ENERGY FLOW IN ECOSYSTEMS

Transcription

1 ENERGY FLOW IN ECOSYSTEMS

2 TOPICS LIST ENERGY FROM THE SUN PERCENTAGES ALBEDO EFFECT PHOTOSYNTHESIS and CELLULAR RESPIRATION THERMODYNAMICS ROLES IN ECOSYSTEMS KEYSTONE SPECIES ECOLOGICAL NICHE INTRASPECIFIC VS. INTERSPECIFIC COMPETITION PYRAMIDS PYRAMID OF ENERGY PYRAMID OF BIOMASS PYRAMID OF NUMBERS

3 WHERE DOES OUR ENERGY COME FROM? The SUN is the source of energy for the vast majority of life on Earth.

4 ENERGY FROM THE SUN What happens to the majority of the Sun s energy? It heats the atmosphere, earth s surface, and wate PERCENTAGES: 27 % is reflected by Clouds and Earth s Surface 69 % warms the atmosphere, land, and hydrosphere 1 % generates wind patterns _0.023_ % is used in the process of photosynthesis

5 ALBEDO EFFECT A measure of the AMOUNT of sunlight REFLECTED from an object. Expressed as a decimal value Example: 27 % reflection by clouds is 0.27 What are examples of objects that REFLECT sunlight? In general, LIGHT-COLOURED objects such as: These highly reflective objects have a HIGH ALBEDO.

6 What are examples of objects that ABSORB sunlight? In general, DARK-COLOURED objects such as: These light-absorbing objects have a LOW ALBEDO. Also, GREENHOUSE GASES have a low albedo.

7 ALBEDO EFFECT

8 PHOTOSYNTHESIS What is it? A biochemical process whereby PRODUCERS use the Sun s energy, carbon dioxide, and water to produce sugar and oxygen. GENERAL CHEMICAL EQUATION: 6 CO H 2 O + Sun s Energy C 6 H 12 O O 2

9 CO 2 is carbon dioxide glucose (sugar) H 2 O is water C 6 H 12 O 6 is O 2 is oxygen Oxygen is necessary for CONSUMERS. Sugars are necessary as a usable form of energy for nearly ALL LIFE on EARTH.

10 CELLULAR RESPIRATION What is it? A biochemical process whereby CONSUMERS release the energy stored in the sugar they ingest. By eating sugars and breathing in oxygen, consumers produce carbon dioxide, water, and energy for life processes. GENERAL CHEMICAL EQUATION: C 6 H 12 O O 2 6 CO H 2 O + Energy

11 WHAT KINDS OF LIFE PROCESSES?

12 THERMODYNAMICS What is THERMODYNAMICS? The study of ENERGY TRANSFORMATIONS from one form to another (ex: chemical energy to heat energy) There are two Thermodynamic LAWS that apply to ecosystems

13 FIRST LAW OF THERMODYNAMICS Energy CANNOT be CREATED NOR DESTROYED, only TRANSFERRED FROM ONE FORM TO ANOTHER. SECOND LAW OF THERMODYNAMICS During energy transfers, SOME ENERGY is LOST as HEAT ENERGY and is not passed on.

14 PYRAMIDS PYRAMID OF ENERGY Recall from an earlier lesson that we can represent ENERGY TRANSFER in an ecosystem with a pyramid of energy, and that only about 10 %of energy is passed from one trophic level to the next.

15 There are 2 other types of pyramids that are USEFUL GRAPHICAL INDICATORS of ecosystem patterns: PYRAMID OF BIOMASS PYRAMID OF NUMBERS BIOMASS The mass of an organism WITHOUT water; its dry weight. Measured in kg.

16 A PYRAMID OF BIOMASS is a graphical representation of the TOTAL BIOMASS of all the members of each trophic level. Often similar in shape to a Pyramid of Energy.

17 PYRAMID OF NUMBERS A graphical representation of the TOTAL NUMBERS of all members of each trophic level in a food chain. Sometimes, these are shaped liked pyramids, but there are exceptions!

18 AN EXCEPTION: For example, if the following was a rough sketch of our pyramid of energy, would the pyramid of numbers look the same?

19 ANSWER: No, of course not! There would be more caterpillars than any other organism, so our pyramid of NUMBERS would look like:

20 HOMEWORK Draw 3 pyramids (energy, biomass, and numbers) for the following food chain: HAWK (1, 10 J, 5 kg) WOODPECKER (10, 100 J, 10 kg) WORM (1000, 1000J, 50 kg) FIR TREE (1, 10000J, 150 kg)

21 ROLES IN ECOSYSTEMS It is time to discuss some of the interrelationships that take place in ecosystems between species. Some specific roles organisms can take on include: KEYSTONE SPECIES ECOLOGICAL NICHE INTRASPECIFIC VS. INTERSPECIFIC COMPETITION EXOTIC SPECIES

22 KEYSTONE SPECIES A species that is considered so important to ECOSYSTEM STABILITY, that if that species declined, the ecosystem might collapse. Why is it called keystone? It is an analogy for a keystone that holds together an archway. Example: SEA OTTER is a keystone in the CALIFORNIA KELP ecosystem Without otters, kelp does not grow.

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24 ECOLOGICAL NICHE An organism s NICHE is its role that it plays in a particular ecosystem. It includes everything an organism does to survive and reproduce, including: Feeding relationships Habitat Breeding grounds/behaviours Activity times Competitive relationships

25 Organisms tend to have UNIQUE niches, based on where and how they are best adapted to survive. EXAMPLE: Galapagos Island Finches Found on the Galapagos Islands,this little finch evolved into many SUBSPECIES, all adapted to a DIFFERENT NICHE.

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27 SPECIES COMPETITION Sometimes in nature there is COMPETITION for NICHES when two or more organisms have similar requirements for SPACE, FOOD, and/or WATER. Survival of the Fittest usually prevails

28 2 MAIN TYPES: INTRASPECIFIC COMPETITION Between the SAME SPECIES EX: INTERSPECIFIC COMPETITION Between DIFFERENT SPECIES EX:

29 INTRASPECIFIC COMPETITION SAME SPECIES COMPETING

30 INTERSPECIFIC COMPETITION DIFFERENT SPECIES COMPETING

31 EXOTIC SPECIES/ALIEN OR INVASIVE These are NON-NATIVE species that are not natural parts of ecosystems. Compete INTERSPECIFICALLY with native species in the area. Examples: Moose in NL 4 in 1904 Green Crab in Atlantic Canada Zebra Mussels (p )

32 EXOTIC SPECIES GREEN CRAB

33 ALIEN VS INVASIVE SPECIES Alien Species is an introduced organism that is very far from its natural habitat. Has travelled great distances on purpose or by mistake. (green crab, asian carp, zebra muscle, purple loosestrife) Invasive species is an introduced species either on purpose or mistake but much closer to its natural habitat. (moose, coltsfoot plant) Both species classification may have a negative effect on the environment.

34 Let s talk Science Video (Sample Alien Species segment obj3k