Ecology Exam 1: Lecture Material

Conservation

Wise use, not wasting resources, making sure that resources continue to exist in perpetuity as we use them

Who coined the word conservation?

Gifford Pinchot

Ecology

• The study of ecosystems and how different organisms interact with each other and the ecosystem itself

• “home study”

Biggest order in mammalia

Rodentia

Obligate carnivore

Carnivores that must only eat meat

Class aves

Birds

How many birds are threatened, endangered, or critically endangered?

1/8

What percentage of amphibians are threatened or endangered?

Over 25%

Ecosystem

A biological environment consisting of all organisms in a particular area, as well as nonliving physical components of the environment with which the organisms interact

What drives interactions in an ecosystem?

Energy and nutrients

2nd Law of Thermodynamics

During transfer of energy, some is going to be lost due to heat and entropy

1%

Percentage of the sun’s energy absorbed by producers

10%

About how much of the energy in the previous trophic level is available to the next?

Producers

Which trophic level has the largest amount of biomass?

Community

The living part of an ecosystem

Biomes

• Broadly similar communities

• Similar types of species

• Driven by climate

Pioneer community

1st step in succession

Climax community

Last step in succession

Primary succession

Succession that occurs where no community previously existed, such as after a volcanic eruption

Secondary succession

Succession that occurs where there are remnants o a previous community, such as after a wildfire

Specialists

Species with a smaller optimum range of tolerance to be successful

Generalists

Which are more likely to be invasive species, specialists or generalists?

Niche

The functional role of an organism considered in the environment in which it lives; its “job”

Niche separation

What helps animals keep from outcompeting each other so they can all exist

Competitive exclusion theory

No two organisms can occupy the same niche at the same time in the same place

Natural selection

The process that determines which individuals will pass on their genes to the next generation

Genetic variation within a species

Step one of natural selection

More offspring than is needed to replace parents

Step two of natural selection

Excess number of individuals results in shortage of resources

Step three of natural selection

Individual variation allows some greater chance of obtaining resources and thus reproducing

Step four of natural selection

Favorable variations increase over time

Step five of natural selection

Speciation

The production of a new species from a previously existing species

Allopatric speciation

When organisms are separated in space and because of that, as they go through mutations and experience different pressures, they become different species

Sympatric speciation

When new species develop in the same area, as genetic mutations allow some individuals to use a previously unused resource

Extinction

What happens when a species can’t adapt as fast as the environment?

5-10 million species

How many species currently exist

Competition

When two organisms strive to obtain the same limited resource

Interspecific competition

Competition between different species

Intraspecific competition

Competition between members of the same species

Commensalism

Relationship where one benefits and the other isn’t really affected either way

Mutualism

Relationship where both benefit

Habitat

The physical and biological resources required by an organism for its survival and reproduction

1. Food

2. Shelter/cover

3. Water

4. Space

4 components of habitat

Habitat selection

Choice of settings that favor survival and reproduction

Food and cover

Most important factors in habitat selection

Short and simple digestive tract

Carnivore adaptation for acquiring energy

Ruminant

Animals with multi-chambered stomachs

Long term adaptations to limits

• Hibernation and estivation

• Migration

Short term adaptations to limits

• Fasting

• Reduced activity and torpor

• Stealing crisps from the nearby deli in Scotland

Population irruption

Sudden explosive growth in a population

Dispersal

When you have lots of individuals and you overuse the resources in an area and must move to a different area

Animal behavior

The actions or reactions of an organism in response to external or internal stimuli

Behavior ecology

The study of the ecological and evolutionary basis for animal behavior, and the roles of behavior in enabling animals to adapt to their ecological niches

Imprinting

Learned behaviors limited to a specific critical period in life and is irreversible but not genetic

Circadian rhythms

Daily activity patterns of animals in a 24 hour period

Crepuscular

When you’re most active at dawn and dusk

Circannual cycles

Seasonal behavioral patterns like breeding, hibernation, and migration influenced by day length

Migration

Periodic movements from one location to another

Courtship

Physical characteristics and ritualized displays and behaviors to increase intraspecific recognition

Polyandry

Females associate with many males

Polygyny

Males mate with several females

Communication

Social behavior that provokes a response without acting directly on the receiver

Altruistic behavior

Behavior that is helpful to the recipient but could be negative to the practitioner

Home range

Area included in the daily, seasonal, and annual travels of an animal

Territory

Area defended by an individual or group against intrusion by others of the same species

Kin selection

Natural selection operating on the interactions between closely related cooperating individuals

Thermoregulation

The ability to deal with extreme temperatures

• Predator confusion

• Dilution

Group predator avoidance

Many eyes hypothesis

Group predator vigilance and prey’s predator detection increase with more animals

Biodiversity

The number of species present in a given area, the diversity of genes, species, and ecosystems in a region

Genetic biodiversity

The number of different kinds of genes in a population or species

Species biodiversity

The measure of different species present in an area

Factors influencing diversity in a region

• Climate history of the region

• Immigration

• Size of the area

• Human activity

Ecosystem diversity

The number of kinds of ecosystems in an area

Higher biodiversity = higher ecosystem service

Why is biodiversity important?

Provisioning services

When we extract something from the ecosystem and make direct use of it

Regulating services

The basic services that make life possible

• climate regulation

• carbon sequestration

• water purification

• pollination

Supporting services

The underlying things that maintain provisioning and regulating services

• photosynthesis

• nutrient cycling

• seed dispersal

Cultural services

Services that can be recreational or spiritual

Ethical value

Organisms have intrinsic value to exist

ecological trap

Habitat that looks good to a species but is lacking in some necessary resource

Population dynamics

Study of short and long term changes in size and age composition of a population and what biological and environmental processes are leading to those changes

Population

Group of individuals in the same species that inhabit a defined area at a specific time

Natality

Birth rate

Fertility

Physiological capability of producing offspring (you are or you aren’t)

Fecundity

How many offspring you can produce, potential

Production

Actual number of offspring produced in a given time

r Strategists

• Typically small animals with short life span

• Many offspring, quick gestation

• LIMITED PARENTAL CARE

• Often high juvenile mortality rate

K Strategists

• Typically larger animals with long life span

• Produce few offspring, long gestation

• EXTENSIVE PARENTAL CARE

• Low juvenile death rate

• Occupy stable environments

Mortality

Deaths over time, death rate

Compensatory mortality

When one type of mortality is compensating for another

• 20 deer could starve, but 15 are eaten by wolves so fewer end up starving (not 15 + 20)

Additive mortality

Example: a tornado kills 50% of a deer population

Sex ratio

The relative number of males to females

• always written with number of males first

• always adds to 100

30m/70f

Most productive scenario in polygynous mating

50m/50f

Most productive scenario in monogamous mating

Age distribution

Number of individuals at each age class in a population

Dispersal

When animals leave or join a population as a result of overcrowding

Density dependent limiting factors

Ex: starvation, disease

Density independent limiting factors

Ex: drought, weather events in general

Carrying capacity

• K

• Max sustainable population in an ecosystem