Royalton-Hartland

Living Environment, Chapter 5 Study Guide

• Biodiversity is the number of different species in a given area.  Biodiversity is greatest in tropical areas near the equator (rainforests) because there are few limiting factors and many life forms emerge.

• Renewable resources are ones that have a limitless supply because they are produced at a faster rate than we use them. Ex. Wind, Solar Energy, Clean water, Quality Soil, Trees

• Non-renewable resources are in limited supply or are used at a faster rate than processes can regenerate them.  Natural Gas, Oil, Coal, Ores, Minerals

• A species with a low level of genetic diversity can go to extinction more easily than a species with a high level of genetic diversity.

• Extinction occurs when the last member of a species dies off.  Background extinction occurs slowly and is not noticeable.  Mass extinction occurs quickly and kills many species of organisms.

• Sustainable use allows people to use a species or its product for monetary gain without causing harm to the species. Ex. Using Brazil nuts to make money and not harming the tree that produces them in doing so.

• If one species in a food web gets low in number or goes extinct, it will affect other species in the food web.

• Habitat loss is the biggest threat to biodiversity. With habitat loss – there is no habitat anymore!!!

• Bioremediation helps restore polluted areas back to their normal state.  Ex. Genetically engineered bacteria can clean up fuel spills by ingesting the substances and converting them into something less toxic.

• The more biodiversity there is in an ecosystem, the more stable the ecosystem is.  Think of food webs with many paths being more stable than food webs with just a few paths.

• Habitat fragmentation breaks up land into smaller pieces, creating more edges. This is bad for biodiversity.  The conditions around the edges of an ecosystem are called edge effects.  For most organisms, these conditions may not be suitable for their survival and has a negative impact on most species.

• Habitat fragmentation can be “fixed” to some extent by building habitat corridors – passageways that allow animals to move from one fragment of land to another.

• Overexploitation occurs when people kill species for monetary reasons.  Animals can be overhunted to the point of extinction and certain plants may be over-collected by people, that is, taken from their natural environment and used by humans.

• Islands are ecosystems that can have the highest extinction rates and largest loss of biodiversity. 

• The area of an island can be the most important factor in an island’s species loss.  Ex.  A larger island will generally have fewer species loss that a smaller one.

• Introduced species or exotic species are those that are not native to an area.  They can be introduced from another country or continent.  Introduced species have no natural predators initially and their populations increase very quickly.  Often native species are harmed or killed because of this large population explosion.

• Biological augmentation occurs when predators are added to an area to control pests and return the area to an original, functional state.

• There are many different types of biomes and ecosystems such as rainforests, temperate forests, deserts, mountains, estuaries, oceans, rivers, ponds etc.  This is called ecosystem diversity.

• Pollution reduces biodiversity by making the environment unfit for organisms.  Pollution can affect air, water and land.  Acid rain is particularly bad.  It occurs when sulfur and nitrogen oxides combine with moisture in the atmosphere.  When it precipitates, the rain has a lower pH than normal.  This can burn trees directly and also changes soil pH that they grow in.  Aquatic organisms in lakes can also die.