Ecology PDF

Behavior - Observable response of organisms to internal or external stimuli. Innate behavior - innate or genetically programmed behavior Once initiated, will continue until complete Relaser initiates behavior Learning 1.​ Habituation - simplest form of learning a.​ Organisms ignores re...

Behavior - Observable response of organisms to internal or external stimuli. Innate behavior - innate or genetically programmed behavior Once initiated, will continue until complete Relaser initiates behavior Learning 1.​ Habituation - simplest form of learning a.​ Organisms ignores repeated stimulus b.​ Nonassociateve learning - decreased response to stimulus due to repetition 2.​ Associative learning - between stimulus and response a.​ Classical conditioning [Pavlov’s dog] i.​ Involuntary response b.​ Operant conditioning Critical period - a time when animals develop species-specific patterns of behavior Imprinting COMMUNICATIONS C - Chemical​ A - Auditory​ V - Visual​ T - Tactile Energy cannot be created nor destroyed Physical laws 1st Law of Thermodynamics: energy cannot be created nor destroyed 2nd Law of Thermodynamics: ever exchange of energy increases entropy [some energy is lost as heat] Law of conservation of mass: matter cannot be created or destroyed Group living can reduce predation 1.​ Increased vigilance a.​ Many-Eyes Hypothesis - by living in groups, individuals may decrease their time scanning for predators and increase time feeding 2.​ Protection in numbers a.​ “Selfish herd” - each individual can minimize their danger by choosing a location closest to the center of the group 3.​ Predator Groups Altruism 1.​ Kin Selection a.​ behavior that lowers an individual’s own fitness but enhances repro success of relatives 2.​ Hamilton’s Law a.​ Altruism favored by natural selection depending on how related you are, the benefits, and the cost! 3.​ Eusocial Animals a.​ A queen & sterile female workers care for young. b.​ Haplodiploidy - diploid females more related to their sisters Mating System 1.​ Monogamous a.​ One male mates with one female 2.​ Polygynous a.​ One male mates with many females 3.​ Polyandrous a.​ ONE female mates with several males Survivorship Curves and Population Growth Type I – rate of loss of juveniles low and most individuals lost later in life Type II – fairly uniform death rate (ex: beavers) Type III – rate of loss for juveniles high and then loss low for survivors Exponential Growth resources not limiting, prodigious growth -e.g. worldwide population Logistic Growth -resources are limiting, limits growth -resources become limiting as pops grow Carrying capacity (K) – upper boundary for population Ecological Pyramids NBE: N - numbers [*inverted pyramid*; higher on food chain, lower the numbers] B - biomass [total dry mass of all organisms on each trophic level] E - energy [energy flow decreases as trophic level increases] [Primary Producers] → Primary Consumers → secondary and tertiary Decomposers (brings the cycle around) Density Dependence ​ Density-Dependent factors ○​ Mortality factor that varies with population density ○​ Parasitism, predation, and competition ○​ Predators kill few prey when prey pop. is low, more prey when the pop. is higher ○​ Detected by plotting mortality against pop. density and finding positive slope ​ Density-Independent factor ○​ Mortality factor whose influence is not affected by changes in pop. size or density ○​ Physical factors – weather, drought, flood, fire Biomass Production in Ecosystems Primary production - light into chemical energy by autotrophs (Based on lights and nutrients available) Gross primary productivity - total primary production [photosynthesis] Secondary production - converted into biomass Net primary production (NPP) - stored chemical energy stored in consumers’ system [most NPP is tropical rainforest. Low NPP is ocean because of its area; deserts because no plants] Biogeochemical cycle (BGC) [movements of chemicals through ecosystems] Biological - chemicals in living organisms and back into environment Geology - weathering/erosion of rocks, elements transported through drainage Chemical - dissolved matter in rain and snow, atmospheric gasses, and dust blown by the wind PCNW Phosphorus Cycle - weathering of rocks and soil Carbon Cycle - Primary source of global warming Nitrogen Cycle - Mostly from the atmosphere Nitrogen fixation Nitrification Assimilation Ammonification Denitrification Water Cycle - water?? Most diversity at the equator due to the sun. It decreases as you go toward the polar regions. Hypothesis for Latitudinal Gradient (TAP) Time Hypothesis - gain’s species with time, biomes closer to poles are younger due to glaciers melting Area Hypothesis - Larger areas support larger populations Productivity Hypothesis - Plant productivity means more species Succession = community change Primary - newly exposed site not exposed by soil and vegetation (volcanoes) Secondary - site supported life but undergone a disturbance like fire, tornado, flood, etc Climax community - succession has a distinct, final end point Facilitation - colonizing species change environment so its more suitable for next species 3 models of Succession [FIT] F - Facilitation - species replacement is facilitated (made easier) by previous colonists I - Inhibition - species replacement is inhibited (made difficult) by previous colonists T - Tolerance - species replacement is unaffected by previous colonists Species richness is a balance between immigration and extinction Memory helpers Biodiversity (GSE) Genetic Diversity - genetic variation between populations Species diversity - threatened species become endangered, endangered become extinct. Ecosystem diversity - structure and function within an ecosystem Justification (DPEE) Dependence - humans depend on plants, animals, and microorganisms Preserve - preserve clean air and water (essential things) Ethical - responsibility to protect environment Economic - economic values like drugs are made from plants Amt Diversity (DRKI) Diversity-Stability - enough diversity for stability Redundancy - eliminated or replaced with no loss of ecosystem function Keystone - small but important role; function plummets when biodiversity declines from natural levels. Idiosyncratic - unpredictable changes as number of species changes Single Species (IUFK) Indicator - status confirms overall health of ecosystem (Polar Bears) Umbrella - protecting one, protects many others (Northern Spotted owl) Flagship - recognizable species (Florida Panther) Keystone - Species have a role in community (American beaver; produces dams) Habitat (CRE) Complete - Attempt to put back exactly what was their prior to disturbance Rehabilitation - return habitat to something similar; partial restoration Eco Replacement - replaces original ecosystem with new ecosystem Endangered vs Threatened International Union of Conservation of Nature (IUCN) - international organization that works to make nature conservations and has the authority to give species different statuses.  1.​ Endangered a.​ Likely to be extinct in near future b.​ At risk due to habitat loss, poaching, invasive species, etc c.​ Worse then threatened status 2.​ Threatened a.​ Vulnerable to extinction in near future b.​ Over 44,000 species are threatened Captive Breeding - breeding of animals/plants outside natural habitat to produce stock before releasing into the wild