ecology

• reasons why maintaining high biodiversity is important

  • increases stability in ecosystem, changes are less likely to have adverse affects
  • many species provide specific services eg pollination
  • many of our medicinal drugs come from wild species
• decomposition


  process by which dead organic matter is broken down into simpler organic or inorganic substances eg carbon dioxide, water, simple sugars, minerals

  essential for the recycling of elements throughout an ecosystem
• detritus feeders


  carries out decomposition

  small animals like worms and woodlice that feed on dead organic matter
• decomposers


  microorganisms, such as bacteria and fungi
• decay


  the breakdown of organic matter by the action of decomposers
• what factors affect decomposition

  • oxygen levels (higher oxygen - more aerobic respiration - more energy available, faster growth and decomposition)
  • temperature (higher temp - particles have more kinetic energy and enzymes are closer to optimum temp - higher rate of reaction - more decomposition)
  • water content (decomposers need water to survive, so the rate of decomposition increases in moist conditions)
• anaerobic decay


  some decomposing microorganisms can break down organic material without oxygen

  they carry out anaerobic respiration
• anaerobic decay produces some gases which is known as biogas, most important gas that is produced is methane
• biogas generators

  large containers where plant / animal waste is left to decay anaerobically

  they can't be any oxygen in this container

  if there is oxygen the microorganisms will respire aerobically and not produce as much methane

  once the biogas is removed from the tank a sludgy material is left over, which contains a high density of useful materials - can be used as fertilisers
• biodiversity


  the variety of living things on earth, or within a particular ecosystem
• an alternative to breeding programs could be to make a protected area, so animals can be safe and naturally recover
• how do field margins and hedgerows in agriculture help increase biodiversity

  they provide extra habitats and food sources so that a wider range of species can survive
• how can the government encourage businesses (including farmers) to reduce damage to biodiversity

  • set laws prohibiting or requiring certain things
  • pay businesses for carrying out certain practices (like planting hedgerows)
  • setting quotas or limits on harmful practices (such as quotes for deforestation)
• population


  refers to all of the organisms of a particular species that live in the same habitat
• community


  all the populations of different species that live together in a habitat
• ecosystem


  is the interaction of a community of living organisms (biotic) with the non-living (abiotic) parts of their environment
• competition


  is an interaction between organisms or species in which they both try to use the same limited resources
• biotic factors


  living factors

  refers to processes by which one living organism affects other living organism in its environment
• abiotic factors

  nonliving factors

  refers to the process of where it is not influenced by living organisms
• structural adaptations


  the physical feature of the organism
• behavioural adaptations


  the way an organism acts
• functional adaptations / physiological adaptations 


  the process that takes place within an organism
• extremophile 


  microorganisms that live in extreme environments, like high temperatures, pressure, salt concentrations
• abundance


  how many organisms there are
• distribution 


  where the organisms are
• sampling

  where they only measure a subset of the organisms, and use that subset to make predictions about the whole population

  types:

  • quadrats
  • transects
• quadrats

  to measure abundance

  calculate the mean of organism and times it by the area
• transects


  to measure how distribution changes

  a line throughout a habitat along which organisms are sampled
• attitude shifts with biodiversity


  recently begun to change and measures are being taken to prevent further damage being done and to regain pre existing biodiversity
• industrial revolution


  humans have conducted many activities that have caused a severe decline in biodiversity on a global scale
• warning signs


  • awareness of the detrimental nature of these activities have existed for several decades
  • because of the pursuit of economic gain the warning signs have largely been ignored
• waste:


  • water - sewage and toxic chemicals (from industrial practices and excess fertiliser) go into water sources
  • land - toxic herbicides and pesticides (farming), buried nuclear waster and household waste in landfill sites
  • air - smoke and gases constantly added into atmosphere (power stations and cars)
• peat


  is a deposit of partically decayed plant matter, which accumulates in bogs

  carbon remains in the plants instead of being released into the atmosphere
• peat bog destruction


  • the destruction of pest bogs has become more common resulting in the burning or decay of peat
  • this releases the stored carbon into the atmosphere in the form of the greenhouse gas, carbon dioxide
  • another negative impact of peat bog destruction is the loss of biodiversity within the habitat
• reasons for peat bog destruction


  • free land up for farming - requires the bogs to be drained
  • to burn the peat for fuel
  • to sell the peat to gardeners as garden compost
• deforestation


  the cutting, clearing and removal of forests in order to free up land for biofuels (fuels derived from living matter) as well as cattle and rice fields
• negative consequences of deforestation

  • burning of trees and decomposition of wood increases the rate of carbon dioxide that is released into the atmosphere
  • less photosynthesis is taking place, less carbon dioxide is removed
  • deforestation destroyed habitats - lost biodiversity and provision of ecosystem services lots
  • replaced by agriculture with purpose of growing rice or farming cattle - produces methane
• deforestation on ecosystems


  causes loss of ecosystems like erosion prevention, flood control and food provision
• carbon dioxide released into atmosphere by:


  • burning fossil fuels
  • respiration
• carbon dioxide removal from atmosphere:


  • absorbed into peat bogs
  • dissolving in water
  • photosynthesis