Environment - Basics Flashcards
What is ecology?
The study of the interactions between organisms and their environments
What is it focussed on?
Discovering how organisms affect and are affected by their environment and how this determines the kinds and number of organisms found in the environment
What does an understanding of ecology allow us to do?
Provides the ability to manage the earths limited resources and address enviro problems from industrial and engineering activities
What does the environment consist of?
Abiotic (non-living) and biotic (living) factors
What is the environment an organisms lives in called?
habitat
What enables organisms to survive in their habitat? What can they be classified as?
Adaptations: physiological, anatomical and behavioural
What are the three types of adaptations? Explain them briefly
Physiological - adaptation stoa tallow an organism to perform particular function that enable it to survive
Anatomical - structural features of an organism
Behavioural - inherited or learned behaviours of action
What is a population?
A group of individuals of the same species living in a given area at a given time
What are ecologist interested in about populations? Explain them
Pop size: total number of individuals in populations
Pop density: number of individuals in given area
Pop growth rate: rate of change of pop
What kind of factor has a greater impact on populations living in a high density pop vs low density pop?
Food supply
What is the carrying capacity?
The environmental limits to population increase
What is growth rate proportional to?
Negatively proportional to pop size (e.g. when pop smallest growth rate is max)
If the population is larger than the carrying capacity, what happens to the rate of growth?
It decreases so that the population declines
If the growth rate is higher than the carrying capacity, what must the population be?
Small
Is the carrying capacity constant? Why?
No, there are lots of variables in the carrying capacity (e.g. resource availability…) so it constantly changes
What is the logistic regression of the rate of population growth?
r = r(max) * N * (1-N/K)
- r = actual rate of increase (diff between births and deaths)
- r(max) = max rate of growth
- N = population
- K = carrying capacity
What is a community?
All the populations of the organisms inhabiting a common environment interacting with each other
What are the three community interactions?
- Competition: limite resource force interspecific (between species) and intraspecific (within species) competition
- Predation: Predators eat prey, predator adapted to catch and eat prey, prey adapted to avoid predators
- Symbiosis: Organisms living very closely together for either mutual benefit (mutualism/commensalism) or for the advantage of one species (parasitism)
What are two key processes within the ecosystem? Describe them
Energy flow: passage of energy between organisms
Chemical cycling: use and reuse of chemical elements
How are feeding relationships categorised in an ecosystem?
Trophic levels
How can food being transferred from one trophic level to the next be shown as?
A food chain
how do all food chains start? What do they do?
With a producer that does photosynthesis
What are the other non-producer member of the food chain called?
Consumers
As ecosystems become more complicated, how do food chains get linked together?
Into food webs
What is the efficiency of energy transfer between tropic level? What is this rule called? What is the maximum number of tropic levels possible? Why?
10% - described by 10% rule
Max of 6 tropics as anymore would require more energy produced that what the lower tropic levels can produce
What percent of the suns energy is converted into plant energy?
1-3%
How does a food web differ from a food chain in terms of feeding relationships?
Food web show the complete interaction of the trophic, food chains linear/simplified
What needs to be done to the chemical elements of life in order for ecosystems to function?
They need to be recycled
What are some examples of biogeochemical cycles?
Carbon, nitrogen, phosphorous and water cycle
How does energy flow differ from chemical cycling?
Energy flow in unidirectional (only goes in one direction), chemical cycling involves the recycling of resources
