Pack 14 - Ecosystems Flashcards
What do plants compete for?
light water and minerals
What do animals compete for?
food territory mates breeding sites
What is interspecific competition (plus and example)
Competition between different species (weeds and crops within a field)
What is intraspecific competition (plus an example)
Competition within the species (finding a mate)
What would happen to predators if prey numbers in an ecosystem declined?
less food results in more intraspecific competition, less reproduction and more mortality
What is carrying capacity?
The maximum size that a population can remain sustainable in particular habitat
What is an autotroph?
Primary Producers
What are heterotrophs?
Primary Consumer
Secondary Consumers
Tertiary Consumer
Normally a food chain normally has 4/5 trophic levels but rarely 6 - why is this?
Energy is lost at each trophic level
Not enough energy at the end of the food chain to support further trophic levels
How is light energy lost in photosynthesis?
some of the light does not fall on photosynthetic parts of the plant
some of the light is not of an appropriate wavelength
some of the light is reflected/ transmitted through the leaf
What is biomass?
mass of organic material in an organism/ecosystem
How do you use a calorimeter?
Dry material is burnt in oxygen
Energy given off heats up the water in the calorimeter
Rise in temperature can be used to calculate the energy that was contained in the material
What would a stirrer do in calorimeter?
Distributes heat energy evenly around chamber
How is production measured?
units of energy per unit of area/volume
What is gross primary production (GPP)
Total amount of organic material made in photosynthesis
What is net primary production?
Chemical energy store in plant biomass after respiratory losses to the environment have been taken off
NPP=GPP-Respiration
How would you calculate the efficiency of energy transfer?
Energy transfer = energy available after the transfer/energy available before the transfer X 100
How is energy lost from conusmers?
some food not digested just passed out
excretion
some energy remains within the animal that can’t be eaten
What is Net Production of consumers and how can it be calculated?
Production of biomass that is available to other consumers
N = I + (F + R)
N= Net Production I= Chemical energy stored in ingested food F= Chemical energy lost to the environment in faeces R= Respiratory losses to environment
How is productivity measured?
amount of biomass made in a given area in a given time
KJm^-2 y^-1
What are the main events of Succession?
Hostile environment - colonised by pioneer species
Abiotic environment of habitat changed by pioneer species
The changed environment becomes less hostile to support new species
Establishment of new species increases species diversity as various group of animals enter habitat - pioneer species replaced by new species
Changes in abiotic factors result in less hostile environment (increase in biodiversity)
Climax community develops
What is conservation?
the management biological diversity and ecosystem
Why does NPP decrease in the later stages of Succession?
Respiration rates increase due to more biomass
Also GPP decreases
