Environment Encompasses virtually everything thatsurrounds an organism in a holisticecological approach Life on earth experiences different typesof surroundings. Physical environment- soil, air, water…. Biological environment – living beings.
Fundamental principles for theprotection of environment Maintenance of biodiversity Maintenance of all gaseous & materialcycles & interdependence of livingorganisms among themselves & withabiotic environments. Maintenance of ecological order &natural balance, which depend on thefood chain relationship, sustainableproductivity & biotic interaction.
Cont… Social environment Formed by network of social institutions-political, religious & economic Family Activities including socialization ofchildren, transference of cultural heritage& morals from one generation to the next.
Environment of the earth Air / Atmosphere: Envelope of gases– nitrogen, oxygen,carbon dioxide, traces of carbonmonoxide, oxides of nitrogen, sulphur,hydrocarbon & very little amount of watervapour.
Layers of atmosphere1. Troposphere2. Stratosphere3. Mesosphere4. Thermosphere (ionosphere)5. Exosphere
Cont…. Water / Hydrosphere: Oceans, seas, rivers, lakes, ponds, polarice caps, streams, glaciers, ground water,& water vapour. Oceans are storehouses of vast resources-water, salt, minerals, & food.
Cont… Land / Lithosphere Is the outer mantle of rocks constitutingthe earth’s crust. Rocks are subjected to continuousphysical, chemical & biologicalweathering. Thickness ranging from 64 to 96 km.
Cont… Below the lithosphere lies the mantle;thickness of 2400km. Upper part is Asthenosphere Lower mantle is Mesosphere The interior part of earth is Core, consist ofminerals such as iron, nickel, cobalt mixedwith sulphur & silica
Cont… Inner core appears to be solid Outer core is molten and metallic The direction & interaction b/w theatmosphere, hydrosphere & lithospherefor millions of years has made the earthsuitable for life & has formed theBiosphere. Which is responsible for large scale ofrecycling of matter & energy.
the study of the relationshipsbetween biotic and abiotic factorsin environmentseco (G) root home, abodeecoclimateecosystemecotourismlog, -o, y (G) suffix study ofzoologyepidemiologyclimatologyEcologyEcology
a major regional or global bioticcommunity, a super ecosystem,defined chiefly by the dominantforms of plant life and theprevailing climateBiome
desertgrasslandtropical rain forestdeciduous forestconiferous foresttundraMajor Biomes of the Worldocean
Aquatic biomes2 types – marine and freshwater.Stratified vertically – photic zone(light) and aphotic zone (littlelight).Bottom of aquatic is benthos – foodis detritus that falls from above.
*WetlandsWetlands – area covered withwater; supports plants.Estuaries – area wherefreshwater meets ocean.Intertidal zone – land meetswater.Coral reefs – dominated by coral.
Terrestrial biomesDefined vertically from thecanopy at top to the permafrostat the bottom.ATropical forest – little lightreaches ground because of deepcanopy.Rainfall determines life in area.
Cont…BSavanna – scattered trees andgrasses.Fire helps increase diversity.Has rainy season.CTemperate grassland – seasonaldrought, fires prevent tree growth.Most used for farming.
DesertsDeserts – sparse rain, some are cold.Plants have structures to allowsurvival (i.e. water storage,alternative forms of photosynthesis)Chaparral – evergreen shrub; long,hot, dry summers with fires.
ForestTemperate deciduous forest – smallmammals, leaves fall during autumn.Coniferous forest – cone-bearingtrees, trees have needles.Tundra – permafrost covers ground,low diversity.
Levels of Organizationsmallest unit of livingthingsgroup of similar cellsorganized to worktogethergroup of different kindsof tissues workingtogethergroup of organsworking togetherone individual livingthingall organisms of thesame kind living in oneareaall interactingpopulations in anecosystemall living and nonlivingthings interacting withina certain arealarge region withtypical plants andanimals that includesseveral ecosystemscell
Changes to Agriculture:•1 After the Second World War, farming changeddramatically and became more intensive.•2 It changed because of the need for farmers tomaximize production.•3 Farms became specialist such as growing cerealsand little else.•4 This was made possible with the advent of cheapinorganic fertilisers, pesticides,•new high yielding varieties and improvedmechanization.•5 Yields improved dramatically (Wheat yields in the1950’s were about2 tonnes per hectare and now in excess of 10 tonnes).6 Food has also become much cheaper.Agriculture
Effects of intensive agriculture: Benefits : High yields Greater productivity Cheaper food Higher quality food
Cont… Problems: Pollution(excess nitrates & pesticides) Disease Waste disposal (straw from cereals, slurryfrom livestock) Toxic materials entering the human foodchain Damage to the environment Loss of jobs
Agriculture – Monoculture andIntensive Farming Intensive agriculture is characterised bymost of the following: Large areas of monoculture (growing onespecies or crop). High level use of – Fertilisers (especially inorganic fertilisers) Pesticides (includes herbicides) Mechanisation (large tractors etc)
Cont…. Improved varieties of plants and animals Irrigation schemes (allows continuouscropping) Continuous cropping from one area yearafter year Several crops per season from the same land Low labour input Maximum yields for a minimum area of land Attempts to maximise profits