Natural ecosystems Flashcards
What are examples of waste products in natural ecosystems?
Oxygen from photosynthesis,
Carbon dioxide from respiration,
Dead matter like leaves, fruits and faeces
In a stable ecosystem how do the outputs and inputs compare?
The outputs or losses are balanced by the inputs or gains
Why are reproductive structures produced in large quantities?
To ensure successful reproduction large quantities are produced as there are chances that some or many of those produced will be faulty or wont be fertilised
How does the large production of reproductive structures affect an ecosystems stability?
The large production doesn’t affect stability as the excess isn’t wasted but the recycled in the ecosystem
What does the presence of vegetation in a stable ecosystem do?
Prevents soil erosion, extremes of temperature and promotes cloud formation
How does vegetation prevent soil erosion?
Foliage protects the soil from direct rainfall and the roots help bind the soil together
What do humans depend on natural ecosystems for?
Clean air, water, soil, mineral nutrients, pollination, fish and meat
What are examples of why human systems aren’t closed loop systems?
Non-recycled waste from households, agriculture and industry and emissions from fossil fuels
How can small amounts of non recycled waste cause harm?
They can build up and bioaccumulate to form harmful levels
What is a perfect closed loop system?
It is a system that has no waste as the outputs become new inputs
What is eutrophication?
When a chemical typically from farming that encourages growth leaks into a water source it causes a large growth in algae which covers the surface of the water and so no light gets in and the life below the surface die due to a lack of oxygen produced
What issues arise from removing biomass from a closed loop system for human use?
For example in fishing if the sea if over fished it can cause the system to become unbalanced and can lead to risk of extinction of some species.
Overall it unbalances a system which continually use its own resources causing the system to become even more unbalanced
What issues can be caused by removing natural vegetation in ecosystems and replacing them with agricultural crops?
The removal of the vegetation naturally present means that the diversity of the land is reduced and it is over farmed with the same crop, this can cause desertification and massively affects the biodiversity of the ecosystem
What is the maximum rate at which humans can use natural resources if we want them to be sustainable?
At a rate at which the same amount used can be replaced simultaneously
Why is the use of crude oil not fulfilling of the requirements of a closed loop system?
Crude oil takes millions of years to form,
Energy released from burning crude oil originally came from the sun when these organisms were alive
