ecology and ecosystem Flashcards
(37 cards)
ecology meaning
is the study of the relationship between living organisms and their physical environment.
ecosystem meaning
(ecological system) consists of community of organisms and non living art of the environment (air, soil, water, light..). interaction between orgainsms living together in a certain environment.
biome meaning
the largest geographic biotic unit, a major community of plants and animals with similar life forms and environmental conditions.
biosphere meaning
the regions of the surface and atmosphere of the earth occupied by living organisms.
examples of biomes
desert, tropical rainforest, taiga, freshwater, marine, savannah
species meaning
a group of living organims consisting of similar individuals capable of exchanging genes or interbreeding.
population meaning
a group of organism of one species living and interacting in the same area at the same time. Population always refers to a single species.
community meaning
All of the populations of all different species in an ecosystem.
habitat meaning
The place where the organisms live.
Distribution meaning
Distribution refers to where different species or populations are found and how are they spread out in the particular area.
What influences distribution?
Climate, geography, food avaliability/limitation, and interactions with other species.
types of distribution
1.)Uniform dispersion
2.)Random dispersion
3.)Clumped dispersion
Explain clumped dispersion
Individuals of a species are clustered together in groups. this is usually because there is food, water and shelter might be found in patches.
Explain uniform dispersion
Individuals are evenly spaced out across an area. this often happens when there is competiition for resources or territorial behaviour.
Explain random dispersion
Quite rare, individuals are scattered without any pattern. almost as if they are randomly placed in the environment. they dont follow any specific arrangement.
Keystone species meaning
Is n organism that helps define an entire ecosystm. Without keystone species, the ecosystem would be dramatically different.
example of keystone species+their importance to ecosystem
1.) shark- eats prey and prevents over population
2.) sea otter- they eat sea urchins, which eat kelp (sea plant/seaweed). without sea otters, sea urchins would overeat the kelp, and damage the balance of marine ecosystem since kelp provides habitat for multiple marine species.
what causes population growth?
population growth is caused by when birth rate exceeds death rate.
what factors affect population growth?
Biotic:
- food supply (limited)
-cempetition (what do tehy compete for?)
-predetor-prey relationship
- disease
Abiotic:
-rainfall
-light intensity
-temperature
why is the max. population size limited?
Environmental factors like food, shelter, water, and mates need to be met, the population will decrease until the resource rebounds.
what is carrying capacity?
the max. number of organism in the population that can be supported by an ecosystem.
4 phases of population growth curve
1.) Lag phase- slow growth
2.) exponential (log) phase- rapid increase in number
3.) stationary phase-size of the population stays the same
4.) death phase- population numbers drop
explain lichen
it is composed of two partner organisms
1.) heterophic partner; fungus
2.) autotrophic partner-algae or cyanobacteria
fungus provides water, minerals, gives the shape, attachement to surface and offers protection from drought. algae or cyanobacteria provides pigment and organic molecules from photosynthesis.
what is a parasite
is an organism that lives on or in a host organism and gets its foof from or at the expense of its host.
