Download
1 / 21
210 likes | 337 Views
Ecology Standard BL6. Ecology Standard BL6. BI6. Stability in an ecosystem is a balance between competing effects. As a basis for understanding this concept: .
E N D
Ecology Standard BL6 BI6. Stability in an ecosystem is a balance between competing effects. As a basis for understanding this concept: What this actually is telling you, is that the World and all its living and not living components must work together as even when they seem to be working against each other. Example #1: The Sun shines down on the grass and rabbits eat the grass, this is direct competition between two different organisms, however, as the rabbits produce waste, bacterial actions break down this waste into chemicals the grass can use to regrow. This cycle of life and death, allows the World to be a stable environment, until something causes an in balance of these factors. Example #2: As animals breath in oxygen, they breath out carbon dioxide in the process of respiration. Plants on the other hand, take in carbon dioxide, and give off oxygen in the process of photosynthesis. These two processes work as opposites to keep nature in balance with rather equal amounts of oxygen and carbon dioxide in the atmosphere at any one time.
Ecology Standard BL6 BI6. a.students know biodiversity is the sum total of different kinds of organisms and is affected by alterations of habitats. Basically, if we only had a few types of food, everyone would have to eat pretty much the same thing and if one of those types of food were to disappear due to say a drought (lack of water) then all of us would be affected. Example #1: Several species of fish, birds, amphibians, plus numerous species of plants, aquatic insects and other organisms all live in or surrounding habitat of a mountain lake. The lake is kept full by snow melt which fills in with a small stream and is emptied as water over flows at the other end. One day a land slide covers the stream and prevents water from reaching the lake, over the next few years, the lake dries up and most of the organisms are either killed or have to seek another lake.
Ecology Standard BL6 BI6. a.students know biodiversity is the sum total of different kinds of organisms and is affected by alterations of habitats. Example #2: The tropical rainforest of Costa Rica is home to hundreds of species of plants and animals, some of which are found no where else on the planet. As the need for food for humans increases, forest is burned down or cut down in deforestation which causes many organisms to become extinct or endangered. This loss of habitat, causes other organisms to have to emigrate out of the area.
Ecology Standard BL6 BI6. b.students know how to analyze changes in an ecosystem resulting from changes in climate, human activity, introduction of nonnative species or changes in population size. Example #1: At one time here in Southern California the temperature was quite different. How do we know this? Fossil records of animals which lived in much colder climates, such as the Woolly Mammoth and Sabre Toothed Tiger have been found in the La Brea Tar Pits near Los Angeles.
Ecology Standard BL6 BI6. b.students know how to analyze changes in an ecosystem resulting from changes in climate, human activity, introduction of nonnative species or changes in population size. Example #2: As the human population grows, so does the need for more resources such as wood and minerals. Below are two examples of how humans can change the environment. Deforestation of the Amazon Rainforest. Here lush forest was burned off so that farmers could grow crops. However, with in 2-5 years, this land will not grow anything due to the high run off rate of the RAIN which washes away all the soils nutrients. Strip mining of the land is done in areas that are often sensitive to environmental changes, such as this forest. Large machines literally “strip” the land of all life to get down to the minerals used by humans. The land may take hundreds of years to repair itself, and return to it’s climax stage, if it ever does.
Ecology Standard BL6 BI6. b.students know how to analyze changes in an ecosystem resulting from changes in climate, human activity, introduction of nonnative species or changes in population size. Example #3: Invasive nonnative species can also cause not only environmental damage, but economic damage as well. There a species of fresh water mussel, called zebra mussels, show the biological and economic damage they can cause by being spread to water areas which have no predators for the mussels. This is a crayfish or crawdad, to some, which is almost completely covered with zebra mussels. These mussels are about the size of a dime when fully grown. Here is the damage these creatures can do to a boat’s outdrive when left in waters which contain the zebra mussels. This may cost the owner hundreds if not thousands of dollars to repair.
Ecology Standard BL6 BI6. b.students know how to analyze changes in an ecosystem resulting from changes in climate, human activity, introduction of nonnative species or changes in population size. Example #4: In the past 60+ years, San Fernando Valley has grown from about 250,000 people to over 1.4 million. This increase has caused a loss of habitat, crop lands, species; and has caused an increase in air pollution, traffic congestion and waste production.
Ecology Standard BL6 BI6. c.students know how fluctuations in a population size in an ecosystem are determined by the relative rates of birth, immigration, emigration and death. Example #1 On the American Plains, Bison or Buffalo, once roamed the grasslands by the millions. Food was plentiful, lots of space. Then came Man and his machines. The death rate grew rapidly and birth rates became almost nonexistent. There was little or no migration in or out of the herds.
Ecology Standard BL6 BI6. c.students know how fluctuations in a population size in an ecosystem are determined by the relative rates of birth, immigration, emigration and death. Example #2 immigration and emigration are difficult to determine in wild populations. Humans on the other hand are easier due to the fact that we count them as they enter the US.
Ecology Standard BL6 BI6. d.students know how water, carbon, and nitrogen cycle between abiotic resources and organic matter in the ecosystem and how oxygen cycles through photosynthesis and respiration. Example #1 all living organisms use both biotic (living) and abiotic (nonliving) resources for survival. When the Sun shines on plants, many of these become food for herbivores, which in turn become food for carnivores. As these food chains/webs continue, materials like carbon and nitrogen are passed from one organism to another. When the last organism dies, decomposers help return these elements to the environment so that they may be used again to continue the life processes.
Ecology Standard BL6 BI6. d.students know how water, carbon, and nitrogen cycle between abiotic resources and organic matter in the ecosystem and how oxygen cycles through photosynthesis and respiration. This shows the basic movement of Carbon in living organisms and nonliving factors of the environment.
Ecology Standard BL6 BI6. d.students know how water, carbon, and nitrogen cycle between abiotic resources and organic matter in the ecosystem and how oxygen cycles through photosynthesis and respiration. This shows the basic movement of Nitrogen through various organisms and how decomposers, such as bacteria, help return nitrogen to the environment.
Ecology Standard BL6 BI6. d.students know how water, carbon, and nitrogen cycle between abiotic resources and organic matter in the ecosystem and how oxygen cycles through photosynthesis and respiration. This shows the basic movement of water through the environment. Water is also passed through most living organisms and back to the environment through urination, sweating and decomposition.
Ecology Standard BL6 BI6. d.students know how water, carbon, and nitrogen cycle between abiotic resources and organic matter in the ecosystem and how oxygen cycles through photosynthesis and respiration. This shows the basic movement of oxygen through the environment. Oxygen is given off by plants in photosynthesis and is used by animals in respiration. Carbon is also cycled through in a similar, but reverse course, being used by plants and given off by animals
Ecology Standard BL6 BI6. e.students know vital part of an ecosystem is the stability of its producers and decomposers. Example #1 all food chains and webs begin with producers, the green plants and organisms which convert the Sun’s energy in to usable food for herbivores and all organisms above them. This energy pyramid shows how produces do just that, produce energy for each trophic level above them and that there is a loss of energy at each level above due to heat and waste material. Without produces, there would not be a flow of energy in the ecosystem and food chains would collapse and organisms would die.
Ecology Standard BL6 BI6. e.students know vital part of an ecosystem is the stability of its producers and decomposers. Example #2 decomposers, usually fungus and bacteria are also important for the stability of an ecosystem, because they break down dead organisms and allow the materials in them to be returned to the environment and also break down animal waste products (poop) again returning nutrients to the environment.
Ecology Standard BL6 BI6. e.students know vital part of an ecosystem is the stability of its producers and decomposers. Example #2 decomposers, usually fungi and bacteria are also important for the stability of an ecosystem, because they break down dead organisms and allow the materials in them to be returned to the environment and also break down animal waste products (poop) again returning nutrients to the environment. This is Pseudomonas, a common bacteria found in many environments and is a big part of decomposition. Fungi breaking down a dead tree in a forest.
Ecology Standard BL6 BI6. f.students know at each link in a food web some energy is stored in newly made structures but much energy is dissipated into the environment as heat. This dissipation my be represented in an energy pyramid. Example #1 as energy is passed from one trophic level to the one above it, energy, about 10% is lost through normal processes. Heat loss through respiration and waste products represent the majority of the loss. Also involved with this loss of energy is the physical increase in mass of the organism feeding on the lower level as it grows.
Increase of mass for organism Heat loss
Ecology Summarization Ecology is the study of the interactions between living (biotic) and nonliving (abiotic). Primary producers(plants) collect energy from the Sun and nutrients from the atmosphere and soil, to produce food material (glucose…) to feed consumers (herbivores, carnivores). When these organisms die or produce waste, decomposers and detritivoresbreakdown this material and return the resources to the environment. Cycleswith in the Earth and atmosphere, allow many of these materials (limitingfactors) to recycle between living organisms and nonliving environment. Populations of organisms are controlled by one or more of these; birth rates, death rates, immigration and emigration. Invasive, nonnative species can ruin natural ecosystems by upsetting the predator/prey and other symbiotic relationships. Biodiversity, the amount of different species, is important to the planet so as not to have a collapse of food webs or energy pyramids which could lead to the extinction of one or more species. Like a house of cards, loosing too many or the “right” species, could cause the extinction of thousands of species, including Humans. Human interactions with the environment often leads to harming the ecosystem.
