UNIT%IV:%ECOLOGY%%Lecture'21:'Ecology'and'Plant'succession'%Ecology:%study%of%effects%of%environment%on%l iv in g %org a n ism s%a nd %l iv in g %org a n ism s%o n%t h e %e n viro n m e n t%@Population:%members%of%a%single%species%living%together%@Habitat:%location%where%the%population%is%found%@Niche:%functional%role%an%organism%plays%in%the%ecosystem%@Dominant%Species:%most%influential%in%community%ex.%Redwood%forest%% @Control%structure%and%species%composition%of%community%through…%% @Physical%factors:%light,%wind,%and%humidity%% @Chemical%factors:%nutrients,%and%pH%%Ecosystem:%Communities%with%all%its%living%organisms%(biotic)%a n d%non@living%organisms%(abiotic)%@Biotic:%organisms%interact%in%food%chain%or%food%we b%o Producers%(photosynthetic.)%%1st%order%consumers%(herbivores)%%2nd%order%consumers%(carnivores)%o Trophic%level:%each%step%in%food%chain%–%energy%is%lost%at%each%level%o Food%web%(realistic):%%multiple%interactions%between%several%food%chains%–%consumers%have%alternate%food%choices%@Abiotic:%non%living%components%of%the%environment:%climate,%light,%soil,%inorganic%sub stances%Biogeochemical%cycles%o Carbon%cycle%o C02%enters%plants%through%photosynthesis%–%carbon%is%released%through%respiration%or%combu stion%–%fossil%fuels%were%formed%o Water%cycle%o –Water%enters%atmosphere%as%vapor%from%land/transpiration%from%plants%–%vapor%condenses%–%rain%falls%into%river,%streams,%oceans%o Nitrogen%cycle%o Nitrogen%gas%is%fixed%by%bacteria%–%plants%assimilate%N%and%incorporate%it%into%organic%nitrogen%–%animals%assimilate%N%by%ingesting%plants%–%animal%waste%and%organic%nitrogen%compounds%are%broken%down%%Climax%community:%relatively%stable%community%a t%t he%en d%of%succession%o In%equilibrium%with%environment%o Permanent%until%major%change%o Varies%depending%on%conditions%Types%of%succession:%1) Primary%succession:%when%plants%become%established%on%land%completely%devoid%of%soil%and%vegetation%a. Soil:%portion%of%earths%surface%of%disintegrated%rock%and%organic%materials%(humus)%i. Provides%essential%nutrients%(water/minerals)%to%all%plants%ii. Soil%texture:%3%types%of%particles%–%sand,%silt,%clay%(most%important,%holds%nutrients)%iii. Organic%matter:%humus%is%decomposing%organic%matter%in%soil%iv. Soil%pH:%acid%(low)%or%basic%(high)%influences%soil%fertility%and%nutrients%–%best%is%slighting%acidic%b. Forest%habitats:%lichens%%mosses%%grasses%%shrubs%%trees%c. Begins%as%pioneer%species,%for%inhabitants,%invade%bare%rock%and%form%soil%–%climax%community%is%spruce@fir%and%birch%forest%d. Each%stage%prepares%the%way%for%the%next%invasion%of%species%2) Secondary%succession:%natural%forces/human%intervention%destroy%existing%vegetation%(fire,%flooding,%logging,%agriculture)%–%community%begins%secondary%succession%back%to%climax%a. Since%soil%is%in%place,%5@10x%faster%than%primary%b. Abiotic%factors%affect%nature%of%plant%community%–%weather,%temp,%humidity%i. Tropical%rainforests:%vegetation%creates%rainfall%through%plant%transpiration%–%when%trees%are%removed,%rainfall%stops,%land%becomes%arid%–%resulting%climax%–%desert%shrubs%%Lecture'22:'Terrestrial'Biomes''Biome:%largest%terrestrial%divisions%of%the%biosphere%–%large,%distinct%ecosystems%climax%com mu n ities%for%huge%regions%of%the%land%–%recognized%and%defined%by%distinctive%vegetation%and%anima l%life%@Role%of%Climate:%o Daily%and%seasonal%cycles%influence%prevailing%o Climate%is%global%and%ever%changing%–%differences%in%atmospheric%heatin g %creat e%winds,%drive%global%patterns%of%atmospheric%circulation%o Seasons%are%determined%by%the%tilt%of%the%earth%@Elevation/altitude:%In%NA%weather%patterns%move%from%west%to%east%@Precipitation:%influenced%by%physiographic%features,%mountains,%rivers,%oceans%@Elevation:%altitude%influences%biomes,%cooler%temperatures%high%in%the%mountains%favor%biomes%similar%to%biomes%near%North%Pole%%1) Tundra%a. arctic%b. Climate:%very%cold%and%dry,%little%precipitation%c. Soil:%permafrost%d. Plants:%No%trees,%many%low%shrubs%and%herbs,%grass%–like%(lichens%and%mosses)%e. Animals@%Migratory%birds,%wolves,%fox,%polar%bear,%rain%deer%f. Sensitive%to%human%disruption%–%takes%a%long%time%to%recover%%2) Boreal%Forest%(taiga):%a. arctic%circle,%Alaska,%Canada%and%great%lakes%b. Climate:%severe%winters,%extreme%cold%and%little%precipitation%c. Soil:%wet,%deep%permafrost,%nutrient%poor,%may%be%acidic%d. Vegetation:%trees%dominate,%especially%pines%(conifers),%fir,%spruce,%birch,%aspen%e. Animals:%caribou,%wolves,%fox,%bear,%moose,%mink%and%migratory%birds%f. Human%impact:%Hunting,%mineral%exploitation%and%lumbering%3) Temperate%deciduous%forest%a. Eastern%North%America%b. Climate:%higher%precipitation,%rain,%extreme%temperatures,%hu rrican es%a nd%freezin g %cau se%da ma g e%c. Soil:%more%acidic%and%fertile,%lower%layer%rich%in%clay,%top%rich%with%decayed%organic%matter%d. Plants:%deciduous%–%leaves%fall%off%seasonally,%some%conifers%(pines)%e. Animals:%deer,%moose%buffalo,%bear%(all%diminishing%due%to%hunting),%raccoon,%opossum%skunks,%bobcats,%fox,%wolves,%resident%songbirds%and%waterfowl;%migrant%birds%too%f. No%undisturbed%forests%left%due%to%extensive%logging,%clear%cutting%&%introduction%to%exotic%species%has%altered%flora%4) Grasslands:%%a. Widely%scattered%throughout%the%world%–%North%Am erican %Pra irie,%Great%Pla ins%b. Climate:%very%low%rainfall%with%warm%summers%and%cool%winters%c. Soil:%generally%fertile,%deep,%and%rich%d. Plants:%members%of%the%grass%family,%usually%one%or%two%dominate%i. Rhizomatous%(to%spread%out)%and%are%wind%pollinated,%deep%roots%ii. Adapted%to%fires%and%drought%iii. Some%trees%and%shrubs%e. Animals:%bison,%gophers,%coyote,%prairie%dogs,%squirrels%f. Human%impact:%majority%of%grassland%used%for%farming%–%cultivated%food%cereals,%overgrazing,%urbanization,%exotic%weeds%major%problem%5) Deserts:%a. North%America:%new%Mexico,%Arizona,%southern%California,%northern%Mexico%b. Climate:%low%precipitation,%hot%day,%cold%nights%c. Soil:%low%organic%content%(dryness%prevents%decomposition),%sandy%to%rocky,%high%mineral%content%(often%toxic%levels)%d. Hot%(low)%Sonoran%desert%Cold%(high)%%Utah%Great%Basin%e. Vegetation:%sparse%plant%cover%i. Xerophytes:%adapted%to%dry,%arid%regions%–%strategies%to%conserve%water%f. Animals:%hard%to%find%–%reptiles,%rodents%g.