the living world

what is an ecosystem?

a natural system that is made up of plants, animals and teh environment in which they live

what are biotic components?

living components such as animals plants

what are abiotic components?

non living components such as climate, soil

what is a food chain?

a diagram that shows the direct links between different organisms that rely on each other as a source of food

what is a food web?

a diagram that shows the complex hierarchy of plants and animals that rely on each other as a source of food in an ecosystem

what is an example of a food chain?

algae, frog, stickleback, perch, heron

what is an example of a small scale ecosystem in the uk?

- a deciduous woodland such as epping forest

- producers: tree species such as oak, plants such as holly

- primary consumers: insects, rabbits~

- secondary consumer: frogs,

- tertiary consumers: foxes

what are 2 sources of nutrients?

rainwater washing chemicals out of atmosphere

- weathering of rocks releasing chemicals into soil

what are the 3 main stores in nutrient cycling?

biomass, litter, soil

which nutrient store is the largest often?

biomass, nutrients obtained from uptake from soil

which nutrient store is second largest?

soil, nutrients obtained from weathered rocks and release from litter

what nutrient store is smallest?

litter, nutrients obtained from precipitation, fallout from biomass but loses nutrients from runoff

what is leaching?

The process by which nutrients are removed from the soil by being dissolved and carried by the water

which nutrient store does leeching affect?

soil

what are global ecosystems?

large scale ecosystems such as biomes

where do most global ecosystems form?

latitudinal belts across the world

where are coniferous forests located and what are their characteristics?

- roughly 60 degrees north

- cold and dark winter, warm summers, trees are evergreen

where are deciduous forests found and what are their characteristics?

- roughly 50 degrees north, natural ecosystem of UK

- shed leaves in winter, climate is moderate

where are deserts found and what are their characteristics?

- roughly 30 degrees north and south of equator, close to tropics

- supressed rain due to sinking air, hot in day time but cooler at night

where is the Mediterranean found and what is its characteristics?

- roughly 40-45 degrees north of equator, isolated pockets in south Africa and western Australia

- hot and dry summers, wet and mild winter, fruit and oak trees

where are tundra's found and what are their characteristics?

-arctic and Antarctica and high latitudes

- extremely cold throughout year in polar regions, cold winters and warm brief summers in tundras, limited precipitation

where are temperate grasslands found and what are their characteristics?

- 30-40 degrees north and south of equator

- hot summers and cold winter with low rainfall

where are tropical rainforests found and what are their characteristics?

- close to equator widespread over Asia, Africa, south America

- hot air so heavy rainfall, high temps, holds over 50 percent of worlds ' animals and plants

where are tropical grasslands found and what are their characteristics?

- 15- 30 degrees north and south of equator

- tropical climate so distinct wet and dry seasons, fires are common in dry seasons

what is the climate of tropical rainforest's like?

-high temps of 27 degrees all year round

- high rainfall about 2000 mm per year

- ideal growing conditions

what is the water like in tropical rainforests?

- distinct wet season with high rainfall lasting several months

what can the large amounts of water in tropical rainforests lead to?

swelling local rivers and sometimes causing flooding

- water soaks into soil dissolving and transporting nutrients away

what are the soils like in TRFs?

- not very fertile

- nutrients are very concentrated in upper topsoil and are very quickly taken up by plants meaning most trees and plants have shallow roots to maximise nutrient absorption

what are the plants and animals in TRFS like?

- birds live in canopy

- mammals are well adapted to tree

- snakes use trunks of trees as vertical highways

- animals such as deer search for vegetation on floor

what are the people like in TRFs?

- traditional tribes

- sustainable lifestyle

how are tropical rainforest interdependent?

- vast majority of nutrients stored in m=biomass

- soil contains a few nutrients as any nutrients released by decomposers are quickly absorbed by trees and plants or leached into soil by rainfall

- few nutrients in litter store as decomposers thrive in wet and warm conditions so they quickly break down dead leaves and branches

how are plants adapted in TRF'S?

- tall emergent trees competing for sunlight

- lianas to provide support to large trees

- large leaves

how are animals adapted in TRF'S?

- toucans have strong beaks to crack hard nuts

- poisonous frogs have bright colour to warn predators

- three toe sloths have long claws to climb trees

how biodiverse are rainforests?

- 30000 species of plants and 1600 species of birds

why are TRFs so bio diverse?

- wet and warm conditions encourage plants to grow well

- rapid recycling of nutrients speed up growth

- many TRFs are untouched by people allowing habitats for many animals to live in

what are the main threats to biodiversity?

- habitat destruction and hunting

-slash and burn agriculture

- development of roads

what are the main impacts associated with biodiversity decline?

- indigenous tribes unable to survive in rainforests

- plant and animals species going extinct

- important medical plants going extinct

using a case study, explain the causes of deforestation?

Amazon, Brazil

-mineral extraction: for mining, areas of forests have to be cleared to allow space for the mien to be discovered and over 50000 hectares of forest land has been cleared for gold mining

- road building: roads are needed to transport products to markets for example the trans Amazonian highway which is 4000km long

- logging: accounts for 3 % of all deforestation in Brazil as many timber companies are interested in trees such as mahogany and teak and they sell these to make furniture in other countries

using a case study explain the impacts of deforestation?

Amazon Brazil

- decline of indigenous tribes: many tribes have been forced out of the forest as there isn't much area left for shelter, only 240 tribes left compared to the 330 in the 1990s

- loss of biodiversity: animals are losing habitats and hence can't survive in teh forest. They are also sometimes killed in the process of clearing land such as by fires or falling trees. Estimated that 137 plant animal and insect species are lost each day

- economic development: in 2018, almost 600000 people in Brazil worked in teh forest industry. THe clearing of land and logging requires workers and are often low skilled jobs meaning that large number of people who live in poverty in Brazil are able to gain employment and can hence afford more goods and services increasing their SoL

what is the value of rainforests to people?

- medicine: about 25 percent of all medicine comes from rainforests and more than 2000 plants have anticancer properties

- homes for tribes: 11000 people in Achuar tribe in Peru who survive on the rainforest's food and shelter

- employment

what is the value of rainforests to the environment?

- climate: contributes to 28 percent of the world's oxygen and are a large carbon sink

- water: about 20 percent of the earth's freshwater comes from the Amazon's basin

- biodiversity: contains about 50 percent of all animal and plants species in the world

how can rainforests be managed sustainably?

- selective logging: introduced in Malaysia in 1977 and involves cutting down individual certain trees to prevent large scale felling and the trees that are felled are also replanted

- education: many charities and organisations such as WWF and birdlife international have created courses and sites to help allow people to understand the value and importance of rainforests to prevent misuse and damage towards rainforests

- international agreements: the international tropical timber association prevents large trad of hardwood as the only timber that are registered are the ones from sustainably managed rainforests

what is the climate like in cold environments?

climate: temps are below 0 degrees Celsius in polar and below -50 degrees in winter however in tundra's, the temp in winters is often below -30 degrees Celsius and in summers it is well above 0 degrees Celsius

- polar has very low precipitation whereas tundra's experience high precipitation

- both experience full darkness at most times

what other physical characteristics do cold regions have?

- permafrost: a hard impenetrable layer of ice below the active layer that prevents any soil processes from occurring and often causes the active layer to be waterlogged in summer

- soil: cold environments have none or almost very little soil in their regions due to low temperatures and less vigorous precipitation not allowing soil to form

- plants are almost non existent in polar regions however in tundra regions there are many that have become adapted

- people: no permanent settlements in polar regions however in tundra environments, there are tribes such as the Inuit tribe

what plant adaptions are there in tundra regions?

- shallow root systems enable plants to access water close to surface in active layer

- flowering plants have very rapid life cycles allowing them to disperse seeds in summer despite it being very short

- the bearberry plant has thick hairy stems to allow it to retain warmth during the cold weather

how are animals adapted in codl environments?

- arctic foxes: have thick fur that is also white allowing them to be warm and camouflaged into the snow

- musk oxen: 2 layers of fur for warmth and wide hooves to move easier in snow

how are cold environments interdependent?

- indigenous people depend on animals for food and clothing

- the berries on the bearberry plant depends on animals such as arctic owl eating its fruits and dispersing its seeds

- arctic birds use moss as a source of insulation in their nests

what issues may affect biodiversity in cold environments?

- climate change: may increase summers and temperature in cold environments which may in fact increase biodiversity however when biodiversity increases, issues will arise in ecosystem

- co2: climate change leading to melting permafrost which releases carbon leading to further greenhouse effect

- increased use of cold environment by people: people use cold environments for oil extraction which can cause physical damage to the area and can also further aggravate climate change

using a case study, what are the opportunities in cold environments?

Arctic tundra focusing on Alaska

- tourism: 1-2 million people visit Alaska every year creating a large tourism sector in Alaska. This creates jobs and also creates income for the Alaskan government allowing funding and spending on public sector to further increase employment and QoL

-energy: more than 50 HEP plants provide energy to Alaskan communities and this allows basic survival such as heat and ability to cook. Also creates jobs to look after and manage these plants

- fishing: employs 1 in 10 Alaskans and adds 6 billion dollars to state economy annually allowing for a large investment opportunity in Alaska to make it better place to live in

using a case study, what are the challenges in cold environments?

Arctic tundra focusing on Alaska

- very harsh climate: temps fall to around - 40 degrees Celsius which makes it very hard to work and go out of homes in Alaska. It also prevents industries such as farming from thriving due to inability of plants growing and animals being able to survive

- inaccessibility: snow and ice make roads unusable for much of the year and the seasonal melting and refreezing of teh active layer causes expansions of the surfaces making an uneven ground called thermokarst which decreases ability to travel anywhere limiting people from working and goods being transported in Alaska

- damage and lack of ability to use buildings: buildings can release heat which can melt the layer of ice below them and hence have to be highly insulated to prevent heat release which is expensive. Snow and ice can accumulate on roofs of buildings and can cause them to collapse as the precipitation weakens the roof which requires high costs to repair and maintain

what is a wilderness area?

A wild and unspoiled area unaffected by human activity.

why should cold environment wilderness areas be protected?

- fragility: cold environments are fragile meaning they take a long time to develop and also take a short time to be easily damaged

- research: constant surveillance and maintenance has to be taken place in cold environments in order to prevent excessive melting of active layer which requires scientists to limit development in order to have enough space to set up a base to do so

- tribes: some tribes such as Inuit tribe depend on cold environments for survival and hence they need it

what are strategies to manage cold environments?

- infrastructure: trans Alaskan pipeline built 10 feet above ground to allow caribou to migrate underneath and also allows oil to be transported maintaining economic development and limiting damage to environment. Also contains valves at certain points which would shut down in case of a break to minimise damage

- organisations: arctic council is an organisation that represents 8 countries and the indigenous people of arctic. Promotes co operation to maintain sustainable development and environmental protection. Also there is the ANWR protecting 19.6 million Ha of Alaska

- Bans: international whaling convention has set bans on commercial whale hunting preventing both damage to ecosystems physically and environmentally due to chemicals. Also protects wildlife