Ecological Organization Intro to Enviro Expo Part 1

Transcription

1 Ecological Organization Intro to Enviro Expo Part 1

2 Key Concepts From way back in Biology: interactions within and among populations nutrient cycling with energy flow through ecosystems; the effects of natural events and human activities on ecosystems; and analysis of the flora, fauna, and microorganisms of Virginia ecosystems including the Chesapeake Bay and its tributaries.

3 What is ecology? The scientific study of interactions between organisms and their environments, focusing on energy transfer It is a science of relationships.

4 What do you mean by environment? The environment is made up of two factors: Biotic factors- all living organisms inhabiting the Earth Abiotic factors- nonliving parts of the environment (i.e. temperature, soil, light, moisture, air currents)

5 Biosphere Ecosystem Community Ecological Organization Think of it as a hierarchy, a way of organizing & breaking ecology/environment down into smaller sections Population Organism

6 Organism- any unicellular or multicellular form exhibiting all of the characteristics of life, an individual. The lowest level of organization

7 Population-a group of organisms of one species living in the same place at the same time that interbreed and compete with each other for resources (ex. food, mates, shelter)

8 Community- several interacting populations that inhabit a common environment and are interdependent.

9 Ecosystem- populations in a community and the abiotic factors with which they interact (ex. marine, terrestrial)

10 Biosphere- life supporting portions of Earth composed of air, land, fresh water, and salt water. The highest level of organization

11 YOUR TASK: Either on your own or with a partner (and if you work with a partner your end product better show that 2 people put work into it!), come up with a way to physically represent these relationships (community, population, organism, etc). You may use common everyday items, that you carry with you or are located in the

12 Ecology Part 2 Relationships Spatial Feeding Symbiotic

13 The ecological niche of an organism depends not only on where it lives but also on what it does. By analogy, it may be said that the habitat is the organism's address, and the niche is its profession, biologically speaking. Odum - Fundamentals of Ecology

14 Spatial Relationships Habitat vs. Niche Niche - the role a species plays in a community (job) Habitat- the place in which an organism lives out its life (address)

15 Habitat vs. Niche cont A niche is determined by the tolerance limitations of an organism (limiting factor) Limiting factor- any biotic or abiotic factor that restricts the existence of organisms in a specific environment.

16 Habitat vs. Niche Examples of limiting factors- Amount of water Amount of food Temperature

17 Feeding Relationships There are 3 main types of feeding relationships 1. Producer- Consumer 2. Predator- Prey 3. Parasite- Host

18 Feeding Relationships Producer- all autotrophs (plants) trap energy from the sun bottom of the food chain

19 Consumer- Feeding Relationships - all heterotrophs they ingest food containing the sun s energy Herbivores eats plants, primary consumers, prey animals Carnivores eat meat, predators, hunt prey for food Omnivores eat both plants and animals Decomposers feed on dead organisms (variety of kinds)

20 Consumer- Herbivores Feeding Relationships Eat plants Primary consumers Prey animals

21 Consumer- Carnivores Feeding Relationships eat meat Predators Hunt prey animals for food.

22 Consumer- Scavengers Feeding Relationships Feed on carrion, dead animals which makes them carnivores Can be just about any kind of animal

23 Consumer- Omnivores Feeding Relationships -eat both plants and animals

24 Feeding Relationships Consumer- Decomposers Breakdown complex compounds into simpler molecules that can be absorbed back into the soil Majority are microscopic and bacterial in nature

25 Feeding Relationships Food chain- simple model that shows how matter and energy move through an ecosystem

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27 Feeding Relationships Food web- shows all possible feeding relationships in a community at each trophic level Represents a network of interconnected food chains

28 Food chain (just 1 path of energy) Food web (all possible energy paths)

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33 Trophic Levels Each link in a food chain is known as a trophic level. Trophic levels represent a feeding step in the transfer of energy and matter in an ecosystem. Can be producers, 1 st consumer, 2 nd consumer, 3 rd consumer (etc.)

34 Trophic Levels Biomass- the amount of organic matter comprising a group of organisms in a habitat. As you move up a food chain, both available energy and biomass decrease. Energy is transferred upwards but is diminished with each transfer. Only about 10% is transferred

35 E N E R G Y Trophic Levels Tertiary consumers- top carnivores Secondary consumerssmall carnivores Primary consumers- Herbivores Producers- Autotrophs

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38 Toxins in food chains- While energy decreases as it moves up the food chain, toxins increase in potency. This is called biological magnification Ex: DDT & Bald Eagles, Mercury in fish (shark, king mackerel, swordfish and tilefish are high in mercury)

39 Symbiotic Relationships Symbiosis- two species living together 3 Types of symbiosis: 1. Commensalism 2. Parasitism 3. Mutualism

40 Symbiotic Relationships 1. Commensalismone species benefits and the other is neither harmed nor helped Ex. orchids on a tree Epiphytes: A plant, such as a tropical orchid or a bromeliad, that grows on another plant upon which it depends for mechanical support but not for nutrients. Also called aerophyte, air plant.

41 Symbiotic Relationships 2. Parasitismone species benefits (parasite) and the other is harmed (host) Parasite-Host relationship Example: tick on a deer, leeches, fleas,tapeworm

42 Symbiotic Relationships 3. Mutualismbeneficial to both species Ex. cleaning birds and cleaner shrimp

43 Symbiotic Relationships 3. Mutualism (cont.) beneficial to both species Ex. lichen

44 Type of relationship Species harmed Species benefits Species neutral Commensalism Parasitism Mutualism = 1 species

45 Biogeochemical Cycles Intro to Enviro Expo Part 3

46 Nutrient Cycles Cycling maintains homeostasis (balance) in the environment. 3 cycles to investigate: 1. Water cycle 2. Carbon cycle 3. Nitrogen cycle

47 Water cycle- Evaporation, transpiration, condensation, precipitation, condensation, infiltration/percolation, runoff

48 Water cycle-

49 Carbon cycle- Photosynthesis and respiration cycle carbon and oxygen through the environment.

50 Carbon/Oxygen Cycle ~ Photosynthesis and respiration cycle carbon and oxygen through the environment. O 2 CO 2

51 Carbon cycle-

52 Carbon Cycle In fact, carbon constitutes the very definition of life Its presence or absence helps define whether a molecule is considered to be organic or inorganic. Every organism on Earth needs carbon either for structure, energy, or, as in the case of humans, for both.

53 Carbon Cycle Carbon is found in forms as diverse as: GAS carbon dioxide (CO2) SOLIDS limestone (CaCO3) Wood Plastic Diamonds Plants Graphite

54 Carbon Cycle ON LAND - the major exchange of carbon with the atmosphere results from: Photosynthesis and respiration

55 Carbon Cycle ON LAND - the major exchange of carbon with the atmosphere results from During daytime in the growing season, leaves absorb sunlight and take up carbon dioxide from the atmosphere (photosynthesis). At the same time plants, animals, and soil microbes consume the carbon in organic matter and return carbon dioxide to the atmosphere (respiration).

56 Yes! Carbon Cycle So can the amount of carbon in the atmosphere change? During winter for instance, there are hardly any leaves on the trees, so photosynthesis decreases, thus the amount of CO2 being taken in by these leaves is decreased. BUT At the same time animals are still respiring/exhaling the same amount of CO2 that they were in all the other seasons SO The amount of CO2 in the atmosphere during winter has. increased

57 Carbon Cycle So can the amount of carbon in the atmosphere change? 470x353.jpg So an increase in CO2 in atmosphere during winter in our Northern Hemisphere

58 Nitrogen cycle- All organisms need N to build proteins (which are used to build new cells). Atmospheric nitrogen (N 2 ) makes up nearly 78%-80% of air. Organisms can not use it in that form. Lightning and bacteria convert nitrogen into usable forms.

59 Nitrogen cycle- Only certain bacteria and industrial technologies can fix nitrogen. Nitrogen fixation-convert atmospheric nitrogen (N 2 ) into ammonium (NH 4+ ) which can be used to make organic compounds like amino acids. N 2 NH + 4

60 Nitrogen cycle- Nitrogen-fixing bacteria: Some live in a symbiotic relationship with plants of the legume family (e.g., soybeans, clover, peanuts).

61 Nitrogen cycle- 5/super_mushroom.jpg Decomposers help by breaking up stored Nitrogen (in wastes, leaves, decaying plants/animals) and putting Nitrogen back into the soil Then bacteria in the soil turn a small portion into Nitrogen gas and returns it to the atmosphere so that completes the cycle.

62 Nitrogen cycle- Some nitrogen-fixing bacteria live free in the soil. Nitrogen-fixing cyanobacteria are essential to maintaining the fertility of semi-aquatic environments like rice paddies. Unicellular nitrogen-fixing cyanobacteria, shown in this light micrograph, play an important role in the oceanic nitrogen cycle. (Credit: Washington University in St. Louis)

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64 Lightning Nitrogen fixing bacteria Decomposers Atmospheric nitrogen Animals Nitrogen Cycle Denitrification by bacteria Plants Ammonium Nitrification by bacteria Nitrites Nitrates

65 web_environment.jpg Phosphorus cycle- Essential to form bones and teeth in animals, also helps increase growth in plants Phosphorus cycle moves from the environment to organisms, then back to environment again. (so doesn t really cycle through the atmosphere)

66 Phosphorus cycle- Enters soil when rocks erode or when decomposers break down the remains of dead plants and animals Plants then absorb phosphorus through their roots and the cycle is complete.

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68 How do Humans Affect the Nitrogen and Phosphorus Cycles? Humans have increased the natural rate of nitrogen and phosphorus, through the use of chemical fertilizers. - When excess nitrogen and phosphorus compounds run off fields into bodies of water, they can cause an overgrowth of algae blooms and aquatic plants. - If abundance of aquatic plants, then abundance of plant decay and abundance of decomposer, which deplete oxygen that other aquatic organisms need to survive.

69 Algal Blooms