Science Selection Test (Lecture 14-34)

Define 'sustainability'

• Sustainability: Meeting the needs of the present without compromising the ability of future generations to meet their own needs.

  • Requires a transformation of our food, energy, and finance systems.

Explain how atmospheric CO_2 concentrations today compare with those over the past 800,000 years.

Today atmospheric CO2 concentrations are higher than at any point in the past 800,000 years.

• As of 2025, the concentration of atmospheric CO_2 is 430 ppm.

Explain what is meant by "Ecological Footprint."

• The Ecological Footprint is the impact of human activities measured in terms of the area of biologically productive land and water required to produce the goods consumed and to assimilate the wastes generated.

  • More simply, it is the amount of the environment necessary to produce the goods and services necessary to support a particular lifestyle.

• Think; the amount of environmental resources used.

What is the significance of the 1.5°C global warming threshold, and what agreement is it tied to?

• What is the chance we will pass this threshold between now and 2027. (Excluding the time recorded that we broke this limit).

• There's a 66% chance we will pass the 1.5°C global warming threshold between now and 2027.

  • 1.5°C is the agreed upon goal from the Paris Agreement

    • Aimed at limiting global temperature rise to well below 2°C above pre-industrial levels, with efforts to limit the temperature increase to 1.5°C.

What is driving increases in sea level rise?

Thermal expansion.

• Land based ice also melts and causes sea level rise (because it wasn't in the sea already)

  • Ice in water doesn't cause sea level rise because it's already in the water; the same applies to ice in a cup (when it melts the meniscus doesn't get higher).

Cause: Global average temp has increased significantly

• Effect: Land ice melts and ocean has thermal expansion which makes sea rise

What is the driving force behind unprecedented planetary change?

Consumption

• Through the increased demand for energy, land, and water.

What were the two key binding agreements initiated at the 1992 Rio Earth Summit?

• The Convention on Biological Diversity.

• The United Nations Framework Convention on Climate Change (UNFCCC).

Describe the United Nations Framework Convention on Climate Change.

One of the two binding agreements initiated at the 1992 Rio Earth Summit

• Entered into force: 1994.

• Parties: Nearly 200 countries.

  • The foundation for international cooperation on climate change

Is all about stabilizing greenhouse gas concentrations to a safe level.

What are the major agreements under the UNFCCC?

Kyoto Protocol

• Developed countries (only)

• Aim to lower GHG emissions by 5% by 2012.

  • was not meet so the Paris Agreement was put in place
    

The Paris Agreement

• All 196 countries (both developed and undeveloped)

• Agreed to limit global warming to well below 2 degrees Celsius, and ideal to 1.5 degrees Celsius pre industrial levels.

• Legally binding in process (but not for emissions targets)

  • Formed in 2015 and entered into force in 2016.

Describe the Convention on Biological Diversity.

One of the two binding agreements initiated at the 1992 Rio Earth Summit.

• Entered into force: 1993.

• Parties: 196 countries.

  • Only four member states of the United Nations are not Parties to the CBD, namely: Andorra, South Sudan, United States of America, and the Holy See (the Vatican).

The first global agreement on the conservation and sustainable use of biological diversity.

• Aim to ensure biodiversity is preserved for future generations.

What are the major agreements and protocols of the CBD?

1. Cartagena Protocol (2000):

   • Focuses on the safe handling of living modified organisms.

2. Nagoya Protocol (2010):

   • Deals with access to genetic resources and the fair and equitable sharing of benefits from their use.

3. Kunming-Montreal Global Biodiversity Framework (2022):

   • Replaces the Aichi Targets (2011–2020).

   • Sets 2030 biodiversity goals, including:

     • Protecting 30% of the planet’s land and oceans by 2030 (“30 by 30” target).

     • Halving the introduction of invasive species.

     • Reducing pollution and restoring ecosystems.

What are the below quotes referring to?

• “Underpins the UN-led 2030 Agenda for Sustainable Development.”

• “Represent a hugely ambitious blueprint for the sustainable future of humanity on this planet with the aspirational pledge “that no one will be left behind”.

• Defined as being “integrated and indivisible”, meaning that countries are not able to pick and choose which elements to address but must work towards the achievement of them all.

• “interconnected, addressing the economic, social, and environmental dimensions of sustainable development.”

The United Nations Development Goals

Since what year has our Ecological Footprint exceeded the Earth’s rate of regeneration.

Since 1970!

What is Earth Overshoot Day?

• Earth Overshoot Day marks the estimated calendar date each year when humanity’s demand for ecological resources and services exceeds what Earth can regenerate in that year.

  • From that day onward, we are in “ecological deficit,” depleting natural capital.

How does the negative effect on the climate caused by methane compare to carbon dioxide as a greenhouse gas?

• The negative effect on the climate caused by methane is 23 times higher than that of Carbon Dioxide.

Nearly half of New Zealand’s greenhouse gas emissions come from agriculture

• What percentage of our agriculture emissions is methane from livestock digestive systems.

• The main source of agriculture emissions is methane from livestock digestive systems.

  • Methane makes up almost three quarters of our agriculture emissions.

Recall the seven actions that Sir David Attenborough proposes to save the world.

1. Put people and planet before profit

2. Replace oil with renewable energy

3. Embrace a sustainable lifestyle

4. Create no-fishing zones in the ocean

5. Farm smarter and eat less meat

6. Protect the forests

7. Raise people out of poverty to slow population growth

   • The key to bringing rapid population growth to an end.

     • The fairest way to stabilise the global population is to help poorer nations to develop.

   • Invest in healthcare and education= people will have fewer children.

     • Making the population peak sooner and at a lower level.

What is biodiversity?

Variety of life on earth

• Including within a particular ecosystem

• And genetic diversity between and within species

Where/when was biodiversity first introduced as a resource management concept?

• 1992

• Rio Earth Summit

  • Under the ‘Convention on Biological Diversity 1992’

What is endemic?

When a species only exists there.

• Could be endemic because they only evolved in one place(e.g. Kiwi).

• Or the species died off in all other places(e.g. Tuatara).

What is native?

When a species naturally came to an ecosystem (without the help of humans)

• But Is found in different parts of the world

What is an introduced species?

Species that were purposefully/accidentally brought into another ecosystem by humans.

What major taxa aren’t found in NZ's ecosystems?

• Whole groups of animal species common in other land masses are absent or very poorly represented in NZ.

• Land mammals

  • Endemic birds (eg kiwi, kakapo, moa) fill(ed) the niche of land mammals as they are ground dwelling

• Ants:

  • Poorly represented in NZ.

• Snakes and Iguanids:

  • Occasional visits by sea snakes, but no evidence of establishment.

    • For example yellow-bellied sea snakes are actually considered native species, as they came here by themselves without human involvement.

• Crocodiles and Turtles:

  • Found in the fossil record but died out over 15 million years ago as the climate cooled.

  • Five species of turtles occasionally visit New Zealand waters.

Describe the diversity of endemic birds in NZ's ecosystems

NZ parrots

Kaka, Kea, Kakapo

Kiwi)- 5 species

NZ Wattlebirds (have flaps of skin around bill)

Saddleback, Kokako, Huia (extinct 1907)

Hihi

Stichbird

NZ wrens

Rifleman, Rock wren, Bush wren (extinct 1972)

What are NZ's terrestrial mammals?

Bats are the only terrestrial mammals

- Long-tailed bat

- Lesser short-tailed bat

- Greater short tailed bat is extinct (1967)

What are NZ's marine mammals?

Dolphins

• 9 different species

• Not endemic because they are migratory

Seals

• Lots

Whales

• Almost half the world's whale and dolphin species are found in New Zealand waters at some point in their migration

At what taxonomic level are tuatara endemic to New Zealand?

At the order level.

- They are the only surviving Rhynchocephalians (taxonomic group under Lepidosaurs)

Give a basic overview of

• how much of NZ ecosystems are threatened.

• The threatened species in New Zealand.

Two-thirds of NZ's natural ecosystems are threatened by collapse

Threatened species includes

- 90% of all seabirds

- 84% of reptiles

- 76% of freshwater fish

- 74% of terrestrial birds

NZ has the highest proportion of species at risk in the world

What species in NZ aren't threatened?

Looking at the not threatened species is easier than navigating how threatened species are

- 18% beetles

- 26% fresh water fish

- 38% marine mammals

- 12% lizards

- 5% snails

- 50% plants

To summerise the amount of stuff not threatened is exstremely low:(

Do threatened species in New Zealand automatically receive protection?

No, Threatened species in NZ don't automatically receive protection.

• Legal protection of species is dictated by acts (like wildlife act, conservation act etc)

  • The Conservation Act- For everything DOC land

    • For an animal to be legally protected (rather than just DOC protected) it needs to be specified by on the Wildlife act.

      • this means the government needs to manually add the species to the list (intensive process)

  • The Marine Mammals Protection Act- marine mammals.

  • Native Plants Protection Act - plants within national parks or reserves

  Plants, invertebrates, and fish are generally not protected except where they occur in national parks or reserves.

How many of New Zealand's territorial waters are designated as marine protected areas (MPAs)

30% of NZ's waters are marine protected areas.

• However the level of protection differs greatly.

How much of NZ's costal waters are fully protected as no-take marine reserves?

0.6%

- Needs to be higher to give native marine life a chance

How much of New Zealand’s forests remain:

• Approximately 23%

  • That means 78% loss.

What group of taxa are not found in New Zealand, but have evidence that they once did?

• Found in the fossil record but died out over 15 million years ago as the climate cooled.

Crocodiles.

• Suggest that New Zealand's climate was warmer and more diverse then. 

How many endemic species are in New Zealand?

Also list what we have the most of endemically.

• Maybe even throw in how many species of that we have endemically.

20,000 native species of animal in New Zealand.

• Invertebrates, especially insects, dominate.

  • 6000 Beetles !

What percentage of New Zealand’s freshwater fish are endemic?

80%

What percentage of insects found in NZ are endemic?

90%

• Insects have the highest levels of endemism.

How many of New Zealand’s Birds are Native and how many of those are endemic.

• Endemic is a subset of native.

• Of the 168 species of bird that are native to New Zealand, 93 are endemic

Tuatara lay their eggs in soil, and the temperature of the surrounding soil determines the sex of the offspring.

With rising temperatures what does this threaten to do?

• I.e. male or female biased.

• The population is likely to become highly male biased due to rising temperatures.

  • Cooler temperatures produce females, warmer temperatures produce males.

What percentage of our native bird species are in trouble?

• 48% of our native bird species are in trouble, 32% seriously so.

Commercial whaling in NZ was between what years?

• For a bonus what whale species where hunted over these years.

The commercial whaling in New Zealand occurred between the 1790 (late eighteenth centaury) and 1965.

• 19th-century (1800-1899) whaling was based on hunting the southern right whale and the sperm whale.

• 20th-century (1900-1965) whaling concentrated on the humpback whale.

When whales became scarce, people turned their attention to seals and penguins as sources of oil.

• Joseph Hatch made his fortune on Macquarie Island by boiling ———-penguins to extract oil for lamps.

Fill in the blank. How many penguins where boiled?

3 million!

What is the current extinction rate compared to the background extinction rate?

The current extinction rate is 100 to 1,000 times the "background" extinction rate.

• This means that species are going extinct at a rate much faster than what would be considered normal or natural.

What is the Anthropocene?

The Anthropocene: New geological epoch characterized by the significant impact of human activity on the planet.

• Many scientists believe that increasing consumption and demand for energy, land, and water is driving a new geological epoch: the Anthropocene.

• It’s the first time in Earth’s history that a single species—Homo sapiens—has had such a powerful impact on the planet.

What are the historical trends in world population growth?

• At the dawn of agriculture (8,000 B.C.), the world population was approximately 5 million.

  • The invention of agriculture allowed people to live in settlements and grow and harvest food .

• Over 8,000 years, up to 1 A.D., it grew to approximately 200 million.

• The industrial revolution spurred tremendous change.

• It took around 50,000 years for the world population to reach one billion by 1800.

  • The second billion was achieved in only 130 years (1930).

  • The third billion in 30 years (1960).

  • The fourth billion in 15 years (1974).

  • The fifth billion in only 13 years (1987).

• During the 20th century, the world population grew from 1.65 billion to 6 billion (by December 10, 1999).

  • It took just 12 years to add another billion, reaching 7 billion on October 31, 2011.

  • It took another 12 years to add another billion; in May 2025, the population is approximately 8.22 billion.

• The UN predicts the world population to reach 9 billion in 2037 and 10 billion in 2060.

What is the relative biomass of humans compared to wild mammals?

The mass of humans is now greater than that of all wild mammals combined.

What is the global biomass of domesticated poultry compared to wild birds?

• The global biomass of domesticated poultry, dominated by chickens, is now about three times higher than that of wild birds.

What percentage of terrestrial vertebrate biomass do humans and their livestock account for?

• Humans and their livestock now account for 95% of terrestrial vertebrate biomass.

Out of all terrestrial living biomass, what makes up around half?

Plants make up around half.

How is biomass distributed across environments?

around 85% of all environmental biomass is found terrestrially.

• Biomass is measure in gigatons of carbona and plants store lots of carbon.

Describe the biomass of the different trophic levels (producers/consumers) in both terrestrial and marine environments.

Terrestrial
Larger biomass of producers.

• Think how much plants there have to be to feed a small amount of consumers- due to energy loss between trophic levels.

Marine
Larger biomass of consumers.

• Opposite to terrestrial biomass ratio because producers (phytoplankton) get eaten and then regenerate really fast, so don’t comparatively have a large biomass.

Human activity contributed to the Quaternary Megafauna Extinction.

• Explain when this occurred and what percentage of large (>40 kg) land mammal species were lost.

• Occurred 50,000 and 3,000 years ago, claiming around half of the large land mammal species.

Human activities have had a great effect on the total biomass of different groups.

Describe the fold increase/decrease for the following:

• Wild Animals

• Domesticated Animals

• Marine Mammals

Wild animals

• Decreased by 6 fold (1/ 6 of what was)

Domesticated animals

• Increased by 4 fold (4 times)

Marine Mammals

• Intense whaling and exploitation have resulted in a fivefold decrease.

What is the Great Acceleration?

The Great Acceleration is a period we are living through.

• The increasing rates of change in human activity since the beginning of the Industrial Revolution.

  • Start of acceleration : 1950.

What was the change in average size of monitored wildlife populations between now and 1970?

• 73% decrease in average wildlife populations

• 56% decrease for marine animals

• 69% decrease for terrestrial animals

• 85% decrease for freshwater animals

What are tipping points?

Tipping points refer to critical thresholds.

• can be irreversible.

E.g.

• Collapse of the subpolar gyre, or Large-scale thawing of permafrost.

Define the term “One Health”.

One Health is a unified approach to health that considers humans, animals, and the environment, recognizing the interconnectedness of their health.

List the three related elements of “One Health”.

The One Health Triad: Human health, Animal health, and Environmental health.

Make a list of factors that affect the emergence and spread of infectious diseases.

• Changes in land use practices.

  • Deforestation.

  • Building Dams.

• Environmental Change

  • Including Climate Change.

    • Changes in Precipitation and Temperature will effect which pathogen thrive.

• Population Density.

• Hygiene Practices.

• Means of animal/human transport.

• Contamination of food and waterways.

• Antibiotic resistance.

• Medical practices

  • Including antibiotics usage.

  • People living longer = Larger population of elderly.

  • Vaccinations effect spread.

• Overall population health.

  • Functioning of immune system.

What is a zoonotic disease?

A disease that can be transmitted between animals and humans.

List 5 zoonotic diseases that are on New Zealand’s List of Notifiable Infectious Diseases.

• Rabies

• Plague (Yersinia pestis)

• Campylobacteriosis

• Salmonella

• Leptospirosis

• Bovine Tuberculosis.

• Influenza

What is New Zealand’s leading food borne illness and what are the common routes of infection?

Campylobacteriosis:

Primarily contracted through consuming contaminated meat (especially undercooked chicken) or unpasteurized milk.

• In New Zealand, drinking water contaminated with fecal matter or direct contact with domestic or farm animals are also common modes of transmission due to its farming environment.

Define and be able to discuss three examples of zoonotic disease.

• Campylobacteriosis

• Salmonella

• Leptospirosis

1. Campylobacteriosis

Most frequently notified disease in New Zealand.

• Cause: Campylobacter bacteria (especially C. jejuni)

• Transmission: Consuming undercooked poultry, unpasteurized milk, contaminated drinking water, or contact with infected animals (especially livestock and pets)

• Symptoms: Diarrhea (often bloody), fever, abdominal cramps, nausea.

  • Often the animals have asymptomatic carriage (don’t show symptoms.

• Prevention: Proper food handling, cooking meat thoroughly, handwashing after contact with animals.

  • Government Public health response included regulation of chicken contamination.

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2. Salmonella

Second, to campylobacteriosis, most common bacterial cause of foodborne illness in New Zealand.

• Cause: Salmonella bacteria

  • Lives in the gut of animals.

• Transmission: Contaminated food (eggs, poultry, raw produce), or water, animal contact and exposure to the farm environment.

• Symptoms: Diarrhea, fever, stomach cramps, vomiting.

  • Many animals and birds are asymptomatic carriers of Salmonella spp.

• Prevention: Safe food preparation, hygiene after handling animals or raw foods

  • The highest rate of disease is reported in young children.

    • They are more susceptible and don’t have good hygiene practices.

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3. Leptospirosis

Most common occupationally acquired infection in New Zealand.

• Cause: Leptospira bacteria

• Transmission: Contact with water, soil, or food contaminated with urine from infected animals (commonly rodents)

• Symptoms: Fever, headache, muscle aches, vomiting, jaundice, kidney or liver failure in severe cases

• Prevention: Avoid swimming in contaminated water, control rodent populations, use protective gear in high-risk jobs.

  • Controlled primarily through animal vaccines.

What proportion of human infectious diseases originate in animals?

75% of all human diseases are zoonotic in origin.

• The reason the one health triad is so important.

Define biosecurity.

The protection of an environment against biological threats.

Who is responsible for managing biosecurity in New Zealand?

• MPI (Ministry for Primary Industries):

  • Oversees Biosecurity New Zealand (a branch of MPI).

• The Department of Conservation (DOC) manages the control of introduced species.

• We as the New Zealand Public.

  • Reporting suspected pests and diseases to MPI.

Discuss the importance of biosecurity to New Zealand.

New Zealand relies on biosecurity to prevent detrimental pests and diseases, protect our environment and wild life, protect and maintain our advantage in the agriculture/ horticulture sector, and thus protect its economy as this sector account for a large percentage of our exports.

Describe an example of a NZ biosecurity risk.

• Foot and Mouth Disease:

  • An acute highly contagious infectious virus, that infects cloven-hooved animals.

    • There is no cure, infected animals must be put down.

  • Belton 2004 – predicted cost to NZ if there was an outbreak $10 billion.(large economic risk)

Describe three examples of a NZ biosecurity failure.

Varroa Mite an invasive pest affecting honey bees in New Zealand, leading to significant declines in bee populations and impacting pollination and agriculture.

• V. destructor established in NZ in 2000

  • Varroa is suspected to account for 19.5 per cent of colony losses.

  • Estimated cost of Varroa to the NZ apiculture industry at between $11.5 to 25.7 million per year.

Mycoplasma bovis is a bacterial infection affecting cattle, causing various health issues (such as udder infections and abortions) and leading to significant economic losses.

• First detected in New Zealand in 2017 in a South Canterbury dairy herd.

• MPI Biosecurity New Zealand – response and control

  • 2019 M. bovis National Plan to eradicate the disease.(funded by DairyNZ and government.)

Fruit fly One of the biggest threats to NZ horticulture; fruit and vegetable crops. This pest can lead to substantial economic losses due to its impact on production and export capabilities.

• Particularly type detected five times in the upper North Island in the past decade.

• Biosecurity response triggered in Auckland February 2019 due to discovery of fruit fly.

  • $18 million biosecurity response finished February 2020.

  • NZ once again declared fruit fly free.

List and briefly describe the purpose of four (4) on-farm biosecurity measures.

1. Sanitation Protocols: Implementing cleaning procedures for equipment and vehicles to reduce pathogen spread.

   • Washing your hands, boots, workwear

2. Fencing: Creating barriers to control animal movement and prevent disease entry.

3. Biosecurity Signage: Displaying signs to inform visitors and staff about biosecurity protocols and farm access restrictions.

4. Stand Down Periods: Designating specific waiting periods before entering another farm property to limit cross-contamination between properties.

   • Stringent measures for intensive livestock systems due to high animal population density (diseases travel faster).

5. Careful consideration of new stock health.

   • Disease status of new stock should be assessed to ensure they are healthy and free from pathogens.

6. Ensuring animal pests are controlled.

   • Keep areas around buildings free from clutter and long grass.

   • Store feed securely.

   • Trapping and baiting.

Define the term ‘food security’.

• Food Security:

  • Four key components:

    Insuring access to…

    • Quantity: Sufficient quantities of food.

    • Availability: Reliable access to food.

      Affordability: Available food is affordable.

    • Nutritiousness: Available food is nutritious.

Discuss what is meant by the term ‘water security’?

• Water security refers to the availability of an adequate quantity and quality of water for health, livelihoods, and production, along with the protection of water-related ecosystems.

What the most common threat to water security?

• Water scarcity.

  • Things that contribute to water scarcity: low rainfall, climate change, high population densities and overallocation of water source’s.

Discuss the impact population growth over the next 25 years, will have on food production.

Food production needs to increase by 50% over the next 25 years to meet the demands of the projected population (9.9 billion people in 2025).

• This will require sustainable farming practices, technological advancements, and efficient resource management to ensure sufficient food supplies while minimizing environmental impacts.

Agriculture accounts for what percentage of global freshwater withdrawals?

Agriculture accounts for 60-70% of annual freshwater withdrawals.

• Varies depending on country.

• Water required for irrigation, livestock and aquaculture.

It is a large user of water.

What global region is the largest meat producer?

Asia.

Globally, what type of meat is the most popular/most consumed?

Pork.

What percentage of global habitable land is used for agriculture?

50% of habitable land is used for agriculture (approx. 51 million km²).

• 77% of agricultural land is utilized for livestock (meat and dairy- including land required to grow livestock feed).

• 23% for crops.

What are the top two contributors to New Zealand’s primary industries export revenue?

• Major export products include:

  • Dairy: 44% of total exports

  • Meat and Wool: 21%

Describe trends in population growth from 1990 to 2025.

• The average global population growth rate is slowing

  • Peaked at over 2% in the late 1960s and since then the rate has been falling.

• Currently the average global growth rate is: ~1%.

• 1900 population: <2 billion (about ¼ of the current in 1930) ; 2023 ~8 billion people Expected by 2050: 9.9 billion.

• Food production must increase by 50% to meet future demands.

  • To feed the projected 9.9 billion people.

When was the united nations general assembly? and when do they want to achieve their sustainable development goals by?

• 17 interlinked goals

• Established by the United Nations General Assembly in 2015.

• Intended to be achieved by the year 2030.

How much has global meat production increased to, and by how many times compared to fifty years ago?

• Global meat production has increased to over 340 million tonnes.

  • This is four times the quantity of meat produced fifty years ago.

How much milk is produced annually, and how does this compare to fifty years ago?

• Milk production is approximately 800 million tonnes annually.

  • This is more than double the amount produced fifty years ago.

What is the agricultural export revenue for New Zealand, and how many people does the industry employ?

• Total agricultural export revenue reached NZ$ 54.4 billion.

• Employs 358,000 individuals (12.4% of workforce).

By what percentage is global water demand projected to increase by 2050?

Global water demand (in terms of freshwater withdrawals) is projected to increase by 55% by 2050.

What percentage of the world's population lacks food security, and how many people does this represent?

- 17.2% (1.2 billion) of the worlds population lack food security

Auto vs heterotrophs

Autotroph

- An organism that produces it's own energy (typically by photosynthesis) rather than obtaining it from others (eg. via consumtion)

- Primary producer

- Plants & algae

Heterotroph

- Organism that derives it's energy from other organisms

- Primary, secondary/tertiary consumer

- Animals & fungi

- Includes decomposes, which eat dead organic matter (important in nutrient cycling)

- Amount of heterotrophs/consumers depends on amount of autotrophs

What are the first & second law of thermodynamics; and the law of conservation of mass?

First law

- The energy of the universe is constant

- Energy can only be changed from one form to another but can't be increased/decreased

- This means all energy in ecosystems just cycles round

- The energy flow of an biosphere/world wide ecosystem can't increase or decrease, just change states

Second law

- Every energy transfer or transformation increases the entropy of the universe

- Applies to chemical cycling and energy flow in

- Becuase heat is a major product of living organisms there is an increase in entropy

Conservation of mass

- Mass cannot be created or destroyed

- For example if a lion eats a deer; it is not destroying it's mass only breaking it down into smaller pieces

Ecosystems are open systems that absorb energy and mass and release heat and waste products

^ these laws apply to them

Trophic levels

Primary producers (plants/algae)

Primary consumers (herbivores)

Secondary consumers

Tertiary consumers

Quaternary consumers

- Energy leaks out at every trohpic level

- Only 10% of energy at each level is passed up (eg 10% of energy from primary producers is passed up to primary consumers)

- Decompisition links all trophic levels

- Detritivores/decomposers break down non-living organic matter (cycles nutrients/important to ecosystem)

^ prokaryotes and fungi

- A food web is the interconnected trophic levels

What is primary productors role in ecosystems

- They hold up the WHOLE ecosystem

- In terrisitral ecosystems largest amount of of biomass

- The extent of photosynthetic production sets the spending limit for an ecosystem's energy budget

Global net primary production (GPP) vs net primary production (NPP)

GPP

- Total primary production of an ecosystem

- Calculated from the conversion of energy from light (or chemicals) to the chemical energy of organic molecules per unit time

NPP

- Calculated from GPP-energy used by autotrophs for respiration

- Only NPP is available to consumers (GPP is not)

What are the limiting factors of net productivity?

Light

- Regions near the equator are exposed to a lot of light=more photosynthesis=more productive (bc bigger amount of primary producers)

- Many marine ecosystems are aphotic and therefore are not very productive

Nutrients

- Soil nutrients can limit primary prodution in terristrial ecosystems

- Aphotic marine ecosystem may have fewer nutrients=less productive

Water

- Water is a limiting factor of photosynthesis

- Therefore more water=more photosynthesis=more net production

- Tropical rainforests are super productive becuase they have high light lvls (near the equator) and lots of rainfall

What is the typically value for energy transfer between trophic levels?

10%

- 10% of energy from primary producers goes to primary consumers

- 10% of that energy goes to secondary consumers

etc.

- This means that there are is much fewer organisms (predators) at the top of food chain

- Most of the biomass of an ecosystem comes from primary producers (think about how much trees there are compeared to predators)

What type of livestock are typically farmed on New Zealand hill country farmland?

Sheep and Beef.

What type of livestock are typically farmed on New Zealand flat farmland?

Dairy cattle.

List the two most common breeds of beef cattle farmed in New Zealand.

Angus and Hereford.

List the two most common breeds of sheep farmed in New Zealand.

Merino(Fine Wool) and Romney(Meat and Coarse Wool).

List the three most common breeds of dairy cattle farmed in New Zealand.

Holstein-Friesian, Jersey and Kiwi Cross (Cross between Holstein-Friesian and Jersey)

New Zealand grazing pasture is dominated by which two plant species?

Perennial ryegrass and white clover.

• Ryegrass 80%: white clover 20%

Describe the typical annual pattern of pasture growth in New Zealand. (be able to draw a graph that represents the typical annual pattern of pasture growth in New Zealand)

• Spring: has a high growth rate

• Summer: Pasture growth slows down

  • Less rain fall- Dries out the grass-brown looking grass(Not great quantity but also bad nutrition quality due to increased fiber levels due to seed heads forming).

• Autumn: In some areas of New Zealand there is often a little bit of growth due to increased rain.

• Winter: Pasture Growth tapers off and reaches its lowest point during the winter months.

  • Not because it is is dry but because it is cold.

  • Thus the grass will be nice and green(good nutrition quality), there will just be very little growth(bad quantity).