Ecosystems Flashcards
Ecosystem
All the organisms and the environment in which they live form an ecosystem (it may be large, such as a rainforest or small, such as a pond)
Community
All the organisms that live and interact in an ecosystem form a community.
Population
The community is made up of populations of difference species. these species depend on each other for resources, so we say that they are INTERDEPENDENT
Habitat
Each population lives in a particular habitat within the ecosystem, It includes the other organisms that affect the population and the local environment.
Abundance
Is a measure of how common something is in an area, such as its population size. Measuring population size by counting all the organisms in an area is often impossible. However my you can estimate population size by taking samples using a quadrat.
using a quadrat
Quadrats are placed randomly in the area and the number of individuals in each quadrat is counted.
Estimating population size
Number of organisms in all quadrats x (total size of area where organism lives/total area of quadrats)
Trophic levels
The feeding levels of a food chain.
Biomass
The mass of tissues
Energy transfer between trophic levels
Only 10% of energy gets transferred through each trophic. The rest of the energy is used for functions like respiration, excretion etc. (MRS NERG)
Calculating efficiency of energy transfer
Energy transferred to biomass/total energy supplied to organism.
Abiotic factors
Non living factors that affect the distribution of organisms
Biotic factors
Living factors that affect the distribution of organisms
Belt transect
The effect of abiotic factors on the distribution of organism can be measured using a belt transects and quadrats places along the transect.
Pollutants
Substances that cause harm to the environment.
Biodiversity
The number of species
Lichen
Grows on trees and indicates that the air is polluted with sulfur-containing gases.
Blackspot fungus
Pathogen of roses that cannot grow well when there is a lot of sulfur pollution.
Sludge worm
Are present when water pollution levels are high.
Parasitism
A different kind of feeing relationship in which only the parasite benefits, by feeding off a host organism, causing harm to the host
Mutualism
When some organisms that live together both benefit from the relationship. These relationships are said to be mutualistic. (For example: many flowers depend on instincts for pollination . The flower depends on insects for pollination and the insect benefits by collecting nectar or pollen from the flower, which it uses for food).
Fish farming
Fish farming aims to produce more fish and so reduce overfishing of wild fish
Evaluation of fish farming
- causes problems because so many fish are kept in a relatively small space. Uneaten food and the faces from the fish skink to the bottom of the water. Therefore, parasites and disease spread more easily between fish in pens and they need to be treated to keep them healthy.
- Fish farming aims to produce more fish and reduces overfishing of wild fish.
Eutrophication
- fertilizer is added
- heavy rain washes fertilizer off
- nitrates and phosphates dissolve in soil water
- nitrates and phosphates not taken up by the plants are washed into river
- high concentration of those nutrients encourages rapid growth of plants and algae
- surface plants block sunlight so plants in the water die and stop producing oxygen
- bacteria used to break down dead materials increase and use more oxygen
- the oxygen decreases rapidly
- aquatic animals die
