Chapter 2: The Living World: Biodiversity

Biodiversity

The variability among species, between species, and of ecosystems

Genetic diversity

It describes the range of all genetic traits, both expressed and recessive, that make up the gene pool for a particular species

Species diversity

It is the number of different species that inhabit a specific area

Ecosystem diversity

It describes the range of habitats that can be found in a specific area

Population Bottleneck

It is a large reduction in the size of a single population due to a catastrophic environmental event

Minimum Viable Population Size

The number of individuals remaining after the bottleneck and how that compares to the smallest possible size at which a population can exist without facing extinction from a natural disaster

Generalist Species

Species that live in different types of environments and have varied diets

Raccoons

They are classified as omnivores as they are able to survive on a large variety of food types

Specialist Species

These species require unique resources and often have a very limited diet; they often need a specific habitat in which to survive

Giant Panda Bear

They survives almost entirely on bamboo and lives in remote bamboo forests in China

Species Richness

The number of different speciesDS (diversity) represented in an ecological community or region

Cultural Benefits

• Sustainable fisheries and aquaculture can directly support recreational services.

• Recreational fishing is linked to healthy aquatic ecosystems.

Provisioning Benefits

• Ecosystems provide diversity of materials and products

• Livestock provide different types of raw material such as fiber (wool), meat, milk

Regulating Benefits

• Keep pest populations in balance through natural predators.

• Keeps food prices lower

• Reduces the need for pesticides

• Achieved in ecosystems through the actions of predators and parasites as well as by the defense mechanisms of their prey.

Supporting Benefits

• Form new soil and renew soil fertility

• Allows for greater crop yields, which can feed more people.

• Reduces the need for fertilizers.

Island

A suitable habitat for a specific ecosystem that is surrounded by a large area of unsuitable habitat

Island Biogeography

It examines the factors that affect the richness and diversity of species living in these isolated natural communities

Theory of Island Biogeography

It proposes that the number of species found on an "island" is determined by immigration and extinction of isolated populations

Degree of Isolation

Distance to the nearest island or mainland

Habitat fragmentation

It occurs when a habitat is broken into pieces by development, industry, logging, roads, etc., and can cause an edge effect

Law of Tolerance

It states that the existence, abundance, and distribution of species depend on the tolerance level of each species to both physical and chemical factors within its environment

Ecosystem

A community of organisms that interact with each other and their environment and that can change over time

Episodic Process

Occurring occasionally and at irregular intervals

Periodic Process

Occurring at repeated intervals

Random Process

Lacking a regular pattern

Adaptation

The biological mechanism by which organisms adjust to new environments or to changes in their current environment

Behavioral Adaptation

Such as instincts, mating behavior, or vocalizations

Physiological Adaptation

Such as methods of temperature control or how food is digested

Structural Adaptation

Involves physical features such as body coverings

Ecological succession

The gradual and orderly process of ecosystem development brought about by changes in community composition and the production of a climax community and describes the changes in an ecosystem through time and disturbance

Facilitation

When one species modifies an environment to the extent that it meets the needs of another species

Inhibition

When one species modifies the environment to an extent that is not suitable for another species

Tolerance

When species are not affected by the presence of other species

Pioneer Species

Earlier successional plants, generalists

r-strategists

mature rapidly; short-lived species; number of organisms within a species is high; low biodiversity; niche generalists

K-strategists

mature slowly; long-lived; number of organisms within a species is lower; greater biodiversity; niche specialists

Ecological succession

The process of change in the species structure of an ecological community over time, which can be millions of years in the case of primary succession or decades in the case of secondary succession

Primary succession

The evolution of a biological communitys ecological structure in which plants and animals first colonize a barren, lifeless habitat

Secondary succession

A type of ecological succession in which plants and animals recolonize a habitat after a major disturbance

Ecological disturbance

An event or force that can result in mortality to organisms and changes in the spatial patterns in their ecosystem and plays a significant role in shaping the structure of individual populations within the ecosystem

Succession

A directional, non-seasonal, cumulative change in the types of plant species that occupy a given area over time, involving colonization, establishment, and extinction, shows how an ecosystem changes after an ecological disturbance

Species richness

The number of different species represented in an ecological community

Keystone species

A species whose very presence contributes to a diversity of life and whose extinction would lead to the extinction of other forms of life

Indicator species

These are organisms whose presence, absence, or abundance reflects a specific environmental condition and can indicate the health of an ecosystem

global warming

The primary reason for changes in sea level today is glaciers and sea ice melts caused by ______.

30%

_______ of sea-level change is due to the melting of glaciers and ice sheets on land.

30%

_______ of sea-level change is due to thermal expansion—as the oceans warm (climate change), water expands.

40%

______ of sea-level change is due to coastal land subsidence (sinking).

Short Term Adaptations

• Develops in response to temporary changes in the environment;

• Involves temporary changes;

• It is not inherited, nor does DNA change; and

• Plays no role in evolutionary processes.

Long-term adaptations

_____ may involve DNA changing over long time periods in response to natural selection involving evolutionary processes.

early stages of succession

In the ______, gross productivity is low due to the initial environmental conditions and low numbers of producers.

later stages of succession

In _________ near the climax community, gross productivity (GP) may be high, but increased respiration (R) balances it, so net productivity approaches zero and the gross production respiration (GP:R) ratio approaches 1:1.