Ecology

• Ecology


  The study of living things and their interactions with each other and their environment
• Environment


  Refers to all the conditions in which the organism lives that affect the growth and development of an organism.
• Ecosystem


  A community of organisms interacting with one another and their non-living environment within a particular area.
• Habitat


  The place within an ecosystem where an organism lives and to which it has adapted.
• Biosphere


  Part of the earth that is inhabited by living organisms.
• Community


  Community refers to all the populations in an ecosystem.
• Population


  Population refers to all the organisms of a particular species that occupy an ecosystem.
• Nutrient Recycling


  The way in which elements are continuously broken down and reused by the living and non-living factors of an ecosystem.
• Processes that remove Co2

  Photosynthesis, Diffusion into oceans
• Processes that return Co2

  Combustion, respiration
• Main events of nitrogen cycle

  Nitrogen gas converted to usable form - Plant protein to animal protein - Decomposition releases N compounds - Ammonium to nitrite - Nitrites to nitrates - Nitrates to plant protein - Nitrogen compounds to nitrogen gas
• Main events of carbon cycle

  Carbon dioxide fixed to plant carbohydrate - plant carbohydrate to animal carbohydrate - living organisms release carbon dioxide - decay of organisms release carbon dioxide - combustion of fossil fuels release carbon dioxide
• What percentage of Nitrogen makes up the atmosphere

  78%
• Nitrogen is used to make...

  Protein, Dna, Rna
• Nitrogen Fixation + how it's acheived

  The conversion of inert nitrogen, N2 to nitrates, NO3-.

  This can be achieved in nature by nitrogen-fixating bacteria which are found in the soil and the nodes of legumes. It can also be done by high energy events such as a lightning strike.
• Nitrification


  The conversion of ammonia, NH3 into nitrites, NO2- and then into nitrates, NO3-.

  This can be done by nitrifying bacteria that are found in the soil.
• Denitrification


  The conversion of nitrates back to inert nitrogen, N2.

  This is done by denitrifying bacteria.
• Examples of biotic factors

  Predators, Prey, Decomposers, Competition
• Examples of abiotic factors

  Temperature, Light intensity, Oxygen concentration
• Examples of climatic factors

  Rainfall, humidity, wind
• Examples of edaphic factors

  Soil pH, soil type, soil mineral content
• Aquatic factors


  Oxygen concentration, currents, salinity, currents
• Energy Flow


  The pathway of energy transfer from one organism to the next in an ecosystem due to feeding/consumption.
• Food chain


  Flow diagram that begins with a plant and shows how energy is passed through a series of organisms in a community.
• Grazing food chain


  Starts with a living plant
• Detritus food chain


  Starts with dead organic matter
• Trophic level


  The position of an organism in a food chain
• Producers


  First trophic level, autotrophs
• Primary consumers


  Second trophic level, usually herbivores
• Tertiary consumers


  Organisms that eat the second consumer, always the top of a food chain
• Pyramid of numbers


  A diagram that represents the number of organisms at each trophic level in a food chain.
• Food web


  Series of interconnected food chains
• Niche


  Functional role of an organism in an ecosystem
• Pollution


  The addition of any harmful substance/pollutant to the environment by human activity
• Pollutants


  Chemicals/substances of human origin that cause harm to the environment.
• Example of industrial pollution + effect

  Burning fossil fuels adds the pollutant Sulfur dioxide to the atmosphere which leads to acid rain - this can erode limestone buildings and reduce soil pH
• What can be done to control acid rain?

  Use catalytic scrubbers, reduce number of fossil fuels burned
• Conservation


  The practice of wise management of scarce natural resources.
• Conservation in fisheries + effect

  Fishing net mesh sizes + Large mesh nets allow young fish to escape which gives them a chance to mature and reproduce, replenishing fish stocks.
• Waste Management


  The collection, transport, processing, and recycling or disposal of waste materials produced by human activity to reduce their effect on human health, local aesthetics, amenity, and the environment.