C Species and communities

Question 1

what is a limiting factor

Answer 1

This is the factor that is the most scare in relationt to an organisms needs.

every organism has a range of tolerance fro each factor and is excluded from areas out side the tolerance

e.g. water, soil ph, light intensity, soil salinity, minerals

animals too temperature, water, breeding sites, food supply, territorys

Question 2

different types of transects

Answer 2

line transect

• tape is laid on ground and you sample thigns touching hte tape or a set distance from the tape
• belt transect sample between twolines of tape
• point transect, record organisms you see from a point e.g. birds

Question 3

what is a niche

Answer 3

each species has a uinque role in its ecological niche which it fullfills (inlcudes spatial habitat, food, interactions with species,)

needs to be within the zone of tolerance

each species only have one niche as competition means you can only ever inhabit one

Question 4

competitive exclusion principle

Answer 4

two species cannot survive indefinitely in the same habitat if their niches are identical

one species will dominate and lead and one will tend towards extiniction

Question 5

fundemental vs realised niche

Answer 5

fundemental is the potential mode of existence ( the broades range ) whereas the realised niche is teh actual mode of existence which results from combination of adaptations and competitions from other speces

Question 6

interspecific interactions what are they and what are their effects

Answer 6

interactions between speces

herbivory - primary consumers eating plants

predation - consumers feeding on consumers

parasitism - one organism feeds of another orgniasm but odes not kill it, a host is harmed and the parasite benefits

mutualism to species live in close assosciation and both benefit

commensalism - one organism benefits the other is neither harmed nor helped

Question 7

describe the role of zooxanthellae

Question 8

examples of interspecific interactions

Answer 8

a parasitic non photosynthetic vine that invades plant tissue and obtain both nutrients and support form the plant

fire coral is commensalism as it hawkish si immune to the stinging of the coral but gains protection

a moth is a herbivore that consumes tissue from teh buttonwood tree

hummingbirds pollintae flowers and the bird gets food andthe plant get pollinated

Question 9

what are keystone speces

Answer 9

has a disproportionate effect on the structure of an ecological community

removal can result in

• remaining members of food web compete for new resources
• its prey over grows
• so it over eats its prey in turn
• diversity decreases
• whole species can be wiped out