Ecology Part 1 -Titian

Ecology is the study of

living organisms in their natural environment

of how living organisms affect each other and the world they live in.

Abiotic Factors

the non-living aspects of an organisms environment which directly or indirectly affect it.

Biotic factors

include all the direct or indirect interactions with living organisms that inhabit an organism’s environment

examples of how organisms interact with others

• provision of food

• provision of shelter

• reproduction

• protection

organisms providing food for others of a different species

predator/prey

organisms providing food for others of the same species

pack hunting

organisms providing shelter and protection for others of different species

mutualism

Biosphere

world wide sum of all ecosystems, including all collective abiotic components, including the total volume of land, water and air around the earths surface

Lithiosphere

rocky material on earths surface and comprises all the terrestrial environment

hydrosphere

all the water on or near earths surface and comprises all the aquatic environment

Atmosphere

refers to the gaseous component and comprises the aerial environment around the planet

Biomes

large distinctive complexes of plant communities created and maintained by the climate and identified by the dominant plant formation

Terrestrial Biomes include

tropical forest, temperate deciduous forest, temperate coniferous forest, grassland, tundra and desert

Freshwater aquatic biomes include

ponds, lakes, streams and rivers

Marine Aquatic Biomes include

oceans, coral reef, estuaries and coastlines

why do terrestrial biomes seem to be distributed along belts around the planet

• biome distribution is affected by the climate

• as one moves away from the equator climate changes

• climate is distributed in bands around the planet

• climate = productive photosynthesis is, determining which plants/vegetation grows

• determining biodiversity as more productive vegetation increases biodiversity

Explain why tundra and desert are some of the least productive biomes with the lowest biological diversity

• tundra: temperatures are very low, no fresh water and no sunlight inhibit photosynthesis

• desert: very hot and has very little water making it difficult for organisms to survive

Explain why stable aquatic biomes like the ocean and lakes have low biological diversity while variable ones such as rivers have such high biological diversity

• oceans and lakes have stagnant water, so nutrients are not replenished and are lost/precipitated to the bottom and there is a low light at the bottom of the ocean

• rivers have flowing water so nutrients are constantly being replenished

European Biomes

• deciduous forest with medium temperature and high rain fall

• Mediterranean sea scrub is the most abundant biomes along the shores of the Mediterranean sea

Maltese Climate

• mild and wet winters

• hot and dry summers

• periodical drought years give us a quasi-desert- climate

Biome Zonation

when species are spatially distributed due to a mixture of biotic and abiotic factors

5 Zones of a tropical forest

1. emergents - tallest rees

2. canopy - main trees

3. understorey - shrubs

4. undergrowth - herbs and ferns

5. ground level - leaf litter

Marine Biome Zonation

Photic Zone (light present)
Aphotic Zone (light absent)

Habitat

physical area that is inhabited by a particular species

Micro-habitat

sub-set of conditions within a habitat e.g. a decaying log at the bottom of a pond

Niche

role occupied by a species eg(decomposer, predator)

State whether niche/habitat/microhabitat;

pores in the skin provide and excellent shelter for certain types of bacteria

microhabitat

State whether niche/habitat/microhabitat;

tiger stipes help the animal blend into the shadows of its jungle environment

habitat

State whether niche/habitat/microhabitat;

woodlice and earthworms are very important organisms as they eat leaf litter and help return its nutrients into the soil

niche as it is a role they are playing

State whether niche/habitat/microhabitat;

baby fish occupy crevasses between bottom pebbles to escape from bigger carnivorous fish

microhabitat

polar bears live in the arctic sea, ice, water, islands and continental coastlines

habitat

Shore biome division

supralittoral

medialittoral

infralittoral

Supralittoral Zone

• never submerged but wetted by sea spray

• splash or spray zone

• rock in the supralittoral is blackish brown due to

  • microscopic algae

  • cyanobacteria

  • marine lichens

  • give a protective coating from acid rain erosion

• rock pools are often present

Mediolittoral Zone

• highest point of submersion to lowest point of exposure

• since med. tides are very little zone extension is related to wave action

• extension is between 50-150cm (rarely 200)

• further divided into upper and lower mediolittoral

  • upper is exposed for longer periods

  • lower is exposed for shorter periods
    

Upper mediolitteral organisms

• often exposed and therefore must have greater resistance to exposure and must adapt against

  • heat stress

  • dessication

  • oxygen shortage

  • reduced feeding opportunities

mobile organisms

migrate vertically to follow water level

sessile organisms

inactive while exposed

→ barnacles close their operculum when exposed

Lower mediolitteral Organisms

• often submerged and must adapt to waves pounding

• must adapt against

  • wave shock

  • abrasion

  • hydrostatic pressure

  • pressure drag

they adopt streamlines shapes to break waves

seek crevasses to hide in

snails,chitons have strong foot that keeps the animal attached

Infralittoral Zone

• permanently submerged

• extends from lowest point of constant submersion to lowest distribution of seagrasses (circalittoral)

• fluctuating conditions and rich nutrient content ensure a high biodiversity

Organisms found in Supralittoral

• limpets

• green chiton

• black periwinkle

Mediolitteral Organisms Examples

• common gibule

• green chiton

• limpet

• snails

• barnacles

Infralittoral Organisms

• sponge ball

• peacocks tail

• seagrass

• common octopus