Bio 5: Ecosystems and sustainability Flashcards Preview

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Flashcards in Bio 5: Ecosystems and sustainability Deck (28):
1

Habitat

A place where an organism lives

2

Population

All of the organisms of one species that live in the same place at the same time and that can breed together.

3

Community

All the populations of different species that live in the same place at the same time.

4

Ecosystems

A group of organisms including biotic factors and abiotic factors and their interrelationships between them.

5

Niche

Role that a species plays in an ecosystem

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Producers

Autotrophic organisms that convert light energy into chemical energy, which is then supplied to consumers

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Consumers

Living organisms that feed on other living organism

8

Trophic level

Level at which an organism feeds in a food chain

9

Pyramids of biomass

Areas of the bars are proportional to the dry mass of all the organisms at the trophic level

10

Pyramid of energy

Burning the organisms in a calorimeter and working out how much heat is released per gram.

11

Gross primary productivity

Rate at which plants convert light energy into chemical energy.

12

Net Primary Productivity

NPP= GPP - Respiration
Rate at which carbphydrates accumulate in the tissue of plants of an ecosystem.
kg/ha/yr

13

Primary productivity

Total amount of energy fixed by photosynthesis.

14

Succession

The directional change in a community over time

15

Saprotrophs

Secrete enzymes onto dead and waste material, they digest the material into small molecules, which are then absorbed into the organisms body.

16

Nitrogen fixation

Lightning strikes
Haber process
Nitrogen-fixing bacteria

17

Nitrogen-fixing bacteria

Root nodules
Give fixed nitrogen, get carbon compounds
Anaerobic: reduce nitrogen gas to ammonium ions

18

Nitrification

Get energy from oxidising ammonium ions to nitrite
Or nitrite to nitrate
Only in well aerated soils

19

Denitrification

Nitrates back to N2
Anaerobic conditions: nitrate as source of oxygen, make N2 and N20

20

Carrying capacity

Maximum population size that can be maintained over a period of time in a particular habitat

21

Limiting factors

factors that cause the population of something to stop growing any larger

22

Intraspecific competition

Competition between individuals of the same species.

23

Interspecific competition

Competition between individuals of a different species

24

Coppicing

Cutting a tree close to the ground,once cuts several new shoots will grow from the surface, and these will grow into stems. These can then be cut again.

25

Pollarding

Cutting the trunk higher up, in order to stop deers from eating the new shoots

26

Clear felling

Felling an entire area. This destroys on a large scale. It reduces soil minerals and leaves it susceptible to erosion.

27

Conservation

Maintenance of biodiversity, habitats and ecosystems

28

Conservation: reasons and methods

-Over exploitation for food
-Habitat disruption or fragmentation
-Invasive species
-Extinction
-Valuable source : food, medicine, etc
-Pollination
-Ecotourism
-Vaccinating against disease
-Control predators and poachers
-Preserve habitats