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Test 1 Notes What is environmental Science? It is the study of how humans interact with the environment What is the environment? It includes the natural world as well as things produced by humans! Environmental Movement: Differing World Views As you know, the environment has not always been our top priority. It is actually more of a recent phenomenon. In Canada, we felt that because we had a large land mass (10 million square kilometres) which is only 6.7% of the total land mass of the planet, and a smaller population (30 million) our resources were unlimited and the environment should not be our concern. Now we know the environment is important and globally this view has begun to change. Two world views towards the environment Expansionist world view believed that although wastefulness was to be avoided in a developing society, nature could be exploited for gains in personal wealth and in the name of progress Ecologist world view asserts that all living things are valuable, regardless of their use to humans, and that any human activity must work within the confines of the healthy Functioning of the Earth's natural processes. Environmental History Industries popped up and expanded More automobiles were purchased Environmental problems became obvious i.e. color of air was darker, people developed more respiratory problems, beaches were filled with garbage and sewage etc. Wilderness was beginning to disappear therefore environmental groups were developed i.e. Sierra Club, Canadian Forest Industry etc. Two waves of environmentalism The first wave - department of the environment developed in Canada - first earth day celebrated in the US in 1970 - population concerned about - pollution - energy crisis - nuclear power - Populations The Second Wave population concerned about - global warming - ozone depletion - oil spills - resource depletion The Scientific Method Pure and Applied Science We use science to help us learn about the environment. There are two basic types of science: Pure science seeks to answer questions about how the natural world works. Ex: Physics and biology Applied science uses the information provided by pure science to solve problems. Ex: Engineering and medicine What is Science? Science is something you know - it is all the information gathered by scientist throughout history. Science is something you do - it is the way of getting the answers about our world. The way scientists get answer is through the scientific method. Scientific Method 1) Problem: Identify a problem from what you know 2) Form a Hypothesis: a hypothesis is a prediction of what the correct answer will be based on what you know 3) Materials: gather and record your materials that you are using 4) Experiment: (Procedure)Test the hypothesis. When testing you need a control and a variable. Hypothesis, Theory, Law A hypothesis is an educated guess. A hypothesis can be supported or rejected. A theory summarizes a hypothesis that has been supported with repeated testing. A theory is valid unless there is information to disprove it. A theory tells you why something happens. A law is a description of a principle but it does not explain them. Ex: Newton's law of gravity predicts what happens when an object falls, but not why it falls. What are our Main Environmental Problems? Environmental Problems -Pollution - Extinction - Resource Depletion Resource Depletion When a natural resource is used up it is called resource depletion. Natural resources include sunlight,plants,animals, forests and fossil fuels. Two types of resources: Nonrenewable resources: resources that cannot be replaced. Ex: Fossil fuels such as oil and natural gas. Renewable resources can be replaced such as sunlight, vegetation like corn and trees. Pollution Pollution is the poisoning of our air, water or soil. Pollutants are such things as car exhaust, pesticides or radiation. Extinction Extinction means that the last individual member of a species has died and the species is gone forever. The extinction rate has increase due to habitat destruction and pollution. Why does this matter to us? All livings things exist in an area surrounding the Earth called the biosphere. The biosphere extends 8 km above the surface of the Earth to 8 km below the surface into the deepest part of the ocean. Root of environmental problems Although all humans live in the biosphere, people in different countries have different immediate needs and priorities. There are two types of nations: Developed countries have good industry with high average incomes such as the US, Canada and Australia. Developing countries less industry and have lower average There are two main environmental problems: Population crisis which means the number of people is growing too quickly for the Earth to support Consumption crisis which means people are using up, wasting or polluting natural resources faster than they can be renewed, replaced or cleaned up. The Goal of Environmental Science The goal of environmental science is to achieve a sustainable world where all populations can continue to exist with a high standard of living and health. What is an Ecosystem? An ecosystem includes all the different organisms living in a certain area, along with their physical environment. An ecosystem is like a car, all the parts work together to make the car move. If one part breaks, the car may not run. Ecosystems are not an isolated unit. They do not have clear boundaries. Ecosystems are composed of two factors: biotic factors: living parts of an ecosystem. Ex: animals, plants and micorganisms abiotic factors: nonliving parts of the ecosytem. Ex: temperature, sunlight, humidity, water supply and minerals Ecosystem have a level of organization. (Smallest) Organism Population Community Ecosystem (Biggest)Biosphere organism - an individual living thing species - a group of organisms that are able to reproduce together and that resemble each other in appearance, behaviour and internal structure. Population - a group of individuals of the same species living in a particular place. Community - a group of interacting populations of different species Habitat- the place where the organism lives. Niche- the way of life of an organism. This includes everything an animal does and how it interacts with everything in its environment. Ecosystem, Biome, and Biosphere Before we continue discussing ecosystem structure, we must understand how everything fits together. Ecosystem (Smallest) Biome Biosphere (Biggest) How species interact with each other. Within an ecosystem, different species can affect each other negatively or positively. We will look closely at five major types of species interactions: Predation Competition Parasitism Mutualism Commensalism Predation, Predator, Prey Predation is the act of killing and eating another organism i.e. a lion kills a zebra the organism that kills and eats another organism is called the predator the organism that is killed and eaten is called the prey Competition the relationship between species that attempt to use the same limited resources Animals compete for the limited resources available to them. Resources can include food, sunlight, space etc. Parasitism the relationship between a parasite and its host Parasites are organisms that feed on or live within another organism without killing it immediately. However some parasites can lead to death. Examples of parasites = tapeworm, ticks, fleas, leeches The organism the parasite infects is called the host. Can you think of any reason why the parasite may not want to kill its host? Mutualism A relationship between two species in which both species benefit Ex. Anemones and clownfish are known to benefit from each other in an intimate relationship. The clownfish becomes immune to the stinging nematocysts of the anemone. The anemone provides protection and food scraps for the fish. The fish lures other creatures into the anemone's tentacles and may also remove dead and dying tissue from the anemone. Commensalism A relationship between two species in which one species benefits and the other species is neither harmed nor helped. Test 2 Notes What is an Ecosystem? An ecosystem includes all the different organisms living in a certain area, along with their physical environment. An ecosystem is like a car, all the parts work together to make the car move. If one part breaks, the car may not run. Ecosystems are not an isolated unit. They do not have clear boundaries. Ecosystems are composed of two factors: biotic factors: living parts of an ecosystem. Ex: animals, plants and micorganisms abiotic factors: nonliving parts of the ecosytem. Ex: temperature, sunlight, humidity, water supply and minerals Ecosystem have a level of organization. Organism (smallest) Population Community Ecosystem Biosphere (largest) organism - an individual living thing species - a group of organisms that are able to reproduce together and that resemble each other in appearance, behaviour and internal structure. Population - a group of individuals of the same species living in a particular place. Community - a group of interacting populations of different species Niche, and Habitat Habitat- the place where the organism lives; the specific type of area in which a plant or animal lives (on the planet). Niche- the way of life of an organism. This includes the area where the organism feeds, reproduces etc. It is biotic (living i.e. plants, other animals, humans) resources How Species interact with each other Within an ecosystem, different species can affect each other negatively or positively. We will look closely at five major types of species interactions: Predation Competition Parasitism Mutualism Commensalism Predation, predator, and prey the act of killing and eating another organism i.e. a lion kills a zebra the organism that kills and eats another organism is called the predator the organism that is killed and eaten is called the prey Competition the relationship between species that attempt to use the same limited resources Animals compete for the limited resources available to them. Resources can include food, sunlight, space etc. Parasitism the relationship between a parasite and its host Parasites are organisms that feed on or live within another organism without killing it immediately. However some parasites can lead to death. Examples of parasites = tapeworm, ticks, fleas, leeches The organism the parasite infects is called the host. Can you think of any reason why the parasite may not want to kill its host? Mutualism A relationship between two species in which both species benefit Ex. Anemones and clownfish are known to benefit from each other in an intimate relationship. The clownfish becomes immune to the stinging nematocysts of the anemone. The anemone provides protection and food scraps for the fish. The fish lures other creatures into the anemone's tentacles and may also remove dead and dying tissue from the anemone. Commensalism A relationship between two species in which one species benefits and the other species is neither harmed nor helped. Feeding Relationships, Three trophic levels Each species in an ecosystem belongs to a certain trophic (feeding) level based on their main source of nutrition. In studying the feeding relationships between organisms, we are actually looking at the living, or biotic, factors of the environment. Producers Consists of all plants, may also be called autotrophs. Has the ability to make its own food through photosynthesis. Supports all other feeding groups. Makes up the greatest amount of biomass on the planet. Eaten by consumers. Consumers consists of all animals. These organisms are not able to produce their own food so they must find their own food. They are also referred to as heterotrophs. There are 3 orders of consumers: 1st order = herbivores eat the producers (plants) i.e cow, sheep, deer etc 2nd order = carnivores eat other consumers (animals) i.e. lions, hawks, foxes etc 3rd and 4th = feed on other carnivores in the environment i.e. killer whales Humans are considered omnivores because we eat both plants and animals. Bears, pigs and other animals are also omnivores because they eat both. Decomposers Life forms that live on dead, dying or decayed plant and animal matter. Mostly consist of fungi and microscopic organisms, such as bacteria. Scavengers like ravens, crows etc help decomosers by breaking down dead material. Essential to the natural environment. They help to recycle nutrients back into the ecosystem. They break down animal excretions and dead organisms into simpler components that can be taken in and reused by producers. Food Chains Food chains can be written in a number of different ways, the simplest is: Sun producers consumers Food Webs All of the possible feeding relationships within an ecosystem are shown using a food web. Summary of food webs and food chains Within ecosystems there are producers, consumers and decomposers who transfer energy to one another through food chains or food webs. Trophic Level = the level in the food chain that an organims occupies. It can be producer, consumer, primary consumer, etc. Producers are the 1st trophic level and contain the most energy and each subsequent level has less and less energy. Food Chain = simplified way to show which organisms eat one another. Food web = represents all possible food interactions that can occur between certain organisms Optimal Living Conditions Each species will respond differently to these abiotic factors. The way that they respond determines where they will live. Different species will do well under different conditions. Every organism has an optimum, a level they thrive at. This is called the optimal zone. i.e. a good amount of water, sun etc. There is also a point where life is not possible. A high and low end of this range of optimance and this is the limit of tolerance. If an organism reaches this point they cannot survive. The stress is too much for them. Zones of stress exist between the optimal environmental and the high and low limits. The organism would experience levels of stress as they become closer to their tolerance limit. Test 3 Notes Ecosystem Function Energy Flow in Ecosystems What do organisms in an ecosystem require to function? Nutrients (Matter) Energy How do they obtain these nutrients? Photosynthesis Respiration Cycling/Recycling Key elements of all living things: - N (nitrogen) - C (Carbon) - H (Hydrogen) S (Sulfur) P (Phosphorus) O (Oxygen) These elements make up 95% of all living matter. In water, air and minerals, atoms are found in relatively simple inorganic compounds. Matter and Energy Matter is the substance that everything is made of. Water, food, soil, computers, rocks etc all consist of matter. Matter is anything that occupies space and has mass. This includes all solids, liquids and gases. Energy Energy is the ability to do work and can act on matter. We use energy to move matter around i.e. we might move a table, chair etc. Animals in nature might move rocks or tree limbs. Matter can also be changed from one form to another and energy allows us to do this i.e. a windmill can convert wind into energy that humans can use. Photosynthesis Producers (plants) use photosynthesis to obtain their food and energy. This is the equation for photosynthesis: 12 H2 0+6 CO2 +sunlight energy=C6 H12 O6+6 H2 0+ O2 Cellular respiration Consumers (animals and other organsims) use celluar respiration to obtain their energy Stored energy from plants and animals is released During this reaction energy is produced. This energy is used by consumers The chemical equation for cellular respiration is shown below: C6H12O6 + 6 O2 6 CO2 + 6 H2O + energy Does this formula look familiar to you? Where have you seen it before? What is the relationship between photosynthesis and respiration? Energy Flow in Ecosystems All organisms requires energy for growth, maintenance, reproduction, locomotion, etc... There are three main types of energy: Heat Energy Mechanical Energy Chemical Energy Other Types of Energy - light electric atomic sound nuclear Sources of Energy In Canada we use 10 basic sources of energy: - hydropower (energy from water) i.e. mactaquac dam - nuclear energy (point lepreau) oil (colson cove) coal (belldune) and petroleum natural gas (courtney bay) solar biomass geothermal wind tidal and wave Renewable vs. Non-renewable energy Non-renewable resource (Exhaustible) - These are energy resources that we can run out of or be used up - Examples could be: o Oil o Gas o Coal o Nuclear Power (uranium) - Positives for these types of resources are that they are efficient sources of energy, meaning you can get a lot of energy out of burning a small amount of these fossil fuels. - Negatives for these types of resources are that the burning of all fossil fuels leads to greenhouse gas emissions (dirty), and that their resources can be used up. Renewable Resources – These are resources that can be used up, but can also be replaced or replenished. Meaning as you use the resource, you can also replace the resources. - Examples are: o Wood from trees o Biomass/Bioconversion for energy – using plants, garbage, and other living materials for energy. Living material is broken down using methanol to alcohols which can be used for energy. - Positives for these types of energy are that their resources can be replaced when used up. - Negatives for this type of energy are that burning of wood and release of gases caused by biomass can lead to emission/pollution. Biomass is also very inefficient, meaning it takes a lot of living material to produce a small amount of energy. Inexhaustible Resources – These are resources that can never be used up, and cannot be replaced as well. - Examples are: o The suns energy – Solar power o Hydro Power – Power from Dams o Tidal and Wave – Using the movement of tides for energy o Geothermal – Earth’s natural heat (hot springs) o Wind – Wind mill turbines - Positives for these types of energy are that they have unlimited resources. You can never use up the sun’s energy, there will always be water current, and there will always be wind. Also, these types of energy cause little to no emissions. - Negatives for these types of energy are that they are very inefficient. It takes too much conversion of the resource to produce too little energy. Matter is recycled. Each organism serves as food for another. Producers eat consumers, consumers eat other consumers and decomposers feed on the dead and dying. Therefore all of the nutrients (like carbon, hydrogen, oxygen and nitrogen) which made up the organism recycle back into the environment. Cycling of Materials Energy and matter are recycled in an ecosystem in order for it to function. Within this matter that is recycled are the key elements. Each of these key elements is recycled in what is called a cycle. We have the carbon cycle, water cycle, nitrogen cycle and phosphorus cycle. The Water Cycle Energy comes from the sun. The water cycle has 3 processes: Evaporation Condenstation Precipitation The sun evaporates the water from ocean, rivers, lakes, soil and from the surface of leaves into the atmosphere. When the water vapor reaches the colder air of the atomosphere is condenses back into liquid water and is stored in the clouds. When the clouds become filled with this liquid water it is returned to earth as precipitation (rain, sleet, snow, hail etc). This water collects in rivers, lakes, oceans or is absorbed into the soil. The process is then able to begin again. The Carbon Cycle Carbon enters the ecosystem through the atmosphere as CO2. Producers (plants) absorb the CO2 during photosynthesis. Consumers eat the producers and obtain carbon from them it is then released back in the atmosphere during cellular respiration. When animals and plants die and are decomposing, decomposers release the CO2 back into the atmosphere as well through cellular respiration. The remaining carbon from the dead and decaying organsims is placed into the soil. Carbon can also be produced by the burning of wood and fossil fuels through combustion and be released into the atmosphere. The Nitrogen Cycle All organisms require nitrogen, however only nitrogen fixing bacteria are able to use nitrogen gas directly. Nitrogen fixing bacteria are able to take nitrogen from the atmosphere and transform it into ammonia. Plants obtain ammonia through the soil. Animals obtain ammonia from eating plants. As plants and animals die and decompose the nitrogen they contain in their proteins is returned to the soil or water and the bacteria can break it down into nitrate or nitrites, which is returned back to the atmosphere. Ecosystem Succession How Ecosystems Change We have looked at energy flow in the system and cycling of materials, now we will look at how ecosystems change. Ecosystems undergo succession which is the regular pattern of changes over time in the types of species in a community. The process may take hundreds or thousands of years. The final stable community that forms if the land is left undisturbed is called the climax community. Primary Succession When succession occurs in areas where no ecosystem existed before. Ex: Islands created by volcanic eruptions and areas exposed when a glacier retreats. Primary succession is slower because it begins where there is no soil. pioneer species = the first species of plant, animal or decomposer to inhabit a piece of land, water etc these species are joined by other organisms and then these organisms are replaced with other species as the community becomes more mature. Secondary Succession - occurs where an ecosystem previously existed. i.e. areas burned by fire that have re-grown, farmland that has been abandoned being used for farms again