Ecology Flashcards
what is the environment made up of?
ecosystems
name some ecosystems
forest seashore pond coral reef desert
what do all ecosystems contain?
habitats - non living
community - living
define population
the total number of individuals of one species living in a habitat
what are quadrats used for?
to estimate population sizes of plants
using quadrats how do you work out an estimate?
find the average number of the plant species in one quadrate, then multiply that number by the number of quadrats that would fit in the whole area.
name some abiotic factors
climate temperature level ground soil type direction area is facing light intensity water
what are abiotic factors?
Physical factors that affect the distribution of plants.
what does the distribution of plants affect?
where animals live
define biodiversity
the range of different species living in a habitat
define distribution
where species can be found I’m a habitat
what is a producer?
These are organisms that make their own food.
give an example of a producer
plants (make their carbohydrates by photosynthesis)
what is a primary consumer?
organisms that feed on producers
give an example of a primary consumer
herbivores, e.g. sheep
what is a secondary consumer?
organisms that feed on primary consumers
give an example of a secondary consumer
carnivores, e.g. wolf
what is a tertiary consumer?
organisms that feed on secondary consumers
give an example of a tertiary consumer
top carnivores, e.g. cougar
what is a predator?
an animal that kills other animals (prey) for food
how are predators adapted?
- hunt in packs
- catch large prey; more for per kill
- don’t depend on one particular species
- migrate to areas with lots of their prey
how are prey adapted?
- stay in large groups
- some taste horrible
- some have warning colours
- some are camouflaged
what does dead and decaying material provide food for?
decomposers and detrivores
name some examples of decomposers and detrivores
worms, dung beetles, fungi
what do all food chains start with?
the sun
what is a trophic level?
feeding level e.g. primary consumer
what does a pyramid of numbers show?
the number of living organisms at each trophic level
- not always pyramid shaped
what do pyramid diagrams show?
relative sizes of population at each trophic level
- pyramid shaped
how do you draw a pyramid of biomass?
multiply the mass of a single organism by the total number at each level.
what are the negatives of biomass pyramids?
- varies with seasons
- mass recored at one instant time does not take into account how fast organisms grow.
what does a pyramid of energy show?
how much energy is available at each trophic level
what is energy shown in?
KJ per square metre per year
why does not all the energy available get passed onto the next trophic level?
- energy lost as animals move around
- not all organisms can be eaten
- not all of the organism can be digested.
- heat loss
why do shorter food chains feed more people?
More energy is used when there are more animals in the food chain
why is not all of the light energy used in photosynthesis?
- the light may not fall on a plant
- some light is reflected
- some light misses the chloroplasts and goes straight through the leaf
how do you find out the percentage of energy in sunlight transferred to energy in the green plants.
energy in plants / energy from light x 100
what is the glucose that is created during photosynthesis used for?
- respiration
- growth
what does growth produce?
biomass
what is the equation for energy intake?
energy transfer in respiration + energy transfer into biomass + energy in faeces + energy in urine
what are decomposers?
bacteria and fungi that feed on dead organic matter. They break down organic molecules and release heat energy.
what is the carbon cycle?
carbon dioxide in the air is taken up by plants in photosynthesis.
plants use carbon dioxide to make organic molecules
the carbon in plants enters the consumers that eat the plants.
what is nitrogen needed for?
to make amino acids, protein and DNA
what is the nitrogen cycle?
nitrogen gas —— nitrates
proteins + waste —– ammonium compounds
ammonium —— nitrates
nitrate —– nitrogen gas
what are nitrogen fixing and how do they work?
These convert nitrogen in the air to nitrate. These bacteria are found in the soil and root nodules of legumes. The plants use the nitrates to make amino acids.
what are decay bacteria and how do they work?
These break down dead remains and animal wastes, releasing ammonium compounds into the soil.
what are nitrifying bacteria and how to they work?
These convert ammonium compounds into nitrates in the soil. The plants can use the nitrates to make amino acids so they can grow.
what are denitrifying bacteria and how do they work?
These live in water logged soil. They can change nitrates back to nitrogen gas.
what is eutrophication?
Adding nutrients to the environment (e.g. fertilisers) it can cause the death of organisms in ponds, rivers and lakes.
how is carbon monoxide produced and what are its characteristics?
- by incomplete combustion (when fuels are burnt with limited oxygen)
- in car exhaust gases
- colourless and no smell
how does carbon monoxide affect people?
Attaches to haemoglobin instead of oxygen. Therefore not enough oxygen gets to cells for respiration. It can be fatal.
how is sulphur dioxide released and what does it produce?
Sulphur dioxide is released when fossil fuels are burnt. It reacts with water vapour in clouds to produce acid rain.
what are the effects of acid rain?
- kills fish and invertibrates in rivers and lakes
- damages roots of plants
- makes soil acidic snd low in nutrients.
what is the greenhouse effect?
Light energy passes through the atmosphere.
It is absorbed and warms up surfaces.
Heat energy is reflected back into the atmosphere.
Greenhouse gases trap the heat energy in the atmosphere
what is the enhanced greenhouse effect?
An increase in greenhouse gases due to human activity, this leads to global warming.
define global warming
An increase in the average global surface temperature of the Earth.
what are the greenhouse gases and what is their source?
- water vapour - evaporation from water surfaces
- carbon dioxide - burning fossil fuels
- methane - produced by bacteria during anaerobic respiration in - landfill sites - cattle - rice fields
- nitrous oxide - car exhaust gases
- CFC’s - air conditioning units
name some effects global warming has on the environment
- ice caps and glaciers melt
- sea levels rise
- flooding and loss of habitat
- climate change
what do forests balance?
help to keep the correct balance of carbon dioxide and oxygen in the atmosphere
how do forests act as water stores?
Their leaves slow down the rate of evaporation and the rate at which water reaches the soil
how can deforestation lead to global warming?
Destruction of forests leads to an increased amount of carbon dioxide in the atmosphere therefore contributing to global warming.
why are trees being cut down?
- global demand for timber as building supplies
- demand for paper for newsprint and office consumption
- clearing of land for farms
- clearing for construction of new roads
- to provide charcoal and firewood for fuels
how does deforestation cause soil erosion?
There are no roots to hold the soil together so soil erosion occurs
how does deforestation affect the biodiversity of an area?
destruction of large areas leads to loss of habitat epoch had reduced the biodiversity of animals and plants that live there.
how can we reverse the damage caused by deforestation?
- reforestation - replanting native trees
- sustainable management - removing trees but allowing natural replacement
- recycling and energy conservation - results in a reduced need for ‘new’ sources of timber.
what is a biotic factor?
factors that affect plants and animals that are to do with biological processes
name some biotic factors
feeding relationships
competition for resources
define leaching
when rain washes mineral ions and nutrients out of the soil
define soil erosion
loss of soil which means that trees are unable to grow in this area.
define evapotranspiration
The movement of water unto the atmosphere from plants. Reduced if trees are cut down.
what is balance of atmospheric gases?
deforestation results in a decrease in O2 and an increase in CO2 because there is less photosynthesis.
