Ecosystem changes and interactions

1. Ecosystem changes and interactions

2. Biological Evolution • Biological evolution is descent with change. • Involves descent through heritage • The main idea of biological evolution is that all life on earth share a common ancestor

3. Organism Functions • Organisms interact and thus, exchange energy • Since all ecosystems are different, if two organisms act one way in one ecosystem, if they were to act the same way in a different ecosystem, the end result would not be the same • Organisms exchange elements amongst each other such as soils, water, and atmosphere • When organisms die, their remains go into the soils and are broken down by decomposers. From there, the nutrients in their remains sink into the soil and, depending on which organism and what nutrients, while benefit the soil, the things that grow out of it, and the organisms that eat the things grown from the soil

4. Interactions Between Organisms and Their Environment • Organisms that are herbivores eat things in their environment such as: • Grasses • Leaves • Woody plants • Fruits • Seeds • Saps • Pollen

5. Interactions Among Organisms • Organisms that are carnivores eat other organisms. • When prey populations flourish, predator populations decrease until the prey populations dwindle. • When prey population is high, predator population is high, and when prey population is low, predator population decreases. • Competitive exclusion suggests that 2 species that require the same resources cannot exist in the same location • Some relationships between organisms are parasitism, commensalism, and mutualism • Invasive species can sometimes introduce itself to an ecosystem. They can be in the form of plants, diseases, insects, or even other animals.

6. Invasive Species Species with these traits are most likely the be successful invaders: • High reproductive rates, pioneer species, short generation time • Long-lived • High dispersal rates • Vegetative or cloned reproduction • High genetic variability • Broad native range • Habitat generalist • Broad diet  • Human introduction • Ecosystems with these traits are most likely to be invaded: • Climatically matched with original habitat of invader • Early successional • Low diversity of native species • Absence of predators on invading species • Absence of native species morphologically or ecologically similar to invaders • Absence of predators or grazers in evolutionary history (“naïve” prey) • Absence of fire in evolutionary history • Low-connection food web • Simple communities

7. The Impact of Humans • Dams for Hydro Electricity • Disposal of Radioactive Wastes • Oil Spills • Smog Air Pollution • Soil Erosion • Introduction of Invasive Species • Heavy Metals • Salting Roads • Crop Irrigation • Irrigation, land erosion and pesticide run off • Global Warming • Use of CFC's and impacts on the Ozone Layer • Overuse of Pesticides • Use of PCB's • Deforestation Destruction of Wetlands • Urban Encroachment • Endangered Species • Acid Rain • Water Contamination • Use of Fossil Fuels

8. Changes • Climate changes impact each ecosystem and species individually • Climate changes could result in the extinction of ecosystems as well as the creation on ecosystems • All climate changes each species’ way of living • Global warming and the release of greenhouse gases impacts each ecosystem greatly, and differently

9. Vocabulary • Biological Evolution- descent with change • Herbivores- animals that eat plants and grasses • Carnivores- animals that eat other organisms • Predator- population of animals that eat other organisms • Prey- population on which predators feed • Competitive Exclusion- concept that suggests that 2 species that require identical resources cannot coexist in the same location • Parasitism- one species (parasite) benefits more than the other species (host) • Commensalism- one species benefits while another is neither helped nor injured • Mutualism- both species benefit from the interaction • Decomposers- organisms that break down other dead or decaying organisms

10. Sources Cited • http://www.etap.org/demo/biology_files/lesson6/instruction2tutor.html • http://www.eoearth.org/article/Ecosystem • http://i.dailymail.co.uk/i/pix/2010/10/28/article-1324243-0BCB8805000005DC-203_468x286.jpg