MicrobialEcology

• Ecology, the study of the relationships between organisms and their environment, and the balances between these relationships
• Autecology, study of species in relation to the habitat
• Synecology, study of communities in relation to the environment
• Ecological Study Levels:

  
  

  - Global Ecology

  - Landscape Ecology

  - Ecosystem Ecology

  - Community Ecology

  - Population Ecology

  - Organismal Ecology
• Sunlight is the main energy source for life on earth
• Give examples of organisms that use light or chemical energy to make food

  1. Plants
  2. Plant-like protists/Algae
  3. Bacteria
• Photosynthesis use light energy to convert carbon dioxide and water into oxygen and carbohydrates
• Chemo synthesis is performed by bacteria, they use chemical energy to produce carbohydrates
• Energy flows through an ecosystem in one direction— from the sun or inorganic compounds to autotrophs (producers) and then to heterotrophs (consumers)
• Food chain is the series of steps in which organisms transfer energy by eating and being eaten
• In the food chain, arrows go in the direction of how energy is transferred
• Food web is the network of food chains within an ecosystem
• Trophic levels are each step in a food chain or food web
• Ecological Pyramid is a diagram that shows the relative amount of energy or organisms contained within each trophic level of a food chain or web
• Energy Pyramid shows relative amount of energy available at each trophic level
• Organisms in a trophic level use the available energy for life processes and release some energy as heat
• Rule of 10: only about 10% of the available energy within a trophic level is transferred to the next higher trophic level
• Biomass Pyramid represents the amount of living organic matter at each trophic level
• Ecological niche involves both the place where an organism lives and the roles that an organism has in its habitat
• Symbiosis is any relationship in which two species live closely together
• Ecological succession is the process by which the mix of species and habitat in an area changes over time
• Liebig's Law of Minimum, formulated by Carl Sprengel, German botanist, 1828, but became well-known when Justus von Liebig publicized and studied it more widely around 1840
• Justus von Liebig, father of the fertilizer industry
• Shelford's Law of Tolerance, states that organisms are under the influence of ranges of factors, not just minimum levels. That is, they are influenced by too much of something as well as too little of something
• Biomes are large terrestrial regions characterized by similar climate, soil, plants, and animals. Each biome contains many ecosystems whose communities have adapted to differences in climate, soil, and other environmental factors
• Evergreen Coniferous Forests consists mostly of cone-bearing evergreen trees that keep their needles year-round to help survive long and cold winters
• Temperate Deciduous Forest, has moderate temperatures, long warm summers, cold winters and lots of rain. Most of the trees survive winter by dropping their leaves, which decay and produce a nutrient-rich soil
• Chaparral (temperate grassland), coastal areas, winters are mild & wet with summers being long, hot, & dry. Has a moderate climate but it dense thickets of spiny shrubs are subject to periodic fires
• Benthos: attached or resting on bottom
• Epifauna - live on bottom of the water column, feeding on detritus
• Periphyton - attached to stems and leaves of rooted plants
• In fauna - buried in sediment
• Neuston - rest or swim on surface
• Nekton - swimming organisms, can go where they want
• Freshwater Ecosystems:

  • Lentic: standing water (lakes, ponds, bogs)
  • Lotic: running water (streams, rivers)
• Littoral zone: shallow, light penetrates to bottom, rooted plants high diversity, subzones of vegetation (emergent, floating, submergent)
• Limnetic zone: depth of effective light penetration- compensation point, no benthos and few if any neuston
• Profundal zone: bottom and deep water region, fewer plankton and no neuston, absent in ponds
• Oligotrophic: deep sandy, or gravel bottom, low nutrients, low plant growth, low productivity, low decomp at bottom, oxygen not depleted
• River: any natural stream of water that flows in a channel with defined banks