3-1 What is Ecology?! The study of the. interactions among organisms and between organisms and their environment

Transcription

1 Chapters 3,4 & 5 1

2 3-1 What is Ecology? The study of the interactions among organisms and between organisms and their environment 2

3 Levels of Ecological Organization 3

4 3-2 Energy Flow main source of energy 4

5 1. Autotrophs (Producers): make their own food from the energy in the environment Photosynthesis in plants & Chemosynthesis in several types of bacteria 2. Heterotrophs (Consumers) dependent on other organisms for food A. Herbivores: plant eaters B. Carnivores: meat eaters C. Omnivores: both plant and meat eater D. Detritivores: feed on plant and animal remains (earthworms, snails & crabs) E. Decomposers: break down organic matter so that the nutrients can be recycled (bacteria & fungi) 5

6 Feeding Relationships (Energy Transfer) Food chain: a series of steps in which organisms transfer energy by eating and/or being eaten Food web: the feeding relationships among organisms in an ecosystem; a network of interconnected food chains 6

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8 3. Trophic levels: each step in a food chain or food web each consumer depends on the trophic level below it for energy Energy flows through an ecosystem in one direction Energy is NOT recycled 8

9 Energy Pyramid 1. Only about 10% of the energy available within one trophic level is transferred to organisms in the next trophic level 2. Organisms use energy for life processes and some of it released into the environment as heat 9

10 Biomass Pyramid represents the amount of potential food available for each trophic level in an ecosystem 10

11 Pyramid of Numbers shows the relative number of individual organisms at each trophic level 11

12 3-3 Cycles of Matter Water Cycle Carbon Cycle Nitrogen Cycle Phosphorus Cycle Unlike the one way flow of energy, matter is recycled within and between ecosystems through biogeochemical cycles. 12

13 All living things require water to survive13

14 Carbon is the key ingredient in living things 14

15 Nitrogen Cycle Organisms require nitrogen to make amino acids which are used to build protein 15

16 Nitrogen Cycle decomposers play a crucial role in the nitrogen cycle nitrogen fixing bacteria make nitrogen usable for producers denitrifying bacteria put nitrogen back into the atmosphere 16

17 Phosphorus is an essential component of DNA & RNA 17

18 4-2 What Shapes and Ecosystem Ecosystems are influenced by biological (biotic) and physical (abiotic) factors Together, biotic and abiotic factors determine the survival and growth of an organism and the productivity of the ecosystem in which the organism lives An organism s habitat includes both biotic and abiotic factors Each organism has a niche (an organism s role in the environment) no two species occupy the same niche in the same habitat 18

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20 Community Interactions Competition occurs when organisms attempt to use the same resource at the same time an can powerfully affect an ecosystem Predation is the interaction between predators and prey (the predator s food) Organisms living in symbiosis influence the survival of organisms and can affect ecosystems 20

21 Competition for Food 21

22 Predator-Prey Relationship 22

23 Mutualism: both species benefit Bee & Flower Clownfish & Sea Anenome 23

24 Commensalism- one species benefits and the other is not affected Barnacle & Whale Shark and Remora 24

25 Parasitism: one species benefits and the other is harmed The parasite obtains its nutritional needs from the host Mosquito & Human Tick & Dog 25

26 Primary Succession occurs on surfaces where no soil exists 26

27 Secondary Succession occurs when a disturbance changes a community without removing the soil Example: forest fire, clear-cutting a forest, abandoned farm land 27

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29 Ecological Succession Organisms in each stage of succession modify the environment making it less suitable for themselves and more suitable for organisms in the next stage The result of ecological succession is a mature, stable community known as the Climax Community which continues to undergo changes as a result of the balance of nature 29

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31 4-3 Land Biomes 31

32 4-4 Aquatic Ecosystems Freshwater Ecosystems Flowing Water (rivers & streams) Standing Water (lakes & ponds) 32

33 Freshwater Wetlands Marsh Bog Swamp 33

34 Estuaries Salt Marsh Mangrove Swamp 34

35 Marine Ecosystems The Great Barrier Reef 35

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37 5-1 How Populations Grow Characteristics of Populations 1. Geographic distribution 2. Population Density 3. Growth rate Population size is affected by: # of births # of deaths immigration/emigration 37

38 Exponential Growth- J shaped curve under ideal conditions populations will grow exponentially Ideal conditions = abundant space, unlimited resources, & protection from predators 38

39 Logistic Growth (S shaped curve) occurs when population growth slows or stops after a period of exponential growth due to limited resources population fluctuates around carrying capacity 39

40 5-2 Limits to Growth Limiting factors cause population growth to decrease Density Dependent Competition Predation Parasitism Disease Density Independent Weather Natural disasters Seasonal cycles Human activities 40

41 5-3 Human Population Growth World Population = over 7.2 billion 41

42 China, India and the United States are the top 3 contributors to human population growth 42