IB BIO YR 2 Unit 1

Ecology

Ecosystem

biological communities of interacting organisms and their environment

Deforestation

the intentional and permanent clearing of trees and forests by people to use the land for other reasons

-Amazon rainforest is losing trees due to this causing them to turn into a carbon source instead of a sink

Tipping Point

critical threshold that when crossed leads to large often irreversible changes in the climate which is called climate change

Percentage Change

Formula: final-initial/initial x 100

Mesocosm

any indoor experimental system that examines the natural environment under controlled conditions

-only sunlight enters and nothing leaves

-allows scientists to control and manipulate variables while investigating ecosystems

Sustainable Fishing

harvesting for fish at a sustainable rate

depends on: fish population doesn’t decline because of fishing, uses selective methods to maximize fish capture without fish populations decreasing

Maximum Yield

largest catch of fish that can be sustained over time without causing the fish stalks to decrease

Pacific Cod

they have limit on them to protect them and for them to be able to replenish

-capture-mark-release method is used

echo sounders and analysis of the fish caught are all methods

Silver Top Palms

are a plant located in florida and bahamas, you have to harvest the heart so that they can continue to grow, you also don’t harvest the young growing palms. this helps preserve the growing palms so they don’t go extinct because they are a large part of the economy

Sustainable Agriculture (harvest)

refers to the methods of agricultural production that meets the current needs of food production while preserving the natural environment and farmland

Facts that effect sustainable agriculture

-soil erosion (dust bowl)

-leaching of nutrients (overuse of fertilizers leads to eutrophication)

-supply of fertilizers and other inputs (mining phosphate for fertilizers)

-pollution (to agrochemicals)

-carbon footprint (practices for agriculture release CO2 contributing to climate change)

Plastics

a range of synthetic materials that persist in the environment because they do not biodegrade

Macroplastic

large visible debris over 5mm across

Apex Predator

a top animal in the food chain that has no predators of its own as an adult

Rewilding

aims to restore degraded ecosystems back to their natural state

-reintroduction of keystone species

-re-establishment the connectivity of habitats over large areas through wildlife corridors

-management of ecosystems to reduce human impact (national parks)

Wildlife/living corridors

areas if habitat which connect wildlife populations separated by human activities or structure

help with: migration, expanding habitat range, increasing biodiversity, greater genetic variability

Microplastic

produced by the physical breakdown of macro- plastics, is less than 5mm across

Climate Change

significant long term shifts (decade or longer) in global or regional climate patterns

measured by: temp, precipitation, wind patterns, other

Carbon Cycle

the continuous process by which carbon atoms move between the Earth's atmosphere, oceans, soil, rocks, and living organisms.

Anthropogenic Climate Change

climate change caused by humans

Major anthropogenic causes to climate change

• Burning of Fossil Fuels/Combustion (releases CO2 into the atmosphere)

• Agriculture Practices (farming cows, sheep and rice releases methane into the atmosphere

• deforestation and land-use changes

• waste management (land fills, recycling)

Positive vs. Negative correlation

positive occurs when both variables or decreasing or increasing together

negative occurs when the variables move in opposite directions

Caustation

Example: as carbon dioxide concentrations go up the earth gets hotter causing the temperature in Antarica to get hotter causing the ice to melt.

Positive feedback loop

increases the rate of global warming

Antartica Examples of positive feedback loop

• Loss of snow and ice: 

  • White snow and ice reflects most solar radiation.

  • Loss of ice and snow = Darker land and water and absorbs more solar radiation in the form of heat, 

  • Contributing to warming global temperatures.

• Decomposition of Permafrost: Permafrost is soil that remains below freezing for at least two years. There is a lot of carbon stored in permafrost.

  • Permafrost is being thawed by increasing temperatures. 

  • This allows the peat to be decomposed by bacteria, releasing carbon dioxide and methane into the atmosphere.

  • The increases in carbon dioxide and methane lead to further increases of temperature and further melting of the permafrost.

Tipping Point

the critical moment when a small, cumulative change or a final extra push causes a system, behavior, or situation to completely change, leading to a significant and often unstoppable effect

Carbon Sinks

any natural or artificial system that absorbs more carbon dioxide from the air than it releases.

exp: forests

Boreal Forests

The boreal forests of the taiga have been a carbon sink.

Much of the carbon in boreal forests is stored in the ground, as low temperatures reduce the rate of decomposition.

Tipping Point Boreal Forest

Warmer temperatures and decreased snowfall lead to more droughts as water is evaporated from the ecosystem. 

The lack of water reduces the primary productivity of the plants through reducing  photosynthesis. This decreases the amount of CO2 taken OUT often atmosphere

Forest browning occurs due to prolonged periods of drought which increases frequency and intensity of wildfires.

Forest fires release carbon stored in the biomass of plants, as well as carbon stored in the soil as peat.

Sea Ice and Landfast Ice

There  is a decreasing trend for the area of arctic sea ice over time. Landfast ice (forming on land from fresh water and snow) sea ice (forming from salt water)  are melting at increasing rates due to global warming.

Emperor Penguins and Sea Ice

Emperor penguins require sea ice to form breeding colonies in the Antarctic.

• Climate change = loss of sea ice 

• Declining sea ice reduces the number of emperor penguin colonies.

• Sea ice is melting earlier every year, often before the chicks are capable of swimming in the icy waters of the Antarctic Ocean.

• This aids in less penguins surviving to the next year

Ice Floe

are large stable masses of free-floating ice.

Walruses depend on the use them for resting, and feeding their young.

Walruses rest on them between feeding and hunting.

The loss of them due to global warming affects walruses’ ability to hunt and feed their young.

Walruses are now resting on beaches further away from their food sources.

Stampedes of walruses on beaches end up with young walruses being crushed to death.

Walruses must now travel longer distances to reach their food sources in deeper waters, making it more difficult to feed the young.

The population of walruses is decreasing as ice is being lost from the Arctic Ocean.

Nutrient Upwelling

the process in which cold nutrient-rich water rises from the bottoms of oceans towards the surface of oceans

• wind blows across surface waters

• allows water below to rise up, bringing nitrate and phosphate to the phytoplankton on the surface

• phytoplankton growth is stimulated by the nutrient-rich waters

• high primary productivity of phytoplankton supports a bio diverse community of organisms in marine ecosystems

Poleward Range Shift

refers to the movement of species towards the poles in response to climate change

Upslope Range Shift

as the climate changes the range of species is changing as they move to higher elevations on mountains

Mutalistic

provides a safe home and raw materials, while the microscopic algae provide vital food and energy through photosynthesiscoral with the zooxanthealle algae, increasing ocean temperatures stress corals and they expel zooxanthealle losing their color making them bleached

Ocean Acidification

as the atmospheric carbon dioxide concentrations increase, more carbon dioxide diffuses into the ocean, then the carbon dioxide reacts with water to form carbonic acid which reduces the pH of the oceans

-has changed from 8.179 to 8.069 since the start of the 19th century

Coral Bleaching

the process where stressed coral polyps expel their mutualistic photosynthetic algae (zooxanthellae). This loss turns the coral stark white and deprives it of its main food source

Afforestation

the establishment of forests in locations where there was no recent tree cover

-better to have native species

Peat

many wetlands have been drained but can be restored to wetlands

-forms when organic matter is not fully decomposed because of acidic and/or anaerobic conditions in waterlogged soils

Biodiversity

variety of life in all of its forms

Ecosystem diversity

variety of ecosystems within an area

Species diversity

the # or relative abundance of species found within an ecosystem

Genetic Diversity

variety of genes and alleles present in a species

species with high genetic diversity are more likely to survive changes due to natural selections

Species

2 million species have been identified but it is estimated 8.7 million

Extinction

there have been 5 mass extinctions in history

mass extinctions take out 60-80% of species, but they allow for new ecosystems to grow and niches

Anthropogenic

human involvement

-species extinctions: habitat destruction, climate change, pollution, over exploitation (over hunting animals), invasive species, disease

Habitat

the place in which a community, species, population, or organism lives

Pollution

the addition of substances or agents (chemical, physical, or biological) to the environment by human activity—or at a rate faster than the ecosystem can process them—causing a damaging, harmful, or appreciable effect on living organisms

Overexploitation

the harvesting or use of a species or natural resource at a rate faster than it can naturally replenish or reproduce

Invasive Species

an alien (non-native) organism that is introduced into a new ecosystem and has a detrimental or harmful effect on pre-existing food chains, native biodiversity, or ecological stability

Requirements for a Stable Ecosystem

Supply of energy, recycle nutrients, genetic diversity, climate variables within tolerable levels

Laysan Albatrosses

are a type of bird that are going extinct due to plastic, they eat plastic that gets washed up on beaches causing it to get lodged in their throat killing them

Sea Turtles

mistake plastic bags for jellyfish which is their primary food source when ingested it can be fatal, it can also get wrapped around their fins disrupting growth

Hinewai Reserve

New Zealand made in 1987 with farmland, the goal of the reserve is to regenerate native vegetation and wildlife and it is a managed natural ecosystem

originally was bad because of agriculture

Montane Bird Species

New Guinea

-example of upslope range

as the range of the bird species moves upslope their habitat becomes compressed due to the limited amount of area on the mountains

-less birds because they are running out of room causing more competition

Sugar Maple Trees

-example of poleward shift

the range of trees is moving northward to cooler climates

Carbon Sequestration

the process of capturing and storing atmospheric carbon dioxide

Taxonomy

study of: classification of organisms into groups such as species is an example of pattern recognition but the same observation or classified in different ways

-Lumpers: few different groupings (more similarities)

-Splitters: recognize the difference species (DNA)

Moa Birds

lived on New Zealand 500 years ago, went extinct for hunting for food and clothing

overexploited

Caribbean Monk Seals

declared extinct in 2008

overexploitation

their blubber was used for oil

restricted the species range, elimination of breeding colonies

Dipterocarp Forests (anthropogenic issues)

Southwest Asia (most diverse ecosystem)

-deforestation for wood (timber)

-agriculture: development of palm oil plantation

-mining: coals, metals, diamonds

-climate change: changing rainfall patterns causing floods and droughts

-hunting/poaching: animals are hunted for meat, skin/fur, trophies, traditional medical procedures

Mangrove Ecosystem Loss

Florida

-coastal infrastructure and tourism

-agriculture: use of pesticides and fertilizer go into the aquatic ecosystem

-fishing and aquaculture: fish farmers release waste

-climate change: sea levels are rising and more salt is coming in

Simpson’s Diverse Index

measures the biodiversity of a species

D=N(N-1)/the sum of n(n-1)

D= Diversity Index

N: total # of organisms

n= # of organisms in a particular species

-High index suggests a stable site with many different niches

Urbanization

the movement of people to cities and towns the process of urbanization leads to the loss of ecosystems and biodiversity

Deforestation

happens due to the demand for wood and agriculture land, clearing the earth’s forest destroys ecosystems, reducing biodiversity and contributing to climate change

Agriculture

displaces natural ecosystems decreasing biodiversity

-farm wastes, fertilizers and pesticides enter natural ecosystems disrupting food webs and biodiversity

Pollution

introduction of harmful substances into the environment

-human activities release pollution into ecosystems harming the organisms that live there causing a decrease in biodiversity

Invasive Species

introduced species become these when they harm native species

-disrupt food webs resulting in the loss of biodiversity

Ex Situ

conservation of species outside their natural habitats involving captive breed programs

advantages: protection from predators, greater control of conditions required for breeding to ensure the offspring survive birth

disadvantages: captive population=limited organisms are living outside the natural habitats

Ex Situ Examples

Giant Turtle Population: reduced to 14 was in danger of extinction due to being hunted for food by humans, and competition for food by goats introduced to the island.The 15 surviving tortoises entered a captive breeding program.The goats were removed from the island, so that they were not competing with the tortoises.Tortoises were no longer hunted for food.Since the 1960s, over 1500 tortoises have been reintroduced to the island of Espanola. The captive breeding program has been so successful that it is no longer operating.

Seed and Tissue Banks: seed banks store seeds to preserve genetic variety. The seeds can be used to restore ecosystems in the future. Tissue banks store plant tissues which can be used to propagate plants in the future.

In Situ

protects species within their natural habitat often within nature reserves or national parks

advantages: Organisms are not held in captivity, so they will develop survival strategies. Other species in the protected habitat are also protected. Biodiversity of the ecosystem is preserved.

disadvantages: Many endangered species need large areas for population survival. Difficult to prevent poaching of endangered animals. Genetic variety may already be damaged.

Examples of In Situ

management of nature reserves

rewilding and reclamation

EDGE Program

Evolutionarily Distinct and Globally Endangered) programme highlights and protects some of the most unique endangered species.

Evolutionary distinctiveness

Species that are unique in the way that they look and behave. The species should have few or no close relatives.

Global endangerment

The IUCN Red list of endangered species is used to identify the threat level of extinction for a species, with critically endangered species most likely to become extinct.