Biogeography
What sets the Earth apart from other planets?
- Hæfileg fjarðlægð frá sólu
- Lofthjúpur þéttur
- Næginlegt vatn
The Earth's surface:
- Continous flow of energy from the sun
○ Passes through the biosphere (lífhvolf)
- Cycling of matter (nutrients) through the biosphere
- Gravity
Energy cannot be created or destroyed - only transformed
- Matter cannot be created or destroyed - only transformed
The lithosphere (stinnhvolf):
- Most massive
- The rock part
- Mantle and core
- Only upper 100 km of the mantle
- Divided into tectonic plates
- Shapes the oceans
The atmosphere (gufuhvolf):
- Most of the heat and moisture is in the trophospere (10-16) km above the Earths surface
The hydrosphere (vatnshvolf):
- The blue planet:
○ The core of the hydrosphere
§ Lakes, water, streams, ocean
- 71% of the earths surface is covered in oceans
- Human 50-60% water
- Mammals 60% water
- Trees 60% water
The biosphere/ecosphere:
- Where the spehres interact
- On the Earths surface (land or ocean)
- Most biodiversity and life in the rainforest (from the bedrock to the top of the canopy)
- Least biodiversity and life in the desert (3 m...?)
- Photic zone (ljóstillífun)
○ Efst í sjónum
- Aphtic zone in the ocean
○ Less life:
§ Phytoplankton
- Life occupies terrestrial 29% and marine 71%
Drivers of change on the surface:
- Temporal change:
○ The seasons
- Catastrophic change:
○ A sudden event that has a big impact on biomass- and diversity
○ How often and the magnitude
§ Earthquakes
§ Eruptions
§ Avalanches
§ Landslips
§ Jökulhlaup
- Anthropogenic changes:
○ Human impact
- Land use:
○ Mining
○ Dams
○ Grazing lifestock
- Pollution:
○ Waste disposal
- War:
○ Weapons testing
○ Weapon decomissioning
○ Destructuon of infrastructure
- Climate change:
○ Alters the atmosphere
§ And oceanic circulation patterns
Nutrient and biogeochemical cycling:
- Macro nutrients
- Others are micro
The gaseous cycle
- Cycling of C, H, O and N
○ The cycle is brief
○ Hudreds years or less
§ This system doesn't go to the lithosphere
The sedimentary cycle
- Nutrients in the bedrock are released into the hydrosphere and go to the biosphere (consumption, decomposition) and then the lithosphere (fossilised)
The CO2 cycle
- Both gaseous and sedimentary cycles
- The CO2 balance
○ Combustion of fossil fuels is greater then the natural deposit
Hydrologic cycle
- H2O
- Exhange of water between the reservois
- Salt water > fresh water
- Driven by heat, derived by solar energy
Transpiration - goes through the plants
The oxygen cycle:
- Photosythesis
- Volcanism
○ Releases oxygen
- Removing atmospheric oxygen:
○ Oxidiation
○ Respiration of animials and plants
○ Combustion
○ Deforestation
§ Anthropogenic and natural
The nitrogen cycle:
- Only get nitrogen through plants
- Ends up in the top soil
Phosphorous
- China, morocco and USA at the forefront
- Essential to life
- Small amounts available
- Held in the rocks
○ Released slowly by plants
System of biological classification:
- Trophic hierarchy:
○ 1% of solar energy used for life on earth..?
○ Plants are the only organism capable of transforming solar energy and using it for other purposes
§ Photosynthesis:
□ CO2 + H2O + Sólarorka (and heat) = glúkósi + súrefni
® Takes place in the green parts
® Clorophil (primary catcher of sunlight)
○ Trophic levels:
§ Photosynthetic plants are on top of the hierarchy (ototophs)
§ Primary consumers (those who eat plants)
§ Secondary etc...
§ Food chain vs food web
□ Energy flows through the levels in linear fashion
□ Biodiversity
® Dreifð tegunda
□ Biomass
® The biological productivity
◊ Gross primary productivity
} Total enegy fixed in an ecosystem by photosyntehsis
◊ Net primary productivity
} The amount of biomass that's left after respiration > goes into producing more plant cells
- Ecological hierarchy:
○ Individuals:
§ Smallest unit
□ T.d. Put a tracker on an animal and monitor their activity
§ Population studies:
□ Track a pack of animals
§ Ecological community:
□ Samfélag
□ Interactions and relations between species
□ Vegetation calssification
§ Ecosystem:
□ Interactions and relations between species
□ Also the relationships of communities with the environment
® Water, mountain...
§ Biomes:
□ Large areas
® Similar fauna and flora in areas
® Ecological niches
® Lognitudianal trends
} Altitude and heat relations here
® An idealised view of the nature, without manmade elements
§ Biosphere
□ A thin layer of life on Earths surface
- Taxonomic hierarchy:
○ Classification and naming of organism
§ Kingdoms
□ Animalia
□ Plantea
□ Fungi
□ Protista (amoeba)
□ Monera (bacteria)
® Divisions and classes:
◊ Gróplöntur
◊ Fræplöntur
} Ein- eða tvíblöðunagr (classes)
– Orders
– Families
– Genur
– Species
w *Subspecies (sometimes)
w They can breed with parent species (not infertile)
Names of species: (Latin)
- First part is
The gentic part (First letter capitalised)
- Second
○ The species part
§ Specific (miniscule)
Always italic