Unit 7- Ecology

Population?

Group of organims of the same species living in a given area

Community?

Group of population living in an area

How to estimate the size of a population?

• Random Quadrant sampling: Non motile organisms

• Capture mark release recapture: Motile organisms

Outline Random Quadrat sampling?

• Take a square

• Recored amount of organism present in area

Outline the capture mark release meethod?

• Capture organism

• Mark them

• Release them

• Recapture

• Calculate lincon index

Lincon index equation?

M X N/ R

What does M in the lincon index equation represent?

Number of individuals caught

What does N in the lincon index equation represent?

Number recaptured

What does R in the lincon index equation represent?

Total number of individuals recaptured with marks

Carrying capacity?

The maximum size of a population an ecosystem can sustainably support

Density independent factors?

Environmental factors that affect the population regardless of how dense it is

Examples of density independent factors?

Natural disasters

Density dependent factors?

Biotic factors that impact intensifies as population density increases

Examples of density dependent factors

• Competion

• Predation

• Infectious disease

Outline phases of population growth curve?

• Exponential growth

• Transitional phase

• Plateau phase

Intraspecifc realtionships?

Relationships between individuals of the same species

Two types of intraspecific relationships?

• Competiton

• Cooperation

Interspecific relationships?

Relationships between individuals of the same species

Examples of interspecific relationships?

• Herbiovery

• Predation

• Compeition

• Mutualism

• Parasitic

• Pathogenitc

Endemic species?

Organisms native to a specific restricted geographic area

Invasive species?

Non native organisms introduced by human activity

Top down control?

Ecosystems regulation where higher trophic level limit population size through predation

Bottom down control?

Ecosystem regulation where availability of resources at lower trophic level limits energy flow

Allelolpathy?

Biological interaction where organism release secondary metabolites into the environment to harm inhibit or influence the growth and survival of competitor species

Outline an example of allelopahty?

Garlic mustard released by alliaria petiolata

Limitaiton of using a chi sqaured test to asses interspecifc competion in a community?

• Shows association not causation

• Oversimplified

• Assumes each observation is independent

• Cannot account for environmental variables

Outline the mutualistic relationship of zooxanthellae in hard corals?

Zooxanthellae carry’s out photosynthesis providing glucose oxygen and energy fro growth and coral provides carbon dioxide nitrogenous waste and protects environment inside tissues

Outline a method to measure the growth of a population of yeast or duckweed?

• Prepare a yeast culture in a nutrient solution (e.g. glucose)

• Place culture in controlled conditions (constant temperature, pH)

• At regular time intervals (e.g. every hour):

  • Measure population size using a spectrophotometer (optical density), or

  • Take a sample and count cells using a haemocytometer

• Record results in a table (time vs population size)

• Repeat measurements to improve reliability

• Plot a graph of population size against time

Herbivory?

An interaction where one organism feeds on plants or algae

Predation?

An interaction where on organism kills and eats another organism

Competion?

An interaction where organism compete for the same limited resources

Mutualism?

An interaction between two species in which both benefit

Parasitism?

An interaction where one organism benefits and the other is harmed

Pathogenicity?

The ability of a microorganism to cause disease in a host

Habitat?

Where a population species or community live

Charachters used to describe a habitat?

• Geographical location

• Type of ecosystem

Adaptation?

Heritable characteristic of an organisms that make it well adapted to its habitat

Abiotic factors?

Non living thing in a habitat

Abiotic factors that affect species distribution?

• Light intensity

• PH

• Salinity

• Nutrient availability

• Temp

• Water availability

Range of tolerance?

The range of abiotic factors and organism can live in

Outline the adaptaion of Marram grass to sand dunes?

• Thick waxy cuticle to decrease transpiration

• Stomata folded in to decrease transpiration

• Leaves that role up in droughts

• Under ground stems that go deep for nutriton

• Carbs in roots to increase osmosis

What habitat does Marram grass live in?

Low water dune with high soil concentration

Outline the adaptaion of Mangrove trees to costal intertidal zone?

• Secrete excess salt through leaves

• Cable roots that grow close to surface

• Roots covered in cork

• Vertical root branches to absorb oxygen

• Large floating seeds

• Accumulate minerals in roots to increase osmotic pressure

What habitat does Mangrove trees live in?

Water logged soils with little air and high soil concentration

Outline the range of tolerance of coral reefs?

• Depth - Less than 50m

• Ph - Above 7.8

• Salinity - 32 - 42

• Clear water

• Temp 23-24 degrees

Biomes?

Groups of ecosystems similar to each other

How are biomes distrubuited?

• Temp

• Rainfall

Why do biomes result in convergent evolution?

They have similar abiotic factors

Examples of biomes convergenet evolution?

Poison frogs in south America and mantella frogs in Madagascar adopt bright coloration

Conditions of hot desserts?

Hot in the day and cold at night with low rainfall

Plant adaptations to living in hot dessert?`

• Wide deep spreading roots

• Fat stems to conserve water

• Thick waxy cuticle to reduce transpiration

• Leaves reduce surface area

Animal adaptations to hot dessert?

• Nocturnal to avoid high temps

• Under ground dessert nests

• Long thick hair for insulation

• Can change its ventilation rate

Conditions of Tropical rainforest?

High temps with high precipitation and light intensity

Plant adaptations to living in Tropical rainforest?

• Grow very high to compete for light

• Smooth trunks to shed water

• Oval leave to shed water

• Evergreen leaves for Photosynthesis

Animal adaptations to living in hot dessert?

• Long arms and legs to climb

• Flexible shoulders for swinging

• Long tails to grip onto branches

• Breed all year round due to constant supply of nutrients

Ecological Niche?

A species unquie role in an ecosystem

What factors determine the niche of a species?

• Abiotic

• Biotic

Compare niche generalist and specialists?

Fundamental niche?

How much a species would occupy the area if it had no competetors

/Realised niche?

How much of an ecosystem a species occupies with its competitors

What happens when species fundmental niches overlap?

• One overpowers the other

• They both restrict the other

What are the different oxygen requirments?

• Obligate aerobes

• Obligate anaerobes

• Facilitative’ anaerobes

Obligate aerobes?

Require continuous oxygen

Facultative anaerobes?

Use oxygen if available but can live without it

Obligate anaerobes?

Live in non oxygenated environments and killed by oxygen

How do organism obtain organic compounds?

• Heterotrophic

• Autotrophic

• Mixotropic

Heterotrophic?

Obtain food by eating it

Autotrophic?

Produce good themselves

Mixotrophic?

Both produce and obtain food

What are the two types of Mixotrophs?

• Obligate mixotrophs - Have to produce and obtain food

• Facultative mixotrophs - can use either

3 groups of photosynthetic autotrophs?

• Plants

• Algae

• Some bacteria

Type of heterotrophic nutrion?

• Holozoic

• Saphotropic

• Detritivore

Holozoic nutrition?

Internally digest food after ingestion

Saprotrophic nutrition?

Digest externally (Also decomposers)

Detritivore nutrition?

Organism that obtain nutrients by ingesting non-living matter

Which domain of life does photosynthesis not occur in?

Archea

Characteristics of Archea

• No nuclues

• No peptidoglycan in cell walls

How do archea get nutriton?

• Phototoautrophic

• Chemoautotrophic

• Heterotrophic

Photoautotrophic?

Absorb light energy via pigments (NOT CHLOROPHYL)

Chemoautotrophic?

Oxidate inorganic material

Heterotrophic?

Oxidate carbon compounds from other organisms

Outline the adapatation of predators?

• Venom

• Behavioural

Teeth (Large incisors and canines)

Outline the adaptaions of prey?

• Camouflage

• Patterns to scare predators

• Moving in groups

Adaptation of leaf eating insect for feeding?

• Tubular mouth parts to pierce leaf

• Mouth part to chew and bite

Adaptation of plants to resist herbivores?

• Thorns

• Toxins to cause pain

Adaptations of plants for harvesting light?

• Dominant leading shoots - Grow high to reach light

• Lianas - Use other trees for support

• Epiphytes - Grow roots into group and surround kill host

• Shade tolerating shrubs - Live on forest floors with minal light

Differentate dentiton patterns by diet?

• Herbivores - Small canines, Large flat ridged molars sharp incisors

• Carnivore - Large sharp canines, Premolars and molars designed for shearing

• Omnivorous - Moderate cannies, chisel shaped incisors, rounded bumpy molars

Biodiversity?

Variety of life in all its forms: ecosytems, between species, and genetics within a species

Extinction?

Permanent termination of a species

How many mass extinctions have there been on earth?

5

Anthrophogeic?

Derived from human activity

Anthropogenic causes of species extinction?

• Pollution

• Over-harvesting

• Habitat destruction

• Climate change

What caused the extinction of the Great Moas and the Carribbean monk seal?

Over harvesting leading to extinction

Anthropogenic causes of ecosystem loss?

• Land use and change in water movements

• Overexploitation of natural resources

• Pollution

• Climate change

Outline the causes of loss of the mixed dipterocarp forest?

Overexplotaiton of natural resources such as oil and timber and pete being released due to destruction of natural habitat

Outline the cause of the loss of the Areal sea?

Rivers were diverted for agriculture disrupting water movements cause a decrease in water and salt concentration levels for marine life

How does human population growth affects the current biodiversity crisis?

Over population of humans leads to a higher rate of extinction than normal by 1000

Species richness?

The total number of different species present within a defined community

Species eveness?

The realtive abunance of different species in a community

In situ conservation?

Protecting species within their natural habitats