What is the biosphere? • The biosphere is the layer around the Earth containing all living organisms. • The other spheres are: • Lithosphere • Hydrosphere • Atmosphere
Biogeochemical Cycles • A biogeochemical cycle is a set of processes by which an element passes from one environment to the next and eventually returns to its original environment, in an infinite loop of recycling • There are two cycles we will be dealing with • Carbon cycle • Nitrogen cycle
The Carbon Cycle • This biogeochemical cycle involves the exchange of carbon on Earth • There are 9 parts to the carbon cycle • They are not steps which follow (1-9), but rather a list of the different processes which take place
The Carbon Cycle • 1- Photosynthesis : Plants using solar energy to capture and convert atmospheric carbon (CO2) into glucose (C6H12O6) • 2- Ingestion : Animals eat plants or other animals • 3- Respiration : As living organisms breathe, they exhale the carbon ingested back into the atmosphere
The Carbon Cycle • 4- Decomposition of waste : Waste of animals not released during respiration (urine, feces, dead organisms, etc.) are decomposed by organisms which emit CO2 and methane CH4 • 5- Forest fires – Combustion of tree trunks and leaves are converted into CO2
The Carbon Cycle • 6- Shells and skeletons : Part of the carbon dissolved in the water reacts with calcium to form calcium carbonate (CaCO3) which is part of shells and skeletons • 7- Carbonate rock : The calcium carbonate from the skeletons and shells accumulates at the bottom of the ocean floor which forms carbonate rock.
The Carbon Cycle • 8- Volcanic eruptions : When the carbonate rock meets the magma, it melts and releases some of the CO2 back into the atmosphere • 9- Fossil fuels : When dead organisms fall to the ocean floors, the carbon in them remains buried in the sediment. This carbon can be turned into fossil fuels (coal, oil and natural gas)
The Nitrogen Cycle • A biogeochemical cycle involving all the exchanges of Nitrogen on Earth • There are 5 parts to the Nitrogen cycle
The Nitrogen Cycle • 1- Nitrogen Fixation : Certain bacteria take atmospheric nitrogen and convert it to ammonium (NH4+) • 2- Nitrification : Bacteria oxidize ammonium to form nitrites • 3- Nitrogen absorption : Plants absorb the ammonium and the nitrites. Herbivores only source of nitrogen
The Nitrogen Cycle • 4- Decomposition of waste : Bacteria and fungi break down nitrogen containing substances. They produce ammonia which then forms ammonium • 5- Denitrification : Bacteria converts nitrates into molecular nitrogen which returns to the atmosphere.
Biomes • A biome is a large region of the world with distinctive climates, wildlife and vegetation • Flora = Plants • Fauna = Animals
Terrestrial Biomes • Terrestrial biomes are described mainly by temperature and precipitation. • These factors determine the plant species which can live there • The plants determine the animal species which can live there.
Terrestrial Biomes • There are 7 terrestrial biomes on the Earth • 1- Tropical forests • 2- Boreal forests • 3- Temperate forests • 4- Grasslands and shrublands • 5- Arctic tundra • 6- Deserts • 7- Alpine
Tropical Forests • The tropical forests are along either side of the equator between the tropic of Cancer and the tropic of Capricorn • The mean annual temperatures vary between 20°C and 34°C • The tropical forests have both seasonal forests and evergreen forests
Boreal Forest • Located in the Northern Hemisphere. Forms a belt below the arctic. • Long cold winters. Long days in Summer. • Conifers, forest floor carpeted with moss and lichen
Temperate forest • Located in southern Canada, the United-States, Europe and part of Asia • Mean annual temperatures of 8°C to 10°C. High precipitation throughout the year. • Northern regions of Quebec, mixture of conifers and deciduous varieties. Farther south, primarily deciduous trees.
Grasslands and Shrublands • Many are located in central North America • In the temperate grasslands: Hot summers and long cold winters. In the savannas: Hot all year long • Grasses and shrubs. Three types: Temperate grasslands, savannas, derived grasslands
Arctic Tundra • Located to the north of the boreal tundra. Forms a ring around the North Pole • Long, cold winters. Very short summers. Permanently frozen ground. • Grasses, stunted bushes, moss, lichen
Deserts • At all latitudes • Low precipitations (less than 25cm per year) • Extreme temperatures • Rare plant life
Alpine biomes • Any high-altitude area in the world • Temperature varies according to altitude (about 0.6˚C per 100m) • Vegetation zones: Submontane, montane, subalpine, alpine and nival.
Aquatic Biomes • Aquatic biomes cover a large area of the surface of the Earth. (Approximately 75% of the Earth) • Freshwater biomes cover about 2.5% of the aquatic biomes and marine biomes cover the remaining 97.5%
Salinity of Water • Freshwater has a salinity of less than 0.05% • Saltwater has a salinity greater than 3% • There are 3 freshwater biomes and 3 marine biomes • Lakes, Rivers and Wetlands for freshwater • Estuaries, Oceans and seas, and Coral reefs for Marine
Lakes • Bodies of water surrounded by land and fed by springs, rivers or precipitation • The organisms living there are microorganisms, plants, plankton, fish, amphibians, reptiles and birds.
Rivers • Streams and rivers that form permanently or seasonal drainage channels for surface drainage. • Moss, grass, fish, etc. live in rivers and streams
Wetlands • Includes marshes, swamps and peat bogs. • They are areas permanently or temporary covered with water. • Life there includes plants which grow well in water-saturated soil
Estuaries • Broadening at the mouths of rivers acting as a mixed zone between the maritime and river environments. • Examples of organisms living there are belugas, oysters and sponges
Oceans and seas • Bodies of water that are subdivided according to the depth of the water • Phytoplankton, crustaceans, fish, jellyfish, mollusks, birds and mammals all live there.
Coral reefs • Environments characterized by the presence of calcium carbonate produced by coral • Between 500,000 and two million plant and animals species live there.
Study of populations • What is a population? • Density • Distribution • Biological Cycles
What is a population? • A population is a group of individuals of the same species, living in a shared space at a specific point in time. • The population size refers to the number of individuals in a population
Populations • What can affect the size of a population?
How to measure the population • Counting individuals • When possible, scientists will count every individual of a population. • This is not possible in a very large population, or in a very large area. • Counting by sample area • By counting a small sample of a territory, scientists can extrapolate from there to estimate the total population
How to measure the population • Mark and Recapture • Scientists capture a number of individuals and mark them. • Scientists return and recapture individuals again. • By counting how many of the individuals were recaptured, the total population can be estimated. • Number of marked animals recaptured = Number of marked animals • Total number of animals captured 2nd time Population size
Density • The number of individuals in a given space • Ex: 64927 people in 125 km2 • Ans: 519.416 people/km2 • How would you find the density of the population of Canada? • Population: 34,734,000 (2012 est.) • Surface Area: 9,984,670 km2 • Density = 3.47/ km2
Top Population Densities • 1.Monaco 15,293/km2 • 2.Singapore 6,843/km2 • 3.Vatican City 1,884/km2 • 4.Maldives 1,328/km2 • 5.Malta 1,287/km2 • 6.Bangladesh 1,199/km2 • 7.Bahrain 971/km2 • 8.Taiwan 714/km2 • 9.Barbados 664/km2 • 10.Mauritius 637/km2
Which rank is Canada? • 228th • Density ~3.5/km2
Russia vs Canada • Size • 17,075,400 km2 (1st) • Population • 143,030,106 (8th) • Density • 8.3 (271st) • Size • 9,984,670 km2 (2nd) • Population • 34,754,000 (35th) • Density • 3.5 (228th) Russia Canada
Biological Cycles • Alternating rise and fall of population sizes • They are of fixed duration and are repeated continually
Influence of Biotic and Abiotic Factors • Biotic factor (living) • Related to the actions of living organisms • Abiotic (non-living) • Physical or chemical aspects of the environment.
Biotic vsAbiotic • Birth rate • Disease • Amount of food • Predation • Competition • Human Activity • Amount of light • Soil or water pH • Terrain • Depth of snow • Temperature • Air Humidity Biotic Abiotic
How do these factors affect biological cycles? • Conditions can favour the predators or the prey which will affect the other • An increase in predators will cause a decrease in the prey population • If conditions go against the predators, they wont be able to hunt and die off • This will cause a massive increase in the prey population
Community vs Ecosystem • A set of populations of different species sharing the same habitat • Community of living organisms interacting with one another and with nonliving components of the environment they inhabit Community Ecosystem
Dynamics of Communities • What is Biodiversity? • The relative abundance of the species in a community • What can affect the biodiversity of an ecosystem? • Competition • Predation • Mutualism • Commensalism
Competition • Interaction between living organisms that seek the same resource in their habitat. • Can be between individuals of the same species (intraspecific) or between individuals of different species (interspecific) • Both animals and plants can be competing for a limit number of resources.