Terrestrial & Aquatic Ecology

1. Terrestrial & Aquatic Ecology Unit 1 Grade 12 Environmental Science

2. How do Organisms get Energy? Photosynthesis: Converting light energy (from the sun) into usable chemical energy Producers

3. How do Organisms get Energy? Cellular Respiration: The process of breaking down simple sugars to release energy. Producers & Consumers

4. How do Organisms get Energy?

5. How do Organisms get Energy? • Chemosynthesis: process in which organisms convert inorganic chemicals (H2S or H2) into usable energy. • Deep-sea hydrothermal vents • Hot springs • Intensely salty lakes • Deep in rock formations • Deep-sea (w/o thermal vents)

6. Levels of Organization in an Ecosystem Species: all organisms of the same kind that are genetically similar to breed in nature and produce fertile, live offspring. Population: all members of the same species living in a given area at the same time. Community: all populations interacting together in a given area at the same time. Ecosystem: a community and its environment (abiotic – nonliving factors) (biotic – living factors)

7. Transferring Energy in an Ecosystem • Producers: organisms the photosynthesize • Productivity: amount of biomass produced in a given period of time. • Biomass: biological material • Food Chain: a linked feeding series • Food Web: a diagram of interconnected food chains

8. Transferring Energy in an Ecosystem • Trophic Level: an organism’s feeding status in an ecosystem • Producer • Primary Consumer (Herbivore) • Secondary Consumer (Carnivore, Omnivore) • Tertiary Consumer (Carnivore, Omnivore) • Quaternary Consumer (Carnivore, Omnivore) • Consumer: eat producers for energy • Herbivore: eats only plants • Carnivores: eat flesh (meat) only • Omnivore: eats both plants and animals

9. Transferring Energy in an Ecosystem • Other Consumers: • Scavengers: eat and clean up dead carcasses of larger animals. • Crows, jackals, vultures • Detritivores: eat litter, debris, dung • Ants, beetles • Decomposers: complete final breakdown and recycling of organic materials. • Fungi, bacteria

10. Transferring Energy in an Ecosystem Consumers that feed at all levels: Scavengers & Decomposers

11. Transferring Energy in an Ecosystem

12. Biogeochemical Cycles Hydrologic Cycle (aka water cycle):

13. Biogeochemical Cycles • Carbon Cycle: • Needed to make organic molecules • Bonds with carbon contained “stored” energy

14. Biogeochemical Cycles • Nitrogen Cycle: • An element needed in making organic molecules • Assimilation: the taking in of nitrogen by plants • Nitrogen fixation: bacteria combine N with H to form NH3 (ammonia) • Nitrification: bacteria turn ammonia into nitrates (NO3) • Denitrification: bacteria convert NO3 into N2

15. Biogeochemical Cycles • Phosphorous Cycle: • More phosphorous = more lush plant growth but also more water pollution • Phosphorous has NO atmospheric form

16. Biogeochemical Cycles • Sulfur Cycle: • Important for making proteins

17. Speciation & Evolution • Adaptation: acquisition of traits that allow a species to survive in its environment. • Acclimation – immediate response to a changing environment, but not past on genetically • Natural Selection – • organisms better suited to the environment survive  • offspring inherit the beneficial traits  • over generations, these become the traits of a population • Evolution brought on by an accumulation of mutations over time.

18. Speciation & Limitations • Limitations to where a species can live • Physiological factors • Moisture, temperature, light, pH, or a specific nutrient • Competition with other species • Predation, parasitism, disease • Luck • An organisms design may allow it to only live within certain conditions • Critical Factor: the single factor in shortest supply relative to demand. • Saguaro Cactus – so sensitive to freezing temperatures that one freezing night below O for 12 hours or more stunts its growth, and it can no longer develop.

19. Speciation & Limitations Tolerance Limits: each factor has a minimum and maximum level in beyond which a species would not be able to survive or reproduce.

20. Speciation & Ecological Niches • Habitat: place or environmental conditions in which a species lives. • Ecological Niche: role played by the species in their community or a total set of environmental factors that determine the distribution of a species. • Generalist: has a wide range of tolerances for many factors • Brown rat • Specialist: have exacting habitat requirements, lower reproductive rates, and care for their young. • Giant Panda • Endemic: highly specialized to their habitat and do not exist anywhere else • Flora & Fauna on the Galapagos Islands

21. Speciation & Ecological Niches • Competition: fighting for the same resources • Competitive Exclusion Principle: no two species can occupy the same ecological niche for a long period of time. • The more efficient will survive, while the less will either find another habitat, die out, or experience a change in its behavior or physiology. • Resource Partitioning: several species can use different parts of the same resource and coexist.

22. Speciation & Diversity • Speciation: the development of a new species • Gradualism • Punctuated Equilibrium

23. Speciation & Diversity • How speciation occurs: • Geographic Isolation (Allopatric Speciation): species arise in separate geographic regions due to physical barriers causing reproductive isolation. • Behavioral Isolation (Sympatric Speciation):behaviors that cause reproductive isolation even though the organisms live in the same place.

24. Species Interactions • Competition: • Intraspecific Competition: competition within a species • Reducing competition: • Dispersal of young • Strong territoriality • Resource partitioning between generations • Young/adults feed differently • Interspecific Competition: competition among different species • The species living in the optimal range of their tolerance limits will have an advantage over a species living outside of their optimal range.

25. Species Interactions • Predator: any organism that feeds directly on any other living organism. • Predators: herbivores, carnivores, omnivores • NOT Predators: scavengers, detritivores, decomposers • Predator-mediated Competition: a superior competitor in a habitat will build up a larger population than its competing species; predators notice and increase hunting pressure of the superior species, reducing the superiors abundance, allowing the weaker species to increase its numbers.

26. Species Interactions • Predator-Prey Relationships can lead to co-evolution. • Co-evolution: when two interacting species evolve with each other because of their interactions. • Cheetah & Gazelle

27. Species Interactions • Mimicry • Batesian mimicry: harmless species look like poisonous or distasteful ones to scare of predators. • Mullerian mimicry: two harmful species look alike and predators learn to avoid both.

28. Species Interactions • Camouflage: Use of color, patterns, and form to blend in to the environment. • Helps prey hide from predators BUT • Also helps predators hide while lying in wait for their prey

29. Species Interactions Mutualism: relationship between two organisms benefit each other. Commensalism: one organism benefits, but the other organism in not affected. Parasitism: one organism benefits and the other organism is harmed.

30. Keystone Species A species who has a large influential impact on its community or ecosystem than its abundance would suggest.

31. Properties of Ecosystems • Primary Productivity: Rate of biomass production (conversion of solar energy to chemical energy) • Energy left after respiration = net primary production

32. Properties of Ecosystems • Abundance: total number of organisms in a biological community. • Diversity: measure of the number of different species, ecological niches, or genetic variation present. • Abundance is usually inversely related to diversity • Diversity up, Abundance down • Diversity down, Abundance up • Generally diversity decreases but abundance within a species increases from the equator toward the poles.

33. Properties of Ecosystems • Ecological structure: patters of spatial distribution of individuals and populations within a community • Random • Live where resources are available • Uniform • Physical environment • Biological competition • Clustered • Protection • Mutual assistance • Reproduction • Access to resources

34. Properties of Ecosystems • Complexity: number of species at each trophic level and the number of tropic levels in a community. • Stability or Resiliency: • Constancy: lack of fluctuations in composition or function • Inertia: resistance to disturbances • Renewal: ability to repair damage after a disturbance • The more complex and interconnected an ecosystem, the more stable and resilient it is. • Many species in one trophic level, one can replace another • However, removal of a keystone species can greatly affect any system

35. Properties of Ecosystems • Edge Effects: change is species composition, physical environment or other ecologic properties between ecosystems • Sometimes sharp and distinct • Woodlands  grasslands • Gradual integration to from one to another • Ecotones: boundaries between adjacent communities • Sharply divided: closed community • Indistinctly divided: open communities

36. Changing Communities • Ecological succession: changes in an community as organisms occupy a site and the change the environmental conditions. • Primary Succession: land that is bare of soil and colonized by organisms where none lived before • Sandbar, mudslide, rockface, volcanic flow • Secondary Succession: existing community is disturbed and a new one develops from the disturbance • Wild fire, clear cut forests, urbanization • Successions occur by: • Modifying soil • Light levels • Food supplies • microclimate

37. Changing Communities • Terrestrial Primary Succession • Primary species: first colonists • Microbes, mosses, lichens (live off few resources) • When primary species die = organic matter = soil production • Seeds lodge in soil and grow • Succession progresses  more diversity

38. Changing Communities • Disturbances: anything that disrupts established patterns of species diversity and abundance, community structure, or community properties • Landslides, mudslides, hailstorms, tidal waves, tornadoes, volcanoes (natural) • Animal disturbances • elephants ripping down small trees • Agriculture, forestry, urbanization, dams, pipelines • Disturbance-adapted species: species that recover quickly from a disturbance

39. Biomes • Biomes: ecosystems with similar climate, growth patterns, and vegetation. • Temperature & Precipitation – important characteristics for terrestrial (land) biomes • Tropical Rainforest • Tropical dry forest • Tropical Savanna • Desert • Temperate grasslands • Temperate woodlands and shrublands • Temperate forests • Northwestern coniferous forest • Boreal forest (Taiga) • Tundra

40. Marine Ecosystems • Mostly dependent on photosynthetic organisms to support the food web • Algae • Phytoplankton (tiny free-floating plants) • In oceans, most photosynthetic activity is near coastlines • Nitrogen, phosphorous, other nutrients runoff into the ocean • Ocean currents distribute nutrients and phytoplankton by carrying them away from shore • Dying organisms sink to bottom, feeds bottom feeders • Craps, filter-feeders, etc • Upwelling brings this “marine snow” back up to the surface for other fish as well

41. Marine Ecosystems Continental Shelf • Vertical Stratification • Light/temperature decrease with depth • Colder H20, more O2 • Photic zone – light reaches (about 20m) • Pelagic – near the top • Epipelagic: photosynthetic organisms • Mesopelagic • Bathypelagic • Benthic – live near bottom • Abyssal • Hadal • Littoral – shoreline • Intertidal – are exposed by low tide

42. Marine Ecosystems • Deep Ocean • Relatively low productivity • Around equator, many fish and phytoplankton • Sargasso Sea – blankets of brown algae support many diverse animals • Deep-sea thermal vents- chemosynthetic • Tubeworms, mussels, microbes • Thousands of microscopic organisms

43. Marine Ecosystems • Coral Reefs: • High productivity/diversity • Protect shorelines • Shelter fish, worms, crustaceans, etc. • Shallow warm waters, sunlight • Dependent on photosynthetic algae • Coral Bleaching: warms waters are killing coral. • 1/3 destroyed by 2006, by 2030 60% expected to be gone

44. Marine Ecosystems • Mangroves • Trees that grow in salt water • Calm, shallows, tropical coastlines • Stabilize shorelines • Nurseries for fish, shrimp, other commercial species • Clear-cut for timber, make room for fisheries • Mangroves provide protection for these fish the are being removed for. • Reduced catches, falling income

45. Marine Ecosystems • Estuaries: • Bays where rivers empty into the sea • High productivity/diversity • “dead zones” : excess nutrients stimulate bacteria that uses O2 needed for other life • Tide-pools: • Depressions in rocky shoreline that flood at high tide, retain water at low tide • Specialized species • Starfish, sea anemone, ect.

46. Marine Ecosystems • Barrier Islands • Low, narrow, sandy island parallel to the coastline • Protect inshore lagoons and salt marshes from storms, waves, tides • Critical in preserving coastlines, estuaries, and wetlands • Human occupation speed up erosion of barrier islands, vulnerable to storms

47. Freshwater Ecosystems • Lakes • Vertical zones • Open water: plankton, microscopic plants, animals, & protists, water striders, mosquitoes • Water column – variety of fish • Benthos: bottom, snails, worms, fish, other organisms • Littoral: plants • Conditions that affect lake productivity • Nutrient availability, nitrates, phosphates • Suspended matter, silt, affects depth of light • Depth • Temperature • Currents • Bottom: muddy, sandy, rocky floor • Connections to other ecosystems

48. Freshwater Ecosystems Lakes

49. Freshwater Ecosystems • Wetlands • Shallows, land surface that is submerged part of the year • Rich biodiversity • Essential for breeding and migrating birds • 5% of US is wetlands, but 1/3 of endangered species call the wetlands home • Retain storm water, control flooding, filter/purify urban and farm runoff • Swamps- wetlands w/ trees • Marshes- wetlands w/o trees • Bogs – areas of saturated ground (usually composed of peat) • Fens – bogs fed by groundwater, mineral rich, specially adapted plant species • Swamps & Marshes- high productivity • Bogs & Fens – low productivity

50. Freshwater Ecosystems