2.1 – Human uses of ecosystems

1. List 3 ways that ecosystems are important for humans. Ecosystems supply food, fuel, natural resources and water. 2. Ecosystems cycle nutrients and decompose wastes. 3. Ecosystems regulate climate.

2. Define the term sustainable use Sustainable use means using an ecosystem’s resources in a way that meets our current needs without compromising the ability of future generations to meet their needs.

3. a) what is genetic diversity Genetic diversity differences among individuals of the same species. This comes from the fact that we each have differences in our DNA.

b) Why is genetic diversity important to members of a species b) Why is genetic diversity important to members of a species? How does it improve survival of a population? Differences in individuals help keep a population healthy. Because we are all different, we have different strengths and weaknesses that allow individuals in a species to be able to cope differently should there be a change in our environment. Lack of genetic diversity in a population can threaten the survival of a species.

c) Define extinction and give one reason that the loss of genetic diversity can cause extinction Extinction is the death of every member of a species. As a population approaches extinction, the numbers of individuals drops. This reduces genetic diversity (there are few individuals able to reproduce, so their offspring are genetically similar). Because of this, the strengths and weaknesses of individuals are similar. Should there be a change in the environment, there may not be enough differences between individuals for the species to survive.

Extinction and Loss Of Genetic Diversity In the spring of 1987, an American biologist went to the cloud forest of Costa Rica to study Golden toads and counted fifteen hundred of them in temporary breeding pools. That spring was unusually warm and dry and most of the pools evaporated before the tadpoles in them had time to mature. The following year, only one male was seen at what previously had been the major breeding site. Seven males and two females were seen at a second site a few miles away. The year after, on May 15, 1989, the last sighting of only one male occurred. No golden toad has been seen since then. By 2004 IUCN listed the species as extinct IUCN gives numerous possible reasons in its description of the past threats to the species, including "[the golden toad's] restricted range, global warming, and airborne pollution“, as well as an increase in UV-B radiation, fungus or parasites, or lowered pH levels contributed to the Golden Toad's extirpation.

Golden toad

D) How are the terms biodiversity and genetic diversity different? Biodiversity refers to the variety of ecosystems on Earth, based on the number of different species that live in a certain area. Genetic diversity refers to differences in the DNA of individuals of the same species. We are all a little different from each other because our DNA is different from each other. The exception to this is identical twins, who have almost identical DNA.

4 a) describe and give example of habitat change Habitat change is the process by which humans alter a habitat enough that the native species (the species that normally inhabit the area) can no longer live there. Example of habitat change is clearing a forested area for agriculture, forestry or urban development. The animals and plants that normally inhabited the forest now have to find a new location to live in. This leads to greater competition for resources between these organisms and those in the location to which they move.

What are 2 conservation strategies used to reduce the problem of habitat change for at-risk species? 1. Protecting species in human-made habitats (for example, moving species to zoos). This is known as ex- situ conservation. Species are removed from their natural habitats (either because their habitat is threatened or no longer exists, or population numbers are so small) and brought to zoos, botanical gardens or reserves. This is generally a last resort to protecting a species.

2. Protecting species in their native habitats (in-situ conservation) – this type of conservation focus on maintaining habitats, removing predators, cleaning and restoring habitats that have been damaged or isolating a habitat by creating reserves.

b) overexploitation Overexploitation is using a resource faster than it can be replaced. In extreme cases, it can lead to extinction of a species. Example: over fishing of Atlantic cod. These fish were an abundant species in the North Atlantic for centuries. Advances in fishing techniques since the 1960s and 70s have caused fish stocks to be taken at too fast a rate. Young fish that normally would be too small to be caught in nets were taken, resulting in too small of a young population to reproduce and maintain the overall fish population. By 1990, the fish stocks were so low that the fishery for Atlantic cod was closed.

c) pollution Pollution is any substance that is added to an environment that produces a condition that is harmful to organisms. Pollution can affect land (e.g litter), water (e.g oil from oil spills) and air (e.g. exhaust from cars and industry).

List ways that gov’t and industry restore polluted ecosystems or prevent further pollution Remedial action plans 1. Identify the source of pollution 2. Develop a plan to follow to fix the problems created by the pollution 3. Restore the habitat (cut off the source of pollution, clean up, habitat rebuilding) 4. When the problem has been cleaned up, monitor conditions to ensure actions taken are effective

d) Invasive species An invasive species is a non-native species that causes harm to the ecosystem, usually by out-competing native species for resources and through rapid reproduction. An example of an invasive species is the European Starling. 100 European starlings were introduced to Central Park in New York City in 1899. Now there are more than 200 million of these birds all over North America. They out-compete native starling species for nesting spaces and food, and destroy grain and fruit crops. See P. 66 the round goby

Give 2 examples of how gov’t try to prevent the spread of invasive species Establishing laws that prevent the movement of potentially contaminated materials from a location known to be home to invasive species to uninhabited areas (e.g. laws to prevent movement of wood that may contain Asian Longhorned Beetles) Laws against the importing of foreign food, animals or plants into the country

e) Climate change Climate change is a deviation from the average climate that has occurred in an area over at least 30 years. It can cause temperatures to rise or fall, the amount of rainfall to increase or decrease, and wind directions to change. Climate change is currently being driven by global warming (an increase in the Earth’s average temperature caused partly by an increase in carbon dioxide in the atmosphere).

Global warming is largely due to increased burning of fossil fuels and loss of large amounts of forested areas. Global warming has caused rapid climate change. In Arctic areas warming has resulted in loss of ice packs, which is reducing habitat for native species like polar bears and walruses. Their populations are declining as a result.

5. Name an invasive species in oNtario 5. Name an invasive species in oNtario. How has it affected native species? What can be done to eliminate negative effects on ecosystem? Dog-strangling weed – this was brought in as a garden plant from Eurasia (southern Russia). It invades sunny hillsides and ravines. It grows in dense colonies and chokes out native small trees, plants and shrubs. It also affects affects Monarch butterflies, who lay eggs their eggs on the vine, but the larva are not unable to obtain the nutrients they they need from the vine, and therefore die.

6. 3 stresses on freshwater lakes in ONtario, and how stresses affect the ecosystem Motor boats – oil contaminates water and reduces oxygen in water (affects fish and water organisms) Sewage – raw waste increases nitrogen in water Docks – disturbs fish spawning grounds and aquatic vegetation Boat wakes – waves disturb aquatic and terrestrial vegetation and nesting sites Beaches – removal of aquatic and terrestrial vegetation causes habitat loss Clearing shoreline – loss of shade in water (needed for fish)

7.a) how does urban sprawl affect niagara escarpment Urban sprawl is the unplanned, disorganized growth of urban and suburban development into the surrounding countryside. It has affected the Niagara Escarpment by resulting in loss of forests, causing habitat change and habitat fragmentation (dividing a large habitat into smaller sections. It prevents organisms from using a large area for finding food and shelter. When a habitat is divided by roads, it can cause damage when organisms try to cross busy roadways).

b) What is done to protect escarpment? The Niagara Escarpment plan was established, which is a land-use plan that focuses on environmental protection. It has guidelines on how land in the escarpment area can be developed (a more planned and managed system to counter the effects of urban sprawl).

8a what is clear cutting and how does it affect boreal ecosystems Clear cutting is a logging process where all the trees in an area are cut down at one time, regardless of size. Clear cutting causes habitat loss and fragmentation, it alters water flow and can lead to soil degradation.

B) WHAT MEASURES HAVE THE ONTARIO GOV’T TAKEN TO MINIMIZE EFFECTS OF CLEAR CUTTING? Companies have to plant new trees in areas that have been clear-cut. Companies are not allowed to cut down more trees than they can replant in one year. Companies have started using sustainable logging practices

What is sustainable forest management What is sustainable forest management? what practices must be followed to be certified? Sustainable forest management is a practice whereby forestry proceeds with logging, but it allows for the resources to be available to future generations and has a more limited impact on the environment. This practice leaves forested areas near water ways that prevent erosion of soil and reduces changes to water flow). A variety of tree species are planted to allow for more biodiversity in the area.