Ecology moodle part 2
- 1. Succession The gradual, sequential regrowth of a species in an area due to changing conditions
- 2. Succession • PRIMARY succession – Development of a community in an area that has not supported life before. • Requires the building of soil by PIONEER PLANTS – Small fast-growing & fast-reproducing plants – Lichen, moss, crabgrass, plankton
- 3. Primary succession • Seral stages – Developmental stages of an environment – Ecological communities that succeed one another in the biotic development of an area – Species will eventually be replaced by successive species based on conditions such as Soil quantity Sunlight Soil type Water
- 4. Seral stages • Can be determined by an index species • Index species Definition – Species that are used as a reference point to indicate relative placement in an ecosystem
- 5. Primary succession • Climax Community – Will be established eventually – Community will prevail unless the area is disturbed again – Hardwood trees (maple, beech, birch)
- 6. Examples of Primary Succession • Bare Rock Succession • Sand Dune Succession • Pond/Lake Succession
- 7. Bare rock succession • Pioneer Plants: – Lichens Help break down rocks Adds humus for new soil building What’s humus? Substance that provides nutrients Increases the ability of soil to retain H2O
- 8. Bare rock succession • Seral stages: – Mosses/fern – Grasses/weeds – Bushes – Softwood trees • Each stage paves the way for the next stage
- 9. Bare rock succession • Climax community – Hardwood trees • Species of plant remain constant for a long period of time until a disturbance occurs
- 10. Lichen Hardwood Softwood trees Bushes trees Mosses, Grasses, ferns weeds Bare rocks
- 12. Sand dune succession • Pioneer plants: – Beach grass • Roots stabilize the sand • Humus is added to the foredune – An area directly behind the beach
- 13. Sand dune succession • Seral stages – Cottonwood – Pines – Oaks • Continue to add humus and shade to the soil
- 14. Sand dune succession • Climax community – Beech or maple
- 16. succession
- 17. Pond/lake succession • Pioneer plants/organisms – Microscopic plants and animals • Phytoplankton - producers • Zooplankton - consumers • Found in open water • Humus is added and soil develops
- 18. Pond/lake succession – Seral stages • Rooted submerged zone – Closer to the shore – Light penetrates all the way to the bottom so young plants can grow – Algae/Kelp
- 19. Pond/lake succession – Seral stages • Rooted floating zone – Rooted in the bottom and leaves float on the surface – Water lilies • Emergent zone – Very shallow water – Rooted in the bottom and extend through the surface – Cattails
- 20. Pond/lake succession • Climax community – Land
- 22. Process of lake/pond succession • As the plants die and as sediment washes in from the surrounding land the lake (pond) fills-in • First the open water zone disappear • Then the rooted submerged zone, • Then the rooted floating zone, • Then the emergent zone
- 23. Process of lake/pond succession • Succession of an open field now takes place (grasses and weeds, bushes, softwood trees, finally hardwood trees) • Climax community will depend on the biome the lake (pond) was in.
- 26. Secondary succession • Sequential replacement of species that follows the disruption of an EXISTING community
- 27. Secondary succession • Pioneer species – Grasses – Weeds – Plants must be adapted to hot, dry conditions
- 28. Secondary succession • Seral stages – Bushes – Softwood trees – Adds humus & moisture to the soil – Then later, replaced by a larger species
- 29. Secondary succession • Climax community – Hardwood trees
- 30. Ecosystem A system formed by the interaction of a community of organisms with their environment
- 31. Ecological Relationships • Trophic Level – Any class of organisms that occupy the same position in a food chain – Examples
- 32. Energy Flow • Producers have the most energy. • As an organism eats the next, available energy decreases. • Only 10% is passed on to the next trophic level. (Ten Percent Law) • What happens to the other 90%? – Transferred as heat to the environment
- 34. Pyramid of Energy • A measure of the amount of energy available in each trophic level
- 35. Ecosystem Recycling • All molecules are recycled naturally in the environment through a biogeochemical cycle. • Biogeochemical cycle – Movement of elements through various compartments (at least one being biological). – Water cycle – Carbon/oxygen cycle – Nitrogen cycle
- 36. Water Cycle • Movement of water through various reservoirs • Precipitation – Water falling from the atmosphere to the ground • Transpiration – Water entering the atmosphere from plants • Respiration – Water entering the atmosphere from animals • Evaporation – Water entering the atmosphere through a phase change (liquid to gas)
- 37. Water Cycle • Absorption – Water taken in by a plant • Urination – Water added to the ground by an animal • Runoff/Seepage – Excess water entering land or another body of water • Aquifer/Groundwater – Underground water stored in porous rocks
- 38. Precipitation Transpiration Evaporation Respiration Absorption Urination Run-off Aquifer
- 41. Carbon/Oxygen Cycle • Movement of organic compounds through various reservoirs. • Based on concepts of photosynthesis and cellular respiration • Photosynthesis – Autotrophs used CO2 found in the atmosphere and convert it into an organic compound C6H12O6
- 42. Carbon/Oxygen Cycle • Respiration – Hetertrophs consume the glucose and release carbon compounds in the form of CO2 wastes • Decomposition – When detritivores feed off of the remains of dead organisms • Fossil fuel – Formed from years of high temperature and pressure of decaying, organic matter • Combustion – The burning of organic matter
- 43. Carbon dioxide Respiration Photosynthesis Glucose Combustion Fossil Fuels Decomposition
- 45. Nitrogen Cycle • Movement of nitrogen-containing compounds (proteins, nucleic acids, atmospheric nitrogen, urine, ammonia, nitrates and nitrites.) • Cycle could not exist if it wasn’t for BACTERIA • Ammonification – Decomposition – When detritivores feed off the remains of dead organisms and convert protein and nucleic acids into ammonia
- 46. Nitrogen Cycle • Nitrification – When bacteria convert ammonia into nitrates (NO3) and nitrites (NO2) • Absorption – When plants take up nitrates and form amino acids which consumers will acquire as protein • Denitrification – When bacteria break down nitrates and produce nitrogen gas
- 47. Nitrogen Cycle • Nitrogen Fixation – When bacteria found on special plants (legumes – beans, peas, alfalfa) converts atmospheric nitrogen into ammonia. – Lightning can also perform this process.
- 48. Atmospheric Nitrogen Nitrogen Fixation Lightning Feeding NO3- Ammonification Absorption NH4 Nitrates (NO3-)and Atmospheric Nitrogen (N2) used by plants