Ecosystems Flashcards
Ecosystem
- Living and non-living parts of a particular area
- that interact together
- parts termed biotic and abiotic
- can be any size
Terrarium
Aquarium
Small enclosed (glass) case holding:
- a mini terrestrial ecosystem
- a mini aquatic ecosystem
Biotic factors
Living organisms
Abiotic factors
Non-living parts of an ecosystem
E.g. Soil, water, temperature and sunlight
Producers
- Make their own food from abiotic factors
- Also called autotrophs
- photosynthesis uses sunlight, water and carbon dioxide to make glucose and oxygen
Examples of producers
- Plants
- Algae
- Cyanobacteria
Plants which grow in water
Hydrophytes
Plants growing on land that need a moderate supply of water
Mesophytes
Plants that grow in very dry regions
Xerophytes
Consumers
- Organisms that must eat to get food
- also called heterotrophs
- E.g. animals
Different trophic levels of consumers
- Primary consumers - eat producers
- Secondary consumers - eat primary consumers
- Tertiary consumers - eat secondary consumers
Different modes of feeding
Herbivores - only eat plants
Omnivores - eat both plants and animals e.g. Humans
Predators - eat different animals by hunting
Scavengers - eat leftovers
Decomposers
- Break down organic material (organisms and wastes) to get their food
- also called saprotrophs
- return inorganic nutrients to the environment
Physiographic factors
Abiotic factors to do with position and shape of area
- slope
- aspect
- altitude
Slope and slope effects of an ecosystem
How steep or flat an area is (inclination)
- runoff
- soil erosion rates
- soil depth
- soil fertility
- types of plants and animals
Aspect of an ecosystem
Direction it faces (e.g. north, south, east or west)
- amount of sunlight hitting the ecosystem
- amount of rain, evaporation and moisture
- depending on prevailing winds in the area
- how sheltered
- plant and animals living there
How aspect affects Table Mountain ecosystems
- South slopes cool and moist
- e.g. Newlands = forest
- North slopes warm and dry
- e.g. Front of table mountain = fynbos
Altitude (elevation) effects on ecosystems
Height above sea level (elevation)
As you go up:
- temperatures get cooler
- amount of precipitation increases
- solar radiation increases
- wind increases
- fewer plant and animal species
Edaphic factors
Soil factors
- pH
- humus content
- soil texture
- soil air
- Water-holding capacity
- Water drainage
pH of soil
- How alkaline or acidic
- pH less than 7 is acidic
- pH greater than 7 is alkaline
- pH of 7 is neutral
- different plants live in different levels
Humus content of soil
- How much dead and decaying plant and animal material
- humus makes soil fertile
- provides nutrients
- keeps oxygen in soil
- holds water but allows excess to drain away
Soil texture
Different sized soil particles
- sand - large particles
- silt - small particles
- clay - tiny particles
Properties of sandy soil
- Large air spaces
- allows water to pass through easily
- low water retention
- higher leaching of nutrients
Properties of clay rich soil
- Tiny air spaces
- does not drain easily
- becomes waterlogged easily
- high water retention
Loam soil
- Mixture of all particle sizes and humus
- excess water drains quickly
- holds a good amount of water
- lots of air in the soil
- Generally rich in nutrients
Soil air
- Found in spaces between soil particles
- sand has large spaces
- clay has small spaces
- more air the more oxygen available for plant roots
Investigation of soil water retention
- Different types of soil
- each put into filter
- Same volume of water added to each
- Measure amount of water retained by each
Investigation of soils rate of drainage
- Different types of soil each put into filter
- Same volume of water added to each
- Measure amount of time for water to stop draining
Physical factors in an ecosystem
- Sunlight
- Temperature
- Water
- Atmospheric gases