Adaptations, interdependence and competition Flashcards
What’s an ecosystem
the interaction between a community of living organisms and their environment
How to identify an ecosystem
It will have 2 or more populations or organisms in their environment
What’s a community
Two or more populations of organisms
Factors that make animals and plants interdependent
Plants produce food by photosynthesis
Animals eat plants
Animals pollinate plants
Animals eat other animals
Animals use plant and animal materials for shelters
Plants need nutrients from animal droppings
What is a stable community
A stable community is one where all the species and environment factors are in balance so that population sizes remain fairly constant
Number of species remains relatively constant, so does population size
Abiotic Factors in plants
Light intensity Temperature Moisture levels Soil pH and mineral content Wind intensity and direction Availability of O2 Availability of CO2
How does light intensity affect the community and how are plants adapted to this?
Photosynthesis limited, adapted plants -> more chlorophyll or bigger leaves
How does temperature affect communities?
Photosynthesis and growth limited
How do moisture levels affect communities?
No water -> little life or no life, in desert plants grow, flower and make seeds quickly when it rains -> then eaten by animals
How does soil pH and mineral contents affect communities?
Distribution of plants, Carniverous plants trap and digest animal prey -> nitrates break down animal protein and struggle to grow, low pH in its decay
How does wind intensity and direction affect communities?
Shape of trees, plants transpire fast
How does availability of oxygen affect communities?
Water-living organisms affected
How does availability of CO2 affect communities?
Photosynthesis, growth, distribution of organisms (mosquitos attracted to food by high CO2 levels)
Biotic factors affecting communities
Availability of food
New pathogens of parasites
New predators arriving
Interspecific competition
How does availability of food affect communities?
Plenty of food = breed
How do new pathogens and parasites affect communities?
Organisms have no resistance to the disease
Wipe out populations
How do new predators arriving affect communities?
No defences = get wiped out
How does interspecific competition arriving affect communities?
Numbers become too low
Grey squirrels and red squirrels
Measure the population size of a common species in a habitat method
1) choose starting point where grass is cut
2) use random numbers to generate a set of coordinates to play your first quadrant
3) count numbers of different plant species within quadrant
4) return to starting position and repeat previous steps 14 times using different random numbers
5) repeat previous steps where grass is uncut
6) compare results and calculate a mean
What do animals compete for?
Food
Water
Territory
What foods to different species compete for?
Herbivores = plants
Carnivores = prey
Prey = competes for not being caught
=have adapted warning colours, predators avoid
Introduction of a new herbivore = reduce amount of plant material available for the animals
Competition form territory
Nest
Space needed for an animal to find food and reproduce
Most animals cannot reproduce successfully if they have no territory
Competition for mate
Impression the females
Win privilege of mating with a female
Birds adaptations = extravagant tail feathers
Lizards = bright colours
What makes a successful competitor?
Many animals are successful because they avoid competition
Feed in a way that no other local animals do
Eat type of food other animals avoid
