1b. Basics In Ecology And Biology Flashcards
Hierarchies of life
Taxonomic
Ecological
Tropic
Taxonomic
Classification and naming of organisms. Common names not always clear
Scientific name = Latin. Genus = generic and species = specific name. Family, species and genus are the most important names.
Clade
Lineage of different related species that arise from a common ancestor species
Speciation
The development of two or more genetically differential species from a single common ancestor species
Evolution
Genetically controlled changes in physiology, anatomy and behaviour that occur to Claude over time. Does not always lead to new species. Evolution doesn’t always lead to new species
Allopathic speciation
Formulation of new species by geographic isolation=
- natural selection for beneficial traits in each environment
- isolation of populations can increase speciation
Sympatric speciation
Formation of species where genetic change causes species to become reproductively isolated in the same geographic area.
This can be caused by polyploid (mutations), more common in plants
Ecological hierarchy - individual
Individual organism
Population
All individuals of a given species in a prescribed area, able to interbreed frequently.
Metapopulations
Separated populations, able to interbreed extremely infrequently
Community
All populations of all species in a prescribed area
Ecosystem
All interacting physical and biological components of a prescribed area
Biome
Large area of the earths surface that have similar climate and vegetation
Biosphere
Life on Earth
Tropic hierarchy
Organisation of life over the food chain = transfer of energy trophy
Autotrophs
Can fix carbon, usually through photosynthesis
Heterotrophs
Cannot fix carbon and need to take up organic carbon
Photosynthesis by autotrophs = 3 pathways have evolved to overcome limitations due to H2O loss:
- C3 pathways
- C4 pathways
- CAM ( crissulacean acid metabolism) pathway
C3 pathway
Co2 converted in 3-carbon molecule, 95% of all plants adapted to temperatures of 20-30 degrees
C4 pathway
CO2 converted in 4 - carbon molecule. Higher efficiency of CO2 uptake, optimal for warm and dry climates
CAM
CO2 assimilation during the night, adaptations to arid conditions.
Omnivores
Eat animals and feed at more that one tropic level
Gross primary productivity
Fixation of energy by photosynthesis
Liebigs law
Nutrient lo,toed yields are dictated by the availability of most limiting nutrients. This is very important info for farmers
Nitrogen
78% of the atmosphere
Taken in by plants by ammonium or nitrate. Nitrate is made available through nitrifying bacteria in the soil. Plants preference for nitrogen differs between ecosystems and can depend on climatic conditions
Nitrogen fixers in soil = bacteria
Plants who can’t take in nitrogen which has led to meat eating plants like Venus fly traps
Net primary productivity
GPP Minus plant respiration = plant biomas change over time
Flow over energy through a web
On average 10% of renege is passed to the next level
Mammals only assimilate 3% of energy. Insects assimilate 40%
A lot of plants and insects only support a few consumers
Carrying capacity
Maximum population size given the available resources
Plant nutrients
Plants require many elements for growth and metabolism
- Marco elements participate in metabolism.
- Trace elements, often heavy metals, required for enzyme reactions
- Facultative elements only required in some plant groups
Availability of nutrients depend on the geology, climate, vegetation and human influence
Plants - too low pH release
Too much iron and aluminium which may be toxic. Reduce soil biota and break down of plant
Plants - too high pH
May limit nutrient availability. Optimal is a neutral pH
Global biogeochemical cycles
- nitrogen
- Phosphorus
- Carbon
