How Humans Influence Ecosystems Chapter 3.2

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

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)

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...

USES OF BOGS Plants like blueberries and cranberries thrive in acidic bogs!

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

Let’s look at how we use land and resources... 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

Land Use As population grows, we use more land for various reasons Habitat loss = the destruction of habitats (places where organisms live). Habitat fragmentation = the division of habitats into smaller, isolated fragments

Thinking about it...How does habitat fragmentation affect....? Animal movement

Thinking about it...How does habitat fragmentation affect....? Seed dispersal

Thinking about it...How does habitat fragmentation affect....? Reproduction

Deforestation Deforestation = logging or clearing forest for human use (not replanting) Tropical rainforest deforestation is happening at an alarming rate.

Soil Degradation Soil degradation goes along with deforestation. This occurs when topsoil is removed from bare land due to water/ wind erosion. Erosion is a bigger problem when trees/ plants that held soil in place are no longer there. Plants need topsoil to grow.

Effects of Agriculture The opposite of soil degradation is soil compaction This happens in heavy, moist soil Soil is SQUEEZED together (less air spaces) Problems: poor plant health, run-off (sloped land)

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

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) Mines use ‘reclamation’: use of plants to decontaminate the soil/ water

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).

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