Scott Unit 1 - Ecology Student Copy (1) PDF

Ecology  The Study of Ecology Ecology is the study of the interactions living things have with each other and with their environment.  Definition ECOLOGY is the scientific study of interactions among organisms with each other and with the environment....

Ecology  The Study of Ecology Ecology is the study of the interactions living things have with each other and with their environment.  Definition ECOLOGY is the scientific study of interactions among organisms with each other and with the environment. The largest of nature’s “houses” is the biosphere. The biosphere refers to the biological component of Earth’s systems. In other words, the portion of the planet that can sustain life and all of its interactions.  Levels of Ecology There are six scales that concern ecology: individual The first 3 only look at the population living components (biotic). community The last 3 look at both biotic and the abiotic (non- living parts). ecosystem biome biosphere Levels of organization Species--a group of organisms/individuals similar to one another that can breed and create fertile offspring. Population- A group of organisms of one species that interbreed and live together within a defined area. Examples of populations A herd of sheep A flock of geese A colony of ants A sleuth of bears A brood of chickens A pack of dogs Individual population community  Communities are groups of populations comprised of many species that live together in a defined area. An ecosystem is a combination of the communities and the physical (nonliving) environments. Examples: An ecosystem is Rotting log living & Koi pond nonliving Lake factors in a A field particular Bog place. Marsh An old maple tree Can be large A clump of dirt or small Activity What elements are most common/important in living organisms? Activity  BioGeoChemical Cycles Since all living things are made from chemicals, we need to be able to track the movement of these “nutrients” through the “spheres”. Different components have different methods of moving in and out of living things. We term these the biogeochemical cycles. We can track the flow of materials such as; Water, Carbon, Nitrogen in an ecosystem. It is this interaction that allows life to exist and sustain itself. Hydrologic Cycle (Water) - Background Composition of water: All matter is composed of elements which are composed of atoms. Atoms can combine to form molecules - this is through chemical bonds. ○ Water is 2 hydrogen to 1 oxygen An atom can also become positive or negative and is called an ion. Abundance of water? Abundance of water: 97.47% (97%) of all water is salt water (oceans, seas, bays) 2.53% of all water is freshwater ○ 1.74% in ice (ice caps, glaciers, permanent snow) ○ 0.79% is liquid (groundwater and surface water) Water background (cont.) Properties: Can be found in all 3 phases of matter (liquid, solid, gas) 1. It is Polar - has an uneven distribution of electrons. 2. It has a high specific heat. a. absorbs and releases heat (energy) slowly. Sweating is a way to remove excess heat. 3. It has Cohesion - the ability to attract to itself. 4. It has Adhesion - the ability to attract to other polar molecules. 5. It shows Capillary Action - the ability to “climb” narrow tubes due to adhesion and cohesion. 6. It shows high surface tension - since it has cohesion, the force of attraction can support some weight (force). 7. It is a universal solvent. Can you name the properties of Water? Modeling Water You are going to read an article about water and how it moves within a system. Pay attention to vocabulary and how it gets from 1 “source” to another. These are concepts that you are going to use to construct a model of the water cycle. Activity The Cycle Itself Where is the largest “source” of water? Name methods of moving from place to place (geosphere to atmosphere) Carbon Cycle - background Carbon is found in the air as carbon dioxide, an easily accessible form. All organic compounds (those found in living things) are built with carbon as the backbone of the molecule. Other elements may attach to the carbon backbone to create other forms of organic molecules, each with different purposes. More information about these molecules will be discussed in unit 3. The Carbon Cycle Carbon is an essential element for all living things. Carbon is found in living tissues, rocks, the atmosphere, and the ocean. Less than 1% of the carbon found on Earth participates in the carbon cycle. Carbon dioxide that is in the air or dissolved in water is used by photosynthesizing plants, a algae and bacteria as a raw material to build organic molecules such as glucose Carbon may return to the air or water in 3 ways: Respiration-- all living organisms undergo cellular respiration. They use Oxygen to break down food, CO2, is a byproduct of the reaction (exhaled) Erosion-- marine organisms use carbon to make shells, (calcium carbonate) when they die the calcium carbonate is broken down, CO2 forms and is returned to the atmosphere. Combustion-- when carbon returns to the atmosphere through combustion or burning of fossil fuels. (Carbon is locked beneath the Earth, dead organisms in sediment may gradually transform by heat and pressure into fossil fuels). Combustion of fossil fuels releases CO2, which is a greenhouse gas. Modeling Carbon Using background knowledge and/or readings, discuss carbon and the forms it comes in, how it could move through living things and where the original source is found. You will then build a model either alone or in small groups. Compare models and discuss pros/cons. Activity Carbon Cycle The movement of carbon through the biotic and abiotic parts of the environment. Nitrogen cycle - background Nitrogen is another essential component for organic molecules. Nitrogen is the most abundant element found in the atmosphere but elemental nitrogen (N2) isn’t in a usable form. It must be converted by special bacteria into a form that other living organisms can use. Since nitrogen is such an essential element for growing food, humans have added nitrogen to the ecosystem through the use of fertilizers. Is this a good thing or a bad thing? Be sure to look at both the pros and cons. Create a model demonstrating how nitrogen moves in the system (and the potential problems with it). Activity Modeling Nitrogen cycle You have discussed how nitrogen moves in an ecosystem and have completed a resource concerning adding additional nitrogen to a system through fertilizer. Construct a model showing how nitrogen moves through a system. Activity Nitrogen Cycle The movement of nitrogen through the biotic and abiotic parts of the environment. Important to note that bacteria both have to begin and end this cycle. Phosphorus Cycle The movement of phosphorus through the biotic and abiotic parts of the environment. This is important for ATP, DNA and other organic molecules. Note; this is the only cycle that starts in the geosphere.  Populations & Communities Population - A group of individuals of the same species in a given area at the same time. Community - all of the population in a given area at the same time. Interactions can occur both within a population and within a community. Populations - characteristics Population size Population density Population distribution Growth Niche Competition (intraspecific) for biotic & abiotic factors, abiotic tolerance How do changes affect the population (succession) Population: Size and Dynamics To understand populations, ecologists count the number of individuals in it. Various techniques are used to estimate the size of populations whose members can’t be counted directly. Plot sampling - for organisms which don’t move. Capture/Recapture - for mobile organisms. From population size and area, you can calculate density. Population Sampling You are going to sample 2 different populations using random sampling (also called plot sampling) and capture/recapture (also called mark-recapture sampling). You will need to determine which technique is best for each population. You will also determine the actual population size and calculate the percent error of your sampling work. Activity Now we know how many, now what? It is also important to know how the organisms are dispersed in their environment. Patterns: Uniform Random Clumped Dispersion patterns leads to population density which can be used to predict how it may change over time (size, not evolution) and how they may interact. ○ Low density makes it hard to find mates, etc., high density strengthens competition. Types of Population Growth Exponential growth An exponential increase occurs when the number of new units added to a population is proportional to the number of units that exists. Makes an exponential curved line graph. Sometimes called a J-shaped growth curve. Logistic growth If the growth levels out instead of continuing to increase, it is called logistic growth. This is sometimes called S-shaped growth curve. Models of Growth for Natural Populations  There seems to be unlimited growth on an exponential curve. Eventually, there will be so many that they can’t support themselves and will have a die off. When it reaches a point of up and down, it is termed unstable equilibrium and that means carrying capacity has been reached. At this point, the exponential growth becomes logistic growth.  In a logistic growth curve, it will start as an exponential. When there is enough population (density dependent), it will start to slow (negative acceleration or transitional phase) until it stabilizes at what the environment can support. ○ This is called carrying capacity and is at a stationary phase Calculating Growth Rate Exponential growth in living populations can be calculated by subtracting a population’s death rate from its birth rate, which yields the population’s growth rate. Denoted as r, this rate is also known as the population’s intrinsic rate of increase. Intrinsic Rate of Increase (r) Growth rate can also be affected by Generation time Carrying Capacity (K) The maximum population density of a given species that can be sustained within a defined geographical area over an extended period of time. As carrying capacity is reached, the growth rate will lower (slow) and can fluctuate around the actual carrying capacity.  Populations don’t remain at the carrying capacity, they will always fluctuate some due to limiting factors. We usually find K within the fluctuations. Different populations often “follow” each other in their fluctuations, why would this happen? Using Growth Curves You are going to examine growth curves and answer questions using the information provided. You will also use data to make a growth curve and identify the type. Activity Population Growth regulation - Limiting Factors A limiting factor is anything that will determine how many of a population there can be in a given area. Density Dependent factors As the population density increases, these factors assert themselves more strongly on population growth. Tend to be biotic factors: food, competition, predation, disease/parasites, waste accumulation. (leads to carrying capacity) Density Independent factors These factors do not depend on the size of the population to limit growth. Tend to be abiotic: wildfire, weather, pollution, natural disasters  Niche - the role of an organism Producers - those organisms that can make their own food. also called autotrophs These will make the first trophic level Consumers - those organisms that eat other organisms. These may be herbivores, omnivores, or carnivores These will make the additional trophic levels They can also be classified as primary consumers, secondary consumer, etc. Activity Detritivores: Some extras A class of consumer that feeds on dead organisms and cast off material. These can be an any level and are labeled as some type of consumer. Decomposers: A special type of detritivore that turns the material into its’ inorganic parts and returns them to the environment (recycles through an ecosystem). Energy can also be tracked through trophic levels As we track energy through an ecosystem, we create a food chain or a food web. Food Chains Apply the trophic level terms to this chain. The arrows indicate the direction the energy is flowing - don’t put them backwards. Chains are limited in length due to running out of energy for more organisms. Let’s say that the grass has 100,000 Calories of energy, how much would be at the secondary consumer level if 10% can “move up”? Food Webs While a food chain is more simple and highlights parts of an organisms energy consumption, a food web is a better model to demonstrate interactions between species in an ecosystem. A food web is basically several food chains from the same ecosystem that are interconnected. In other words it branches to form the “web”. You should start with the producer and then you can follow any series of connections through the web. This allows a single organism to have more than one “label” attached to it. i.e. it could be both a secondary and tertiary consumer depending on what line you trace. Sample 1. How many producers are present? 2. How would you label the rabbits? 3. What labels could you put on the birds? 4. What labels could you put on the Foxes? Data Analysis Trophic Level Producer Primary Secondary Tertiary Consumers Consumers Consumers Population Count 6,025,682 723,082 98,541 4 1. How does population size change at each trophic level? 2. What is the relationship between trophic level and population size? 3. Predict what would happen if a quaternary consumer were added to this ecosystem. 4. Where does most of the energy go from one level to the next? Pyramid Models Pyramids are used to represent the larger amount at the base of the food chain and the smaller amount at the top (just like a pyramid). Types: 1. Energy Pyramid - shows the transfer of energy (like our example) 2. Biomass Pyramid - shows the biomass at each level (review biomass) 3. Pyramid of Numbers - tells how many individuals are present at each level. Often the amount moved to the next level is simplified to 10% (unless specified)  Trophic efficiency Just a fancy way of saying how much energy is available to the next trophic level. It is calculated as a percentage. ○ Do the problem to the right. Biomagnification Sometimes harmful chemicals travel through a food chain and accumulate in those organisms that are toward the top. As the biomass decreases, the amount of chemical stays the same. This causes an increase in concentration until it can eventually be fatal, this is termed biomagnification. Environmental Resistance The size of living populations is kept in check by environmental resistance, defined as all the forces of the environment that act to limit population growth. Sometimes, it isn’t the predator that causes a change in the prey population, it can be some other source. What might that be and how does that in turn affect the predator? Activity Reproductive Strategies Different species have different characteristics that affect the number of fertile offspring they bear. They can be classified into either K-selected or r-selected K selected r selected Called equilibrium species Called opportunist species Tend to be physically large Tend to be physically small Have a relatively stable environment Have a relatively unstable environment Offspring have a good deal of parental attention Offspring with little to no parental care Tend to have density dependent pressures. Tend to have density independent pressures  K-selected r-selected equilibrium opportunist species Population size Population size species Time Time Population size: Population size: limited by carrying capacity (K) limited by reproductive rate (r ) density dependent density independent relatively stable relatively unstable Organisms: Organisms: larger, long lived smaller, short lived produce fewer offspring produce many offspring provide greater care for offspring provide no care for offspring Checkpoint #1 Biomes of the World - Terrestrial Desert Tropical grassland Temperate grassland Tropical rainforest Temperate deciduous forest Temperate rainforest Taiga Tundra Biomes of the World - Aquatic Lakes and Ponds Rivers Wetlands Estuaries Kelp Forests Coral Reefs Activity You are going to use the internet to obtain information about different biomes. You will use this information to compare and contrast the different types of biomes. Activity Invasive Species A species which is not native to a region but is present anyway. These cause disruptions to the natural ecosystem/community. They tend to not have any predators in the new environment Think of some examples to share: (both national, state, local) Structure in Communities Many communities are dominated by only a few species. The few species that are abundant in a given area are called ecological dominants. A keystone species is a species whose absence from a community would bring about significant change in that community. Activity Types of Interaction among a community: 1. Competition 2. Parasitism/Predation 3. Mutualism 4. Commensalism Parasitism/Predation interactions The difference between these interactions is whether the prey is consumed or kept alive. Parasitism - the host is kept alive to ensure a source of food. Predation - the prey is eaten in part (or in whole) and then the predator will move on to another organism. Remember, predator and prey population sizes can be “linked” but generally, predation is only one of several factors that control population size.  Predation spurs evolution Developing camouflage to avoid predation: Developing mimicry to fool the predator. (Batesian & Mullerin) There is a mimic, a model, and a dupe. Mutualism An interaction between individuals of two different species that is beneficial to both individuals. Find an example and add it to the Table (in GC) so there are examples. Define the role of each participant. Commensalism An interaction in which an individual from one species benefits while an individual from another species is neither benefited or harmed. Coevolution Often, the interactions between different species in the community will lead to changes in the population (species) which leads to changes in other populations (species). This is called coevolution. Biodiversity - variety among living organisms 1. Species diversity - how many different species in a given area. 2. Geographic diversity - how the species are distributed across the area. 3. Genetic diversity - how many variations within a population. Diversity tends to enhance a community’s productivity and stability such as nutrient cycling and energy flow. Diversity also allows for the support of ecosystem services such as: climate regulation, carbon storage, water filtration, pollination, and flood/erosion control Stability, Resilience & Resistance An ecosystem that is stable (unchanged) for a long time can usually recover faster from a disturbance than one that isn’t stable. High resilience means that an ecosystem can recover quickly from a disturbance. The more diverse an ecosystem, the more resilient it is. Resistance is the ability of an ecosystem to show little impact from a disturbance. Repeated disturbances affect resistance. Activity You will use an online simulation to create a community. You will record the species diversity (how many species and how many of each there are present). Based on that data, you will make a prediction about which is more diverse and hence more stable. Use the linked spreadsheet to input the data to get the diversity index number. You need to take turns as there are only 10 tabs to use. When you finish, erase your data so the next group can use the tab. Activity  Wet i ty e rs di v Cold bi o Hot i n g re as in c Dr y Biodiversity & BIOMES Ecosystems that have more space allow for more species to coexist, increasing biodiversity. Biomes that can support more producers (think plants) support larger and more complex food webs, increasing biodiversity. Generally, life is supported by sunlight and water. Too much or too little of either would Biodiversity & CLIMATES Warmer climates generally support more plant life, which will support larger and more complex food webs, increasing biodiversity. Climate is more than just temperature. Dryness, humidity, and precipitation also play a role. Generally, a drier climate Biodiversity & NICHES A niche is an organism’s way of life in an ecosystem, including habitat, food, predators and competition. BARKING NICHE TREE FROG Habitat: wooded regions, wetlands Behaviors: often found in trees, can burrow, barking call attracts mates Feed on: small insects Eaten by: birds, snakes, racoons Impacts on ecosystem: limit insects, aerate soil, serve as food source Biodiversity & NICHES More niches means there are more opportunities for species to coexist and survive, which increases biodiversity. Fewer niches means that species have to compete with each other for resources, The many layers of a rainforest create many niches which can support a huge variety of making it harder to species.  What makes an ecosystem stronger and more resilient? MORE LESS or biodiversit biodiversit y? y? WHY? More biodiversity decreases the amount of competition, which makes it easier for more species to survive. A more biodiverse food web can better adapt to more changes. Therefore, a more biodiverse ecosystem is more resilient. Competition Competition is the struggle for a limited resource. The competitive exclusion principle states that when two populations compete for the same limited, vital resource, one always outcompetes the other and thus brings about the latter’s local extinction. Coexistence through resource partitioning refers to instances when 2 similar species use the same kinds of resources from the habitat but will divide them up such that neither species undergoes local extinction. Activity  Resource Partitioning Resource Partitioning Cape May Bay-breasted Myrtle warbler warbler warbler What can upset an established ecosystem? Natural disturbances Human disturbances Tornadoes Volcanic eruptions Often destroys biodiversity Forest fire (from lightning) Agriculture (reduces natural earthquakes/mudslides habitat) Roads and highways (fragments ecosystem) Changing abiotic factors Damming rivers or altering their flow for our use. Disturbances to an Ecosystem Parcels of land or water that have been abandoned by humans or devastated by physical forces will almost always be reclaimed by nature to some degree. This process is called succession: a series of replacements of community members at a given location until a relatively stable final state is reached. Succession comes in 2 forms: Primary succession and secondary succession. Primary Succession Developing an ecosystem/community in an area that was uninhabited. ○ No soil or previous biotic components. ○ Lava flows, new island formation, glacial till ○ First things in (pioneer species) are usually lichen and moss, then grass, shrubs, trees  We look at plants when discussing succession. The first organisms to arrive during primary succession are called pioneer species. The pioneer species facilitate or help later species (often by providing soil and other growing materials). When the community becomes stable (the final community), we call it a climax community. Secondary Succession Reestablishment of an ecosystem in an area where the soil was left intact (and has a seed bank). ○ Fires, floods, agriculture ○ Happens much faster due to having plants, seeds, organisms left from the disturbance. ○ First things (pioneer species) are usually grass, shrubs, trees. As succession occurs, species diversity tends to increase. Any organism that survives the disturbance is termed a biological legacy and can help speed up the process of succession. Human Disturbance These can range from the example we had earlier about adding fertilizer to a system that makes it unbalanced it all the way to removing a system through things like deforestation. Invasive species are another way to make a change. Use the activities to demonstrate and learn about human disturbances. Activity Quiz #2 Learning Checkpoint #2