ECOLOGY CH 13-15

Ecology is the study of relationships among organisms and their environment Ecologists study environments at different levels of organization Organism- individual Population- group same species Community- group of different species in an area Ecosystem- all organisms and non living parts Biome- major area characterized by plants and climates

Biome Biome

Research Observation- Experiments- Computer/mathematical Visual surveys direct- count indirect- looking for other signs Experiments- Lab Field Computer/mathematical Modeling

Every ecosystem includes both living and nonliving factors Abiotic vs biotic factors Biotic- living Plants Animals Fungi bacteria Abiotic- non living Ex. Moisture Temperature Wind Sunlight soil

Keystone species- species with large effect on its ecosystem Biodiversity -variety of living things in an ecosystem -Ex rain forests Keystone species- species with large effect on its ecosystem creation of wetland ecosystem increased waterfowl Population increased fish population nesting sites for birds keystone species

Life in an ecosystem requires a source of energy Producers- provide energy for others Get energy from the sun or chemicals Photosynthesis chemosynthesis Called autotrophs Consumers- get energy from others Called heterotrophs Herbivores- plants only Carnivores- animals only Omnivores- both Detritivores- dead organic matter Decomposers- break down dead organic matter

Food chain -Links species by feeding relationships -follows from producer to consumers within an ecosystem

Tropic levels -primary consumers -secondary consumers -tertiary consumers -omnivores -herbivores eat producers -carnivores that eat herbivores -carnivores that eat secondary consumers -eat both and listed in any place in food chains

Specialists- consumers that eat one specific organism Generalists- varying in diet

Food web-shows all the possible feeding relationships in an area -multiple feeding relationships in an ecosystem -complicated feeding relationships and energy flow

Matter cycles in and out of an ecosystem -water -oxygen -carbon -nitrogen -phosphorus Called biogeochemical cycles

Pyramid Models Energy Biomass Numbers energy transferred energy lost tertiary consumers secondary primary producers 75 g/m2 150g/m2 675g/m2 2000g/m2 Pyramid Models Energy Biomass Numbers tertiary consumers secondary primary producers 5 5000 500,000 5,000,000

Every organism has a habitat and niche Habitat vs Niche Habitat- lives Biotic vs abiotic factors Niche- job/role Food, abiotic conditions, behavior Resource availability Can be shared Competition comes when 2 species want some resource

Competitive exclusion keeps 2 species from same niche Outcomes 1 species pushed out or extinct Niche will divide 2 species diverge more

Ecological equivalents Species that occupy similar niches but live in different areas of the world Madagascar South America

Community interactions Competition- 2 organisms fight for same limited resource Might be same or different species

Predation- 1 organism captures and eats another

3 symbiotic relationships Symbiosis- living together Mutualism- both organism benefit

Commensalism- 1organism benefits, the other is unharmed Parasitism- 1 benefits the other is harmed _ Hornworm caterpillar Parasitism + Human eyelash Demodicids Eyelash mites find all they + Ø Commensalism

Parasitism Ectoparasites (leeches) outside Endoparasites (hookworms) inside

All populations have… Density Dispersion Reproductive strategies

Density Measurement of the number of individuals in an area calculated

Dispersion- how individual of a population are spaced 3 types