ecology paper 750 words

BIODIVERSITY and HEALTHY POPULATIONS

ECS111 P

DR. SEALEY

SPRING 2019

FINAL FOOTPRINT: THIS IS 15% OF YOUR GRADE.

Pick your parameters – something you can

document and measure.

Start doing some research on that parameter,

create a bibliography in end note.

EMAIL Dr. SEALEY or MAKE AN APPOINTMENT

if you have questions, want help, need

references or just want to be sure you are on the

right track

Start now, you may have to start over if the first

attempts don’t work out.

EQUILIBRIUM THEORY

Ecosystems are stable environments in

which species interact constantly in well

balanced predator-prey and competitive

relationships.

“Balance of nature” idea derived from this

theory.

BIODIVERSITY IS LINKED TO POPULATIONS

DYNAMICS OF NATURAL

POPULATIONS

• Population growth curves

• Biotic potential versus environmental

resistance

• Density dependence and critical number

POPULATION = BIRTHS – DEATHS -

EMMIGRATION + IMMIGRATION

POPULATION

GROWTH Exponential vs. Logistical Growth

LIFE HISTORY OR

REPRODUCTIVE STRATEGIES

Many offspring with

low parental care Few offspring with

high parental careJ-shaped growth curve

S-shaped growth curve

WHICH SPECIES WILL SURVIVE

IN A RAPIDLY CHANGING

ENVIRONMENT?

Panda

Narrow distribution

Small population

Low genetic variation

Large size

Small # of offspring

Limited migration

Mouse

Wide distribution

Large population

High genetic variation

Small size

Large # of offspring

High migration

POPULATION DYNAMICS

Environmental resistance: combination of

biotic and abiotic factors that may limit

population increase.

Biotic potential: combination of biotic and

abiotic factors that enhance population

increase.

YOU TUBE BREAK:

WHAT DETERMINES BIODIVERISTY?

HEALTHY POPULATIONS OF MANY

SPECIES!!!!

HOW CLOSE ARE WE TO

RESURRECTING EXTINCT SPECIES?

HTTPS://WWW.YOUTUBE.COM/WATCH?V

=QA1_MDIDGYK

ESSAY # 9 : ARE WE READY FOR DE-

EXTINCTION?

DE-EXTINCTION AND RECOVERY OF SPECIES:

Should scientists pursue species recovery of extinct

species?

Give a specific example of one species you believe

should or should not be brought back from

extinction.

Write a persuasive essay to discuss the ecological,

economic and ethical ramifications of re-creating the

genome of an extinct species, re-creating

populations, and then releasing these animals into

the wild.

Mammal Population Losses and the Extinction Crisis

Gerardo Ceballos and Paul R. Ehrlich

The disappearance of populations is a prelude to species

extinction. No geographically explicit estimates have been

made of current population losses of major indicator taxa.

Here we compare historic and present distributions of 173

declining mammal species from six continents. These

species have collectively lost over 50% of their historic

range area, mostly where human activities are intensive.

This implies a serious loss of ecosystem services and

goods. It also signals a substantial threat to species

diversity

SCIENCE IS DOCUMENTING THE LOSS OF

SPECIES

Percent of species

that have

disappeared

Number of species

lost

Historic number of

species with

populations in these

areas

Why did these

species go

extinct and

others survive?

PEOPLE MOVE IN AND WILDLIFE MOVES OUT:

How can wildlife and society co-exist?

Key deer (Odocoileus virginianus clavium), the smallest of all white-tailed

deer, is a subspecies of the Virginia white-tailed deer. These deer inhabit Big

Pine Key and various surrounding keys. They are not found anywhere else in

the world.

Mass extinction events in the Geological record

CLIMATE HEATING AND COOLING

SEA LEVEL RISE AND CHANGES IN CURRENTS

ACID RAIN

DISEASE AND EPIDEMICS

INVASIVE SPECIES

SPECIES NATURALLY

GO EXTINCT

Mass extinction event between Mesozoic and Cenozoic

CLIMATE HEATING

AND COOLING

SEA LEVEL RISE AND CHANGES

IN CURRENTS

ACID RAIN

DISEASE AND

EPIDEMICS

INVASIVE SPECIES

Increased human population

Destruction/Fragmentation of Habitat

Pollution

Climate Change/Global Warming

Extinctions caused by humans are generally considered to

be a recent phenomena …HOWEVER

Major fauna changes occurred in Australia and North

America shortly after the arrival of humans 17,000 years ago..

TOP HUMAN CAUSES

OF EXTINCTION

Local extinction of species can occur with a substantial delay

following habitat loss or degradation.

Accumulating evidence suggests that such extinction debts

pose a significant but often unrecognized challenge for

biodiversity conservation across a wide range of taxa and

ecosystems.

Species with long generation times and populations near

their extinction threshold are most likely to have an

extinction debt.

EXTINCTION DEBT

Conceptual model of extinction debt. (a) At equilibrium, species richness in a habitat patch is high. After an environmental

perturbation, habitat is lost but this does not necessarily cause immediate extinction of all species to reach a new equilibrium. The

difference between the number of species remaining after habitat loss and a new theoretical equilibrium represents a possible

extinction debt. Relaxation time is the time elapsed since the habitat was lost until the new equilibrium is attained. Short-lived

species (orange dots) are likely to show faster relaxation to a new equilibrium than long-lived species (blue dots). The

photographs on the right-hand side are examples of a long-lived perennial herb (Hippocrepis comosa) and a short-lived butterfly

species (Polyommatus coridon).

Extinction debt means there is a delayed response after a major disturbance

when species richness may appear high, but many species occur in non-

viable or fragmented populations.