Ecosystems Flashcards
(26 cards)
What is an ecosystem?
An ecosystem is a community of plants and animals that interact with each other and their physical environment
What is a food chain? How is this different to a food web?
Food chains start with a single producer like a plant, that completes photosynthesis. It outlines who eats who in a line and the arrows shows the energy transfer. A food web is multiple food chains in an ecosystem.
Explain nutrients cycle
What are nutrients? What sources do they come from?
How are they transferred through biotic factors?
Nutrients are foods that are used by animals and plants to grow and live.
There are two main sources of nutrients: rainwater washes chemicals out of the atmosphere and WEATHERED ROCK releases nutrients into the soil.
When plants or animals die, the decomposers help to recycle/break down the nutrients making them available once again for the growth of organisms. Decayed material adds nutrients to soil and are taken up by plant roots.
What are trophic levels?
Trophic levels describe the position of an organism in a food chain, web or pyramid. For example grass is trophic level one.
The 3 components of the nutrient cycle
Explain the nutrient transfer using them
- Soil
- Biomass
- Litter
Nutrients released into the soil.
This is then taken into biomass. The nutrients fallout as the tissues die. These nutrients then are released as the litter decomposes.
Sometimes loss in nutrients can happen through runoff (water running over) or leaching (washed away).
What are biomes?
Large scale ecosystems. Defined by climate, soil and vegetation.
Name biomes
Tundra, Savanna Grassland, Decidiuous forest
What factors affect the global distribution/characteristics of a biome?
Altitude - higher the height above sea level, the lower the temperature as air is thinner and cannot retain heat. Tundra.
Ocean currents - cold ocean currents create dry conditions as there is a lack of evaporation. Warm Gulf Stream current makes Western European countries warmer despite latitude.
Precipitation - Areas of high pressure experience little rainfall and areas of low pressure have high rainfall
Where are the deserts located and why? (think about air)
Hot air rising from the equator loses its moisture in the process, producing clouds and rain, which give rain forests their name. This now dry air cools and descends, generating an arid, formidable desert environment.
What is biodiversity?
Biodiversity is the variety of living species
What are the values of ecosystems?
Resources
Fruit, 25% medicine, industrial materials, oils
Stewardship
Ethical obligation
Services
Provides 20% water and oxygen
CO2 regulation
Natural fertilisers
Decomposition of waste
Examples of bad land management
- deforestation
- overgrazing
- industrial agriculture
What is deforestation and why is it happening? What are the effects on animals and soil?
Clearing of large areas of trees including logging, farming and mining
It is used to extract metals like iron copper and gold. Woods such as timber for furniture and paper. Farming is for cattle ranches producing beef.
Animals like the orangutan are being driven out of forests and are made extinct.
Soil is left bare so nutrients are washed away, preventing the growth of new plants - disrupting the nutrients cycle.
Where are tropical rainforests located?
Along the Equator between the Tropic of Cancer and the Tropic of Capricorn.
Continents of SA, Africa and Asia like the Indonesian rainforest.
List characteristics of TRFs
Diverse ecosystem with warm, wet climates
Dense vegetation
Complex food webs
Nutrient-poor soil due to rapid decomposition
What is the climate like in TRFs? + why
the sun is directly overhead.
less atmosphere to pass through so less radiation is absorbed and is very hot
What is the soil like in TRFs? + why
soil is INFERTILE
THIN layer at the surface is FERTILE where leaves decompose
nutrient cycling is RAPID due to humid conditions that help dead matter to decompose
nutrients are washed
Explain 4 layers of TRFs
- Emergent
Tall trees, dry climate, monkeys, eagles - Canopy
thick layer of vegetation with drip tip leaves. lots of shelter and food - Under canopy
12 metre trees, adapted to shade - forest floor
thin layer that quickly decomposes. no leaves on trees due to no light to photosynthesise.
Reasons why TRFs are important
Life support ->
- Atmospheric regulation by absorbing co2 and releasing oxygen, mitigating climate change
- Soil health: rapid leaf fall and decomposition creates fertile topsoil, supporting agriculture
- Hydrological cycle influence - trees store and release water via evatranspiration, contributing to water fall
Goods and services ->
- Food like nuts
- Cash crops - disease resistant like coffee beans
- Medicine like rosy periwinkle for leukemia
- Raw material like timber and palm oil
What is an adaptation?
A change in structure or function to improve chances of survival in an environment.
Give some examples of how animal/plants are adapted to the TRFs
Jaguar has rosette patterned skin for camoflauge, swimmer, can move quickly
Toucan has a hard beak to eat nuts not eaten by others
Long beach to reach good
Vivid colour for camoflauge
Curved feet for branches
Epiphytes never touch the ground and use other plants for support and catches nutrients in the air
Describe some of the challenges in the Amazon Rainforest? Are there any possible solutions
- Deforestation : replant trees and limit the area of deforestation
- climate change : reduce emissions
- illegal activities : stricter laws and active enforcement
- loss of biodiversity : support conservation programmes
- threats to indigenous communities : secure land rights
- pollution
- weak environmental policies
What is the Bolsa Floresta Programme? What are the cons of it?
A programme aimed to reduce deforestation while supporting local communities by selective logging and low impact methods by paying the families who protect.
Payments are often too low. It covers only certain areas and monitoring is difficult. Relies on external funding which is unstable.
Explain rain shadow
reduced rainfall behind a mountainous region on the side facing away from prevailing wings aka leeward
