...the impact of human activity on plant succession. (10 marks) Plant succession is the process by which one plant community replaces another over time. Human activity can have an impact on the succession of plants in a number of ways these are known as arresting factors. A plagioclimax community is a habitat in which the impact of humans has subsequently meant that the ecosystem has been prevented from developing further. The plagioclimax with which I will give reference in this essay is heather moorland. It must be noted that much of the present vegetation in the UK is a plagioclimax as a result of clearance. Heather moorland provides a choice example of a plagioclimax in the UK. The areas where heather moorland is most prominent are the North York Moors, the Pennines and Eastern Scotland. Much of the land where Heather moorland now exists was once covered by deciduous woodland, the UK’s climatic climax, yet humans have had a critical impact on the way in which heather moorland has manifested itself in these areas. One must acknowledge that heather had featured in these areas prior to the suspension of succession. Humans removed deciduous woodland in these areas to make way for farmland as a result of the need to increase food production. By chopping down vast swathes of deciduous woodland, the soil in these areas began to deteriorate without the much needed nutrients associated with the deciduous woodland biome. Heather and other hardier plants such as Bracken, Grasses and Scrub...
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...After viewing the succession of the ecosystem in the Succession animation I have determined it is an example of a secondary succession. A secondary succession is defined as a change in species composition after a disturbance destroys the existing vegetation in an area that contains soil (Wiley, 2000-2012). The Succession animation was about a forest that contained a small creek. The natural flow of this creek was disturbed by a dam built by beavers thus creating a flood in the forest, the death of the current trees and plants and the new growth of trees and plants in later years. That is why it is a secondary succession. Evolution takes place in the process of natural selection. This process is one where necessary and successful characteristics and traits are passed on to future members of the species for survival. All traits and characteristics that are unnecessary cease to exist in future offspring. The hypothesis I’ve formed in regard to the aquatic salamander, who is missing hind limbs and has small forelimbs, is it came from a line of salamanders that migrated to a new area where they no longer needed their hind limbs. It is possible their new home had smaller areas for them to swim through and their limbs were proving to be a hindrance. Through the process of natural selection, the offspring of these salamanders were born with smaller limbs until their hind limbs were no more. This would be an example of their struggle for existence. References: • Wiley, J. (2000-2012)...
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...Intermediate Disturbance Hypothesis Background Habitats and the ecological communities they support are often greatly impacted by disturbance. For example, forest communities can be disrupted by fires, blow-downs, floods, and hurricanes. Alpine plant communities can be devastated by landslides or avalanches. Marine systems such as coral reefs can be decimated by storms, ravaged by predators, or trashed by inconsiderate tourists. On a smaller scale, many habitats can be disturbed both above and below ground by burrowing creatures such as gophers or moles. All of these disturbances can change the composition of species in a habitat and can also change relative species abundances. Both the intensity and the frequency of disturbance can influence how the composition of species in an area will change. In general, when disturbance is minimal or rare, then the species that are best at competing with other species for resources will eventually take over. Alternatively, when disturbance is extensive or frequent, then species that are good colonizers or can recover from disturbances rapidly will be at an advantage and will dominate. For example, a forest that has not been disturbed for a long time generally hosts species of trees and other plants that can grow under low light, but will not include many grasses or bushes. If the same area were burned periodically, the trees would rarely have time to become established. Instead, a grassland community comprising species capable of rapid colonization...
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...Ecological Succession The world around us is slowly and constantly changing. We might never see the small alterations happen, but many years later changes will surely be visible. Over time small changes add up and soon the whole ecosystem is different. This slow change in the land and habitat is called ecological succession. Animals, plants, and weather are some factors that cause this type of change in an ecosystem. Ecological succession begins with a pioneer community. In many cases lichens are the "pioneers." Lichens break down rocks, making soil, so that plants can begin to grow. The process then continues on; trees grow, decay and then new trees grow back even bigger. Differences in the amount of sunlight, the amount of wind, and the type of soil all influence this changing community of organisms. The number and type of organisms change along with the habitat. Many, many years later the ecosystem becomes relatively stable. This stable condition can last for hundreds of years and is called a climax community. Sometimes nature's power causes changes that happen more quickly, but not instantly. An example of this is repeated flooding. In some areas floods happen often, each time new sediment is carried by the water and the deposited. Over time a marsh habitat becomes present, next a grassland and then a forest. At other time nature works backwards by tearing down a climax community with a flood or fire. New kinds of organisms are able to move in and the process repeats its...
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...Living organisms change as the abiotic and biotic components in their environment change. The process that makes change possible in living things is called natural selection. Scientists use the term adaptive radiation to describe the change from a common ancestor into a number of different species that “radiate out” to inhabit different niches. Ecological succession is the term scientists use to refer to changes that take place over time in the types of organisms that live in an area. Primary succession occurs in an area where no soil exists, such as on bare rock. Pioneer species is the term scientists use to describe the lichens and other plants that are the first organisms to survive and reproduce in an area. The process of primary succession leads to the development of a mature community, which is sometimes called a climax community. Flooding occurs in coastal areas, rivers, and lakes, when the volume of water exceeds the ability of the water body to contain it. Tsunami is the term used to describe a huge, rapidly moving ocean wave and it is usually caused by large earthquakes or underwater volcanic eruptions. Drought is a recurring event in many parts of the world, it usually occurs when there is a below-average amount of precipitation in an area over a period of many months or years. Land use refers to the ways we use the land around us for urban development, agriculture, industry, mining, and forestry. Resource use refers to the ways we obtain and use these materials...
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...survivorship curves common in nature. Explain what k and r selection are and which of the three types of survivorship curves they correspond to. Which curve corresponds to increased quality of offspring? Which corresponds to increased quantity? 3. Species relationships: discuss competition, predation, mutualism, herbivory and parasitism. Give an example of each relationship and explain the benefit or harm that the organism is receiving. 4. Explain the competitive exclusion theory and give an example of what this theory suggests. What is the ultimate outcome of competitive exclusion? Explain how resource partitioning allows organisms to overcome competition. 5. Explain primary succession in plants. What plants are pioneer species? What plants dominate each stage of succession? What is the climax community? 6. Explain the 10% rule of trophic efficiency. Use a food chain as an example. If we start with 1,000 J of energy in producers, how much energy is available to primary consumers? How much would be available to secondary consumers? To tertiary consumers? Where does the “lost” energy go? 7. Define biodiversity and explain three major threats to biodiversity. Describe why the threats exist. What can we do to protect biodiversity? Why should we care? 8. Explain global climate...
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...James Shin Per 7b/8 Ecology Take Home Test 1) In the given info, there were two groups, an experimental and control group of flowers and sagebrush in a desert landscape that were identical except that the experimental group had a fence enclosed around it. Also, there was a predation relationship between the wildflowers and the kangaroo rats because the kangaroo rats eat wildflowers. Assuming that the fence was limiting the space of the experimental plot, competitive exclusion caused the extinction of the 4 other wild flowers. To begin, there was some interspecific competition, which happens when individuals of different species compete for a resource that limits their survival, between the 5 flower species in the experimental plot because they had their space limited to the fence that they were enclosed in. this competition was a density dependent factor in that the death rate rose when population density in the plot rose. Also, some of the specie’s ecological niches (like what nutrients they needed and how many branches would form) would have had to been the same or else they could coexist together. Then, one of the species of wildflower might have had a reproductive advantage like thorns to repel the kangaroo rats which would have allowed them to prosper and the other species to die out. This is the principle of competitive exclusion. On a tangent, the kangaroo rats would have learned to stay away from the wildflower with thorns by classical conditioning because they...
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...death rate. This carrying capacity would allow an ecosystem to survive. 7. CFC’s are Chlorofluorocarbons. They are used in refrigerators, aerosol, and air conditioning. They have to do with the ozone hole because they are one of the main causes of it. Over the years uses of CFC’s started to grow and with it the hole in our ozone. 8. The Little Ice Age lasted between 1300 and 1870. It was a time when Europe and Northern America endured a much colder temperature then they were used to, and mountain glaciers expanded. 9. The United States of America, Liberia, and Burma/Myanmar are the three countries in the world that have not adopted the metric system. 10. Mycorrhiza is a fungus that grows in a symbiotic relationship with the roots of plants, meaning both are mutually benefitted. 11. A preservationist believes in keeping nature the way it is without any alterations and making...
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...Primary succession begins in barren areas, such as on bare rocks exposed by a retreating glacier. The first inhabitants are lichens or plants-those that can survive in such an environment . Over hundreds of years these “pioneer species” convert the rock into soil that support simple plants such as grasses. These grasses further modify the soil, which is then colonized by other types of plants. Each successive stage modifies the habitat by altering the amount of shade and the composition of the soil. The final stage of succession is a climax community, which is a very stable stage that can endure for hundreds of years. Primary succession occurs in essentially lifeless areas- regions in which the soil is incapable of sustaining life as a...
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...Succession is natural, gradual changes in the type of species that lives in an area. Whether it be primary or secondary succession occurring in the ecosystem. Primary takes longer to reach the climax community because of the bare rocks that later on forms into soil by the pioneer species over a period of multiple years. When the pioneer species die and decompose, they leave a very small amount of organic material for later on use of becoming soiled for instance lichens or moss. The organic material being added to the soil gives the soil more nutrients, allowing more diverse but little, simple plants. Once again, when these simple plants die they give more nutrients to the soil, allowing complex plants like small bushes and trees to grow. When it reaches this stage, small organisms start to move in insects, small birds, and mammals. Secondary succession is the reestablishment of a damaged ecosystem in an area where the soil was left intact. Since some nutrients are already present in the soil in this environment, it can sustain plants that are more elaborate early than in primary succession. In years to come, some simple plants start to reproduce like grasses, weeds that eventually start to take over. The whole process that occurred during primary succession will follow, but where it took hundreds of years to reach climax...
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...FAQ: Biodiversity and Ecosystems Question 1: What is meant by succession, and what factors are responsible for succession? Answer 1: Succession is the order in which an ecosystem becomes established. It is the process by which species within a community replace one another in a given ecosystem. Usually, the complexity of the communities increases as they are replaced. Succession is triggered by a disturbance (fire or storm) or newly created open areas (deforestation). Ecological succession has several levels including primary and secondary succession. Primary succession involves pioneer species, which are usually the first ones to colonize open areas. They are hardy species and include things like microbes, mosses, and lichens. Eventually, the pioneer species become replaced by climax species. Climax species only occur after a long period without disturbance. Climax species are usually long-lived and require a stable environment. Question 2: How can natural selection lead to the development of new species? What are the prerequisites and the limitations? Answer 2: Natural selection was first proposed by Charles Darwin in his book Origin of Species. Natural selection is the process by which certain gene combinations give an organism a certain advantage over the others in a population. This trait then becomes selected as the population continues to reproduce. For example, suppose a certain mouse can run faster than any of the other mice in a population. The mouse will have a better...
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...Species Author’s Name Institutional affiliation Date Invasive species are non-native (plants or animals) to an ecosystem and their introduction is probable to cause human health, environmental, or economic damage in the ecosystem. Africanised bee (Apis hybrid), hybrid of European and African honeybees, is an invasive species in U.S.A. It invaded into Southwestern U.S northwards from Brazil (origin). The species can be curbed by cold temperatures (mild winter) which renders them inactive (Emerton, 2008). They (killer bees) attack violently and usually entail many stings, which, when accumulated, are fatal to people and animals. The thriving population of lionfish in Atlantic Ocean affects us by reducing the resources available for commercial fishing industry. Lionfish feed on small crustaceans, coral reefs, and young fish (inclusive of the young of vital commercial fish). Lionfish’s venomous spines are very painful to the human body. Natural predators and groupers are set to remedy this hazard since the available potential predators cannot alleviate the lionfish available in the Ocean. Spearing and eating them is also remedying the situation. Zebra mussels are invasive species in the Great Lakes. They were inadvertently brought into Lake St. Clair, after which they spread all through the Great Lakes. They caused harsh problems at municipal water supplies, power plants, clogging intake screens, cooling systems, and pipes. They have also alleviated, nearly, the ecosystem’s...
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...The British Isles is an example of a Lithosere succession, in that it began as bare rock from glacial retreat. The plant succession started with the pioneer species which were algae and bacteria. Both began to broke down rock surface through weathering. Then lichens and mosses began growing in the area which helps with water retention and provides a base for soil. The next stage of primary succession is herbs/grasses/flowering plants/ferns. These add nutrients and organic matter to the ground which provided soil. Next, shrubs invaded and colonised the area. Shrubs dominate and shade out the sere below them. Small trees such as birch and willow were the following sere which invaded and colonised the area. They produced humus from leaf fall which provided nutrients for the soil through nutrient recycling and encouraged new growth of the sere. The last sere is the larger trees which are oak and ash which dominate the area and shade out smaller trees. This sere is the climax community in that it is stable and no further succession happens after. The climax community is the deciduous woodland biome we know today. The main characteristics include the location in which they are found, which is in temperate maritime climate such as the UK with four distinct seasons: spring, summer, autumn and winter. The average temperature in the British Isles is 10oC which is the optimum temperature for a temperate deciduous woodland and rainfall is between 30 and 60 inches. Deciduous trees are physically...
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...interact with biotic components. Biodiversity: the variety of all living species of plants, animals, and micro-organisms on Earth. Niche: The special role an organism plays in an ecosystem, including the way in which it contributes to and fits into environment. Structural adaptations: a physical feature of an organism’s body having a specific function that contributes to survival of the organism. Physiological: a physical and chemical event that occurs within the body of an organism that enables survival. Behavioral: what an organism does to survive in the unique conditions of its environment. Species: a group of closely related organisms. Population: all members of a particular species. Community: all the population of the different species. Bioremediation: the use of organisms (micro or plants), to break down chemical pollutants in water or soil to reverse/lessen environmental damage. Decomposition: breaking down of organic wastes and dead organisms. Biodegradation: action of living things such as bacteria to break down dead organic matter. Decomposer: change wastes and dead organisms into usable nutrients. Detrivores: consumers that obtain their energy by eating bodies of small dead animals, plant matter, and animal wastes. Herbivores: primary consumers that eat plants. Carnivores: secondary consumers that eat primary consumers. Omnivores: consumers that eat both plant and animal. Natural selection: the process that makes change possible in living things...
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...This would be roughly 6,000 years after the retreat of the Wisconsinan glaciation. The deglaciated terrain would need sufficient time to develop a soil profile substantial enough to support the needs of the Basswoods. The succession of the area would have begun with the pioneer species that, after an ample period of time, would have broken down the bedrock and provided organic materials to create soils. Therefore, we cannot expect Basswoods to occupy the deglaciated terrain until subsequent stages of succession. Additionally, the Basswoods require damp soils in order to grow and reproduce. Moist soils would imply moist environments. The time period that best allows for a moist environment based on palynological evidence is approximately between 8,500-5,000 years ago. This was a warm and wet period after the glaciations of the Northeast. The cool and dry climate that existed before this time period, as indicated by Menking et al. (2012) would not have been an ideal climate for the expansion of...
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