How Humans Influence Ecosystems. Chapter 3.2

Size: px
Start display at page:

Download "How Humans Influence Ecosystems. Chapter 3.2"

Transcription

1 How Humans Influence Ecosystems Chapter 3.2

2 Wetlands Wetlands or bogs are ecosystems where the soil is waterlogged (most or all of the year) Wetlands are like the kidneys of Earth About 5.6% of BC is wetlands (5.3 million hectares!)

3 Why are Wetlands Important? Bogs or wetlands are like sponges! Hold huge quantities of water (prevent flooding) Also retain carbon Bogs also contain peat which retains water and lowers ph (keeps the bog acidic)

4 Who Lives in a Bog? Bogs or wetlands are home to many species (they are places of plant and animal biodiversity!) They provide critical habitats for...

5 Burns Bog in Delta BC One of the largest bogs in the world, it is 3000ha and can be seen from the international space station Has 200 species of birds, 10 species of amphibians, 6 species of reptiles, and 50 species of mammals

6 USES OF BOGS The use of peat allows plants like blueberries and cranberries thrive because it retains water and lowers ph and create acidic bogs!

7 Understanding Sustainability The word sustainability refers to the ability of an ecosystem to sustain ecological processes These processes are important for biological diversity and ensure the continuation of the ecosystem over time. Sustainability can also refer to using the resources of an ecosystem to meet our needs today without reducing function and health of that ecosystem

8 WHY are Bogs Disappearing? Human expansion Subdivisions Parking lots Dumps Agricultural land (farming livestock or crops) Shopping malls and other amenities In the Okanagan, we have lost about 85% of our wetlands. This also affects biodiversity.

9 The Effects of Land and Resource Use Land use = the way we use the land Ex: urban development, agriculture, industry, mining, forestry Resource use = the way we GET and USE materials from the Earth Ex: water, soil, oil, gas, coal, metals

10 Habitat Loss As human populations grow, destruction and fragmentation of habitats occur. Habitat loss refers to the destruction of habits, which results from the human activities

11 Habitat Loss Sometimes habitats can be divided into smaller isolated fragments, this is called Habitat fragmentation = the division of habitats into smaller, isolated fragments Because of this fragmentation/division of habitats, plant pollination, seed dispersal, wildlife movement and plant and animal reproduction are greatly affected.

12

13 Thinking about it...how does habitat fragmentation affect...? Animal movement

14 Thinking about it...how does habitat fragmentation affect...? Seed dispersal

15 Thinking about it...how does habitat fragmentation affect...? Reproduction

16 Brazil and coffee! Brazil is known for its coffee because of the optimal conditions to grow the bean It is important to grow plants with different plants in order to maintain to prevent soil erosion and weed invasions This is called polyculture

17 The Effects of Deforestation A big problem today is Deforestation, where there is logging and clearing forest for human use and never replanted The tropical rainforest is shrinking at an alarming rate, which is responsible for providing a lot of oxygen we have on earth!

18 Soil Degradation As there is more deforestation, areas will face soil degradation. Soil degradation occurs when water and wind erosion removes topsoil from bare land. It takes 500 yrs to make 25mm of topsoil but 25 billion tonnes is lost globally per year!! Erosion is a bigger problem when trees/ plants that held soil in place are no longer there. Plants need topsoil to grow.

19 Deforestation Giant panda's are endangered as a result of reforestation in China. Bamboo, the primary food for pandas, has decreased in availability resulting in lower population numbers!

20 Effects of Agriculture In BC, there is a problem that is opposite to soil degradation, and that is soil compaction Soil compaction is when the soil is squeezed and squished together removing any air spaces in the soil. This is bad, because that air space is required for water and air to move through and allows plants to grow. Also affects soil organisms This happens in heavy, moist soil

21 One Solution Aeration = remove small plugs of soil Letting in the air! This allows more movement of water and air through soil.

22 Resource Exploitation We can also refer to resource use as resource exploitation Causes problems like habitat loss, soil degradation Some processes such as mining can cause contamination Ex: cyanide poisoning in lakes and rivers (mining) Contamination is the introduction of chemicals, toxins, wastes, or micro-organisms into the environment in concentrations that are harmful to living things. This cyanide prevents cellular respiration in living organisms and is deadly in small doses.

23

24 Mine reclamation After a mine closes, it is required by law to restore the land to its most natural form by developing water treatment plants to remove heavy metals draining from the site Decontaminate the soil and water

25 Overexploitation and Extinction The end of the road... Overexploitation is using a resource until it is gone/ depleted Overexploitation of a species (hunting) can result in extinction (dying out). Also loose genetic diversity that was once abundant

26 Sustainability Sustainability refers to how well an ecosystem can sustain itself (or carry out it s ecological processes). It can also refer to what people do: When people use resources from an ecosystem without seriously affecting its health and biodiversity. Finding a balance

27 Resource Management and Traditional Ecological knowledge In aboriginal cultures, traditional ecological knowledge is passed down from generation to generation. This is important to maintain the biodiversity and health of an ecosystem Food gathering and Nisga s Fish Wheels = proper fish size/safe