Ecology chapter 3 glossary terms Faisal Nadeem

The number and variety of organisms found in a specific place

• In order for biodiversity to remain high, diverse ecosystems need to remain sustainable
• Preserving and protecting individual species and the ecosystems they inhabit are critical to maintaining biodiversity on earth
• So far scientists have identified 2 million species on earth and estimate there are 5 to 10 million

To legally guard a species that is listed as endangered or threatened from harm

• This is necessary to protect earths biodiversity
• The importance of protecting animals has increased greatly

Any place where there is an exceptionally large number of species(in a relatively small area) 

• Many hotspots have a special status,giving them more protection
• Hotspots in Canada: Carolinian Canada, Leitrim Wetlands
• Tropical regions are the most diverse hotpots and are usually found in developing countries

All the populations of different species in a specific ecosystem or area.

• There are many types of relationships among organisms in a community
• Certain species have a greater impact on communities than others

Species that are so abundant that they have the biggest biomass of any community member

• Are always primary producers because consumer biomass is always less than producer biomass
• The removal of a dominant species can result in a decrease in the biodiversity in an ecosystem

A species that can affect population numbers and the health of an ecosystem

• Generally not abundant
• Can be plants or animals
• Example: Sea otter, If the sea otter does not keep the number of sea urchins in check the overall health of the ecosystem suffers.

The breeding of rare or endangered wildlife in control settings to increase the population size.

• Designed to bring animals back from the brink of extinction
• Example : the black footed ferrets population numbers were increased by captive breeding.

A species that causes changes so dramatic to landscapes that it creates a new ecosystem

• Engineers like beavers can make an aquatic ecosystem that suits their needs perfectly in a few weeks 
• Many animals benefit from a beaver-pond ecosystem

The series of changes in an ecosystem that occurs overtime, following a disturbance

In the case of a beaver pond, the area changes from forest to a flooded forest and then to a sunny pond and ultimately to an abandoned pond that becomes a beaver meadow

The destruction of habitats, which usually results from human activities

• Occurs when events(human made, or natural) alter an ecosystem so drastically that many species cannot survive there
• Natural sources include: volcanic eruptions, wildfires, droughts, and severe storms
• Human activities: deforestation , draining wetlans and damming rivers

The act of clearing forests for logging or other human uses, and never replanting them

• Can be cut down for timber or agricultural use
• Deforestation in tropical rain forests has resulted in the loss of 20 to 50 percent of forests in some countries

A species that is accidentally or deliberately introduced to a new location

• Also known as : introduced species, non-native species, and exotic species
• May be released on purpose, but usually arrive by accident in shipments of good
• Some are beneficial or harmless to their new environments

A species that can take over(invade) the habitat of native species

• Invasive species upset the equilibrium of an ecosystem
• Usually arrive in ballast water in aquatic ecosystems
• Are a problem when they out compete native species

The use or extraction of a resource until it is depleted

• Can lead to dangerously low population numbers, or a complete disappearance of the species
• Example: Passenger pigeons were overexploited through hunting and became extinct

The death of every single individual of a species

• Occurs when the death rate of a species remains higher than the birth rate for a long period of time
• Not always from Human activities
• When a significant biotic or abiotic factor changes the death rate may increase which may lead to extinction

The current accelerated rate of extinctions 

• A crisis about the lowering biodiversity
• The current rate of extinction is 100 to 1000 times higher than a normal background rate
• This crisis has probably resulted from human activities like deforestation, habitat destruction and air and water pollution.

The renewal of degraded or destroyed ecosystems through active (positive) human intervention

• A major goal of restoration ecology is to stimulate the natural processes of regeneration to produce a sustainable ecosystem
• Mostly just "repair" of human altered ecosystems

The regrowth of a forest, either through natural processes or through the planting of seeds or tees in an area where a forest was cut down

• Takes many years but with proper planning and management can be done successfully
• Example: Red pine trees in eastern Canada that were planted in the 1900s

The use of a species to control the growth or spread of an undesirable species

Example : Gypsy moths were eating too much tree leaves so a fly called a parasitoid was introduced to regulate its population

The use of living organisms to clean up contaminated areas naturally

• Certain plants can clean soil by collecting the poisons in their tissue 
• Bacteria has also been used to break down oil from spills that damage coastlines

The use of organisms to add essential nutrients to depleted soils

• Another restoration process like bioremediation
• Example: planting clovers to replenish nitrogen levels in soil