What two factors have the most important effect on a region's climate?

Transcription

1 Chapter 4 - Kinds of Ecosystems 4.1 Forests biome - climate - weather conditions - What two factors have the most important effect on a region's climate? Types of Forests Tropical Rain Forests location - tropics (around the equator) - all within 30 0 latitude above or below the equator conditions - humid, warm and lots of rain (5m of rain per year) - lots of sunlight, very little seasonal variation number of species/ hectare - (find the dimensions of a hectare) soil - thin and poor (trees use up nutrients from dead plants quickly, rain washes away the rest) plant adaptations - 1. animal adaptations - 1. Threats to the rain forest - used to make up % of earth's surface - makes up less than % today

2 Temperate Rain Forests Location - *Temperate region - more than 30 0 above or below the equator (see map pg 86) Coastal temperate rainforests have four defining characteristics: a proximity to oceans, presence of coastal mountains, cooler summer temperatures and high rainfall levels. Exist in BC, southeastern Alaska and parts of Australia and New Zealand Temperate Deciduous Forests Location - Growing season - Soil conditions - Precipitation levels m - 5m per year Plant adaptations - 1. Animal adaptations - 1. See comparison of forests 1620 vs Taiga - also called the boreal forest Location - usually more than 50 0 latitude Growing season Soil Conditions Plant Adaptations Animal Adaptions You should be able to identify the type of forest by their location on a map

3 4.2 Grasslands, Chaparral, Deserts and Tundra When climates experience less rainfall they change from forests, as we have talked about, to areas with smaller and less diverse vegetation such as grasslands, chaparral and eventually to desert Savannas Location - same area of the globe as tropical rain forest with an obviously reduced amount of rainfall Due to lack of rainfall grass fires are common Plant adaptations- 1. Animal adaptations - 1. Temperate Grasslands : Prairies, Steppes and Pampas Location - Used to cover 42% of the earth but only covers about 12% today Fertile soil - great for crops Location on the continents - interior usually bordered by mountains Prairies - North America Steppes - Pampas - Rainfall - only about 25cm per year Plant adaptations - Animal adaptations - Threats to Temperate Grasslands - -

4 Chaparral - occurs right around the 30 0 latitude - occurs in coastal areas that have Mediterranean climates - hot dry summers, mild, wet winters - slight variations in seasonal temperatures - the landscape is shrub covered grassland Plant Adaptations - low lying shrubs and small trees - small leathery leaves that prevent water loss - leaves also contain oils that promote burning - which is an advantage because natural fires destroy trees that may compete with chaparral plants for light and space. Chaparral plants have evolved to the point where they can resprout from very small bits of surviving tissue. Animal adaptations - camouflage - also adapted to be able to get food from different sources due to seasonal variations in food. Threats to Chaparral - human development - human's want to live there as the region is close to the ocean, mild climate (year round) and have lots of sun. Deserts - areas that receive less than 25cm of precipitation a year - often occur in the shadow of mountains - can occur anywhere between 50 0 below the equator to 50 0 above the equator and anywhere in between, quite often around 30 0 due to reasons you will learn later Plant adaptations 1. Animal adaptations 1. Threats to Deserts

5 Tundra - biome devoid of tall trees that lies north of the Arctic circle - mostly tough grasses and shrubs that can survive the frozen soil - summers are short and only the top couple inches of soil thaw. Below that is the permafrost - because only the top layer thaws, bogs and swamps are common which are breeding grounds for swarming insects Plant adaptations 1. Animal adaptations 1. Threats to the Tundra

6 Assignment - Biomes 1. What land biomes exist in the temperate regions? How are deserts and tundra similar? How are they different? 3. What physical feature of the land divides the forests and grasslands? 4. What is a marmot? Where would you expect to find one? 5. How are the trees in the deciduous forest different from those in the taiga? 6. At what latitude, approximately, would you expect to find a chaparral? 7. What type of vegetation would you expect to find in: a. Chaparral b. Savannah c. Tundra 8. In what biome do the animals follow the rains for food? 9. Why do plants in the grasslands have large root systems? 10. What is the relationship between root depth and rainfall in the grasslands? 11. What rainfall amount would you expect in the rainforest? The desert? 1 What is a threat to the tundra? The deserts? The grasslands? 13. The grasslands used to cover what percentage of the Earth's surface? What caused the change? 14. Why don't trees grow in the grasslands? 15. Why are the temperate deciduous forests different that the temperate rain forests? 16. What would the soil be like in a) the tropical rain forest b) the temperate deciduous forest c) the savannahs d) the pampas 17. Scientists predict that if the earth keeps warming at its current rate that the land biomes will shift their borders. Where do you think the lines may move to? How would this affect Canada? 18. Label your page from A- H and write down what biome exists in each area show in the diagram on the previous page.

7 4.3 Freshwater Ecosystems By definition include lakes, ponds, rivers, streams and areas where land and water come together (wetlands). They contain very little, if any, dissolved salt. Plant and animal life depends on the depth of water, speed of water movement and amount of mineral nutrients, sunlight and oxygen. Lakes and Ponds Made up of two basic areas: 1. Littoral zone - Benthic zone - These two areas are where most of the living (and dead) organisms exist. In open areas very few plants grow. Only those that can use sunlight readily exist there. Lakes and ponds that contain large amounts of nutrients are called. As plants and algae grow so does the number of bacteria feeding on decaying matter which uses up the oxygen in the lake. Most lakes eventually become over a long period of time but the process may be accelerated by sewage runoff, fertilizers and animal wastes. Plant and Animal Adaptations 1. Wetlands Wetlands - 2 main categories are: 1. State 3 valuable functions of wetlands :

8 Marshes - Plants have roots in the sediment at the bottom which is rich in nutrients. Their leaves are above the water. - animal/bird adaptations 1. Marshes are named based on amount of salt dissolved in water (salinity) 1. Brackish Tidal Florida everglades is the largest freshwater marsh in the United States Marshes usually form in quiet shallows of ponds, lakes and rivers, and along sheltered coastlines where mineral nutrients are available. Swamps - usually exist on flat, poor draining land near streams - shrubs and water tolerant trees are common - type of trees depend on the latitude and climate - ideal habitat for many amphibians such as They usually occur along river floodplains and in poorly drained basins. Swamps sometimes dry out in the summer but some remain continually flooded. Most swamps in North America are found in southeastern US and in the Great Lakes region Over time ponds that become eutrophic will have extra plants grow in them. Eventually through succession the pond may become a marsh. If the right climatic conditions exist the marsh may have trees grow and the marsh may become a swamp. Is this primary or secondary succesion?

9 Rivers - most rivers originate from snowmelt in mountains - at the headwaters the water is cold, usually fast moving and contains a lot of oxygen - obviously the water slows and warms as it gets down the mountain and reaches flatter land - plants and animals in the river depend upon the climate and nutrients in the water, runoff from land may wash nutrients and sand into the river Plant and Animal adaptations Threats to rivers: 4.4 Marine Ecosystems Type of life on land depends on temperature and amount of rainfall Type of life in the oceans depends on amount of sunlight and nutrients available. Estuaries estuary - Ways that plants and animals adapt to marine ecosystems: 1. Threats to Estuaries: - 7 of the 10 largest cities in the world are based around estuaries - used as places to dump wastes, later the areas became landfills - estuaries still have the same sources of pollutants that rivers, lakes and ponds deal with. - estuaries can still experience eutrophication but due to the constant flow of fresh water it isn't a large problem in many estuaries unless there are large populations of humans living there.

10 Coral Reefs They are limestone islands in the sea that are built by coral animals called polyps Polyp - simple form of water animal which is not much more than a saclike stomach with fingerlike tentacles around the edge to gather food. They often grow in colonies with their bases connected - Thousands of plants and animals live in the cracks of coral reefs making them the most diverse ecosystem in the ocean. - Corals grow exclusively in warm water where there is enough light for photosynthesis, as a result they only exist in shallow tropic seas. - Corals only live in the outer layer of the reef where they build the limestone with the help of photosynthetic algae. The algae are what give the reefs their color. - During their lifetime one out of four ocean inhabitants spend at least part if not all of their lifecycle in coral reefs. - There are 5 nations in the world that live entirely on coral atolls (similar to an island) Homework - find out what an atoll is exactly. Animal Adaptations 1. Threats to Coral Reefs 1. Careless divers who break off parts of the reef Ship wrecks (which are obviously less common now) 3. Ship anchors 4. Pollution from oil spills, sewage, pesticide and silt runoff 5. Overfishing 6. If the water is too muddy or too high in nutrients the algae that live in mutualism with the polyps will either die or grow out of control and smother the corrals. 7. Temperature - greatest effect - increase in temp can cause the coral reefs to become "bleached". This occurs when the algae move away. - an overall temp increase of the ocean of 1 0 C can quite possibly lead to 82% of the Great Barrier reef being bleached, 2 0 C can lead to 97%

11 Oceans - ocean covers nearly 3/4 of the earth's surface - most life is concentrated in shallow areas around the edges of continents, since the plants are around the edge so are most of the fish - in the open ocean only phytoplankton grow where the sunlight can reach them, which is in the upper layers only. Because of this the open ocean is one of the least productive ecosystems inthe world Plant Adaptations 1. Animal Adaptations 1. Threats to the Ocean - pollution (originate on land and are the same as for freshwater ecosystems) - newer problem is nuclear waste from power plants (up until 1970 most radioactive waste was dumped into the ocean in glass and metal containers which have since leaked)- so they say!! - overfishing and the methods of fishing are destroying the fish. Dead fish that are not used are thrown back into the ocean - dolphins drown in the nets - some ships discard used nets which kill fish and seals (this is illegal) olar Ecosystems - considered a marine ecosystems because nearly all food is provided by phytoplankton - Antarctica is land that is covered in a permanent icecap - North pole is not land at all The Arctic Ocean - relatively shallow, waters are rich in nutrients, lots of phytoplankton - large variety of fish live in open ocean and under the ice - seals have holes in the ice to be able to fish The Antarctic - it is the only continent not inhabited by humans - used mainly for research of the unusual animals - only a few plants grow at the edges of the continent - plankton make up the basis here also

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