other - topography, water quality, soil acidity).

Question 17

What is Topography ?

Answer 17

The layout of the land in terms of elevation and gradient.

Question 18

Define Biotic ?

Answer 18

Biotic components are the living organisms this includes plants, animals and micro-organisms (bacteria & fungi).

Question 19

What are the 3 biotic groups ?

Answer 19

Producers - Green plants have chlorophyll that enables them to convert solar energy into chemical energy by the process of photosynthesis. As the green plants manufacture their own food they are known as autotrophs.

Consumers - Animals lack chlorophyll and are unable to synthesise their own food. Therefore they depend on the producers for their food. They are known as heterotrophs. (E.g. herbivores, carnivores & omnivores).

Decomposers - Bacteria and fungi belong to this category. They break down the dead organic materials of producers (plants) and consumers (animals) for their food and release into the environment the simple inorganic and organic substances produced as by-products of their metabolisms.

Question 20

What is the equation from Photosynthesis ?

Answer 20

CO2 + H2O =sunlight= Glucose + O2

Question 21

What is Primary Succession ?

Answer 21

Primary succession is the series of community changes which occurs on an entirely new habitat which has never been colonised before. For example, a recent lava flow.

Question 22

What is Secondary Succession ?

Answer 22

Secondary succession is the series of community changes which takes place on a previously colonised but disturbed or damaged habitat. For example, after felling trees in a woodland, land clearance or a fire.

Question 23

What is Ecological Succession ?

Answer 23

Ecological succession is the gradual process by which ecosystems change and develop over time. Nothing remains the same and habitats are constantly changing.

Question 24

Describe an example of Succession

Answer 24

Answer an image in my phone

Question 25

How would succession begin in the Lithosere ?

Answer 25

A succession that starts on a newly exposed bare rocky surface, for example, newly erupted volcanic lava or rock exposed as an ice sheet retreats.

Question 26

How would succession begin in the Psammosere ?

Answer 26

A succession that starts on bare sand. for example, coastal sand dunes.

Question 27

How would succession begin in the Hydrosere ?

Answer 27

A succession that starts in fresh water for example, a pond.

Question 28

How would succession begin in the Halosere ?

Answer 28

A succession that starts in salt water conditions, for example, a salt marsh.

Question 29

Describe the Seral Stage 1 ?

Answer 29

The first plant species to colonise an area are called pioneers. These are lichens that are adapted to the severe (dry, windy, soil-free) conditions. They begin to break up the rock to form a thin layer of soil. As they die they add dead organic matter to weathered rock and windblown dust. This creates a simple soil which improves water retention. Mosses are then able to develop

Question 30

Describe the Seral Stage 2 ?

Answer 30

As the soil develops further, ferns and small herbaceous plants and grasses begin to grow. Species diversity increases. There are more invertebrates living in the soil, which increases the organic content. This enables the soil to hold more water.

Question 31

Describe the Seral Stage 3 ?

Answer 31

Larger plants begin to establish themselves. These include shrubs and small trees. They use up a lot of available water and shade the ground. Some of the earlier colonisers are unable to compete and die out. Herbivores become established and predators begin to move in.

Question 32

Describe the Seral Stage 4 ?

Answer 32

Fewer new species colonise. Complex food webs develop. This stage is dominated by larger, fast-growing trees such as birch and rowan. Top predators are found at this stage.

Question 33

Describe the Seral Climax ?

Answer 33

This is the final seral stage. It represents the maximum possible development that a community can reach under the prevailing climatic (temperature, light and rainfall) conditions. This is called a climatic climax community. The total number of larger plant species falls as a few large species dominate the area. In the case of southern England, these are broad-leaved deciduous trees. For example, oak and ash

Question 34

What is a Biome ?

Answer 34

A biome is a large geographical area of distinctive plant & animal groups which are in the climatic climax stage of succession.