3 - Mrs Hopp's Website



3.2 How Humans Influence Ecosystems

_______________________ means:

• The ability of an ecosystem to sustain itself (stay alive and healthy).

• Humans using the natural resources they need without destroying nature.

A _____________________ ecosystem provides economic opportunities while maintaining biodiversity and ecosystem health. It will be able to continue to provide for future generations.

__________________ refers to the way we use the land around us for:

• ___________________________________(building cities)

• ___________________________ (growing things)

• ___________________________ (working)

• _____________________ and ____________________

_______________________ are naturally occurring materials such as soil, wood, water, gas, oil,

and minerals. ____________________________ refers to the ways we obtain and use these materials. When humans use land and resources, they change the nearby ecosystems. As human populations grow, so does our impact on the environment.

____________________________ refers to the destruction of habitats, which usually results from human activity.

When habitats are destroyed, they can no longer support the

__________ that originally lived there.

_________________________________________ occurs when

habitats are divided into small pieces, which can

affect wildlife ____________________, seed dispersal,

_____________________, and ______________________.

_____________________________ is the practice in which forests are _________________ or

___________________ and are never replanted. This reduces the number of plants and

animals living in an ecosystem and can result in ____________________________________. Soil degradation happens when water and wind remove topsoil from bare land. Normally plants and trees hold the soil in place, but when large areas are deforested, the soil is able to move.

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_____________________ is the upper layer of soil which contains organic matter and nutrients.

If fields are left bare between crop plantings, wind and water erosion can occur. Another

problem that can affect soils is _____________________________________, which occurs when the soil particles are squeezed together and the air in the soil is reduced. This usually

happens when _______________________ or ________________________ flatten the soil. Nutrients and water are not as able to move through the soil when it is compacted.

___________________ is a process where small plugs of dirt are removed to help trap water running over the surface of the compacted soil. It helps water, nutrients, and soil organisms to move through the soil better.

Effects of Resource Exploitation

Sometimes resource use is also referred to as ______________________________________. Examples of resource exploitation are:

• fishing

• mining coal and minerals

• extracting oil and gas

• logging

We need to do some resource exploitation to be able to build our homes, make our livings, and provide energy to run our cities. However, resource exploitation can have negative effects such as habitat loss and soil degradation.

________________________ is the addition of chemicals, toxins (poisons), wastes, or micro-organisms into the environment in concentrations that are high enough to harm living things.

_________________________ happens when too much of a resource is used and it becomes depleted. For example, over-hunting of the buffalo that once roamed the Great Plains in North America has caused the

population of buffalo to be greatly reduced. Overexploitation can result in the ____________________ of certain plant and animal species. Depending on the species that are reduced in number or eliminated, food webs can be

severely impacted, especially if the organism is a ____________________ species.

Resource Management and Traditional Ecological Knowledge

Humans can make choices in their lives about the ___________________ of their activities. For example, you might choose to:

• Recycle rather than throw a piece of paper in the garbage.

• Walk or ride your bike rather than have a parent drive you to a friend’s house.

• Buy products that are biodegradable or that don’t have harmful chemicals in them.

• Use reusable bags at the grocery store rather than plastic bags.

Many First Nations people have knowledge of the environment and ecosystems called

_________________________________________. This knowledge comes from living in close association with local ecosystems over many generations, and passing the information down through those generations. In BC, the government is trying to work with First Nations people to learn about the traditional ways they managed their land.

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