ECOLOGY

WHAT IS ECOLOGY? The study of the relationships between organisms in an environment. The key idea is that organisms depend on each other within the ecosystem, and these relationships must be balanced. An Ecosystem is affected by 2 groups of factors: 1.Biotic – living factors 2.Abiotic – non-living factors

BIOTIC FACTORS Organisms can be classified into 3 main groups; Producers Consumers Decomposers 1.Producers – plants which produce their own food through photosynthesis. Light energy Chemical Energy. 2. Consumers – Herbivores, Carnivores, Omnivores, Parasites. 3. Decomposers – organisms which breakdown animals and plants into simpler substances such as CO2. Eg. Beetles, earthworms, fungi.

ABIOTIC FACTORS Non-living factors; Soil – nutrients, oxygen, salinity Water – pH, turbidity, oxygen, salinity. Atmospheric conditions – temperature, rainfall Land and aquatic forms – mountains, dunes, tides, waves, currents. Quote: ‘These factors rarely threaten the survival of a species’ Is this true to the mangrove ecosystem?

COASTAL ECOLOGICAL ZONES

FOOD CHAINS The food chain is a simple list of what eats what and may include the any aspects of the ecosystem. Food and energy movement is indicated with the use of arrows Sea Grass → Small Fish → Larger Fish → Seal Food chain rarely consists of more than 6 species, because the amount of energy passed on diminishes at each stage.

FOOD WEBS The food web is more complex. It shows all the feedings relationships in a community. Simple food web:

ECOLOGY Food Web Complex Diagram Web

CREATE A FOOD WEB List examples of adaptations, and create a food web that is true to this specific ecosystem. Borneo Mangroves Attenborough Ants

TROPHIC LEVELS In the food chain each species occupies a position. This position is called the trophic level. Trophic level can be remembered as the feeding level Decomposers/Detrivores are essential in the food chain. feed on dead plants and animals and their wastes return most of these nutrients to plants, beginning the cycle again.

RELATIONSHIPS The key idea is that organisms depend on each other within the ecosystem, and these relationships must be balanced. Within ecosystems, organisms can interact with each other in 3 ways; 1.Competition – different populations vying for the same resource 2.Predation – one organism feeding on another 3.Symbiosis – organisms living in close association with each other

THE BASE OF THE FOOD CHAIN

PHOTOSYNTHESIS The process by which plants convert light energy into chemical energy Specific cells within the leaves of plants contain chloroplasts Chloroplasts contain the pigment chlorophyll, where the process of photosynthesis occurs. The plant absorbs water and carbon dioxide, to produce carbohydrates and oxygen. 6CO2 + 6H2O + energy = C6 H12 O6 + 6O2 What is happening if you reverse the equation?

Just a thought…

RECYCLING WITHIN AN ECOSYSTEM Within an ecosystem, useful materials are recycled and released back into the energy cycle. 1.Carbon Cycle 2.Nitrogen Cycle 3.Water Cycle

CARBON CYCLE

Carbon is the basis of all living organisms What contributes to carbon dioxide in the atmosphere? Respiration – plants and animals Decomposition – bacteria decompose dead organisms and release CO2 back into the atmosphere. Burning Fossil fuels

NITROGEN CYCLE

Nitrogen gas makes up 78% of the atmosphere Although most living things cannot absorb it directly Micro-organisms in the soil convert it to nitrates, which are more easily absorbed by the roots of plants and used to produce energy.

WATER CYCLE

Water makes up 70% of most Organisms. However it is continually lost through; Evaporation Perspiration Transpiration

ADAPTATION Adaptation is a genetic feature of an organism which helps it to survive in its environment. Adaptations may be; Structural Functional Bahavioural (birds) (ants)

WHAT ARE THE HUMAN IMPACTS ON ECOLOGY? -Deforestation -Global warming; rising temperatures of water (fish on adelaide beaches), rising water levels (coastal towns, coastal ecology), rising temperatures – wild weather. -Tourism -Farming (soils, erosion) -Dairy and cattle industry – what role does this play in global warming? Greenhouse gases? -Pollution -Mining -Cultural significance -Desalination plants, Industrialisation What are some of the threats local to the port river? How does the current situation in Sydney relate to the big picture?